ESP-AT User Guide¶

[中文]

This is the documentation for the ESP-AT. To view documentation for a specific AT firmware version or chip series, please click the small triangle at the bottom left corner of this page and select.


Get Started	AT Binary Lists	AT Command Set

AT Command Examples	Compile and Develop	Customized AT Commands and Firmware

Get Started¶

[中文]

This Get Started guide provides users with detailed information on what is ESP-AT, how to connect hardware, and how to download and flash AT firmware. It consists of the following parts:

What is ESP-AT¶

[中文]

ESP-AT is a solution developed by Espressif to integrate connectivity into customers’ products, which can be quickly moved to mass production. It aims to reduce software development costs and quickly form products. With ESP-AT commands, you can quickly join the wireless network, connect to the cloud platform, realize data transmission and remote control functions, and realize the interconnection of everything through wireless communication easily.

ESP-AT is a project based on ESP-IDF. It makes an ESP board work as a slave, and an MCU as a host. The host MCU sends AT commands to the ESP chip and receives AT responses back. ESP-AT provides a wide range of AT commands with different functions, such as Wi-Fi commands, TCP/IP commands, Bluetooth LE commands, Bluetooth commands, MQTT commands, HTTP commands, and Ethernet commands.

AT commands start with “AT”, which stand for “Attention”, and end with a new line (CR LF). Every time you send a command, you will receive an OK or ERROR, which indicates the final execution status of the current command. Please be noted that all commands are executed serially, which means only one AT command can be executed at a time. Therefore, you should wait for the previous command to be executed before sending out the next one. Otherwise, you will receive busy P.... For more details about AT commands, please refer to AT Command Set.

By default, the host MCU connects to the ESP board via UART, and sends/receives AT commands/responses through UART. But you can also use other interfaces, such as SDIO, according to your actual use scenario.

You can develop your own AT commands based on our ESP-AT project and implement more features according to your actual use scenario.

Hardware Connection¶

[中文]

This document introduces what hardware you need to prepare and how to connect them in order to download AT firmware, send AT commands, and receive AT responses. It covers the following four ESP series of modules:

ESP32 Series
ESP32-C3 Series

For different series of modules, the commands supported by AT firmware are different. Please refer to ESP-AT Firmware Differences for more details.

What You Need¶

List of Components Required for ESP-AT Testing¶
Component	Function
ESP board	Slave MCU.
USB cable (ESP borad to PC)	Download/Log output connection.
PC	Act as Host MCU. Download firmware to Slave MCU.
USB cable (PC to serial port converter)	AT command/response connection.
USB to serial port converter	Convert between USB signals and TTL signals.
Jumper wires (serial port converter to ESP board)	AT command/response connection.

Connection of Components for ESP-AT Testing¶

Please note that in the above picture, four jump wires are used to connect the ESP board and USB to serial converter. If you don’t use hardware flow control, two wires connecting TX/RX and a simpler converter will be enough.

ESP32 Series¶

ESP32 AT uses two UART ports: UART0 is used to download firmware and log output; UART1 is used to send AT commands and receive AT responses. Both UART0 and UART1 use 115200 baud rate for communication by default.

All ESP32 modules use GPIO1 and GPIO3 as UART0, but they use different GPIOs as UART1. The following sections illustrate which GPIOs you should connect for each ESP32 series of modules.

For more details of ESP32 modules and boards, please refer to ESP32 Modules and Boards.

ESP32-WROOM-32 Series¶

ESP32-WROOM-32 Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO16 (RX) GPIO17 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

ESP32-WROOM-32 Series Hardware Connection¶

If you want to connect your device directly with ESP32-WROOM-32 rather than the ESP board that integrates it, please refer to ESP32-WROOM-32 Datasheet for more details.

ESP32-WROVER Series¶

ESP32-WROVER Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO19 (RX) GPIO22 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

ESP32-WROVER Series Hardware Connection¶

If you want to connect your device directly with ESP32-WROVER rather than the ESP board that integrates it, please refer to ESP32-WROVER Datasheet for more details.

ESP32-PICO Series¶

ESP32-PICO Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO19 (RX) GPIO22 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-PICO-D4 rather than the ESP board that integrates it, please refer to ESP32-PICO-D4 Datasheet for more details.

ESP32-SOLO Series¶

ESP32-SOLO Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO3 (RX) GPIO1 (TX)	PC TX RX
AT command/response ²	UART1 GPIO16 (RX) GPIO17 (TX) GPIO15 (CTS) GPIO14 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-SOLO-1 rather than the ESP board that integrates it, please refer to ESP32-SOLO-1 Datasheet for more details.

ESP32-C3 Series¶

ESP32-C3 AT uses two UART ports: UART0 is used to download firmware and log output; UART1 is used to send AT commands and receive AT responses. Both UART0 and UART1 use 115200 baud rate for communication by default.

ESP32-C3 Series Hardware Connection Pinout¶
Function of Connection	ESP Board Pins	Other Device Pins
Download/Log output ¹	UART0 GPIO20 (RX) GPIO21 (TX)	PC TX RX
AT command/response ²	UART1 GPIO6 (RX) GPIO7 (TX) GPIO5 (CTS) GPIO4 (RTS)	USB to serial converter TX RX RTS CTS

Note 1: Connection between individual pins of the ESP board and the PC is already established internally on the ESP board. You only need to provide USB cable between the board and PC.

Note 2: Connection between CTS/RTS is optional, depending on whether you want to use hardware flow control.

If you want to connect your device directly with ESP32-C3-MINI-1 rather than the ESP board that integrates it, please refer to ESP32-C3-MINI-1 Datasheet for more details.

Downloading Guide¶

[中文]

This Guide demonstrates how to download AT firmware and flash it into an ESP device by taking ESP32-WROOM-32 as an example. The Guide is also applicable to other ESP modules.

Before you start, please make sure you have already connected your hardware. For more details, see Hardware Connection.

For different series of modules, the commands supported by AT firmware are different. Please refer to ESP-AT Firmware Differences for more details.

Download AT Firmware¶

To download AT firmware to your computer, please do as follows:

Navigate to AT Binary Lists
Find the firmware for your device
Click the link to download it

Here, we download ESP32-WROOM-32_AT_Bin_V2.1 for ESP32-WROOM-32. The list below describes the structure of this firmware and what each bin file contains. Other AT firmware has similar structure and bin files.

.
├── at_customize.bin                 // secondary partition table
├── bootloader                       // bootloader
│   └── bootloader.bin
├── customized_partitions            // AT customized binaries
│   ├── ble_data.bin
│   ├── client_ca.bin
│   ├── client_cert.bin
│   ├── client_key.bin
│   ├── factory_param.bin
│   ├── factory_param_WROOM-32.bin
│   ├── mqtt_ca.bin
│   ├── mqtt_cert.bin
│   ├── mqtt_key.bin
│   ├── server_ca.bin
│   ├── server_cert.bin
│   └── server_key.bin
├── download.config                  // configuration of downloading
├── esp-at.bin                       // AT application binary
├── factory                          // A combined bin for factory downloading
│   ├── factory_WROOM-32.bin
│   └── factory_parameter.log
├── flasher_args.json                // flasher arguments
├── ota_data_initial.bin             // ota data parameters
├── partition_table                  // primary partition table
│   └── partition-table.bin
└── phy_init_data.bin                // phy parameters

The file download.config contains the configuration to flash the firmware into multiple addresses:

--flash_mode dio --flash_freq 40m --flash_size 4MB
0x8000 partition_table/partition-table.bin
0x10000 ota_data_initial.bin
0xf000 phy_init_data.bin
0x1000 bootloader/bootloader.bin
0x100000 esp-at.bin
0x20000 at_customize.bin
0x24000 customized_partitions/server_cert.bin
0x39000 customized_partitions/mqtt_key.bin
0x26000 customized_partitions/server_key.bin
0x28000 customized_partitions/server_ca.bin
0x2e000 customized_partitions/client_ca.bin
0x30000 customized_partitions/factory_param.bin
0x21000 customized_partitions/ble_data.bin
0x3B000 customized_partitions/mqtt_ca.bin
0x37000 customized_partitions/mqtt_cert.bin
0x2a000 customized_partitions/client_cert.bin
0x2c000 customized_partitions/client_key.bin

--flash_mode dio means the firmware is compiled with flash DIO mode.
--flash_freq 40m means the firmware’s flash frequency is 40 MHz.
--flash_size 4MB means the firmware is using flash size 4 MB.
0x10000 ota_data_initial.bin means downloading ota_data_initial.bin into the address 0x10000.

Flash AT Firmware into Your Device¶

Follow the instructions below for your operating system.

Windows¶

Before starting to flash, you need to download Flash Download Tools for Windows. For more details about the tools, please see readme.pdf or the doc folder in the zip folder.

Open the ESP Flash Download Tool.
Select a mode according to your need. (Here, we select Developer Mode.)

Select a download tool. Here, we select ESP32 DownloadTool because this document takes an ESP32 device as an example. You should select a tool based on what chip you actually use.

Flash Download Tools Target Chips — Flash Download Tools Target Chip¶

Flash AT firmware into your device. You can select either of the two ways below.
- To download one combined factory bin to address 0, select “DoNotChgBin” to use the default configuration of the factory bin.
  
  Download to One Address¶
- To download multiple bins separately to different addresses, set up the configurations according to the file download.config and do NOT select “DoNotChgBin”.
  
  Download to Multiple Addresses¶

In case of flashing issues, please verify what the COM port number of download interface of the ESP board is and select it from “COM:” dropdown list. If you don’t know the port number, you can refer to Check port on Windows for details.

When you finish flashing, please Check Whether AT Works.

Linux or macOS¶

Before you start to flash, you need to install esptool.py.

You can select either of the two ways below to flash AT firmware into your device.

To download the bins separately into multiple addresses, enter the following command and replace PORTNAME and download.config:

esptool.py --chip auto --port PORTNAME --baud 115200 --before default_reset --after hard_reset write_flash -z download.config

Replace PORTNAME with your port name. If you don’t know it, you can refer to Check port on Linux and macOS for details.

Replace download.config with the content inside the file.

Below is the example command for ESP32-WROOM-32.

esptool.py --chip auto --port /dev/tty.usbserial-0001 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x8000 partition_table/partition-table.bin 0x10000 ota_data_initial.bin 0xf000 phy_init_data.bin 0x1000 bootloader/bootloader.bin 0x100000 esp-at.bin 0x20000 at_customize.bin 0x24000 customized_partitions/server_cert.bin 0x39000 customized_partitions/mqtt_key.bin 0x26000 customized_partitions/server_key.bin 0x28000 customized_partitions/server_ca.bin 0x2e000 customized_partitions/client_ca.bin 0x30000 customized_partitions/factory_param.bin 0x21000 customized_partitions/ble_data.bin 0x3B000 customized_partitions/mqtt_ca.bin 0x37000 customized_partitions/mqtt_cert.bin 0x2a000 customized_partitions/client_cert.bin 0x2c000 customized_partitions/client_key.bin

To download the bins together to one address, enter the following command and replace PORTNAME and FILEDIRECTORY:

esptool.py --chip auto --port PORTNAME --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x0 FILEDIRECTORY

Replace PORTNAME with your port name. If you don’t know it, you can refer to Check port on Linux and macOS for details.

Replace FILEDIRECTORY with the file directory you would flash to the address 0x0. It is normally factory/XXX.bin.

Below is the example command for ESP32-WROOM-32.

esptool.py --chip auto --port /dev/tty.usbserial-0001 --baud 115200 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB 0x0 factory/factory_WROOM-32.bin

When you finish flashing, please Check Whether AT Works.

Check Whether AT Works¶

To check whether AT works, do as follows:

Open a serial port tool, such as SecureCRT;
Select the Port attached to “AT command/response” line (see Hardware Connection for details);
Set Baudrate to 115200;
Set Data Bits to 8;
Set Parity to None;
Set Stop Bits to 1;
Set Flow Type to None;
Enter the command “AT+GMR” with a new line (CR LF).

If the response is OK as the picture below shows, AT works.

Otherwise, you need to check your ESP startup log, which is visible on PC over “Download/Log output connection”. If it is like the log below, it means that ESP-AT firmware have been initalized correctly.

ESP32 startup log:

ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:4
load:0x3fff0034,len:7184
ho 0 tail 12 room 4
load:0x40078000,len:13200
load:0x40080400,len:4564
entry 0x400806f4
I (30) boot: ESP-IDF v4.2 2nd stage bootloader
I (31) boot: compile time 11:23:19
I (31) boot: chip revision: 0
I (33) boot.esp32: SPI Speed      : 40MHz
I (38) boot.esp32: SPI Mode       : DIO
I (42) boot.esp32: SPI Flash Size : 4MB
I (47) boot: Enabling RNG early entropy source...
I (52) boot: Partition Table:
I (56) boot: ## Label            Usage          Type ST Offset   Length
I (63) boot:  0 phy_init         RF data          01 01 0000f000 00001000
I (71) boot:  1 otadata          OTA data         01 00 00010000 00002000
I (78) boot:  2 nvs              WiFi data        01 02 00012000 0000e000
I (86) boot:  3 at_customize     unknown          40 00 00020000 000e0000
I (93) boot:  4 ota_0            OTA app          00 10 00100000 00180000
I (101) boot:  5 ota_1            OTA app          00 11 00280000 00180000
I (108) boot: End of partition table
I (112) esp_image: segment 0: paddr=0x00100020 vaddr=0x3f400020 size=0x2a300 (172800) map
I (187) esp_image: segment 1: paddr=0x0012a328 vaddr=0x3ffbdb60 size=0x039e8 ( 14824) load
I (194) esp_image: segment 2: paddr=0x0012dd18 vaddr=0x40080000 size=0x00404 (  1028) load
I (194) esp_image: segment 3: paddr=0x0012e124 vaddr=0x40080404 size=0x01ef4 (  7924) load
I (206) esp_image: segment 4: paddr=0x00130020 vaddr=0x400d0020 size=0x10a470 (1090672) map
I (627) esp_image: segment 5: paddr=0x0023a498 vaddr=0x400822f8 size=0x1c3a0 (115616) load
I (678) esp_image: segment 6: paddr=0x00256840 vaddr=0x400c0000 size=0x00064 (   100) load
I (695) boot: Loaded app from partition at offset 0x100000
I (695) boot: Disabling RNG early entropy source...
max tx power=78,ret=0
2.1.0

ESP32-C3 startup log:

ESP-ROM:esp32c3-20200918
Build:Sep 18 2020
rst:0x1 (POWERON),boot:0xc (SPI_FAST_FLASH_BOOT)
SPIWP:0xee
mode:DIO, clock div:2
load:0x3fcd6100,len:0x14
load:0x3fcd6114,len:0x179c
load:0x403ce000,len:0x894
load:0x403d0000,len:0x2bf8
entry 0x403ce000
I (54) boot: ESP-IDF v4.3-beta1 2nd stage bootloader
I (55) boot: compile time 12:09:42
I (55) boot: chip revision: 1
I (57) boot_comm: chip revision: 1, min. bootloader chip revision: 0
I (64) boot.esp32c3: SPI Speed      : 40MHz
I (68) boot.esp32c3: SPI Mode       : DIO
I (73) boot.esp32c3: SPI Flash Size : 4MB
I (78) boot: Enabling RNG early entropy source...
I (83) boot: Partition Table:
I (87) boot: ## Label            Usage          Type ST Offset   Length
I (94) boot:  0 phy_init         RF data          01 01 0000f000 00001000
I (102) boot:  1 otadata          OTA data         01 00 00010000 00002000
I (109) boot:  2 nvs              WiFi data        01 02 00012000 0000e000
I (117) boot:  3 at_customize     unknown          40 00 00020000 000e0000
I (124) boot:  4 ota_0            OTA app          00 10 00100000 00180000
I (132) boot:  5 ota_1            OTA app          00 11 00280000 00180000
I (139) boot: End of partition table
I (144) boot: No factory image, trying OTA 0
I (149) boot_comm: chip revision: 1, min. application chip revision: 0
I (156) esp_image: segment 0: paddr=00100020 vaddr=3c140020 size=29cc8h (171208) map
I (201) esp_image: segment 1: paddr=00129cf0 vaddr=3fc8f000 size=03be8h ( 15336) load
I (205) esp_image: segment 2: paddr=0012d8e0 vaddr=40380000 size=02738h ( 10040) load
I (210) esp_image: segment 3: paddr=00130020 vaddr=42000020 size=135bf0h (1268720) map
I (489) esp_image: segment 4: paddr=00265c18 vaddr=40382738 size=0c778h ( 51064) load
I (502) esp_image: segment 5: paddr=00272398 vaddr=50000000 size=00004h (     4) load
I (508) boot: Loaded app from partition at offset 0x100000
I (544) boot: Set actual ota_seq=1 in otadata[0]
I (544) boot: Disabling RNG early entropy source...
max tx power=78,ret=0
2.1.0

To learn more about ESP-AT, please read What is ESP-AT.

To get started with ESP-AT, please read Hardware Connection first to learn what hardware to prepare and how to connect them. Then, you can download and flash AT firmware into your device according to Downloading Guide.

AT Binary Lists¶

[中文]

Released Firmware¶

[中文]

It is recommended to use the lastest version of firmware. Currently, Espressif only releases AT firmware for the following ESP32 series of modules.

Note

If there is no released firmware for your module, you can either use the firmware for the module that has the same hardware configuration as yours (see ESP-AT Firmware Differences for which module has the same configuration), or create a factory parameter bin for your module (see How to Generate Factory Parameter Bin for details).

ESP32-WROOM-32 Series¶

v2.2.0.0 ESP32-WROOM-32_AT_Bin_V2.2.0.0.zip (Recommended)
v2.1.0.0 ESP32-WROOM-32_AT_Bin_V2.1.0.0.zip
v2.0.0.0 ESP32-WROOM-32_AT_Bin_V2.0.0.0.zip
v1.1.2.0 ESP32-WROOM-32_AT_Bin_V1.1.2.0.zip
v1.1.1.0 ESP32-WROOM-32_AT_Bin_V1.1.1.0.zip
v1.1.0.0 ESP32-WROOM-32_AT_Bin_V1.1.0.0.zip
v1.0.0.0 ESP32-WROOM-32_AT_Bin_V1.0.0.0.zip
v0.10.0.0 ESP32-WROOM-32_AT_Bin_V0.10.0.0.zip

ESP32-MINI-1 Series¶

v2.2.0.0 ESP32-MINI-1_AT_Bin_V2.2.0.0.zip (Recommended)

ESP32-WROVER-32 Series¶

It is not recommended to use the ESP32-WROVER-B module due to hardware limit. Please use other WROVER series modules.

v2.2.0.0 ESP32-WROVER_AT_Bin_V2.2.0.0.zip (Recommended)
v2.1.0.0 ESP32-WROVER_AT_Bin_V2.1.0.0.zip
v2.0.0.0 ESP32-WROVER_AT_Bin_V2.0.0.0.zip
v0.10.0.0 ESP32-WROVER_AT_Bin_V0.10.0.0.zip

It is recommended to use the lastest version of firmware. Currently, Espressif only releases AT firmware for the following ESP32-C3 series of modules.

Note

If there is no released firmware for your module, you can either use the firmware for the module that has the same hardware configuration as yours (see ESP-AT Firmware Differences for which module has the same configuration), or create a factory parameter bin for your module (see How to Generate Factory Parameter Bin for details).

ESP32-C3-MINI-1 Series¶

v2.3.0.0 ESP32-C3-MINI-1_AT_Bin_V2.3.0.0.zip (Recommended)
v2.2.0.0 ESP32-C3-MINI-1_AT_Bin_V2.2.0.0.zip

Each of the linked above ESP-AT firmware contains several binaries dedicated to some specific functions, and the factory/factory_xxx.bin is the combination of all binaries. So you can either download the factory/factory_xxx.bin to address 0, or several binaries to different addresses according to download.config. Please refer to Download AT Firmware for how to download.

at_customize.bin provides a user partition table, which lists the starting address and partition size for the ble_data.bin, SSL certificates, MQTT certificates, factory_param_XXX.bin, and so on. You can read and write contents of the partition listed in this file with the command AT+FS and AT+SYSFLASH.

factory_param_XXX.bin indicates the hardware configurations for different ESP modules (see the table below). Please make sure the correct bin is used for your specific module.

Note

If you design your own module, please configure and compile with reference to How to Generate Factory Parameter Bin, and the binaries will be automatically generated after compilation. Or you can select firmware with similar configuration according to the configuration of UART pins,PSRAM,Flash (The premise is to ensure that the hardware meets the requirements. Please refer to ESP-AT Firmware Differences for the firmware applicable to your module).

When you flash the firmware into module according to the download.config, the customized_partitions/factory_param.bin should be replaced with the actual module-specific customized_partitions/factory_param_XXX.bin. UART CTS and RTS pins are optional.

ESP32 Series

Modules	UART Pins (TX, RX, CTS, RTS)	Factory Parameter Bin
ESP32-WROOM-32 Series (ESP32 Default Module)	GPIO17 GPIO16 GPIO15 GPIO14	`factory_param_WROOM-32.bin`
ESP32-WROVER Series (Supports Classic Bluetooth)	GPIO22 GPIO19 GPIO15 GPIO14	`factory_param_WROVER-32.bin`
ESP32-PICO Series	GPIO22 GPIO19 GPIO15 GPIO14	`factory_param_PICO-D4.bin`
ESP32-SOLO Series	GPIO17 GPIO16 GPIO15 GPIO14	`factory_param_SOLO-1.bin`

ESP32-C3 Series

Modules	UART Pins (TX, RX, CTS, RTS)	Factory Parameter Bin
ESP32-C3-MINI Series	GPIO7 GPIO6 GPIO5 GPIO4	`factory_param_MINI-1.bin`

ble_data.bin provides Bluetooth LE services when the ESP device works as a Bluetooth LE server;
server_cert.bin, server_key.bin and server_ca.bin are examples of SSL server’s certificate;
client_cert.bin, client_key.bin and client_ca.bin are examples of SSL client’s certificate;
mqtt_cert.bin, mqtt_key.bin and mqtt_ca.bin are examples of MQTT SSL client’s certificate;

If some of the functions are not used, then the corresponding binaries need not to be downloaded into flash.

AT Command Set¶

[中文]

Here is a list of AT commands. Some of them can only work on the ESP32 series, so they are marked as [ESP32 Only] at the beginning; those without any mark can work on all ESP series, including ESP32, and ESP32-C3.

Basic AT Commands¶

[中文]

AT: Test AT startup.
AT+RST: Restart a module.
AT+GMR: Check version information.
AT+CMD: List all AT commands and types supported in current firmware.
AT+GSLP: Enter Deep-sleep mode.
ATE: Configure AT commands echoing.
AT+RESTORE: Restore factory default settings of the module.
AT+UART_CUR: Current UART configuration, not saved in flash.
AT+UART_DEF: Default UART configuration, saved in flash.
AT+SLEEP: Set the sleep mode.
AT+SYSRAM: Query current remaining heap size and minimum heap size.
AT+SYSMSG: Query/Set System Prompt Information.
AT+SYSFLASH: Query/Set User Partitions in Flash.
AT+FS: Filesystem Operations.
AT+RFPOWER: Query/Set RF TX Power.
AT+SYSROLLBACK: Roll back to the previous firmware.
AT+SYSTIMESTAMP: Query/Set local time stamp.
AT+SYSLOG: Enable or disable the AT error code prompt.
AT+SLEEPWKCFG: Query/Set the light-sleep wakeup source and awake GPIO.
AT+SYSSTORE: Query/Set parameter store mode.
AT+SYSREG: Read/write the register.

AT: Test AT Startup¶

Execute Command¶

Command:

AT

Response:

OK

AT+RST: Restart a Module¶

Execute Command¶

Command:

AT+RST

Response:

OK

AT+GMR: Check Version Information¶

Execute Command¶

Command:

AT+GMR

Response:

<AT version info>
<SDK version info>
<compile time>
<Bin version>

OK

Parameters¶

<AT version info>: information about the esp-at core library version, which is under the directory: esp-at/components/at/lib/. Code is closed source, no plan to open.
<SDK version info>: information about the esp-at platform sdk version, which is defined in file: esp-at/module_config/module_{platform}_default/IDF_VERSION
<compile time>: the time to compile the firmware.
<Bin version>: esp-at firmware version. Version information can be modified in menuconfig.

Note¶

If you have any issues on esp-at firmware, please provide AT+GMR version information firstly.

Example¶

AT+GMR
AT version:2.2.0.0-dev(ca41ec4 - ESP32 - Sep 16 2020 11:28:17)
SDK version:v4.0.1-193-ge7ac221b4
compile time(98b95fc):Oct 29 2020 11:23:25
Bin version:2.1.0(MINI-1)

OK

AT+CMD: List all AT commands and types supported in current firmware¶

Query Command¶

Command:

AT+CMD?

Response:

+CMD:<index>,<AT command name>,<support test command>,<support query command>,<support set command>,<support execute command>

OK

Parameters¶

<index>: AT command sequence number.
<AT command name>: AT command name.
<support test command>: 0 means not supported, 1 means supported.
<support query command>: 0 means not supported, 1 means supported.
<support set command>: 0 means not supported, 1 means supported.
<support execute command>: 0 means not supported, 1 means supported.

AT+GSLP: Enter Deep-sleep Mode¶

Set Command¶

Command:

AT+GSLP=<time>

Response:

<time>

OK

Parameter¶

<time>: the duration when the device stays in Deep-sleep. Unit: millisecond. When the time is up, the device automatically wakes up, calls Deep-sleep wake stub, and then proceeds to load the application.
- 0 means restarting right now
- the maximum Deep-sleep time is about 28.8 days (2 ³¹-1 milliseconds)

Notes¶

The theoretical and actual time of Deep-sleep may be different due to external factors.

ATE: Configure AT Commands Echoing¶

Execute Command¶

Command:

ATE0

or

ATE1

Response:

OK

Parameters¶

ATE0: Switch echo off.
ATE1: Switch echo on.

AT+RESTORE: Restore Factory Default Settings¶

Execute Command¶

Command:

AT+RESTORE

Response:

OK

Notes¶

The execution of this command will restore all parameters saved in flash to factory default settings of the module.
The device will be restarted when this command is executed.

AT+UART_CUR: Current UART Configuration, Not Saved in Flash¶

Query Command¶

Command:

AT+UART_CUR?

Response:

+UART_CUR:<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

OK

Set Command¶

Command:

AT+UART_CUR=<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

Response:

OK

Parameters¶

<baudrate>: UART baud rate
- For ESP32 and ESP32-C3 devices, the supported range is 80 ~ 5000000.
<databits>: data bits
- 5: 5-bit data
- 6: 6-bit data
- 7: 7-bit data
- 8: 8-bit data
<stopbits>: stop bits
- 1: 1-bit stop bit
- 2: 1.5-bit stop bit
- 3: 2-bit stop bit
<parity>: parity bit
- 0: None
- 1: Odd
- 2: Even
<flow control>: flow control
- 0: flow control is not enabled
- 1: enable RTS
- 2: enable CTS
- 3: enable both RTS and CTS

Notes¶

The Query Command will return actual values of UART configuration parameters, which may have minor differences from the set value because of the clock division.
The configuration changes will NOT be saved in flash.
To use hardware flow control, you need to connect CTS/RTS pins of your ESP device. For more details, please refer to Hardware Connection or components/customized_partitions/raw_data/factory_param/factory_param_data.csv.

Example¶

AT+UART_CUR=115200,8,1,0,3

AT+UART_DEF: Default UART Configuration, Saved in Flash¶

Query Command¶

Command:

AT+UART_DEF?

Response:

+UART_DEF:<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

OK

Set Command¶

Command:

AT+UART_DEF=<baudrate>,<databits>,<stopbits>,<parity>,<flow control>

Response:

OK

Parameters¶

<baudrate>: UART baud rate
- For ESP32 and ESP32-C3 devices, the supported range is 80 ~ 5000000.
<databits>: data bits
- 5: 5-bit data
- 6: 6-bit data
- 7: 7-bit data
- 8: 8-bit data
<stopbits>: stop bits
- 1: 1-bit stop bit
- 2: 1.5-bit stop bit
- 3: 2-bit stop bit
<parity>: parity bit
- 0: None
- 1: Odd
- 2: Even
<flow control>: flow control
- 0: flow control is not enabled
- 1: enable RTS
- 2: enable CTS
- 3: enable both RTS and CTS

Notes¶

The configuration changes will be saved in the NVS area, and will still be valid when the chip is powered on again.
To use hardware flow control, you need to connect CTS/RTS pins of your ESP device. For more details, please refer to Hardware Connection or components/customized_partitions/raw_data/factory_param/factory_param_data.csv.

Example¶

AT+UART_DEF=115200,8,1,0,3

AT+SLEEP: Set the Sleep Mode¶

Query Command¶

Command:

AT+SLEEP?

Response:

+SLEEP:<sleep mode>

OK

Set Command¶

Command:

AT+SLEEP=<sleep mode>

Response:

OK

Parameter¶

<sleep mode>:
- 0: Disable the sleep mode.
- 1: Modem-sleep mode.
  - Only Wi-Fi mode.
    - RF will be periodically closed according to AP DTIM.
  - Only BLE mode.
    - RF will be periodically closed according to advertising interval ( BLE state in advertising ).
    - RF will be periodically closed according to connection interval ( BLE state in connection ).
- 2: Light-sleep mode.
  - Only Wi-Fi mode.
    - CPU will automatically sleep and RF will be periodically closed according to listen interval set by AT+CWJAP.
  - Only BLE mode.
    - CPU will automatically sleep and RF will be periodically closed according to advertising interval ( BLE state in advertising ).
    - CPU will automatically sleep and RF will be periodically closed according to connection interval ( BLE state in connection ).
- 3: Modem-sleep listen interval mode.
  - Only Wi-Fi mode.
    - RF will be periodically closed according to listen interval set by AT+CWJAP.
  - Only BLE mode.
    - RF will be periodically closed according to advertising interval ( BLE state in advertising ).
    - RF will be periodically closed according to connection interval ( BLE state in connection ).

Note¶

Modem-sleep mode and Light-sleep mode can be set under Wi-Fi mode or BLE mode, but in Wi-Fi mode, these two modes can only be set in station mode.
Before setting the Light-sleep mode, it is recommended to set the wakeup source in advance through the command AT+SLEEPWKCFG, otherwise ESP devices can’t wake up and will always be in sleep mode.
After setting the Light-sleep mode, if the Light-sleep wakeup condition is not met, ESP devices will automatically enter the sleep mode. When the Light-sleep wakeup condition is met, ESP devices will automatically wake up from sleep mode.
For Light-sleep mode in BLE mode, users must ensure external 32KHz crystal oscillator, otherwise the Light-sleep mode will work in Modem-sleep mode. At present, AT only supports Light-sleep of ESP32 to work in Modem-sleep without external 32KHz crystal oscillator.
For more examples, please refer to Sleep AT Examples.

Example¶

AT+SLEEP=0

AT+SYSRAM: Query Current Remaining Heap Size and Minimum Heap Size¶

Query Command¶

Command:

AT+SYSRAM?

Response:

+SYSRAM:<remaining RAM size>,<minimum heap size>
OK

Parameters¶

<remaining RAM size>: current remaining heap size. Unit: byte.
<minimum heap size>: minimum heap size that has ever been available. Unit: byte.

Example¶

AT+SYSRAM?
+SYSRAM:148408,84044
OK

AT+SYSMSG: Query/Set System Prompt Information¶

Query Command¶

Function:

Query the current system prompt information state.

Command:

AT+SYSMSG?

Response:

+SYSMSG:<state>
OK

Set Command¶

Function:

Configure system prompt information.

Command:

AT+SYSMSG=<state>

Response:

OK

Parameter¶

<state>:
- Bit0: Prompt information when quitting Wi-Fi Passthrough Mode, Bluetooth LE SPP and Bluetooth SPP.
  - 0: Print no prompt information when quitting Wi-Fi Passthrough Mode, Bluetooth LE SPP and Bluetooth SPP.
  - 1: Print +QUITT when quitting Wi-Fi Passthrough Mode, Bluetooth LE SPP and Bluetooth SPP.
- Bit1: Connection prompt information type.
  - 0: Use simple prompt information, such as XX,CONNECT.
  - 1: Use detailed prompt information, such as +LINK_CONN:status_type,link_id,ip_type,terminal_type,remote_ip,remote_port,local_port.
- Bit2: Connection status prompt information for Wi-Fi Passthrough Mode, Bluetooth LE SPP and Bluetooth SPP.
  - 0: Print no prompt information.
  - 1: Print one of the following prompt information when Wi-Fi, socket, Bluetooth LE or Bluetooth status is changed:
  - "CONNECT\r\n" or the message prefixed with "+LINK_CONN:" - "CLOSED\r\n" - "WIFI CONNECTED\r\n" - "WIFI GOT IP\r\n" - "WIFI GOT IPv6 LL\r\n" - "WIFI GOT IPv6 GL\r\n" - "WIFI DISCONNECT\r\n" - "+ETH_CONNECTED\r\n" - "+ETH_DISCONNECTED\r\n" - the message prefixed with "+ETH_GOT_IP:" - the message prefixed with "+STA_CONNECTED:" - the message prefixed with "+STA_DISCONNECTED:" - the message prefixed with "+DIST_STA_IP:" - the message prefixed with "+BLECONN:" - the message prefixed with "+BLEDISCONN:"

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
If you set Bit0 to 1, it will prompt “+QUITT” when you quit Wi-Fi Passthrough Mode.
If you set Bit1 to 1, it will impact the information of command AT+CIPSTART and AT+CIPSERVER. It will supply “+LINK_CONN:status_type,link_id,ip_type,terminal_type,remote_ip,remote_port,local_port” instead of “XX,CONNECT”.

Example¶

// print no promt info when quitting Wi-Fi passthrough mode
// print detailed connection prompt info
// print no prompt info when the connection status is changed
AT+SYSMSG=2

or

// In the transparent transmission mode, a prompt message will be printed when the Wi-Fi, socket, Bluetooth LE or Bluetooth status changes
AT+SYSMSG=4

AT+SYSFLASH: Query/Set User Partitions in Flash¶

Query Command¶

Function:

Query user partitions in flash.

Command:

AT+SYSFLASH?

Response:

+SYSFLASH:<partition>,<type>,<subtype>,<addr>,<size>
OK

Set Command¶

Function:

Read/write the user partitions in flash.

Command:

AT+SYSFLASH=<operation>,<partition>,<offset>,<length>

Response:

+SYSFLASH:<length>,<data>
OK

Parameters¶

<operation>:
- 0: erase sector
- 1: write data into the user partition
- 2: read data from the user partition
<partition>: name of user partition
<offset>: offset of user partition
<length>: data length
<type>: type of user partition
<subtype>: subtype of user partition
<addr>: address of user partition
<size>: size of user partition

Notes¶

Please make sure that you have downloaded at_customize.bin before using this command. For more details, please refer to How to Customize Partitions.
Before downloading the secondary user partition, please refer How to Generate PKI Files to generate the binary user partition file.
When erasing the targeted user partition in its entirety, you can omit the parameters <offset> and <length>. For example, command AT+SYSFLASH=0,"ble_data" can erase the entire “ble_data” user partition. But if you want to keep the two parameters, they have to be 4KB-aligned.
The introduction to partitions is in ESP-IDF Partition Tables.
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>.
If the operator is write, please make sure that you have already erased this partition.
If the operator is write on a PKI bin, the <length> should be 4 bytes aligned.

Example¶

// read 100 bytes from the "ble_data" partition offset 0.
AT+SYSFLASH=2,"ble_data",0,100

// write 10 bytes to the "ble_data" partition offset 100.
AT+SYSFLASH=1,"ble_data",100,10

// erase 8192 bytes from the "ble_data" partition offset 4096.
AT+SYSFLASH=0,"ble_data",4096,8192

AT+FS: Filesystem Operations¶

Set Command¶

Command:

AT+FS=<type>,<operation>,<filename>,<offset>,<length>

Response:

OK

Parameters¶

<type>: only FATFS is currently supported.
- 0: FATFS
<operation>:
- 0: delete file.
- 1: write file.
- 2: read file.
- 3: query the size of the file.
- 4: list files in a specific directory. Only root directory is currently supported.
<offset>: apply to writing and reading operations only.
<length>: data length, applying to writing and reading operations only.

Notes¶

Please make sure that you have downloaded at_customize.bin before using this command. For more details, refer to ESP-IDF Partition Tables and How to Customize Partitions.
If the length of the read data is greater than the actual file length, only the actual data length of the file will be returned.
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>.

Example¶

// delete a file.
AT+FS=0,0,"filename"

// write 10 bytes to offset 100 of a file.
AT+FS=0,1,"filename",100,10

// read 100 bytes from offset 0 of a file.
AT+FS=0,2,"filename",0,100

// list all files in the root directory.
AT+FS=0,4,"."

AT+RFPOWER: Query/Set RF TX Power¶

Query Command¶

Function:

Query the RF TX Power.

Command:

AT+RFPOWER?

Response:

+RFPOWER:<wifi_power>,<ble_adv_power>,<ble_scan_power>,<ble_conn_power>
OK

Set Command¶

Command:

AT+RFPOWER=<wifi_power>[,<ble_adv_power>,<ble_scan_power>,<ble_conn_power>]

Response:

OK

Parameters¶

<wifi_power>: the unit is 0.25 dBm. For example, if you set the value to 78, the actual maximum RF Power value is 78 * 0.25 dBm = 19.5 dBm. After you configure it, please confirm the actual value by entering the command AT+RFPOWER?.

For ESP32 devices, the range is [40,84]:

set value	get value	actual value	actual dBm
[40,43]	34	34	8.5
[44,51]	44	44	11
[52,55]	52	52	13
[56,59]	56	56	14
[60,65]	60	60	15
[66,71]	66	66	16.5
[72,77]	72	72	18
[78,84]	78	78	19.5

For ESP32-C3 devices, the range is [40,84]:

set value

get value

actual value

actual dBm

[40,80]

<set value>

<set value>

<set value> * 0.25

[81,84]

<set value>

80

20

<ble_adv_power>: RF TX Power of Bluetooth LE advertising. Range: [0,7].
- For ESP32 devices
  - 0: 7 dBm
  - 1: 4 dBm
  - 2: 1 dBm
  - 3: -2 dBm
  - 4: -5 dBm
  - 5: -8 dBm
  - 6: -11 dBm
  - 7: -14 dBm
- For ESP32C3 devices
  - 0: -27 dBm
  - 1: -24 dBm
  - 2: -21 dBm
  - 3: -18 dBm
  - 4: -15 dBm
  - 5: -12 dBm
  - 6: -9 dBm
  - 7: -6 dBm
  - 8: -3 dBm
  - 9: -0 dBm
  - 10: 3 dBm
  - 11: 6 dBm
  - 12: 9 dBm
  - 13: 12 dBm
  - 14: 15 dBm
  - 15: 18 dBm
<ble_scan_power>: RF TX Power of Bluetooth LE scanning. The parameters are the same as <ble_adv_power>.
<ble_conn_power>: RF TX Power of Bluetooth LE connecting. The same as <ble_adv_power>.

Note¶

Since the RF TX Power is actually divided into several levels, and each level has its own value range, the wifi_power value queried by the esp_wifi_get_max_tx_power may differ from the value set by esp_wifi_set_max_tx_power and is no larger than the set value.

AT+SYSROLLBACK: Roll Back to the Previous Firmware¶

Execute Command¶

Command:

AT+SYSROLLBACK

Response:

OK

Note¶

This command will not upgrade via OTA. It only rolls back to the firmware which is in the other OTA partition.

AT+SYSTIMESTAMP: Query/Set Local Time Stamp¶

Query Command¶

Function:

Query the time stamp.

Command:

AT+SYSTIMESTAMP?

Response:

+SYSTIMESTAMP:<Unix_timestamp>
OK

Set Command¶

Function:

Set local time stamp. It will be the same as SNTP time when the SNTP time is updated.

Command:

AT+SYSTIMESTAMP=<Unix_timestamp>

Response:

OK

Parameter¶

<Unix-timestamp>: Unix timestamp. Unit: second.

Example¶

AT+SYSTIMESTAMP=1565853509    //2019-08-15 15:18:29

AT+SYSLOG: Enable or Disable the AT Error Code Prompt¶

Query Command¶

Function:

Query whether the AT error code prompt is enabled or not.

Command:

AT+SYSLOG?

Response:

+SYSLOG:<status>

OK

Set Command¶

Function:

Enable or disable the AT error code prompt.

Command:

AT+SYSLOG=<status>

Response:

OK

Parameter¶

<status>: enable or disable
- 0: disable
- 1: enable

Example¶

// enable AT error code prompt
AT+SYSLOG=1

OK
AT+FAKE
ERR CODE:0x01090000

ERROR

// disable AT error code prompt
AT+SYSLOG=0

OK
AT+FAKE
// No `ERR CODE:0x01090000`

ERROR

The error code is a 32-bit hexadecimal value and defined as follows:

category	subcategory	extension
bit32 ~ bit24	bit23 ~ bit16	bit15 ~ bit0

category: stationary value 0x01.

subcategory: error type.

Subcategory of Error Code¶
Error Type	Error Code	Description
ESP_AT_SUB_OK	0x00	OK
ESP_AT_SUB_COMMON_ERROR	0x01	reserved
ESP_AT_SUB_NO_TERMINATOR	0x02	terminator character not found (“rn” expected)
ESP_AT_SUB_NO_AT	0x03	Starting AT not found (or at, At or aT entered)
ESP_AT_SUB_PARA_LENGTH_MISMATCH	0x04	parameter length mismatch
ESP_AT_SUB_PARA_TYPE_MISMATCH	0x05	parameter type mismatch
ESP_AT_SUB_PARA_NUM_MISMATCH	0x06	parameter number mismatch
ESP_AT_SUB_PARA_INVALID	0x07	the parameter is invalid
ESP_AT_SUB_PARA_PARSE_FAIL	0x08	parse parameter fail
ESP_AT_SUB_UNSUPPORT_CMD	0x09	the command is not supported
ESP_AT_SUB_CMD_EXEC_FAIL	0x0A	the command execution failed
ESP_AT_SUB_CMD_PROCESSING	0x0B	processing of previous command is in progress
ESP_AT_SUB_CMD_OP_ERROR	0x0C	the command operation type is error

extension: error extension information. There are different extensions for different subcategory. For more information, please see the components/at/include/esp_at.h.

For example, the error code ERR CODE:0x01090000 means the command is not supported.

AT+SLEEPWKCFG: Set the Light-sleep Wakeup Source and Awake GPIO¶

Set Command¶

Command:

AT+SLEEPWKCFG=<wakeup source>,<param1>[,<param2>]

Response:

OK

Parameters¶

<wakeup source>:
- 0: wakeup by a timer.
- 1: reserved.
- 2: wakeup by GPIO.
<param1>:
- If the wakeup source is a timer, it means the time before wakeup. Unit: millisecond.
- If the wakeup source is GPIO, it means the GPIO number.
<param2>:
- If the wakeup source is GPIO, it means the wakeup level:
- 0: low level.
- 1: high level.

Example¶

// Timer wakeup
AT+SLEEPWKCFG=0,1000

// GPIO12 wakeup, low level
AT+SLEEPWKCFG=2,12,0

AT+SYSSTORE: Query/Set Parameter Store Mode¶

Query Command¶

Function:

Query the AT parameter store mode.

Command:

AT+SYSSTORE?

Response:

+SYSSTORE:<store_mode>

OK

Set Command¶

Command:

AT+SYSSTORE=<store_mode>

Response:

OK

Parameter¶

<store_mode>:
- 0: command configuration is not stored into flash.
- 1: command configuration is stored into flash. (Default)

Note¶

This command affects set commands only. Query commands are always fetched from RAM.
Affected commands:

Examples¶

AT+SYSSTORE=0
AT+CWMODE=1  // Not stored into flash
AT+CWJAP="test","1234567890" // Not stored into flash

AT+SYSSTORE=1
AT+CWMODE=3  // Stored into flash
AT+CWJAP="test","1234567890" // Stored into flash

AT+SYSREG: Read/Write the Register¶

Set Command¶

Command:

AT+SYSREG=<direct>,<address>[,<write value>]

Response:

+SYSREG:<read value>    // Only in read mode
OK

Parameters¶

<direct>: read or write register.
- 0: read register.
- 1: write register.
<address>: (uint32) register address. You can refer to Technical Reference Manuals.
<write value>: (uint32) write value (only in write mode).

Note¶

AT does not check address. Make sure that the registers you are operating on are valid.

Wi-Fi AT Commands¶

[中文]

AT+CWMODE: Set the Wi-Fi mode (Station/SoftAP/Station+SoftAP).
AT+CWSTATE: Query the Wi-Fi state and Wi-Fi information.
AT+CWJAP: Connect to an AP.
AT+CWRECONNCFG: Query/Set the Wi-Fi reconnecting configuration.
AT+CWLAPOPT: Set the configuration for the command AT+CWLAP.
AT+CWLAP: List available APs.
AT+CWQAP: Disconnect from an AP.
AT+CWSAP: Query/Set the configuration of an ESP SoftAP.
AT+CWLIF: Obtain IP address of the station that connects to an ESP SoftAP.
AT+CWQIF: Disconnect stations from an ESP SoftAP.
AT+CWDHCP: Enable/disable DHCP.
AT+CWDHCPS: Query/Set the IP addresses allocated by an ESP SoftAP DHCP server.
AT+CWAUTOCONN: Connect to an AP automatically when powered on.
AT+CWAPPROTO: Query/Set the 802.11 b/g/n protocol standard of SoftAP mode.
AT+CWSTAPROTO: Query/Set the 802.11 b/g/n protocol standard of station mode.
AT+CIPSTAMAC: Query/Set the MAC address of an ESP station.
AT+CIPAPMAC: Query/Set the MAC address of an ESP SoftAP.
AT+CIPSTA: Query/Set the IP address of an ESP station.
AT+CIPAP: Query/Set the IP address of an ESP SoftAP.
AT+CWSTARTSMART: Start SmartConfig.
AT+CWSTOPSMART: Stop SmartConfig.
AT+WPS: Enable the WPS function.
AT+MDNS: Configure the mDNS function.
AT+CWJEAP: Connect to a WPA2 Enterprise AP.
AT+CWHOSTNAME: Query/Set the host name of an ESP station.
AT+CWCOUNTRY: Query/Set the Wi-Fi Country Code.

AT+CWMODE: Query/Set the Wi-Fi Mode (Station/SoftAP/Station+SoftAP)¶

Query Command¶

Function:

Query the Wi-Fi mode of ESP devices.

Command:

AT+CWMODE?

Response:

+CWMODE:<mode>
OK

Set Command¶

Function:

Set the Wi-Fi mode of ESP devices.

Command:

AT+CWMODE=<mode>[,<auto_connect>]

Response:

OK

Parameters¶

<mode>:
- 0: Null mode. Wi-Fi RF will be disabled.
- 1: Station mode.
- 2: SoftAP mode.
- 3: SoftAP+Station mode.
<auto_connect>: Enable or disable automatic connection to an AP when you change the mode of the ESP device from the SoftAP mode or null mode to the station mode or the SoftAP+Station mode. Default: 1. If you omit the parameter, the default value will be used, i.e. automatically connecting to an AP.
- 0: The ESP device will not automatically connect to an AP.
- 1: The ESP device will automatically connect to an AP if the configuration to connect to the AP has already been saved in flash before.

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.

Example¶

AT+CWMODE=3

AT+CWSTATE: Query the Wi-Fi state and Wi-Fi information¶

Query Command¶

Function:

Query the Wi-Fi state and Wi-Fi information of ESP devices.

Command:

AT+CWSTATE?

Response:

+CWSTATE:<state>,<"ssid">

OK

Parameters¶

<state>: current Wi-Fi state.
- 0: ESP station has not started any Wi-Fi connection.
- 1: ESP station has connected to an AP, but does not get an IPv4 address yet.
- 2: ESP station has connected to an AP, and got an IPv4 address.
- 3: ESP station is in Wi-Fi connecting or reconnecting state.
- 4: ESP station is in Wi-Fi disconnected state.
<”ssid”>: the SSID of the target AP.

Note¶

When ESP station is not connected to an AP, it is recommended to use this command to query Wi-Fi information; after ESP station is connected to an AP, it is recommended to use AT+CWJAP to query Wi-Fi information.

AT+CWJAP: Connect to an AP¶

Query Command¶

Function:

Query the AP to which the ESP Station is already connected.

Command:

AT+CWJAP?

Response:

+CWJAP:<ssid>,<bssid>,<channel>,<rssi>,<pci_en>,<reconn_interval>,<listen_interval>,<scan_mode>,<pmf>
OK

Set Command¶

Function:

Connect an ESP station to a targeted AP.

Command:

AT+CWJAP=[<ssid>],[<pwd>][,<bssid>][,<pci_en>][,<reconn_interval>][,<listen_interval>][,<scan_mode>][,<jap_timeout>][,<pmf>]

Response:

WIFI CONNECTED
WIFI GOT IP

OK
[WIFI GOT IPv6 LL]
[WIFI GOT IPv6 GL]

or

+CWJAP:<error code>
ERROR

Execute Command¶

Function:

Connect an ESP station to a targeted AP with last Wi-Fi configuration.

Command:

AT+CWJAP

Response:

WIFI CONNECTED
WIFI GOT IP

OK
[WIFI GOT IPv6 LL]
[WIFI GOT IPv6 GL]

or

+CWJAP:<error code>
ERROR

Parameters¶

<ssid>: the SSID of the target AP.
- Escape character syntax is needed if SSID or password contains special characters, such ,, ", or \\.
<pwd>: password, MAX: 63-byte ASCII.
<bssid>: the MAC address of the target AP. It cannot be omitted when multiple APs have the same SSID.
<channel>: channel.
<rssi>: signal strength.
<pci_en>: PCI Authentication.
- 0: The ESP station will connect APs with all encryption methods, including OPEN and WEP.
- 1: The ESP station will connect APs with all encryption methods, except OPEN and WEP.
<reconn_interval>: the interval between Wi-Fi reconnections. Unit: second. Default: 1. Maximum: 7200.
- 0: The ESP station will not reconnect to the AP when disconnected.
- [1,7200]: The ESP station will reconnect to the AP at the specified interval when disconnected.
<listen_interval>: the interval of listening to the AP’s beacon. Unit: AP beacon intervals. Default: 3. Range: [1,100].
<scan_mode>:
- 0: fast scan. It will end after finding the targeted AP. The ESP station will connect to the first scanned AP.
- 1: all-channel scan. It will end after all the channels are scanned. The device will connect to the scanned AP with the strongest signal.
<jap_timeout>: maximum timeout for AT+CWJAP command. Unit: second. Default: 15. Range: [3,600].
<pmf>: Protected Management Frames. Default: 0.
- 0 means disable PMF.
- bit 0: PMF capable, advertizes support for protected management frame. Device will prefer to connect in PMF mode if other device also advertizes PMF capability.
- bit 1: PMF required, advertizes that protected management frame is required. Device will not associate to non-PMF capable devices.
<error code>: (for reference only)
- 1: connection timeout.
- 2: wrong password.
- 3: cannot find the target AP.
- 4: connection failed.
- others: unknown error occurred.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This command requires Station mode to be enabled.
After ESP station is connected to an AP, it is recommended to use this command to query Wi-Fi information; when ESP station is not connected to an AP, it is recommended to use AT+CWSTATE to query Wi-Fi information.
The parameter <reconn_interval> of this command is the same as <interval_second> of the command AT+CWRECONNCFG. Therefore, if you omit <reconn_interval> when running this command, the interval between Wi-Fi reconnections will use the default value 1.
If the <ssid> and <password> parameter are omitted, AT will use the last configuration.
Execute command has the same maximum timeout to setup command. The default value is 15 seconds, but you can change it by setting the parameter <jap_timeout>.
To get an IPv6 address, you need to set AT+CIPV6=1.
Response OK means that the IPv4 network is ready, but not the IPv6 network. At present, ESP-AT is mainly based on IPv4 network, supplemented by IPv6 network.
WIFI GOT IPv6 LL represents that the linklocal IPv6 address has been obtained. This address is calculated locally through EUI-64 and does not require the participation of the AP. Because of the parallel timing, this print may be before or after OK.
WIFI GOT IPv6 GL represents that the global IPv6 address has been obtained. This address is combined by the prefix issued by AP and the suffix calculated internally, which requires the participation of the AP. Because of the parallel timing, this print may be before or after OK, or it may not be printed because the AP does not support IPv6.

Example¶

// If the target AP's SSID is "abc" and the password is "0123456789", the command should be:
AT+CWJAP="abc","0123456789"

// If the target AP's SSID is "ab\,c" and the password is "0123456789"\", the command should be:
AT+CWJAP="ab\\\,c","0123456789\"\\"

// If multiple APs all have the SSID of "abc", the target AP can be found by BSSID:
AT+CWJAP="abc","0123456789","ca:d7:19:d8:a6:44"

// If esp-at is required that connect to a AP by protected management frame, the command should be:
AT+CWJAP="abc","0123456789",,,,,,,3

AT+CWRECONNCFG: Query/Set the Wi-Fi Reconnecting Configuration¶

Query Command¶

Function:

Query the configuration of Wi-Fi reconnect.

Command:

AT+CWRECONNCFG?

Response:

+CWRECONNCFG:<interval_second>,<repeat_count>
OK

Set Command¶

Function:

Set the configuration of Wi-Fi reconnect.

Command:

AT+CWRECONNCFG=<interval_second>,<repeat_count>

Response:

OK

Parameters¶

<interval_second>: the interval between Wi-Fi reconnections. Unit: second. Default: 0. Maximum: 7200.
- 0: The ESP station will not reconnect to the AP when disconnected.
- [1,7200]: The ESP station will reconnect to the AP at the specified interval when disconnected.
<repeat_count>: the number of attempts the ESP device makes to reconnect to the AP. This parameter only works when the parameter <interval_second> is not 0. Default: 0. Maximum: 1000.
- 0: The ESP station will always try to reconnect to AP.
- [1,1000]: The ESP station will attempt to reconnect to AP for the specified times.

Example¶

// The ESP station tries to reconnect to AP at the interval of one second for 100 times.
AT+CWRECONNCFG=1,100

// The ESP station will not reconnect to AP when disconnected.
AT+CWRECONNCFG=0,0

Notes¶

The parameter <interval_second> of this command is the same as the parameter [<reconn_interval>] of the command AT+CWJAP.
This command works for passive disconnection from APs, Wi-Fi mode switch, and Wi-Fi auto connect after power on.

AT+CWLAPOPT: Set the Configuration for the Command AT+CWLAP ¶

Set Command¶

Command:

AT+CWLAPOPT=<reserved>,<print mask>[,<rssi filter>][,<authmode mask>]

Response:

OK

or

ERROR

Parameters¶

<reserved>: reserved item.
<print mask>: determine whether the following parameters are shown in the result of AT+CWLAP. Default: 0x7FF. If you set them to 1, it means showing the corresponding parameters; if you set them as 0, it means NOT showing the corresponding parameters.
- bit 0: determine whether <ecn> will be shown.
- bit 1: determine whether <ssid> will be shown.
- bit 2: determine whether <rssi> will be shown.
- bit 3: determine whether <mac> will be shown.
- bit 4: determine whether <channel> will be shown.
- bit 5: determine whether <freq_offset> will be shown.
- bit 6: determine whether <freqcal_val> will be shown.
- bit 7: determine whether <pairwise_cipher> will be shown.
- bit 8: determine whether <group_cipher> will be shown.
- bit 9: determine whether <bgn> will be shown.
- bit 10: determine whether <wps> will be shown.
[<rssi filter>]: determine whether the result of the command AT+CWLAP will be filtered according to rssi filter. In other words, the result of the command will NOT show the APs whose signal strength is below rssi filter. Unit: dBm. Default: -100. Range: [-100,40].
[<authmode mask>]: determine whether APs with the following authmodes are shown in the result of AT+CWLAP. Default: 0xFFFF. If you set bit x to 1, the APs with the corresponding authmode will be shown. If you set bit x to 0, the APs with the corresponding authmode will NOT be shown;
- bit 0: determine whether APs with OPEN authmode will be shown.
- bit 1: determine whether APs with WEP authmode will be shown.
- bit 2: determine whether APs with WPA_PSK authmode will be shown.
- bit 3: determine whether APs with WPA2_PSK authmode will be shown.
- bit 4: determine whether APs with WPA_WPA2_PSK authmode will be shown.
- bit 5: determine whether APs with WPA2_ENTERPRISE authmode will be shown.
- bit 6: determine whether APs with WPA3_PSK authmode will be shown.
- bit 7: determine whether AP with WPA2_WPA3_PSK authmode will be shown.
- [ESP32-C3 Only] bit 8: determine whether AP with WAPI_PSK authmode will be shown.

Example¶

// The first parameter is 1, meaning that the result of the command AT+CWLAP will be ordered according to RSSI;
// The second parameter is 31, namely 0x1F, meaning that the corresponding bits of <print mask> are set to 1. All parameters will be shown in the result of AT+CWLAP.
AT+CWLAPOPT=1,31
AT+CWLAP

// Just show the AP which authmode is OPEN
AT+CWLAPOPT=1,31,-100,1
AT+CWLAP

AT+CWLAP: List Available APs¶

Set Command¶

Function:

Query the APs with specified parameters, such as the SSID, MAC address, or channel.

Command:

AT+CWLAP=[<ssid>,<mac>,<channel>,<scan_type>,<scan_time_min>,<scan_time_max>]

Execute Command¶

Function:

List all available APs.

Command:

AT+CWLAP

Response:

+CWLAP:<ecn>,<ssid>,<rssi>,<mac>,<channel>,<freq_offset>,<freqcal_val>,<pairwise_cipher>,<group_cipher>,<bgn>,<wps>
OK

Parameters¶

<ecn>: encryption method.
- 0: OPEN
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK
- [ESP32-C3 Only] 8: WAPI_PSK
<ssid>: string parameter showing SSID of the AP.
<rssi>: signal strength.
<mac>: string parameter showing MAC address of the AP.
<channel>: channel.
<scan_type>: Wi-Fi scan type. Default: 0.
- 0: active scan
- 1: passive scan
<scan_time_min>: the minimum active scan time per channel. Unit: millisecond. Range [0,1500]. If the scan type is passive, this parameter is invalid.
<scan_time_max>: the maximum active scan time per channel. Unit: millisecond. Range [0,1500]. If this parameter is 0, the firmware will use the default time: 120 ms for active scan; 360 ms for passive scan.
<freq_offset>: frequency offset (reserved item).
<freqcal_val>: frequency calibration value (reserved item).
<pairwise_cipher>: pairwise cipher type.
- 0: None
- 1: WEP40
- 2: WEP104
- 3: TKIP
- 4: CCMP
- 5: TKIP and CCMP
- 6: AES-CMAC-128
- 7: Unknown
<group_cipher>: group cipher type, same enumerated value to <pairwise_cipher>.
<bgn>: 802.11 b/g/n. If the corresponding bit is 1, the corresponding mode is enabled; if the corresponding bit is 0, the corresponding mode is disabled.
- bit 0: bit to identify if 802.11b mode is enabled or not
- bit 1: bit to identify if 802.11g mode is enabled or not
- bit 2: bit to identify if 802.11n mode is enabled or not
<wps>: wps flag.
- 0: WPS disabled
- 1: WPS enabled

Example¶

AT+CWLAP="Wi-Fi","ca:d7:19:d8:a6:44",6,0,400,1000

// Search for APs with a designated SSID:
AT+CWLAP="Wi-Fi"

AT+CWQAP: Disconnect from an AP¶

Execute Command¶

Command:

AT+CWQAP

Response:

OK

AT+CWSAP: Query/Set the configuration of an ESP SoftAP¶

Query Command¶

Function:

Query the configuration parameters of an ESP SoftAP.

Command:

AT+CWSAP?

Response:

+CWSAP:<ssid>,<pwd>,<channel>,<ecn>,<max conn>,<ssid hidden>
OK

Set Command¶

Function:

Set the configuration of an ESP SoftAP.

Command:

AT+CWSAP=<ssid>,<pwd>,<chl>,<ecn>[,<max conn>][,<ssid hidden>]

Response:

OK

Parameters¶

<ssid>: string parameter showing SSID of the AP.
<pwd>: string parameter showing the password. Length: 8 ~ 63 bytes ASCII.
<channel>: channel ID.
<ecn>: encryption method; WEP is not supported.
- 0: OPEN
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
[<max conn>]: maximum number of stations that ESP SoftAP can connect. Range: [1,10].
[<ssid hidden>]:
- 0: broadcasting SSID (default).
- 1: not broadcasting SSID.

Notes¶

This command works only when AT+CWMODE=2 or AT+CWMODE=3.
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The default SSID varies from devices to device as it consists of the MAC address of the device. You can use AT+CWSAP? to query the default SSID.

Example¶

AT+CWSAP="ESP","1234567890",5,3

AT+CWLIF: Obtain IP Address of the Station That Connects to an ESP SoftAP¶

Execute Command¶

Command:

AT+CWLIF

Response:

+CWLIF:<ip addr>,<mac>

OK

Parameters¶

<ip addr>: IP address of the station that connects to the ESP SoftAP.
<mac>: MAC address of the station that connects to the ESP SoftAP.

Note¶

This command cannot get a static IP. It works only when DHCP of both the ESP SoftAP and the connected station are enabled.

AT+CWQIF: Disconnect Stations from an ESP SoftAP¶

Execute Command¶

Function:

Disconnect all stations that are connected to the ESP SoftAP.

Command:

AT+CWQIF

Response:

OK

Set Command¶

Function:

Disconnect a specific station from the ESP SoftAP.

Command:

AT+CWQIF=<mac>

Response:

OK

Parameter¶

<mac>: MAC address of the station to disconnect.

AT+CWDHCP: Enable/Disable DHCP¶

Query Command¶

Command:

AT+CWDHCP?

Response:

+CWDHCP:<state>
OK

Set Command¶

Function:

Enable/disable DHCP.

Command:

AT+CWDHCP=<operate>,<mode>

Response:

OK

Parameters¶

<operate>:
- 0: disable
- 1: enable
<mode>:
- Bit0: Station DHCP
- Bit1: SoftAP DHCP
<state>: the status of DHCP
- Bit0:
  - 0: Station DHCP is disabled.
  - 1: Station DHCP is enabled.
- Bit1:
  - 0: SoftAP DHCP is disabled.
  - 1: SoftAP DHCP is enabled.
- Bit2:
  - 0: Ethernet DHCP is disabled.
  - 1: Ethernet DHCP is enabled.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This Set Command correlates with the commands that set static IP, such as AT+CIPSTA and AT+CIPAP:
- If DHCP is enabled, static IP address will be disabled;
- If static IP address is enabled, DHCP will be disabled;
- The last configuration overwrites the previous configuration.

Example¶

// Enable Station DHCP. If the last DHCP mode is 2, the current DHCP mode will be 3.
AT+CWDHCP=1,1

// Disable SoftAP DHCP. If the last DHCP mode is 3, the current DHCP mode will be 1.
AT+CWDHCP=0,2

AT+CWDHCPS: Query/Set the IP Addresses Allocated by an ESP SoftAP DHCP Server¶

Query Command¶

Command:

AT+CWDHCPS?

Response:

+CWDHCPS=<lease time>,<start IP>,<end IP>
OK

Set Command¶

Function:

Set the IP address range of the ESP SoftAP DHCP server.

Command:

AT+CWDHCPS=<enable>,<lease time>,<start IP>,<end IP>

Response:

OK

Parameters¶

<enable>:
- 1: Enable DHCP server settings. The parameters below have to be set.
- 0: Disable DHCP server settings and use the default IP address range.
<lease time>: lease time. Unit: minute. Range [1,2880].
<start IP>: start IP address of the IP address range that can be obtained from ESP SoftAP DHCP server.
<end IP>: end IP address of the IP address range that can be obtained from ESP SoftAP DHCP server.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This AT command works only when both SoftAP and DHCP server are enabled for ESP devices.
The IP address should be in the same network segment as the IP address of ESP SoftAP.

Example¶

AT+CWDHCPS=1,3,"192.168.4.10","192.168.4.15"

AT+CWDHCPS=0 // Disable the settings and use the default IP address range.

AT+CWAUTOCONN: Automatically Connect to an AP When Powered on¶

Set Command¶

Command:

AT+CWAUTOCONN=<enable>

Response:

OK

Parameters¶

<enable>:
- 1: Enable automatic connection to an AP when powered on. (Default)
- 0: Disable automatic connection to an AP when powered on.

Note¶

The configuration changes will be saved in the NVS area.

Example¶

AT+CWAUTOCONN=1

AT+CWAPPROTO: Query/Set the 802.11 b/g/n Protocol Standard of SoftAP Mode¶

Query Command¶

Command:

AT+CWAPPROTO?

Response:

+CWAPPROTO=<protocol>
OK

Set Command¶

Command:

AT+CWAPPROTO=<protocol>

Response:

OK

Parameters¶

<protocol>:
- bit0: 802.11b protocol standard.
- bit1: 802.11g protocol standard.
- bit2: 802.11n protocol standard.

Note¶

Currently ESP devices only support 802.11b or 802.11bg or 802.11bgn mode.
By default, PHY mode of ESP devices is 802.11bgn mode.

AT+CWSTAPROTO: Query/Set the 802.11 b/g/n Protocol Standard of Station Mode¶

Query Command¶

Command:

AT+CWSTAPROTO?

Response:

+CWSTAPROTO=<protocol>
OK

Set Command¶

Command:

AT+CWSTAPROTO=<protocol>

Response:

OK

Parameters¶

<protocol>:
- bit0: 802.11b protocol standard.
- bit1: 802.11g protocol standard.
- bit2: 802.11n protocol standard.

Note¶

Currently ESP devices only support 802.11b or 802.11bg or 802.11bgn mode.
By default, PHY mode of ESP devices is 802.11bgn mode.
This command is supported since ESP-AT v2.1.0.0

AT+CIPSTAMAC: Query/Set the MAC Address of an ESP Station¶

Query Command¶

Function:

Query the MAC address of the ESP Station.

Command:

AT+CIPSTAMAC?

Response:

+CIPSTAMAC:<mac>
OK

Set Command¶

Function:

Set the MAC address of an ESP station.

Command:

AT+CIPSTAMAC=<mac>

Response:

OK

Parameters¶

<mac>: string parameter showing MAC address of an ESP station.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The MAC address of ESP SoftAP is different from that of the ESP Station. Please make sure that you do not set the same MAC address for both of them.
Bit 0 of the ESP MAC address CANNOT be 1. For example, a MAC address can be “1a:…” but not “15:…”.
FF:FF:FF:FF:FF:FF and 00:00:00:00:00:00 are invalid MAC address and cannot be set.

Example¶

AT+CIPSTAMAC="1a:fe:35:98:d3:7b"

AT+CIPAPMAC: Query/Set the MAC Address of an ESP SoftAP¶

Query Command¶

Function:

Query the MAC address of the ESP SoftAP.

Command:

AT+CIPAPMAC?

Response:

+CIPAPMAC:<mac>
OK

Set Command¶

Function:

Set the MAC address of the ESP SoftAP.

Command:

AT+CIPAPMAC=<mac>

Response:

OK

Parameters¶

<mac>: string parameter showing MAC address of the ESP SoftAP.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The MAC address of ESP SoftAP is different from that of the ESP station. Please make sure that you do not set the same MAC address for both of them.
Bit 0 of the ESP MAC address CANNOT be 1. For example, a MAC address can be “18:…” but not “15:…”.
FF:FF:FF:FF:FF:FF and 00:00:00:00:00:00 are invalid MAC and cannot be set.

Example¶

AT+CIPAPMAC="18:fe:35:98:d3:7b"

AT+CIPSTA: Query/Set the IP Address of an ESP Station¶

Query Command¶

Function:

Query the IP address of the ESP Station.

Command:

AT+CIPSTA?

Response:

+CIPSTA:ip:<"ip">
+CIPSTA:gateway:<"gateway">
+CIPSTA:netmask:<"netmask">
+CIPSTA:ip6ll:<"ipv6 addr">
+CIPSTA:ip6gl:<"ipv6 addr">

OK

Set Command¶

Function:

Set the IPv4 address of the ESP station.

Command:

AT+CIPSTA=<"ip">[,<"gateway">,<"netmask">]

Response:

OK

Parameters¶

<”ip”>: string parameter showing the IPv4 address of the ESP station.
<”gateway”>: gateway.
<”netmask”>: netmask.
<”ipv6 addr”>: string parameter showing the IPv6 address of the ESP station.

Notes¶

For the query command, only when the ESP station is connected to an AP or the static IP address is configured can its IP address be queried.
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The Set Command correlates with the commands that set DHCP, such as AT+CWDHCP.
- If static IP address is enabled, DHCP will be disabled;
- If DHCP is enabled, static IP address will be disabled;
- The last configuration overwrites the previous configuration.

Example¶

AT+CIPSTA="192.168.6.100","192.168.6.1","255.255.255.0"

AT+CIPAP: Query/Set the IP Address of an ESP SoftAP¶

Query Command¶

Function:

Query the IP address of the ESP SoftAP.

Command:

AT+CIPAP?

Response:

+CIPAP:ip:<"ip">
+CIPAP:gateway:<"gateway">
+CIPAP:netmask:<"netmask">
+CIPAP:ip6ll:<"ipv6 addr">
+CIPAP:ip6gl:<"ipv6 addr">

OK

Set Command¶

Function:

Set the IPv4 address of the ESP SoftAP.

Command:

AT+CIPAP=<"ip">[,<"gateway">,<"netmask">]

Response:

OK

Parameters¶

<”ip”>: string parameter showing the IPv4 address of the ESP SoftAP.
<”gateway”>: gateway.
<”netmask”>: netmask.
<”ipv6 addr”>: string parameter showing the IPv6 address of the ESP SoftAP.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The set command correlates with the commands that set DHCP, such as AT+CWDHCP.
- If static IP address is enabled, DHCP will be disabled;
- If DHCP is enabled, static IP address will be disabled;
- The last configuration overwrites the previous configuration.

Example¶

AT+CIPAP="192.168.5.1","192.168.5.1","255.255.255.0"

AT+CWSTARTSMART: Start SmartConfig¶

Execute Command¶

Function:

Start SmartConfig of the type ESP-TOUCH+AirKiss.

Command:

AT+CWSTARTSMART

Set Command¶

Function:

Start SmartConfig of a designated type.

Command:

AT+CWSTARTSMART=<type>[,<auth floor>][,<"esptouch v2 key">]

Response:

OK

Parameters¶

<type>:
- 1: ESP-TOUCH
- 2: AirKiss
- 3: ESP-TOUCH+AirKiss
- [ESP32-C3 Only] 4: ESP-TOUCH v2
<auth floor>: Wi-Fi authentication mode floor. ESP-AT will not connect to the AP whose authmode is lower than this floor.
- 0: OPEN (Default)
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK
[ESP32-C3 Only] <”esptouch v2 key”>: ESP-TOUCH v2 decrypt key. It is used to decrypt Wi-Fi password and reserved data. Length: 16 bytes.

Notes¶

For more details on SmartConfig, please see ESP-TOUCH User Guide.
SmartConfig is only available in the ESP station mode.
The message Smart get Wi-Fi info means that SmartConfig has successfully acquired the AP information. ESP device will try to connect to the target AP.
Message +SCRD:<length>,<rvd data> means that ESP-Touch v2 has successfully acquired the reserved data information.
Message Smartconfig connected Wi-Fi is printed if the connection is successful.
When AT returns Smartconfig connected Wi-Fi, it is recommended to delay more than 6 seconds before executing AT+CWSTOPSMART because the ESP device needs to synchronize the SmartConfig results to the mobile phone.
Use command AT+CWSTOPSMART to stop SmartConfig before running other commands. Please make sure that you do not execute other commands during SmartConfig.

Example¶

AT+CWMODE=1
AT+CWSTARTSMART

AT+CWSTOPSMART: Stop SmartConfig¶

Execute Command¶

Command:

AT+CWSTOPSMART

Response:

OK

Note¶

Irrespective of whether SmartConfig succeeds or not, please always call AT+CWSTOPSMART before executing any other AT commands to release the internal memory taken up by SmartConfig.

Example¶

AT+CWMODE=1
AT+CWSTARTSMART
AT+CWSTOPSMART

AT+WPS: Enable the WPS Function¶

Set Command¶

Command:

AT+WPS=<enable>[,<auth floor>]

Response:

OK

Parameters¶

<enable>:
- 1: Enable WPS (Wi-Fi Protected Setup) that uses PBC (Push Button Configuration) mode.
- 0: Disable WPS that uses PBC mode.
<auth floor>: Wi-Fi authentication mode floor. ESP-AT will not connect to the AP whose authmode is lower than this floor.
- 0: OPEN (Default)
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK

Notes¶

WPS can only be used when the ESP station is enabled.
WPS does not support WEP (Wired-Equivalent Privacy) encryption.

Example¶

AT+CWMODE=1
AT+WPS=1

AT+MDNS: Configure the mDNS Function¶

Set Command¶

Command:

AT+MDNS=<enable>[,<hostname>,<service_name>,<port>]

Response:

OK

Parameters¶

<enable>:
- 1: Enable the mDNS function. The following three parameters need to be set.
- 0: Disable the mDNS function. The following three parameters does not need to be set.
<hostname>: mDNS host name.
<service_name>: mDNS service name.
<port>: mDNS port.

Example¶

AT+CWMODE=1
AT+CWJAP="1234567890","1234567890"
AT+MDNS=1,"espressif","_iot",8080
AT+MDNS=0

AT+CWJEAP: Connect to a WPA2 Enterprise AP¶

Query Command¶

Function:

Query the configuration information of the Enterprise AP to which the ESP station is already connected.

Command:

AT+CWJEAP?

Response:

+CWJEAP:<ssid>,<method>,<identity>,<username>,<password>,<security>
OK

Set Command¶

Function:

Connect to the targeted Enterprise AP.

Command:

AT+CWJEAP=<ssid>,<method>,<identity>,<username>,<password>,<security>[,<jeap_timeout>]

Response:

OK

or

+CWJEAP:Timeout
ERROR

Parameters¶

<ssid>: the SSID of the Enterprise AP.
- Escape character syntax is needed if SSID or password contains any special characters, such as ,, ", or \\.
<method>: WPA2 Enterprise authentication method.
- 0: EAP-TLS.
- 1: EAP-PEAP.
- 2: EAP-TTLS.
<identity>: identity for phase 1. String limited to 1 ~ 32.
<username>: username for phase 2. Range: 1 ~ 32 bytes. For the EAP-PEAP and EAP-TTLS method, you must set this parameter. For the EAP-TLS method, you don’t need to.
<password>: password for phase 2. Range: 1 ~ 32 bytes. For the EAP-PEAP and EAP-TTLS method, you must set this parameter. For the EAP-TLS method, you don’t need to.
<security>:
- Bit0: Client certificate.
- Bit1: Server certificate.
[<jeap_timeout>]: maximum timeout for AT+CWJEAP command. Unit: second. Default: 15. Range: [3,600].

Example¶

// Connect to EAP-TLS mode Enterprise AP, set identity, verify server certificate and load client certificate
AT+CWJEAP="dlink11111",0,"example@espressif.com",,,3

// Connect to EAP-PEAP mode Enterprise AP, set identity, username and password, not verify server certificate and not load client certificate
AT+CWJEAP="dlink11111",1,"example@espressif.com","espressif","test11",0

Error Code:

The WPA2 Enterprise error code will be prompt as ERR CODE:0x<%08x>.

AT_EAP_MALLOC_FAILED	0x8001
AT_EAP_GET_NVS_CONFIG_FAILED	0x8002
AT_EAP_CONN_FAILED	0x8003
AT_EAP_SET_WIFI_CONFIG_FAILED	0x8004
AT_EAP_SET_IDENTITY_FAILED	0x8005
AT_EAP_SET_USERNAME_FAILED	0x8006
AT_EAP_SET_PASSWORD_FAILED	0x8007
AT_EAP_GET_CA_LEN_FAILED	0x8008
AT_EAP_READ_CA_FAILED	0x8009
AT_EAP_SET_CA_FAILED	0x800A
AT_EAP_GET_CERT_LEN_FAILED	0x800B
AT_EAP_READ_CERT_FAILED	0x800C
AT_EAP_GET_KEY_LEN_FAILED	0x800D
AT_EAP_READ_KEY_FAILED	0x800E
AT_EAP_SET_CERT_KEY_FAILED	0x800F
AT_EAP_ENABLE_FAILED	0x8010
AT_EAP_ALREADY_CONNECTED	0x8011
AT_EAP_GET_SSID_FAILED	0x8012
AT_EAP_SSID_NULL	0x8013
AT_EAP_SSID_LEN_ERROR	0x8014
AT_EAP_GET_METHOD_FAILED	0x8015
AT_EAP_CONN_TIMEOUT	0x8016
AT_EAP_GET_IDENTITY_FAILED	0x8017
AT_EAP_IDENTITY_LEN_ERROR	0x8018
AT_EAP_GET_USERNAME_FAILED	0x8019
AT_EAP_USERNAME_LEN_ERROR	0x801A
AT_EAP_GET_PASSWORD_FAILED	0x801B
AT_EAP_PASSWORD_LEN_ERROR	0x801C
AT_EAP_GET_SECURITY_FAILED	0x801D
AT_EAP_SECURITY_ERROR	0x801E
AT_EAP_METHOD_SECURITY_UNMATCHED	0x801F
AT_EAP_PARAMETER_COUNTS_ERROR	0x8020
AT_EAP_GET_WIFI_MODE_ERROR	0x8021
AT_EAP_WIFI_MODE_NOT_STA	0x8022
AT_EAP_SET_CONFIG_FAILED	0x8023
AT_EAP_METHOD_ERROR	0x8024

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This command requires Station mode to be active.
TLS mode will use client certificate. Please make sure it is enabled.

AT+CWHOSTNAME: Query/Set the Host Name of an ESP Station¶

Query Command¶

Function:

Query the host name of ESP Station.

Command:

AT+CWHOSTNAME?

Response:

+CWHOSTNAME:<hostname>

OK

Set Command¶

Function:

Set the host name of ESP Station.

Command:

AT+CWHOSTNAME=<hostname>

Response:

OK

If the Station mode is not enabled, the command will return:

ERROR

Parameters¶

<hostname>: the host name of the ESP Station. Maximum length: 32 bytes.

Note¶

The configuration changes are not saved in the flash.

Example¶

AT+CWMODE=3
AT+CWHOSTNAME="my_test"

AT+CWCOUNTRY: Query/Set the Wi-Fi Country Code¶

Query Command¶

Function:

Query Wi-Fi country code information.

Command:

AT+CWCOUNTRY?

Response:

+CWCOUNTRY:<country_policy>,<country_code>,<start_channel>,<total_channel_count>

OK

Set Command¶

Function:

Set the Wi-Fi country code information.

Command:

AT+ CWCOUNTRY=<country_policy>,<country_code>,<start_channel>,<total_channel_count>

Response:

OK

Parameters¶

<country_policy>:
- 0: will change the county code to be the same as the AP that the ESP device is connected to.
- 1: the country code will not change, always be the one set by command.
<country_code>: country code. Maximum length: 3 characters.
<start_channel>: the channel number to start. Range: [1,14].
<total_channel_count>: total number of channels.

Note¶

The configuration changes are not saved in the flash.

Example¶

AT+CWMODE=3
AT+CWCOUNTRY=1,"CN",1,13

TCP/IP AT Commands¶

[中文]

AT+CIPV6: Enable/disable the network of Internet Protocol Version 6 (IPv6).
AT+CIPSTATE: Obtain the TCP/UDP/SSL connection information.
AT+CIPSTATUS (deprecated): Obtain the TCP/UDP/SSL connection status and information.
AT+CIPDOMAIN: Resolve a Domain Name.
AT+CIPSTART: Establish TCP connection, UDP transmission, or SSL connection.
AT+CIPSTARTEX: Establish TCP connection, UDP transmission, or SSL connection with an automatically assigned ID.
[Data Mode Only] +++: Exit from the data mode.
AT+CIPSEND: Send data in the normal transmission mode or Wi-Fi normal transmission mode.
AT+CIPSENDL: Send long data in paraller in the normal transmission mode.
AT+CIPSENDLCFG: Set the configuration for the command AT+CIPSENDL.
AT+CIPSENDEX: Send data in the normal transmission mode in expanded ways.
AT+CIPCLOSE: Close TCP/UDP/SSL connection.
AT+CIFSR: Obtain the local IP address and MAC address.
AT+CIPMUX: Enable/disable the multiple connections mode.
AT+CIPSERVER: Delete/create a TCP/SSL server.
AT+CIPSERVERMAXCONN: Query/Set the maximum connections allowed by a server.
AT+CIPMODE: Query/Set the transmission mode.
AT+SAVETRANSLINK: Set whether to enter Wi-Fi normal transmission mode on power-up.
AT+CIPSTO: Query/Set the local TCP Server Timeout.
AT+CIPSNTPCFG: Query/Set the time zone and SNTP server.
AT+CIPSNTPTIME: Query the SNTP time.
AT+CIPSNTPINTV: Query/Set the SNTP time synchronization interval.
AT+CIUPDATE: Upgrade the firmware through Wi-Fi.
AT+CIPDINFO: Set “+IPD” message mode.
AT+CIPSSLCCONF: Query/Set SSL clients.
AT+CIPSSLCCN: Query/Set the Common Name of the SSL client.
AT+CIPSSLCSNI: Query/Set SSL client Server Name Indication (SNI).
AT+CIPSSLCALPN: Query/Set SSL client Application Layer Protocol Negotiation (ALPN).
AT+CIPSSLCPSK: Query/Set SSL client Pre-shared Key (PSK).
AT+CIPRECONNINTV: Query/Set the TCP/UDP/SSL reconnection interval for the Wi-Fi normal transmission mode.
AT+CIPRECVMODE: Query/Set socket receiving mode.
AT+CIPRECVDATA: Obtain socket data in passive receiving mode.
AT+CIPRECVLEN: Obtain socket data length in passive receiving mode.
AT+PING: Ping the remote host.
AT+CIPDNS: Query/Set DNS server information.
AT+CIPTCPOPT: Query/Set the socket options.

AT+CIPV6: Enable/disable the network of Internet Protocol Version 6 (IPv6)¶

Query Command¶

Function:

Query whether IPv6 is enabled.

Command:

AT+CIPV6?

Response:

+CIPV6:<enable>

OK

Set Command¶

Function:

Enable/Disable IPv6 network.

Command:

AT+CIPV6=<enable>

Response:

OK

Parameters¶

<enable>: status of IPv6 network. Default: 0.
- 0: disable IPv6 network.
- 1: enable IPv6 network.

Notes¶

You should enable IPv6 network before using IPv6 related upper layer AT commands (TCP/UDP/SSL/PING/DNS based on IPv6 network, also known as TCP6/UDP6/SSL6/PING6/DNS6 or TCPv6/UDPv6/SSLv6/PINGv6/DNSv6).

AT+CIPSTATE: Obtain the TCP/UDP/SSL Connection Information¶

Query Command¶

Command:

AT+CIPSTATE?

Response:

When there is a connection, AT returns:

+CIPSTATE:<link ID>,<"type">,<"remote IP">,<remote port>,<local port>,<tetype>

OK

When there is no connection, AT returns:

OK

Parameters¶

<link ID>: ID of the connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “TCP”, “TCPv6”, “UDP”, “UDPv6”, “SSL”, or “SSLv6”.
<”remote IP”>: string parameter showing the remote IPv4 address or IPv6 address.
<remote port>: the remote port number.
<local port>: the local port number.
<tetype>:
- 0: ESP device runs as a client.
- 1: ESP device runs as a server.

AT+CIPSTATUS (deprecated): Obtain the TCP/UDP/SSL Connection Status and Information¶

Execute Command¶

Command:

AT+CIPSTATUS

Response:

STATUS:<stat>
+CIPSTATUS:<link ID>,<"type">,<"remote IP">,<remote port>,<local port>,<tetype>
OK

Parameters¶

<stat>: status of the ESP station interface.
- 0: The ESP station is not initialized.
- 1: The ESP station is initialized, but not started a Wi-Fi connection yet.
- 2: The ESP station is connected to an AP and its IP address is obtained.
- 3: The ESP station has created a TCP/SSL transmission.
- 4: All of the TCP/UDP/SSL connections of the ESP device station are disconnected.
- 5: The ESP station started a Wi-Fi connection, but was not connected to an AP or disconnected from an AP.
<link ID>: ID of the connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “TCP”, “TCPv6”, “UDP”, “UDPv6”, “SSL”, or “SSLv6”.
<”remote IP”>: string parameter showing the remote IPv4 address or IPv6 address.
<remote port>: the remote port number.
<local port>: the local port number.
<tetype>:
- 0: ESP device runs as a client.
- 1: ESP device runs as a server.

Notes¶

It is recommended to use AT+CWSTATE command to query Wi-Fi state and AT+CIPSTATE command to query TCP/UDP/SSL state.

AT+CIPDOMAIN: Resolve a Domain Name¶

Set Command¶

Command:

AT+CIPDOMAIN=<"domain name">[,<ip network>]

Response:

+CIPDOMAIN:<"IP address">

OK

Parameter¶

<”domain name”>: the domain name.
<ip network>: preferred IP network. Default: 1.
- 1: preferred resolution of IPv4 address
- 2: resolve IPv4 address only
- 3: resolve IPv6 address only
<”IP address”>: the resolved IPv4 address or IPv6 address.

Example¶

AT+CWMODE=1                       // set the station mode
AT+CWJAP="SSID","password"        // access to the internet
AT+CIPDOMAIN="iot.espressif.cn"   // Domain Name Resolution function

// Domain Name Resolution Function for IPv4 address only
AT+CIPDOMAIN="iot.espressif.cn",2

// Domain Name Resolution Function for IPv6 address only
AT+CIPDOMAIN="ipv6.test-ipv6.com",3

// Domain Name Resolution Function for compatible IP address
AT+CIPDOMAIN="ds.test-ipv6.com",1

AT+CIPSTART: Establish TCP Connection, UDP Transmission, or SSL Connection¶

Establish TCP Connection¶

Set Command¶

Command:

// Single connection (AT+CIPMUX=0):
AT+CIPSTART=<"type">,<"remote host">,<remote port>[,<keep alive>][,<"local IP">]

// Multiple Connections (AT+CIPMUX=1):
AT+CIPSTART=<link ID>,<"type">,<"remote host">,<remote port>[,<keep alive>][,<"local IP">]

Response:

For single connection, it returns:

CONNECT

OK

For multiple connections, it returns:

<link ID>,CONNECT

OK

Parameters¶

<link ID>: ID of network connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “TCP”, or “TCPv6”. Default: “TCP”.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host.
<remote port>: the remote port number.
<keep alive>: TCP keep-alive interval. Default: 0.
- 0: disable TCP keep-alive function.
- 1 ~ 7200: detection interval. Unit: second.
<”local IP”>: the local IPv4 address or IPv6 address that the connection binds. This parameter is useful when you are using multiple network interfaces or multiple IP addresses. By default, it is disabled. If you want to use it, you should specify it first. Null is also valid.

Notes¶

If you want to establish TCP connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.
<keep alive> parameter will eventually be configured to the socket option TCP_KEEPIDLE. As for other socket options of keepalive, TCP_KEEPINTVL will use 1 by default, and TCP_KEEPCNT will use 3 by default.

Example¶

AT+CIPSTART="TCP","iot.espressif.cn",8000
AT+CIPSTART="TCP","192.168.101.110",1000
AT+CIPSTART="TCP","192.168.101.110",2500,60
AT+CIPSTART="TCP","192.168.101.110",1000,,"192.168.101.100"
AT+CIPSTART="TCPv6","test-ipv6.com",80
AT+CIPSTART="TCPv6","fe80::860d:8eff:fe9d:cd90",1000,,"fe80::411c:1fdb:22a6:4d24"

// esp-at has obtained an IPv6 global address by AT+CWJAP before
AT+CIPSTART="TCPv6","2404:6800:4005:80b::2004",80,,"240e:3a1:2070:11c0:32ae:a4ff:fe80:65ac"

Establish UDP Transmission¶

Set Command¶

Command:

// Single connection (AT+CIPMUX=0):
AT+CIPSTART=<"type">,<"remote host">,<remote port>[,<local port>,<mode>,<"local IP">]

// Multiple connections (AT+CIPMUX=1):
AT+CIPSTART=<link ID>,<"type">,<"remote host">,<remote port>[,<local port>,<mode>,<"local IP">]

Response:

For single connection, it returns:

CONNECT

OK

For multiple connections, it returns:

<link ID>,CONNECT

OK

Parameters¶

<link ID>: ID of network connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “UDP”, or “UDPv6”. Default: “TCP”.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host.
<remote port>: remote port number.
<local port>: UDP port of ESP devices.
<mode>: In the UDP Wi-Fi passthrough, the value of this parameter has to be 0.
- 0: After UDP data is received, the parameters <"remote host"> and <remote port> will stay unchanged (default).
- 1: Only the first time that UDP data is received from an IP address and port that are different from the initially set value of parameters <remote host> and <remote port>, will they be changed to the IP address and port of the device that sends the data.
- 2: Each time UDP data is received, the <"remote host"> and <remote port> will be changed to the IP address and port of the device that sends the data.
<”local IP”>: the local IPv4 address or IPv6 address that the connection binds. This parameter is useful when you are using multiple network interfaces or multiple IP addresses. By default, it is disabled. If you want to use it, you should specify it first. Null is also valid.

Notes¶

If the remote host over the UDP is an IPv4 multicast address (224.0.0.0 ~ 239.255.255.255), the ESP device will send and receive the UDPv4 multicast.
If the remote host over the UDP is an IPv4 broadcast address (255.255.255.255), the ESP device will send and receive the UDPv4 broadcast.
If the remote host over the UDP is an IPv6 multicast address (FF00:0:0:0:0:0:0:0 ~ FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF), the ESP device will send and receive the UDP multicast based on IPv6 network.
To use the parameter <mode>, parameter <local port> must be set first.
If you want to establish UDP connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.

Example¶

// UDP unicast
AT+CIPSTART="UDP","192.168.101.110",1000,1002,2
AT+CIPSTART="UDP","192.168.101.110",1000,,,"192.168.101.100"

// UDP unicast based on IPv6 network
AT+CIPSTART="UDPv6","fe80::32ae:a4ff:fe80:65ac",1000,,,"fe80::5512:f37f:bb03:5d9b"

// UDP multicast based on IPv6 network
AT+CIPSTART="UDPv6","FF02::FC",1000,1002,0

Establish SSL Connection¶

Set Command¶

Command:

// Single connection (AT+CIPMUX=0):
AT+CIPSTART=<"type">,<"remote host">,<remote port>[,<keep alive>,<"local IP">]

// Multiple connections (AT+CIPMUX=1):
AT+CIPSTART=<link ID>,<"type">,<"remote host">,<remote port>[,<keep alive>,<"local IP">]

Response:

For single connection, it returns:

CONNECT

OK

For multiple connections, it returns:

<link ID>,CONNECT

OK

Parameters¶

<link ID>: ID of network connection (0~4), used for multiple connections.
<”type”>: string parameter showing the type of transmission: “SSL”, or “SSLv6”. Default: “TCP”.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host.
<remote port>: the remote port number.
<keep alive>: reserved item for SSL. Default: 0.
<”local IP”>: the local IPv4 address or IPv6 address that the connection binds. This parameter is useful when you are using multiple network interfaces or multiple IP addresses. By default, it is disabled. If you want to use it, you should specify it first. Null is also valid.

Notes¶

The number of SSL connections depends on available memory and the maximum number of connections.
SSL connection needs a large amount of memory. Insufficient memory may cause the system reboot.
If the AT+CIPSTART is based on an SSL connection and the timeout of each packet is 10 s, the total timeout will be much longer depending on the number of handshake packets.
If you want to establish SSL connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.
<keep alive> parameter will eventually be configured to the socket option TCP_KEEPIDLE. As for other socket options of keepalive, TCP_KEEPINTVL will use 1 by default, and TCP_KEEPCNT will use 3 by default.

Example¶

AT+CIPSTART="SSL","iot.espressif.cn",8443
AT+CIPSTART="SSL","192.168.101.110",1000,,"192.168.101.100"

// esp-at has obtained an IPv6 global address by AT+CWJAP before
AT+CIPSTART="SSLv6","240e:3a1:2070:11c0:6972:6f96:9147:d66d",1000,,"240e:3a1:2070:11c0:55ce:4e19:9649:b75"

AT+CIPSTARTEX: Establish TCP connection, UDP transmission, or SSL connection with an Automatically Assigned ID¶

This command is similar to AT+CIPSTART except that you don’t need to assign an ID by yourself in multiple connections mode (AT+CIPMUX=1). The system will assign an ID to the new connection automatically.

[Data Mode Only] +++: Exit from Data Mode ¶

Special Execute Command¶

Function:

Exit from Data Mode and enter the Command Mode.

Command:

// Only for data mode
+++

Notes¶

This special execution command consists of three identical + characters (0x2b ASCII), and no CR-LF appends to the command tail.
Make sure there is more than 20 ms interval before the first + character, more than 20 ms interval after the third + character, less than 20 ms interval among the three + characters. Otherwise, the + characters will be sent out as normal data.
This command returns no reply.
Please wait for at least one second before sending the next AT command.

AT+CIPSEND: Send Data in the Normal Transmission Mode or Wi-Fi Passthrough Mode ¶

Set Command¶

Function:

Set the data length to be send in the Normal Transmission Mode. If the length of data you need to send exceeds 8192 bytes, please use the AT+CIPSENDL command.

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSEND=<length>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSEND=<link ID>,<length>

// Remote host and port can be set for UDP transmission:
AT+CIPSEND=[<link ID>,]<length>[,<"remote host">,<remote port>]

Response:

OK

>

This response indicates that AT is ready for receiving serial data. You should enter the data, and when the data length reaches the <length> value, the transmission of data starts.

If the connection cannot be established or is disrupted during data transmission, the system returns:

ERROR

If data is transmitted successfully, the system returns:

SEND OK

Execute Command¶

Function:

Enter the Wi-Fi Passthrough Mode.

Command:

AT+CIPSEND

Response:

OK
>

or

ERROR

Enter the Wi-Fi Passthrough Mode. The ESP devices can receive 8192 bytes and send 2920 bytes at most each time. If the length of the currently received data is greater than the maximum number of bytes that can be sent, AT will send the received data immediately; Otherwise, the received data will be sent out within 20 ms. When a single packet containing +++ is received, the ESP device will exit the data sending mode under the Wi-Fi Passthrough Mode. Please wait for at least one second before sending the next AT command.

This command can only be used for single connection in the Wi-Fi Passthrough Mode. For UDP Wi-Fi passthrough, the <mode> parameter has to be 0 when using AT+CIPSTART.

Parameters¶

<link ID>: ID of the connection (0~4), for multiple connections.
<length>: data length. Maximum: 8192 bytes.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host. It can be set in UDP transmission.
<remote port>: the remote port number.

Notes¶

You can use AT+CIPTCPOPT command to configure socket options for each TCP connection. For example, setting <so_sndtimeo> to 5000 will enable TCP send to return results within 5 seconds, whether it succeeds or fails. This can save the time that the MCU waits for AT command response.

AT+CIPSENDL: Send Long Data in Paraller in the Normal Transmission Mode.¶

Set Command¶

Function:

In the Normal Transmission Mode, set the data length to be sent, and then send data to remote host in parallel (the AT command port receives data in parallel with the AT sending data to the remote host). You can use the AT+CIPSENDLCFG command to configure this command. If the length of data you need to send is less than 8192 bytes, you also can use the AT+CIPSEND command.

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSENDL=<length>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSENDL=<link ID>,<length>

// Remote host and port can be set for UDP transmission:
AT+CIPSENDL=[<link ID>,]<length>[,<"remote host">,<remote port>]

Response:

OK

>

This response indicates that AT enters the Data Mode and AT command port is ready to receive data. You can enter the data now. Once the port receives data, it will be pushed to underlying protocol stack and the transmission starts.

If the transmission starts, the system reports message according to AT+CIPSENDLCFG configuration:

+CIPSENDL:<had sent len>,<port recv len>

If the transmission is cancelled by +++ command, the system returns:

SEND CANCELLED

If not all the data has been sent out, the system finally returns:

SEND FAIL

If all the data is transmitted successfully, the system finally returns:

SEND OK

When the connection is disconnected, you can send +++ command to cancel the transmission, then the ESP device will exit from the Data Mode, otherwise, the Data Mode will not end until the AT command port receives all the data of the specified <length>.

Parameters¶

<link ID>: ID of the connection (0~4), for multiple connections.
<length>: data length. Maximum: 2 ³¹ - 1 bytes.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host. It can be set in UDP transmission.
<remote port>: the remote port number.
<had sent len>: the length of data successfully sent to the underlying protocol stack.
<port recv len>: data length received by AT command port.

Notes¶

You can use AT+CIPTCPOPT command to configure socket options for each TCP connection. For example, setting <so_sndtimeo> to 5000 will enable TCP send to return results within 5 seconds, whether it succeeds or fails. This can save the time that the MCU waits for AT command response.

AT+CIPSENDLCFG: Set the Configuration for the Command AT+CIPSENDL ¶

Query Command¶

Function:

Query the configuration of AT+CIPSENDL.

Command:

AT+CIPSENDLCFG?

Response:

+CIPSENDLCFG:<report size>,<transmit size>

OK

Set Command¶

Function:

Set the configuration of AT+CIPSENDL.

Command:

AT+CIPSENDLCFG:<report size>[,<transmit size>]

Response:

OK

Parameters¶

<report size>: report block size for AT+CIPSENDL. Default: 1024. Range: [100,2 ²⁰]. For example, set <report size> to 100, <had sent len> report sequence in the response of AT+CIPSENDL will be (100, 200, 300, 400, …). The final <had sent len> report is always equal to the data length that had been sent out.
<transmit size>: transmit block size of AT+CIPSENDL. It specifies the size of the data block sent to the underlying protocol stack. Default: 2920. Range: [100,2920]. If the received data length is greater than or equal to <transmit size>, it is pushed to the underlying protocol stack immediately, otherwise, the data waits for 20 ms and then is pushed to the protocol stack.

Note¶

For devices with small throughput but high real-time requirements, it is recommended to set a smaller <transmit size>. It is also recommended to set TCP_NODELAY by AT+CIPTCPOPT command.
For devices with large throughput, it is recommended to set a larger <transmit size>. It is also recommended to read How to Improve ESP-AT Throughput Performance first.

AT+CIPSENDEX: Send Data in the Normal Transmission Mode in Expanded Ways¶

Set Command¶

Function:

Set the data length to be send in Normal Transmission Mode, or use \0 (0x5c, 0x30 ASCII) to trigger data transmission.

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSENDEX=<length>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSENDEX=<link ID>,<length>

// Remote host and port can be set for UDP transmission:
AT+CIPSENDEX=[<link ID>,]<length>[,<"remote host">,<remote port>]

Response:

OK

>

This response indicates that AT is ready for receiving data. You should enter the data of designated length. When the data length reaches the <length> value, or when the string \0 appears in the data, the transmission starts.

If the connection cannot be established or gets disconnected during transmission, the system returns:

ERROR

If the data are successfully transmitted, the system returns:

SEND OK

Parameters¶

<link ID>: ID of the connection (0~4), for multiple connections.
<length>: data length. Maximum: 8192 bytes.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host. It can be set in UDP transmission.
<remote port>: remote port can be set in UDP transmission.

Notes¶

When the requirement of data length is met, or when the string \0 (0x5c, 0x30 in ASCII) appears, the transmission of data starts. Go back to the normal command mode and wait for the next AT command.
If the data contains the \<any>, it means that drop backslash symbol and only use <any> character.
When sending \0, please use a backslash to escape it as \\0.
You can use AT+CIPTCPOPT command to configure socket options for each TCP connection. For example, setting <so_sndtimeo> to 5000 will enable TCP send to return results within 5 seconds, whether it succeeds or fails. This can save the time that the MCU waits for AT command response.

AT+CIPCLOSE: Close TCP/UDP/SSL Connection¶

Set Command¶

Function:

Close TCP/UDP/SSL connection in the multiple connections mode.

Command:

AT+CIPCLOSE=<link ID>

Response:

<link ID>,CLOSED

OK

Execute Command¶

Function:

Close TCP/UDP/SSL connection in the single connection mode.

AT+CIPCLOSE

Response:

CLOSED

OK

Parameter¶

<link ID>: ID of the connection that you want to close. If you set it to 5, all connections will be closed.

AT+CIFSR: Obtain the Local IP Address and MAC Address¶

Execute Command¶

Command:

AT+CIFSR

Response:

+CIFSR:APIP,<"APIP">
+CIFSR:APIP6LL,<"APIP6LL">
+CIFSR:APIP6GL,<"APIP6GL">
+CIFSR:APMAC,<"APMAC">
+CIFSR:STAIP,<"STAIP">
+CIFSR:STAIP6LL,<"STAIP6LL">
+CIFSR:STAIP6GL,<"STAIP6GL">
+CIFSR:STAMAC,<"STAMAC">
+CIFSR:ETHIP,<"ETHIP">
+CIFSR:ETHIP6LL,<"ETHIP6LL">
+CIFSR:ETHIP6GL,<"ETHIP6GL">
+CIFSR:ETHMAC,<"ETHMAC">

OK

Parameters¶

<”APIP”>: IPv4 address of Wi-Fi softAP interface
<”APIP6LL”>: Linklocal IPv6 address of Wi-Fi softAP interface
<”APIP6GL”>: Global IPv6 address of Wi-Fi softAP interface
<”APMAC”>: MAC address of Wi-Fi softAP interface
<”STAIP”>: IPv4 address of Wi-Fi station interface
<”STAIP6LL”>: Linklocal IPv6 address of Wi-Fi station interface
<”STAIP6GL”>: Global IPv6 address of Wi-Fi station interface
<”STAMAC”>: MAC address of Wi-Fi station interface
<”ETHIP”>: IPv4 address of ethernet interface
<”ETHIP6LL”>: Linklocal IPv6 address of ethernet interface
<”ETHIP6GL”>: Global IPv6 address of ethernet interface
<”ETHMAC”>: MAC address of ethernet interface

Note¶

Only when the ESP device has the valid interface information can you query its IP address and MAC address.

AT+CIPMUX: Enable/disable Multiple Connections¶

Query Command¶

Function:

Query the connection type.

Command:

AT+CIPMUX?

Response:

+CIPMUX:<mode>
OK

Set Command¶

Function:

Set the connection type.

Command:

AT+CIPMUX=<mode>

Response:

OK

Parameter¶

<mode>: connection mode. Default: 0.
- 0: single connection.
- 1: multiple connections.

Notes¶

This mode can only be changed after all connections are disconnected.
If you want to set the multiple connections mode, ESP devices should be in the Normal Transmission Mode (AT+CIPMODE=0).
If you want to set the single connection mode when the TCP/SSL server is running, you should delete the server first. (AT+CIPSERVER=0).

Example¶

AT+CIPMUX=1

AT+CIPSERVER: Delete/create a TCP/SSL Server¶

Query Command¶

Function:

Query the TCP/SSL server status.

Command:

AT+CIPSERVER?

Response:

+CIPSERVER:<mode>[,<port>,<"type">][,<CA enable>]

OK

Set Command¶

Command:

AT+CIPSERVER=<mode>[,<param2>][,<"type">][,<CA enable>]

Response:

OK

Parameters¶

<mode>:
- 0: delete a server.
- 1: create a server.
<param2>: It means differently depending on the parameter <mode>:

If <mode> is 1, <param2> represents the port number. Default: 333.

If <mode> is 0, <param2> represents whether the server closes all connections. Default: 0.

0: shutdown the server and keep existing connections.

1: shutdown the server and close all connections.

<”type”>: server type: “TCP”, “TCPv6”, “SSL”, or “SSLv6”. Default: “TCP”.
<CA enable>:
- 0: disable CA.
- 1: enable CA.

Notes¶

A TCP/SSL server can only be created when multiple connections are activated (AT+CIPMUX=1).
A server monitor will be created automatically when the server is created. Only one server can be created at most.
When a client is connected to the server, it will take up one connection and be assigned an ID.
If you want to create a TCP/SSL server based on IPv6 network, set AT+CIPV6=1 first, and obtain an IPv6 address.
Parameters <"type"> and <CA enable> must be omitted when delete a server.

Example¶

// To create a TCP server
AT+CIPMUX=1
AT+CIPSERVER=1,80

// To create an SSL server
AT+CIPMUX=1
AT+CIPSERVER=1,443,"SSL",1

// To create an SSL server based on IPv6 network
AT+CIPMUX=1
AT+CIPSERVER=1,443,"SSLv6",0

// To delete an server and close all clients
AT+CIPSERVER=0,1

AT+CIPSERVERMAXCONN: Query/Set the Maximum Connections Allowed by a Server¶

Query Command¶

Function:

Obtain the maximum number of clients allowed to connect to the TCP/SSL server.

Command:

AT+CIPSERVERMAXCONN?

Response:

+CIPSERVERMAXCONN:<num>
OK

Set Command¶

Function:

Set the maximum number of clients allowed to connect to the TCP/SSL server.

Command:

AT+CIPSERVERMAXCONN=<num>

Response:

OK

Parameter¶

<num>: the maximum number of clients allowed to connect to the TCP/SSL server.

Note¶

You should call the command AT+CIPSERVERMAXCONN=<num> before creating a server.

Example¶

AT+CIPMUX=1
AT+CIPSERVERMAXCONN=2
AT+CIPSERVER=1,80

AT+CIPMODE: Query/Set the Transmission Mode¶

Query Command¶

Function:

Query the transmission mode.

Command:

AT+CIPMODE?

Response:

+CIPMODE:<mode>
OK

Set Command¶

Function:

Set the transmission mode.

Command:

AT+CIPMODE=<mode>

Response:

OK

Parameter¶

<mode>:
- 0: Normal Transmission Mode.
- 1: Wi-Fi Passthrough Receiving Mode, or called transparent receiving transmission, which can only be enabled in TCP single connection mode, UDP mode when the remote host and port do not change, or SSL single connection mode.

Notes¶

The configuration changes will NOT be saved in flash.

Example¶

AT+CIPMODE=1

AT+SAVETRANSLINK: Set Whether to Enter Wi-Fi Passthrough Mode on Power-up¶

For TCP/SSL Single Connection¶

Set Command¶

Command:

AT+SAVETRANSLINK=<mode>,<"remote host">,<remote port>[,<"type">,<keep alive>]

Response:

OK

Parameters¶

<mode>:
- 0: ESP will NOT enter Wi-Fi Passthrough Mode on power-up.
- 1: ESP will enter Wi-Fi Passthrough Mode on power-up.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host.
<remote port>: the remote port number.
<”type”>: string parameter showing the type of transmission: “TCP”, “TCPv6”, “SSL”, or “SSLv6”. Default: “TCP”.
<keep alive>: TCP keep-alive interval. Default: 0.
- 0: disable the keep-alive function.
- 1 ~ 7200: detection interval. Unit: second.

Notes¶

This command will save the Wi-Fi Passthrough Mode configuration in the NVS area. If <mode> is set to 1, ESP device will enter the Wi-Fi Passthrough Mode in any subsequent power cycles. The configuration will take effect after ESP reboots.
As long as the remote host and port are valid, the configuration will be saved in flash.
If you want to establish TCP/SSL connection based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.

Example¶

AT+SAVETRANSLINK=1,"192.168.6.110",1002,"TCP"
AT+SAVETRANSLINK=1,"www.baidu.com",443,"SSL"
AT+SAVETRANSLINK=1,"240e:3a1:2070:11c0:55ce:4e19:9649:b75",8080,"TCPv6"
AT+SAVETRANSLINK=1,"240e:3a1:2070:11c0:55ce:4e19:9649:b75",8080,"SSLv6"

For UDP Transmission¶

Set Command¶

Command:

AT+SAVETRANSLINK=<mode>,<"remote host">,<remote port>,[<"type">,<local port>]

Response:

OK

Parameters¶

<mode>:
- 0: ESP will NOT enter Wi-Fi Passthrough Mode on power-up.
- 1: ESP will enter Wi-Fi Passthrough Mode on power-up.
<”remote host”>: IPv4 address, IPv6 address, or domain name of remote host.
<remote port>: the remote port number.
<”type”>: string parameter showing the type of transmission: “UDP” or “UDPv6”. Default: “TCP”.
<local port>: local port when UDP Wi-Fi passthrough is enabled on power-up.

Notes¶

This command will save the Wi-Fi Passthrough Mode configuration in the NVS area. If <mode> is set to 1, ESP device will enter the Wi-Fi Passthrough Mode in any subsequent power cycles. The configuration will take effect after ESP reboots.
As long as the remote host and port are valid, the configuration will be saved in flash.
If you want to establish UDP transmission based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.

Example¶

AT+SAVETRANSLINK=1,"192.168.6.110",1002,"UDP",1005
AT+SAVETRANSLINK=1,"240e:3a1:2070:11c0:55ce:4e19:9649:b75",8081,"UDPv6",1005

AT+CIPSTO: Query/Set the local TCP/SSL Server Timeout¶

Query Command¶

Function:

Query the local TCP/SSL server timeout.

Command:

AT+CIPSTO?

Response:

+CIPSTO:<time>
OK

Set Command¶

Function:

Set the local TCP/SSL server timeout.

Command:

AT+CIPSTO=<time>

Response:

OK

Parameter¶

<time>: local TCP/SSL server timeout. Unit: second. Range: [0,7200].

Notes¶

When a TCP/SSL client does not communicate with the ESP server within the <time> value, the server will terminate this connection.
If you set <time> to 0, the connection will never timeout. This configuration is not recommended.
When the client initiates a communication with the server within the set time, the timer will restart. After the timeout expires, the client is closed. During the set time, if the server initiate a communication with the client, the timer will not restart. After the timeout expires, the client is closed.

Example¶

AT+CIPMUX=1
AT+CIPSERVER=1,1001
AT+CIPSTO=10

AT+CIPSNTPCFG: Query/Set the Time Zone and the SNTP Server¶

Query Command¶

Command:

AT+CIPSNTPCFG?

Response:

+CIPSNTPCFG:<enable>,<timezone>,<SNTP server1>[,<SNTP server2>,<SNTP server3>]
OK

Set Command¶

Command:

AT+CIPSNTPCFG=<enable>,<timezone>[,<SNTP server1>,<SNTP server2>,<SNTP server3>]

Response:

OK

Parameters¶

<enable>: configure the SNTP server:
- 1: the SNTP server is configured.
- 0: the SNTP server is not configured.
<timezone>: support the following two formats:
- The first format range is [-12,14]. It marks most of the time zones by offset from Coordinated Universal Time (UTC) in whole hours (UTC–12:00 to UTC+14:00).
- The second format is UTC offset. The UTC offset specifies the time value you must add to the UTC time to get a local time value. It has syntax like [+|-][hh]mm. This is negative if the local time zone is on the west of the Prime Meridian and positive if it is on the east. The hour(hh) must be between -12 and 14, and the minute(mm) between 0 and 59. For example, if you want to set the timezone to New Zealand (Chatham Islands) which is in UTC+12:45, you should set the parameter <timezone> to 1245. Please refer to UTC offset wiki for more information.
[<SNTP server1>]: the first SNTP server.
[<SNTP server2>]: the second SNTP server.
[<SNTP server3>]: the third SNTP server.

Note¶

If the three SNTP servers are not configured, one of the following default servers will be used: “cn.ntp.org.cn”, “ntp.sjtu.edu.cn”, and “us.pool.ntp.org”.
For the query command, <timezone> parameter in the response may be different from the <timezone> parameter in set command. Because the <timezone> parameter supports the second UTC offset format, for example, set AT+CIPSNTPCFG=1,015, for query command, ESP-AT ignores the leading zero of the <timezone> parameter, and the valid value is 15. It does not belong to the first format, so it is parsed according to the second UTC offset format, that is, UTC+00:15, that is, timezone is 0 in the response.

Example¶

// Enable SNTP server, set timezone to China (UTC+08:00)
AT+CIPSNTPCFG=1,8,"cn.ntp.org.cn","ntp.sjtu.edu.cn"
or
AT+CIPSNTPCFG=1,800,"cn.ntp.org.cn","ntp.sjtu.edu.cn"

// Enable SNTP server, set timezone to New York of the United States (UTC–05:00)
AT+CIPSNTPCFG=1,-5,"0.pool.ntp.org","time.google.com"
or
AT+CIPSNTPCFG=1,-500,"0.pool.ntp.org","time.google.com"

// Enable SNTP server, set timezone to New Zealand (Chatham Islands, UTC+12:45)
AT+CIPSNTPCFG=1,1245,"0.pool.ntp.org","time.google.com"

AT+CIPSNTPTIME: Query the SNTP Time¶

Query Command¶

Command:

AT+CIPSNTPTIME?

Response:

+CIPSNTPTIME:<asctime style time>
OK

Note¶

The asctime style time is defined at asctime man page.

Example¶

AT+CWMODE=1
AT+CWJAP="1234567890","1234567890"
AT+CIPSNTPCFG=1,8,"cn.ntp.org.cn","ntp.sjtu.edu.cn"
AT+CIPSNTPTIME?
+CIPSNTPTIME:Tue Oct 19 17:47:56 2021
OK

or

AT+CWMODE=1
AT+CWJAP="1234567890","1234567890"
AT+CIPSNTPCFG=1,530
AT+CIPSNTPTIME?
+CIPSNTPTIME:Tue Oct 19 15:17:56 2021
OK

AT+CIPSNTPINTV: Query/Set the SNTP time synchronization interval¶

Query Command¶

Command:

AT+CIPSNTPINTV?

Response:

+CIPSNTPINTV:<interval second>

OK

Set Command¶

Command:

AT+CIPSNTPINTV=<interval second>

Response:

OK

Parameters¶

<interval second>: the SNTP time synchronization interval. Unit: second. Range: [15,4294967].

Example¶

AT+CIPSNTPCFG=1,8,"cn.ntp.org.cn","ntp.sjtu.edu.cn"

OK

// synchronize SNTP time every hour
AT+CIPSNTPINTV=3600

OK

AT+CIUPDATE: Upgrade Firmware Through Wi-Fi¶

ESP-AT upgrades firmware at runtime by downloading the new firmware from a specific server through Wi-Fi and then flash it into some partitions.

Query Command¶

Function:

Query ESP device upgrade status.

Command:

AT+CIUPDATE?

Response:

+CIPUPDATE:<state>

OK

Execute Command¶

Function:

Upgrade OTA the latest version of firmware via TCP from the server in blocking mode.

Command:

AT+CIUPDATE

Response:

Please refer to the response in the set command.

Set Command¶

Function:

Upgrade the specified version of firmware from the server.

Command:

AT+CIUPDATE=<ota mode>[,<version>][,<firmware name>][,<nonblocking>]

Response:

If OTA succeeds in blocking mode, the system returns:

+CIPUPDATE:1
+CIPUPDATE:2
+CIPUPDATE:3
+CIPUPDATE:4

OK

If OTA succeeds in non-blocking mode, the system returns:

OK
+CIPUPDATE:1
+CIPUPDATE:2
+CIPUPDATE:3
+CIPUPDATE:4

If OTA fails in blocking mode, the system returns:

+CIPUPDATE:<state>

ERROR

If OTA fails in non-blocking mode, the system returns:

OK
+CIPUPDATE:<state>
+CIPUPDATE:-1

Parameters¶

<ota mode>:
- 0: OTA via HTTP.
- 1: OTA via HTTPS. If it does not work, please check whether ./build.py menuconfig > Component config > AT > OTA based upon ssl is enabled. For more information, please refer to Compile ESP-AT Project.
<version>: AT version, such as, v1.2.0.0, v1.1.3.0, v1.1.2.0.
<firmware name>: firmware to upgrade, such as, ota, mqtt_ca, client_ca or other custom partition in at_customize.csv.
<nonblocking>:
- 0: OTA by blocking mode (In this mode, you can not send AT command until OTA completes successfully or fails.)
- 1: OTA by non-blocking mode (You need to manually restart after upgrade done (+CIPUPDATE:4).)
<state>:
- 1: Server found.
- 2: Connected to the server.
- 3: Got the upgrade version.
- 4: Upgrade done.
- -1: OTA fails in non-blocking mode.

Notes¶

The speed of the upgrade depends on the network status.
If the upgrade fails due to unfavorable network conditions, AT will return ERROR. Please wait for some time before retrying.
If you use Espressif’s AT BIN, AT+CIUPDATE will download a new AT BIN from the Espressif Cloud.
If you use a user-compiled AT BIN, you need to implement your own AT+CIUPDATE FOTA function or use AT+USEROTA or AT+WEBSERVER command. ESP-AT project provides an example of FOTA.
After you upgrade the AT firmware, you are suggested to call the command AT+RESTORE to restore the factory default settings.
The timeout of OTA process is 3 minutes.
The response OK in non-blocking mode does not necessarily come before the response +CIPUPDATE:<state>. It may be output before +CIPUPDATE:<state> or after it.
Upgraded to an older version is not recommended.
Please refer to How to Implement OTA Upgrade for more OTA commands.

Example¶

AT+CWMODE=1
AT+CWJAP="1234567890","1234567890"
AT+CIUPDATE
AT+CIUPDATE=1
AT+CIUPDATE=1,"v1.2.0.0"
AT+CIUPDATE=1,"v2.2.0.0","mqtt_ca"
AT+CIUPDATE=1,"v2.2.0.0","ota",1
AT+CIUPDATE=1,,,1
AT+CIUPDATE=1,,"ota",1
AT+CIUPDATE=1,"v2.2.0.0",,1

AT+CIPDINFO: Set “+IPD” Message Mode¶

Query Command¶

Command:

AT+CIPDINFO?

Response:

+CIPDINFO:true
OK

or

+CIPDINFO:false
OK

Set Command¶

Command:

AT+CIPDINFO=<mode>

Response:

OK

Parameters¶

<mode>:
- 0: does not show the remote host and port in “+IPD” and “+CIPRECVDATA” messages.
- 1: show the remote host and port in “+IPD” and “+CIPRECVDATA” messages.

Example¶

AT+CIPDINFO=1

AT+CIPSSLCCONF: Query/Set SSL Clients¶

Query Command¶

Function:

Query the configuration of each connection where the ESP device runs as an SSL client.

Command:

AT+CIPSSLCCONF?

Response:

+CIPSSLCCONF:<link ID>,<auth_mode>,<pki_number>,<ca_number>
OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCCONF=<auth_mode>[,<pki_number>][,<ca_number>]

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCCONF=<link ID>,<auth_mode>[,<pki_number>][,<ca_number>]

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For multiple connections, if the value is max, it means all connections. By default, max is 5.
<auth_mode>:
- 0: no authentication. In this case <pki_number> and <ca_number> are not required.
- 1: the client provides the client certificate for the server to verify.
- 2: the client loads CA certificate to verify the server’s certificate.
- 3: mutual authentication.
<pki_number>: the index of certificate and private key. If there is only one certificate and private key, the value should be 0.
<ca_number>: the index of CA. If there is only one CA, the value should be 0.

Notes¶

If you want this configuration to take effect immediately, run this command before establishing an SSL connection.
The configuration changes will be saved in the NVS area. If you set the command AT+SAVETRANSLINK to enter SSL Wi-Fi Passthrough Mode on power-up, the ESP device will establish an SSL connection based on this configuration when powered up next time.

AT+CIPSSLCCN: Query/Set the Common Name of the SSL Client¶

Query Command¶

Function:

Query the common name of the SSL client of each connection.

Command:

AT+CIPSSLCCN?

Response:

+CIPSSLCCN:<link ID>,<"common name">
OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCCN=<"common name">

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCCN=<link ID>,<"common name">

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For the single connection, the link ID is 0. For multiple connections, if the value is max, it means all connections. Max is 5 by default.
<”common name”>: this parameter is used to verify the Common Name in the certificate sent by the server. The maximum length of common name is 64 bytes.

Note¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPSSLCSNI: Query/Set SSL Client Server Name Indication (SNI)¶

Query Command¶

Function:

Query the SNI configuration of each connection.

Command:

AT+CIPSSLCSNI?

Response:

+CIPSSLCSNI:<link ID>,<"sni">
OK

Set Command¶

Command:

Single connection: (AT+CIPMUX=0)
AT+CIPSSLCSNI=<"sni">

Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCSNI=<link ID>,<"sni">

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For the single connection, the link ID is 0. For multiple connections, if the value is max, it means all connections. Max is 5 by default.
<”sni”>: the Server Name Indication in ClientHello. The maximum length of sni is 64 bytes.

Notes¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPSSLCALPN: Query/Set SSL Client Application Layer Protocol Negotiation (ALPN)¶

Query Command¶

Function:

Query the ALPN configuration of each connection where the ESP device runs as an SSL client.

Command:

AT+CIPSSLCALPN?

Response:

+CIPSSLCALPN:<link ID>[,<"alpn">][,<"alpn">][,<"alpn">]

OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCALPN=<counts>[,<"alpn">][,<"alpn">][,<"alpn">]

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCALPN=<link ID>,<counts>[,<"alpn">][,<"alpn">][,<"alpn">]

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For the single connection, the link ID is 0. For multiple connections, if the value is max, it means all connections. Max is 5 by default.
<counts>: the number of ALPNs. Range: [0,5].

0: clean the ALPN configuration.

[1,5]: set the ALPN configuration.

<”alpn”>: a string paramemter showing the ALPN in ClientHello. The maximum length of alpn is limited by the command length.

Note¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPSSLCPSK: Query/Set SSL Client Pre-shared Key (PSK)¶

Query Command¶

Function:

Query the PSK configuration of each connection where the ESP device runs as an SSL client.

Command:

AT+CIPSSLCPSK?

Response:

+CIPSSLCPSK:<link ID>,<"psk">,<"hint">
OK

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPSSLCPSK=<"psk">,<"hint">

// Multiple connections: (AT+CIPMUX=1)
AT+CIPSSLCPSK=<link ID>,<"psk">,<"hint">

Response:

OK

Parameters¶

<link ID>: ID of the connection (0 ~ max). For single connection, <link ID> is 0. For multiple connections, if the value is max, it means all connections, max is 5 by default.
<”psk”>: PSK identity. Maximum length: 32.
<”hint”>: PSK hint. Maximum length: 32.

Notes¶

If you want this configuration to take effect immediately, run this command before establishing the SSL connection.

AT+CIPRECONNINTV: Query/Set the TCP/UDP/SSL reconnection Interval for the Wi-Fi Passthrough Mode ¶

Query Command¶

Function:

Query the automatic connect interval for the Wi-Fi Passthrough Mode.

Command:

AT+CIPRECONNINTV?

Response:

+CIPRECONNINTV:<interval>
OK

Set Command¶

Function:

Set the automatic reconnecting interval when TCP/UDP/SSL transmission breaks in the Wi-Fi Passthrough Mode.

Command:

AT+CIPRECONNINTV=<interval>

Response:

OK

Parameter¶

<interval>: the duration between automatic reconnections. Unit: 100 milliseconds. Default: 1. Range: [1,36000].

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.

Example¶

AT+CIPRECONNINTV=10

AT+CIPRECVMODE: Query/Set Socket Receiving Mode¶

Query Command¶

Function:

Query the socket receiving mode.

Command:

AT+CIPRECVMODE?

Response:

+CIPRECVMODE:<mode>
OK

Set Command¶

Command:

AT+CIPRECVMODE=<mode>

Response:

OK

Parameter¶

<mode>: the receive mode of socket data. Default: 0.
- 0: active mode. ESP-AT will send all the received socket data instantly to the host MCU with header “+IPD”.
- 1: passive mode. ESP-AT will keep the received socket data in an internal buffer (socket receive window, 5760 bytes by default), and wait for the host MCU to read. If the buffer is full, the socket transmission will be blocked for TCP/SSL connections, or data will be lost for UDP connections.

Notes¶

The configuration can not be used in the Wi-Fi Passthrough Mode. If it is a UDP transmission in passive mode, data will be lost when the buffer is full.
When ESP-AT receives socket data in passive mode, it will prompt the following messages in different scenarios:
- For multiple connections mode (AT+CIPMUX=1), the message is +IPD,<link ID>,<len>.
- For single connection mode (AT+CIPMUX=0), the message is +IPD,<len>.
<len> is the total length of socket data in the buffer.
You should read data by running AT+CIPRECVDATA once there is a +IPD reported. Otherwise, the next +IPD will not be reported to the host MCU until the previous +IPD has been read.
In case of disconnection, the buffered socket data will still be there and can be read by the MCU until you send AT+CIPCLOSE (AT as client) or AT+CIPSERVER=0,1 (AT as server). In other words, if +IPD has been reported, the message CLOSED of this connection will never come until you send AT+CIPCLOSE or AT+CIPSERVER=0,1 or read all data by command AT+CIPRECVDATA.

Example¶

AT+CIPRECVMODE=1

AT+CIPRECVDATA: Obtain Socket Data in Passive Receiving Mode¶

Set Command¶

Command:

// Single connection: (AT+CIPMUX=0)
AT+CIPRECVDATA=<len>

// Multiple connections: (AT+CIPMUX=1)
AT+CIPRECVDATA=<link_id>,<len>

Response:

+CIPRECVDATA:<actual_len>,<data>
OK

or

+CIPRECVDATA:<actual_len>,<"remote IP">,<remote port>,<data>
OK

Parameters¶

<link_id>: connection ID in multiple connections mode.
<len>: the max value is 0x7fffffff. If the actual length of the received data is less than len, the actual length will be returned.
<actual_len>: length of the data you actually obtain.
<data>: the data you want to obtain.
<”remote IP”>: string parameter showing the remote IPv4 address or IPv6 address, enabled by the command AT+CIPDINFO=1.
<remote port>: the remote port number, enabled by the command AT+CIPDINFO=1.

Example¶

AT+CIPRECVMODE=1

// For example, if host MCU gets a message of receiving 100-byte data in connection with No.0,
// the message will be "+IPD,0,100".
// Then you can read those 100-byte data by using the command below.
AT+CIPRECVDATA=0,100

AT+CIPRECVLEN: Obtain Socket Data Length in Passive Receiving Mode¶

Query Command¶

Function:

Query the length of the entire data buffered for the connection.

Command:

AT+CIPRECVLEN?

Response:

+CIPRECVLEN:<data length of link0>,<data length of link1>,<data length of link2>,<data length of link3>,<data length of link4>
OK

Parameters¶

<data length of link>: length of the entire data buffered for the connection.

Note¶

For SSL connections, ESP-AT will return the length of the encrypted data, so the returned length will be larger than the real data length.

Example¶

AT+CIPRECVLEN?
+CIPRECVLEN:100,,,,,
OK

AT+PING: Ping the Remote Host¶

Set Command¶

Function:

Ping the remote host.

Command:

AT+PING=<"host">

Response:

+PING:<time>

OK

or

+PING:TIMEOUT   // esp-at returns this response only when the domain name resolution failure or ping timeout

ERROR

Parameters¶

<”host”>: string parameter showing the host IPv4 address or IPv6 address or domain name.
<time>: the response time of ping. Unit: millisecond.

Notes¶

If you want to ping a remote host based on IPv6 network, set AT+CIPV6=1 first, and ensure the connected AP by AT+CWJAP supports IPv6 and esp-at got the IPv6 address which you can check it by AT+CIPSTA.
If the remote host is a domain name string, ping will first resolve the domain name (IPv4 address preferred) from DNS (domain name server), and then ping the remote IP address.

Example¶

AT+PING="192.168.1.1"
AT+PING="www.baidu.com"

// China Future Internet Engineering Center
AT+PING="240c::6666"

AT+CIPDNS: Query/Set DNS Server Information¶

Query Command¶

Function:

Query the current DNS server information.

Command:

AT+CIPDNS?

Response:

+CIPDNS:<enable>[,<"DNS IP1">][,<"DNS IP2">][,<"DNS IP3">]
OK

Set Command¶

Function:

Set DNS server information.

Command:

AT+CIPDNS=<enable>[,<"DNS IP1">][,<"DNS IP2">][,<"DNS IP3">]

Response:

OK

or

ERROR

Parameters¶

<enable>: configure DNS server settings
- 0: Enable automatic DNS server settings from DHCP. The DNS will be restored to 208.67.222.222 and 8.8.8.8. Only when the ESP station completes the DHCP process, the DNS server of the ESP station could be updated.
- 1: Enable manual DNS server settings. If you do not set a value for <DNS IPx>, it will use 208.67.222.222 and 8.8.8.8 by default.
<”DNS IP1”>: the first DNS server IP address. For the set command, this parameter only works when you set <enable> to 1, i.e. enable manual DNS settings. If you set <enable> to 1 and a value for this parameter, the ESP-AT will return this parameter as the current DNS setting when you run the query command.
<”DNS IP2”>: the second DNS server IP address. For the set command, this parameter only works when you set <enable> to 1, i.e. enable manual DNS settings. If you set <enable> to 1 and a value for this parameter, the ESP-AT will return this parameter as the current DNS setting when you run the query command.
<”DNS IP3”>: the third DNS server IP address. For the set command, this parameter only works when you set <enable> to 1, i.e. enable manual DNS settings. If you set <enable> to 1 and a value for this parameter, the ESP-AT will return this parameter as the current DNS setting when you run the query command.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The three parameters cannot be set to the same server.
When <enable> is set to 1, the DNS server may change according to the configuration of the router which the ESP device is connected to.

Example¶

AT+CIPDNS=0
AT+CIPDNS=1,"208.67.222.222","114.114.114.114","8.8.8.8"

// first DNS Server based on IPv6: China Future Internet Engineering Center
// second DNS Server based on IPv6: google-public-dns-a.google.com
// third DNS Server based on IPv6: main DNS Server based on IPv6 in JiangSu Province, China
AT+CIPDNS=1,"240c::6666","2001:4860:4860::8888","240e:5a::6666"

AT+CIPTCPOPT: Query/Set the Socket Options¶

Query Command¶

Function:

Query current socket options.

Command:

AT+CIPTCPOPT?

Response:

+CIPTCPOPT:<link_id>,<so_linger>,<tcp_nodelay>,<so_sndtimeo>
OK

Set Command¶

Command:

// Single TCP connection (AT+CIPMUX=0):
AT+CIPTCPOPT=[<so_linger>],[<tcp_nodelay>],[<so_sndtimeo>]

// Multiple TCP Connections (AT+CIPMUX=1):
AT+CIPTCPOPT=<link ID>,[<so_linger>],[<tcp_nodelay>],[<so_sndtimeo>]

Response:

OK

or

ERROR

Parameters¶

<link_id>: ID of the connection (0 ~ max). For multiple connections, if the value is max, it means all connections. By default, max is 5.
<so_linger>: configure the SO_LINGER options for the socket. Unit: second. Default: -1.
- = -1: off
- = 0: on, linger time = 0
- > 0: on, linger time = <so_linger>
<tcp_nodelay>: configure the TCP_NODELAY option for the socket. Default: 0.
- 0: disable TCP_NODELAY
- 1: enable TCP_NODELAY
<so_sndtimeo>: configure the SO_SNDTIMEO option for socket. Unit: millisecond. Default: 0.

Bluetooth® Low Energy AT Commands¶

[中文]

Currently, both ESP32 and ESP32-C3 support Bluetooth LE commands. AT firmware for ESP32 series and ESP32-C3 series supports Bluetooth® Core Specification Version 4.2. Next AT firmware for ESP32-C3 will support Bluetooth® Core Specification Version 5.0.

AT+BLEINIT: Bluetooth LE initialization.
AT+BLEADDR: Query/Set Bluetooth LE device address.
AT+BLENAME: Query/Set Bluetooth LE device name.
AT+BLESCANPARAM: Query/Set parameters of Bluetooth LE scanning.
AT+BLESCAN: Enable Bluetooth LE scanning.
AT+BLESCANRSPDATA: Set Bluetooth LE scan response.
AT+BLEADVPARAM: Query/Set parameters of Bluetooth LE advertising.
AT+BLEADVDATA: Set Bluetooth LE advertising data.
AT+BLEADVDATAEX: Automatically set Bluetooth LE advertising data.
AT+BLEADVSTART: Start Bluetooth LE advertising.
AT+BLEADVSTOP: Stop Bluetooth LE advertising.
AT+BLECONN: Establish Bluetooth LE connection.
AT+BLECONNPARAM: Query/Update parameters of Bluetooth LE connection.
AT+BLEDISCONN: End Bluetooth LE connection.
AT+BLEDATALEN: Set Bluetooth LE data packet length.
AT+BLECFGMTU: Set Bluetooth LE MTU length.
AT+BLEGATTSSRVCRE: Generic Attributes Server (GATTS) creates services.
AT+BLEGATTSSRVSTART: GATTS starts services.
AT+BLEGATTSSRVSTOP: GATTS Stops Services.
AT+BLEGATTSSRV: GATTS discovers services.
AT+BLEGATTSCHAR: GATTS discovers characteristics.
AT+BLEGATTSNTFY: Notify a client of the value of a characteristic value from the server.
AT+BLEGATTSIND: Indicate the characteristic value from the server to a client.
AT+BLEGATTSSETATTR: GATTS sets characteristics.
AT+BLEGATTCPRIMSRV: Generic Attributes Client (GATTC) discovers primary services.
AT+BLEGATTCINCLSRV: GATTC discovers included services.
AT+BLEGATTCCHAR: GATTC discovers characteristics.
AT+BLEGATTCRD: GATTC reads characteristics.
AT+BLEGATTCWR: GATTC writes characteristics.
AT+BLESPPCFG: Query/Set Bluetooth LE SPP parameters.
AT+BLESPP: Enter Bluetooth LE SPP mode.
AT+BLESECPARAM: Query/Set Bluetooth LE encryption parameters.
AT+BLEENC: Initiate Bluetooth LE encryption request.
AT+BLEENCRSP: Respond to the pairing request from the peer device.
AT+BLEKEYREPLY: Reply the key value to the peer device.
AT+BLECONFREPLY: Reply the confirm value to the peer device in the legacy connection stage.
AT+BLEENCDEV: Query bonded Bluetooth LE encryption device list.
AT+BLEENCCLEAR: Clear Bluetooth LE encryption device list.
AT+BLESETKEY: Set Bluetooth LE static pair key.
AT+BLEHIDINIT: Bluetooth LE Human Interface Device (HID) profile initialization.
AT+BLEHIDKB: Send Bluetooth LE HID keyboard information.
AT+BLEHIDMUS: Send Bluetooth LE HID mouse information.
AT+BLEHIDCONSUMER: Send Bluetooth LE HID consumer information.
AT+BLUFI: Start or Stop BluFi.
AT+BLUFINAME: Query/Set BluFi device name.

AT+BLEINIT: Bluetooth LE Initialization¶

Query Command¶

Function:

Check the initialization status of Bluetooth LE.

Command:

AT+BLEINIT?

Response:

If Bluetooth LE is initialized, AT will return:

+BLEINIT:<role>
OK

If Bluetooth LE is not initialized, AT will return:

+BLEINIT:0
OK

Set Command¶

Function:

Initialize the role of Bluetooth LE.

Command:

AT+BLEINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinit Bluetooth LE
- 1: client role
- 2: server role

Notes¶

When using Bluetooth LE function, if you do not need to use SoftAP mode, it is recommended that you can disable the mode through AT+CWMODE.
The file “at_customize.bin” has to be downloaded, so that the relevant commands can be used. Please refer to How to Customize Bluetooth® LE Services for more details.
Before using other Bluetooth LE AT commands, you should run this command first to trigger the initialization process.
After the initialization, the Bluetooth LE role cannot be changed unless you run AT+RST to restart the system first and then re-initialize the Bluetooth LE role.
If you use an ESP device as a Bluetooth LE server, a service bin should be downloaded into flash.
- To learn how to generate a service bin, please refer to esp-at/tools/readme.md.
- The download address of the service bin is the “ble_data” address in esp-at/module_config/module_${platform}_default/at_customize.csv.

Example¶

AT+BLEINIT=1

AT+BLEADDR: Query/Set Bluetooth LE Device Address¶

Query Command¶

Function:

Query the Bluetooth LE Public Address.

Command:

AT+BLEADDR?

Response:

+BLEADDR:<BLE_public_addr>
OK

Set Command¶

Function:

Set the Bluetooth LE address type.

Command:

AT+BLEADDR=<addr_type>[,<random_addr>]

Response:

OK

Parameter¶

<addr_type>:
- 0: Public Address
- 1: Random Address

Note¶

A Static Address should meet the following requirements:
- The two most significant bits of the address should be equal to 1.
- At least one bit of the random part of the address should be 0.
- At least one bit of the random part of the address should be 1.

Example¶

AT+BLEADDR=1,"f8:7f:24:87:1c:7b"    // Set Random Device Address, Static Address
AT+BLEADDR=1                        // Set Random Device Address, Private Address
AT+BLEADDR=0                        // Set Public Device Address

AT+BLENAME: Query/Set Bluetooth LE Device Name¶

Query Command¶

Function:

Query the Bluetooth LE device name.

Command:

AT+BLENAME?

Response:

+BLENAME:<device_name>
OK

Set Command¶

Function:

Set the Bluetooth LE device name.

Command:

AT+BLENAME=<device_name>

Response:

OK

Parameter¶

<device_name>: the Bluetooth LE device name. The maximum length is 32. Default: “ESP_AT”.

Note¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
After setting the device name with this command, it is recommended that you execute the AT+BLEADVDATA command to add the device name into the advertising data.

Example¶

AT+BLENAME="esp_demo"

AT+BLESCANPARAM: Query/Set Parameters of Bluetooth LE Scanning¶

Query Command¶

Function:

Query the parameters of Bluetooth LE scanning.

Command:

AT+BLESCANPARAM?

Response:

+BLESCANPARAM:<scan_type>,<own_addr_type>,<filter_policy>,<scan_interval>,<scan_window>
OK

Set Command¶

Function:

Set the parameters of Bluetooth LE scanning.

Command:

AT+BLESCANPARAM=<scan_type>,<own_addr_type>,<filter_policy>,<scan_interval>,<scan_window>

Response:

OK

Parameters¶

<scan_type>:
- 0: passive scan
- 1: active scan
<own_addr_type>:
- 0: Public Address
- 1: Random Address
- 2: RPA Public Address
- 3: RPA Random Address
<filter_policy>:
- 0: BLE_SCAN_FILTER_ALLOW_ALL
- 1: BLE_SCAN_FILTER_ALLOW_ONLY_WLST
- 2: BLE_SCAN_FILTER_ALLOW_UND_RPA_DIR
- 3: BLE_SCAN_FILTER_ALLOW_WLIST_PRA_DIR
<scan_interval>: scan interval. It should be more than or equal to the value of <scan_window>. The range of this parameter is [0x0004,0x4000]. The scan interval equals this parameter multiplied by 0.625 ms, so the range for the actual scan interval is [2.5,10240] ms.
<scan_window>: scan window. It should be less than or equal to the value of <scan_interval>. The range of this parameter is [0x0004,0x4000]. The scan window equals this parameter multiplied by 0.625 ms, so the range for the actual scan window is [2.5,10240] ms.

Example¶

AT+BLEINIT=1   // role: client
AT+BLESCANPARAM=0,0,0,100,50

AT+BLESCAN: Enable Bluetooth LE Scanning¶

Set Command¶

Function:

Enable/disable scanning.

Command:

AT+BLESCAN=<enable>[,<interval>][,<filter_type>,<filter_param>]

Response:

+BLESCAN:<addr>,<rssi>,<adv_data>,<scan_rsp_data>,<addr_type>
OK

Parameters¶

<enable>:
- 1: enable continuous scanning.
- 0: disable continuous scanning.
[<interval>]: optional parameter. Unit: second.
- If you want to disable the scanning, this parameter should be omitted.
- If you want to enable the scanning, set a value for this parameter:
- When you set it to 0, it means that scanning is continuous.
- When set it to a value other than 0, for example, AT+BLESCAN=1,3, it means that scanning will last for 3 seconds and then stop automatically. The scanning results will be returned.
[<filter_type>]: filtering option.
- 1: “MAC”.
- 2: “NAME”.
<filter_param>: filtering parameter showing the remote device MAC address or remote device name.
<addr>: Bluetooth LE address.
<rssi>: signal strength.
<adv_data>: advertising data.
<scan_rsp_data>: scan response data.
<addr_type>: the address type of broadcasters.

Notes¶

The response OK does not necessarily come before the response +BLESCAN:<addr>,<rssi>,<adv_data>,<scan_rsp_data>,<addr_type>. It may be output before +BLESCAN:<addr>,<rssi>,<adv_data>,<scan_rsp_data>,<addr_type> or after it.

Example¶

AT+BLEINIT=1    // role: client
AT+BLESCAN=1    // start scanning
AT+BLESCAN=0    // stop scanning
AT+BLESCAN=1,3,1,"24:0A:C4:96:E6:88"  // start scanning, filter type is MAC address
AT+BLESCAN=1,3,2,"ESP-AT"  // start scanning, filter type is device name

AT+BLESCANRSPDATA: Set Bluetooth LE Scan Response¶

Set Command¶

Function:

Set scan response.

Command:

AT+BLESCANRSPDATA=<scan_rsp_data>

Response:

OK

Parameter¶

<scan_rsp_data>: scan response data is a HEX string. For example, if you want to set the response data to “0x11 0x22 0x33 0x44 0x55”, the command should be AT+BLESCANRSPDATA="1122334455".

Example¶

AT+BLEINIT=2   // role: server
AT+BLESCANRSPDATA="1122334455"

AT+BLEADVPARAM: Query/Set Parameters of Bluetooth LE Advertising¶

Query Command¶

Function:

Query the parameters of advertising.

Command:

AT+BLEADVPARAM?

Response:

+BLEADVPARAM:<adv_int_min>,<adv_int_max>,<adv_type>,<own_addr_type>,<channel_map>,<adv_filter_policy>,<peer_addr_type>,<peer_addr>
OK

Set Command¶

Function:

Set the parameters of advertising.

Command:

AT+BLEADVPARAM=<adv_int_min>,<adv_int_max>, <adv_type>,<own_addr_type>,<channel_map>[,<adv_filter_policy>][,<peer_addr_type>] [,<peer_addr>]

Response:

OK

Parameters¶

<adv_int_min>: minimum advertising interval. The range of this parameter is [0x0020,0x4000]. The actual advertising interval equals this parameter multiplied by 0.625 ms, so the range for the actual minimum interval is [20, 10240] ms. It should be less than or equal to the value of <adv_int_max>.
<adv_int_max>: maximum advertising interval. The range of this parameter is [0x0020,0x4000]. The actual advertising interval equals this parameter multiplied by 0.625 ms, so the range for the actual maximum interval is [20, 10240] ms. It should be more than or equal to the value of <adv_int_min>.
<adv_type>:
- 0: ADV_TYPE_IND
- 1: ADV_TYPE_DIRECT_IND_HIGH
- 2: ADV_TYPE_SCAN_IND
- 3: ADV_TYPE_NONCONN_IND
- 4: ADV_TYPE_DIRECT_IND_LOW
<own_addr_type>: own Bluetooth LE address type.
- 0: BLE_ADDR_TYPE_PUBLIC
- 1: BLE_ADDR_TYPE_RANDOM
<channel_map>: channel of advertising.
- 1: ADV_CHNL_37
- 2: ADV_CHNL_38
- 4: ADV_CHNL_39
- 7: ADV_CHNL_ALL
[<adv_filter_policy>]: filter policy of advertising.
- 0: ADV_FILTER_ALLOW_SCAN_ANY_CON_ANY
- 1: ADV_FILTER_ALLOW_SCAN_WLST_CON_ANY
- 2: ADV_FILTER_ALLOW_SCAN_ANY_CON_WLST
- 3: ADV_FILTER_ALLOW_SCAN_WLST_CON_WLST
[<peer_addr_type>]: remote Bluetooth LE address type.
- 0: PUBLIC
- 1: RANDOM
[<peer_addr>]: remote Bluetooth LE address.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVPARAM=50,50,0,0,4,0,0,"12:34:45:78:66:88"

AT+BLEADVDATA: Set Bluetooth LE Advertising Data¶

Set Command¶

Function:

Set advertising data.

Command:

AT+BLEADVDATA=<adv_data>

Response:

OK

Parameter¶

<adv_data>: advertising data in HEX string. For example, to set the advertising data to “0x11 0x22 0x33 0x44 0x55”, the command should be AT+BLEADVDATA="1122334455".

Note¶

If advertising data is preset by command AT+BLEADVDATAEX=<dev_name>,<uuid>,<manufacturer_data>,<include_power>, it will be overwritten by this command.
If you run this command to modify the device name, it is recommended to also execute the AT+BLENAME command to set the same device name afterwards.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVDATA="1122334455"

AT+BLEADVDATAEX: Automatically Set Bluetooth LE Advertising Data¶

Query Command¶

Function:

Query the parameters of advertising data.

Command:

AT+BLEADVDATAEX?

Response:

+BLEADVDATAEX:<dev_name>,<uuid>,<manufacturer_data>,<include_power>

OK

Set Command¶

Function:

Set the advertising data and start advertising.

Command:

AT+BLEADVDATAEX=<dev_name>,<uuid>,<manufacturer_data>,<include_power>

Response:

OK

Parameters¶

<dev_name>: string parameter showing a device name. For example, if you want to set the device name to “just-test”, the command should be AT+BLEADVSTARTEX="just-test",<uuid>,<manufacturer_data>,<include_power>.
<uuid>: string parameter. For example, if you want to set the UUID to “0xA002”, the command should be AT+BLEADVSTARTEX=<dev_name>,"A002",<manufacturer_data>,<include_power>.
<manufacturer_data>: manufacturer data in HEX string. For example, if you set the manufacturer data to “0x11 0x22 0x33 0x44 0x55”, the command should be AT+BLEADVSTARTEX=<dev_name>,<uuid>,"1122334455",<include_power>.
<include_power>: If you need to include the TX power in the advertising data, you should set the parameter to 1. Otherwise, set it to 0.

Note¶

If advertising data is preset by command AT+BLEADVDATA=<adv_data>, it will be overwritten by this command.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVDATAEX="ESP-AT","A002","0102030405",1

AT+BLEADVSTART: Start Bluetooth LE Advertising¶

Execute Command¶

Function:

Start advertising.

Command:

AT+BLEADVSTART

Response:

OK

Notes¶

If advertising parameters are NOT set by command AT+BLEADVPARAM=<adv_parameter>, the default parameters will be used.
If advertising data is NOT set by command AT+BLEADVDATA=<adv_data>, the advertising playload will be empty.
If advertising data is preset by command AT+BLEADVDATA=<adv_data>, it will be overwritten by AT+BLEADVDATAEX=<dev_name>,<uuid>,<manufacturer_data>,<include_power> and vice versa.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVSTART

AT+BLEADVSTOP: Stop Bluetooth LE Advertising¶

Execute Command¶

Function:

Stop advertising.

Command:

AT+BLEADVSTOP

Response:

OK

Note¶

After the start of advertising, if the Bluetooth LE connection is established successfully, it will stop advertising automatically. In such a case, this command does NOT need to be called.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEADVSTART
AT+BLEADVSTOP

AT+BLECONN: Establish Bluetooth LE Connection¶

Query Command¶

Function:

Query the Bluetooth LE connection.

Command:

AT+BLECONN?

Response:

+BLECONN:<conn_index>,<remote_address>
OK

If the connection has not been established, there will be no <conn_index> and <remote_address> in the response.

Set Command¶

Function:

Establish the Bluetooth LE connection.

Command:

AT+BLECONN=<conn_index>,<remote_address>[,<addr_type>,<timeout>]

Response:

If the connection is established successfully, it will prompt:

+BLECONN:<conn_index>,<remote_address>

OK

If the connection fails, it will prompt:

+BLECONN:<conn_index>,-1

ERROR

If the connection fails due to parameters error or other reasons, it will prompt:

ERROR

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<remote_address>: remote Bluetooth LE address.
[<addr_type>]: the address type of broadcasters.
[<timeout>]: the timeout for the connection command. Unit: second. Range: [3,30].

Notes¶

It is recommended to scan devices by running AT+BLESCAN before initiating a new connection to ensure that the target device is in the broadcast state.
The maximum timeout for connection is 30 seconds.
If the Bluetooth LE server is initialized and the connection is established successfully, you can use this command to discover the services in the peer device (GATTC). The following GATTC commands can also be used:
If the AT+BLECONN? is executed when the Bluetooth LE is not initialized (AT+BLEINIT=0), the system will not output +BLECONN:<conn_index>,<remote_address> .

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23",0,10

AT+BLECONNPARAM: Query/Update Parameters of Bluetooth LE Connection¶

Query Command¶

Function:

Query the parameters of Bluetooth LE connection.

Command:

AT+BLECONNPARAM?

Response:

+BLECONNPARAM:<conn_index>,<min_interval>,<max_interval>,<cur_interval>,<latency>,<timeout>
OK

Set Command¶

Function:

Update the parameters of Bluetooth LE connection.

Command:

AT+BLECONNPARAM=<conn_index>,<min_interval>,<max_interval>,<latency>,<timeout>

Response:

OK

If the setting fails, it will prompt the message below:

+BLECONNPARAM: <conn_index>,-1

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<min_interval>: minimum connecting interval. It should be less than or equal to the value of <max_interval>. The range of this parameter is [0x0006,0x0C80]. The actual connecting interval equals this parameter multiplied by 1.25 ms, so the range for the actual minimum interval is [7.5,4000] ms.
<max_interval>: maximum connecting interval. It should be more than or equal to the value of <min_interval>. The range of this parameter is [0x0006,0x0C80]. The actual connecting interval equals this parameter multiplied by 1.25 ms, so the range for the actual maximum interval is [7.5,4000] ms.
<cur_interval>: current connecting interval.
<latency>: latency. Range: [0x0000,0x01F3].
<timeout>: timeout. The range of this parameter is [0x000A,0x0C80]. The actual timeout equals this parameter multiplied by 10 ms, so the range for the actual timeout is [100,32000] ms.

Note¶

This command only supports the client role when updating its connection parameters. Of course, the connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLECONNPARAM=0,12,14,1,500

AT+BLEDISCONN: End Bluetooth LE Connection¶

Execute Command¶

Function:

End the Bluetooth LE connection.

Command:

AT+BLEDISCONN=<conn_index>

Response:

OK  // The AT+BLEDISCONN command is received.
+BLEDISCONN:<conn_index>,<remote_address>  // The command is successful.

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<remote_address>: remote Bluetooth LE address.

Note¶

Only clients can call this command to terminate the connection.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLEDISCONN=0

AT+BLEDATALEN: Set Bluetooth LE Data Packet Length¶

Set Command¶

Function:

Set the length of Bluetooth LE data packet.

Command:

AT+BLEDATALEN=<conn_index>,<pkt_data_len>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<pkt_data_len>: data packet’s length. Range: [0x001B,0x00FB].

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLEDATALEN=0,30

AT+BLECFGMTU: Set Bluetooth LE MTU Length¶

Query Command¶

Function:

Query the length of the maximum transmission unit (MTU).

Command:

AT+BLECFGMTU?

Response:

+BLECFGMTU:<conn_index>,<mtu_size>
OK

Set Command¶

Function:

Set the length of the maximum transmission unit (MTU).

Command:

AT+BLECFGMTU=<conn_index>,<mtu_size>

Response:

OK  // The command is received.

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<mtu_size>: MTU length.

Notes¶

Bluetooth LE connection has to be established first.
Only the client can call this command to set the length of MTU.
The actual length of MTU needs to be negotiated. The OK response only indicates an attempt to negotiate the length. The actual length may not be the value you set. Therefore, it is recommended to run command AT+BLECFGMTU? to query the actual length.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:0a:c4:09:34:23"
AT+BLECFGMTU=0,300

AT+BLEGATTSSRVCRE: GATTS Creates Services¶

Execute Command¶

Function:

The Generic Attributes Server (GATTS) creates Bluetooth LE services.

Command:

AT+BLEGATTSSRVCRE

Response:

OK

Notes¶

If you are using an ESP device as a Bluetooth LE server, a service bin should be downloaded into flash in order to provide services.
- To learn how to generate a service bin, please refer to esp-at/tools/readme.md.
- The download address of the service bin is the “ble_data” address in esp-at/module_config/module_${platform}_default/at_customize.csv.
This command should be called immediately to create services, right after the Bluetooth LE server is initialized; If a Bluetooth LE connection is established first, the service creation will fail.
If the Bluetooth LE client is initialized, you can use this command to create local services. Some GATTS commands can also be used, such as those to start and stop services, set attribute values, and send notifications/indications. See the list below for the specific commands.
- AT+BLEGATTSSRVCRE (It is recommended to execute this command before the connection is established)
- AT+BLEGATTSSRVSTART (It is recommended to execute this command before the connection is established)
- AT+BLEGATTSSRV
- AT+BLEGATTSCHAR
- AT+BLEGATTSNTFY
- AT+BLEGATTSIND
- AT+BLEGATTSSETATTR

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE

AT+BLEGATTSSRVSTART: GATTS Starts Services¶

Execute Command¶

Function:

GATTS starts all services.

Command:

AT+BLEGATTSSRVSTART

Set Command¶

Function:

GATTS starts a specific service.

Command:

AT+BLEGATTSSRVSTART=<srv_index>

Response:

OK

Parameter¶

<srv_index>: service’s index starting from 1.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART

AT+BLEGATTSSRVSTOP: GATTS Stops Services¶

Execute Command¶

Function:

GATTS stops all services.

Command:

AT+BLEGATTSSRVSTOP

Set Command¶

Function:

GATTS stops a specific service.

Command:

AT+BLEGATTSSRVSTOP=<srv_index>

Response:

OK

Parameter¶

<srv_index>: service’s index starting from 1.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEGATTSSRVSTOP

AT+BLEGATTSSRV: GATTS Discovers Services¶

Query Command¶

Function:

GATTS discovers services.

Command:

AT+BLEGATTSSRV?

Response:

+BLEGATTSSRV:<srv_index>,<start>,<srv_uuid>,<srv_type>
OK

Parameters¶

<srv_index>: service’s index starting from 1.
<start>:
- 0: the service has not started.
- 1: the service has already started.
<srv_uuid>: service’s UUID.
<srv_type>: service’s type.
- 0: not primary service.
- 1: primary service.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRV?

AT+BLEGATTSCHAR: GATTS Discovers Characteristics¶

Query Command¶

Function:

GATTS discovers characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

The response for a characteristic:

+BLEGATTSCHAR:"char",<srv_index>,<char_index>,<char_uuid>,<char_prop>

The response for a descriptor:

+BLEGATTSCHAR:"desc",<srv_index>,<char_index>,<desc_index>
OK

Parameters¶

<srv_index>: service’s index starting from 1.
<char_index>: characteristic’s index starting from 1.
<char_uuid>: characteristic’s UUID.
<char_prop>: characteristic’s properties.
<desc_index>: descriptor’s index.
<desc_uuid>: descriptor’s UUID.

Example¶

AT+BLEINIT=2   // role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEGATTSCHAR?

AT+BLEGATTSNTFY: Notify a Client of the Value of a Characteristic Value from the Server¶

Set Command¶

Function:

Notify a client of the value of a characteristic value from the server.

Command:

AT+BLEGATTSNTFY=<conn_index>,<srv_index>,<char_index>,<length>

Response:

The symbol > indicates that AT is ready for receiving serial data, and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the notification starts.

If the data transmission is successful, AT returns:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<char_index>: characteristic’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<length>: data length.

Example¶

AT+BLEINIT=2      // Role: server.
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEADVSTART    // Start advertising. After the client is connected, it must be configured to receive notifications.
AT+BLEGATTSCHAR?  // Query the characteristics which the client will be notified of.
// For example, to notify of 4-byte data using the 6th characteristic in the 3rd service, use the following command:
AT+BLEGATTSNTFY=0,3,6,4
// After the symbol ">" shows, enter the 4-byte data, such as "1234". Then the data will be transmitted automatically.

AT+BLEGATTSIND: Indicate the Characteristic Value from the Server to a Client¶

Set Command¶

Function:

Indicate the characteristic value from the server to a client.

Command:

AT+BLEGATTSIND=<conn_index>,<srv_index>,<char_index>,<length>

Response:

The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the indication starts.

If the data transmission is successful, AT returns:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTSCHAR?.
<length>: data length.

Example¶

AT+BLEINIT=2      // Role: server
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEADVSTART    // Start advertising. After the client is connected, it must be configured to receive indications.
AT+BLEGATTSCHAR?  // Query the characteristics which the client can receive indications.
// For example, to indicate 4 bytes of data using the 7th characteristic in the 3rd service, use the following command:
AT+BLEGATTSIND=0,3,7,4
// After the symbol ">" shows, input 4 bytes of data, such as "1234". Then the data will be transmitted automatically.

AT+BLEGATTSSETATTR: GATTS Sets Characteristics¶

Set Command¶

Function:

GATTS sets its characteristic (descriptor).

Command:

AT+BLEGATTSSETATTR=<srv_index>,<char_index>,[<desc_index>],<length>

Response:

The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the setting starts.

If the setting is successful, AT returns:

OK

Parameters¶

<srv_index>: service’s index. It can be fetched with command AT+BLEGATTSCHAR?.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTSCHAR?.
[<desc_index>]: descriptor’s index.
- If it is set, this command is used to set the value of the descriptor.
- Otherwise, this command is used to set the value of the characteristic.
<length>: data length.

Note¶

If the value of <length> is larger than the maximum length allowed, the setting will fail. The service table is defined in components/customized_partitions/raw_data/ble_data.

Example¶

AT+BLEINIT=2   // Role: server.
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEGATTSCHAR?
// For example, to set 1 byte of data of the 1st characteristic in the 1st service, use the following command:
AT+BLEGATTSSETATTR=1,1,,1
// After the symbol ">" shows, input 1 byte of data, such as "8". Then the setting starts.

AT+BLEGATTCPRIMSRV: GATTC Discovers Primary Services¶

Query Command¶

Function:

Generic Attributes Client (GATTC) discovers primary services.

Command:

AT+BLEGATTCPRIMSRV=<conn_index>

Response:

+BLEGATTCPRIMSRV:<conn_index>,<srv_index>,<srv_uuid>,<srv_type>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index starting from 1.
<srv_uuid>: service’s UUID.
<srv_type>: service’s type.
- 0: not primary service.
- 1: primary service.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0

AT+BLEGATTCINCLSRV: GATTC Discovers Included Services¶

Set Command¶

Function:

GATTC discovers included services.

Command:

AT+BLEGATTCINCLSRV=<conn_index>,<srv_index>

Response:

+BLEGATTCINCLSRV:<conn_index>,<srv_index>,<srv_uuid>,<srv_type>,<included_srv_uuid>,<included_srv_type>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<srv_uuid>: service’s UUID.
<srv_type>: service’s type.
- 0: not primary service.
- 1: primary service.
<included_srv_uuid>: included service’s UUID.
<included_srv_type>: included service’s type.
- 0: not primary service.
- 1: primary service.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCINCLSRV=0,1  // set a specific index according to the result of the previous command

AT+BLEGATTCCHAR: GATTC Discovers Characteristics¶

Set Command¶

Function:

GATTC discovers characteristics.

Command:

AT+BLEGATTCCHAR=<conn_index>,<srv_index>

Response:

The response for a characteristic:

+BLEGATTCCHAR:"char",<conn_index>,<srv_index>,<char_index>,<char_uuid>,<char_prop>

The response for a descriptor:

+BLEGATTCCHAR:"desc",<conn_index>,<srv_index>,<char_index>,<desc_index>,<desc_uuid>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<char_index>: characteristic’s index starting from 1.
<char_uuid>: characteristic’s UUID.
<char_prop>: characteristic’s properties.
<desc_index>: descriptor’s index.
<desc_uuid>: descriptor’s UUID.

Note¶

The Bluetooth LE connection has to be established first.

Example¶

AT+BLEINIT=1   // role: client
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCCHAR=0,1 // set a specific index according to the result of the previous command

AT+BLEGATTCRD: GATTC Reads Characteristics¶

Set Command¶

Function:

GATTC reads a characteristic or descriptor.

Command:

AT+BLEGATTCRD=<conn_index>,<srv_index>,<char_index>[,<desc_index>]

Response:

+BLEGATTCRD:<conn_index>,<len>,<value>
OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index>.
[<desc_index>]: descriptor’s index.
- If it is set, the value of the target descriptor will be read.
- if it is not set, the value of the target characteristic will be read.
<len>: data length.
<value>: <char_value> or <desc_value>.

<char_value>: characteristic’s value. String format is read by command AT+BLEGATTCRD=<conn_index>,<srv_index>,<char_index>. For example, if the response is +BLEGATTCRD:0,1,0, it means that the value length is 1, and the content is “0”.

<desc_value>: descriptor’s value. String format is read by command AT+BLEGATTCRD=<conn_index>,<srv_index>,<char_index>,<desc_index>. For example, if the response is +BLEGATTCRD:0,4,0123, it means that the value length is 4, and the content is “0123”.

Notes¶

The Bluetooth LE connection has to be established first.
If the target characteristic cannot be read, it will return “ERROR”.

Example¶

AT+BLEINIT=1   // Role: client.
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCCHAR=0,3 // Set a specific index according to the result of the previous command.
// For example, to read 1st descriptor of the 2nd characteristic in the 3rd service, use the following command:
AT+BLEGATTCRD=0,3,2,1

AT+BLEGATTCWR: GATTC Writes Characteristics¶

Set Command¶

Function:

GATTC writes characteristics or descriptors.

Command:

AT+BLEGATTCWR=<conn_index>,<srv_index>,<char_index>[,<desc_index>],<length>

Response:

The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the writing starts.

If the setting is successful, AT returns:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<srv_index>: service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index>.
<char_index>: characteristic’s index; it can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index>.
[<desc_index>]: descriptor’s index.
- If it is set, the value of the target descriptor will be written.
- If it is not set, the value of the target characteristic will be written.
<length>: data length.

Notes¶

The Bluetooth LE connection has to be established first.
If the target characteristic cannot be written, it will return “ERROR”.

Example¶

AT+BLEINIT=1   // Role: client.
AT+BLECONN=0,"24:12:5f:9d:91:98"
AT+BLEGATTCPRIMSRV=0
AT+BLEGATTCCHAR=0,3 // Set a specific index according to the result of the previous command.
// For example, to write 6 bytes of data to the 4th characteristic in the 3rd service, use the following command:
AT+BLEGATTCWR=0,3,4,,6
// After the symbol ">" shows, input 6 bytes of data, such as "123456". Then the writing starts.

AT+BLESPPCFG: Query/Set Bluetooth LE SPP Parameters¶

Query Command¶

Function:

Query the parameters of Bluetooth LE Serial Port Profile (SPP).

Command:

AT+BLESPPCFG?

Response:

+BLESPPCFG:<tx_service_index>,<tx_char_index>,<rx_service_index>,<rx_char_index>,<auto_conn>
OK

Set Command¶

Function:

Set or reset the parameters of Bluetooth LE SPP.

Command:

AT+BLESPPCFG=<cfg_enable>[,<tx_service_index>,<tx_char_index>,<rx_service_index>,<rx_char_index>][,<auto_conn>]

Response:

OK

Parameters¶

<cfg_enable>:
- 0: all the SPP parameters will be reset, and the following parameters don’t need input.
- 1: you should input the following parameters.
<tx_service_index>: tx service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index> and AT+BLEGATTSSRV?.
<tx_char_index>: tx characteristic’s index. It can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index> and AT+BLEGATTSCHAR?.
<rx_service_index>: rx service’s index. It can be fetched with command AT+BLEGATTCPRIMSRV=<conn_index> and AT+BLEGATTSSRV?.
<rx_char_index>: rx characteristic’s index. It can be fetched with command AT+BLEGATTCCHAR=<conn_index>,<srv_index> and AT+BLEGATTSCHAR?.
<auto_conn>: Bluetooth LE SPP auto-reconnection flag. By default, automatic reconnection is enabled.
- 0: disable Bluetooth LE SPP automatic reconnection.
- 1: enable Bluetooth LE SPP automatic reconnection

Notes¶

In Bluetooth LE client, the property of tx characteristic must be write with response or write without response, and the property of rx characteristic must be indicate or notify.
In Bluetooth LE server, the property of tx characteristic must be indicate or notify, and the property of rx characteristic must be write with response or write without response.
If the automatic reconnection function is disabled, when the connection is disconnected, a disconnection message is displayed (depending on AT+SYSMSG), you need to send the connection command again; If this function is enabled, the connection will be automatically reconnected after disconnection, and the MCU side will not be aware of the disconnection. If the MAC of the peer end changes, the connection will fail.

Example¶

AT+BLESPPCFG=0          // reset Bluetooth LE SPP parameters
AT+BLESPPCFG=1,3,5,3,7  // set Bluetooth LE SPP parameters
AT+BLESPPCFG?           // query Bluetooth LE SPP parameters

AT+BLESPP: Enter Bluetooth LE SPP Mode¶

Execute Command¶

Function:

Enter Bluetooth LE SPP mode.

Command:

AT+BLESPP

Response:

OK

>

This response indicates that AT has entered Bluetooth LE SPP mode and can send and receive data.

If the Bluetooth LE SPP status is wrong ( Notifications are not enabled at the opposite end after the Bluetooth LE connection is established ), the system returns:

ERROR

Notes¶

During the SPP transmission, AT will not prompt any exit the Bluetooth LE SPP passthrough mode information unless Bit0 of AT+SYSMSG is 1.
During the SPP transmission, AT will not prompt any connection status changes unless Bit2 of AT+SYSMSG is 1.
When the packet which only contains +++ is received, the device returns to normal command mode. Please wait for at least one second before sending the next AT command.

Example¶

AT+BLESPP   // enter Bluetooth LE SPP mode

AT+BLESECPARAM: Query/Set Bluetooth LE Encryption Parameters¶

Query Command¶

Function:

Query the parameters of Bluetooth LE SMP.

Command:

AT+BLESECPARAM?

Response:

+BLESECPARAM:<auth_req>,<iocap>,<enc_key_size>,<init_key>,<rsp_key>,<auth_option>
OK

Set Command¶

Function:

Set the parameters of Bluetooth LE SMP.

Command:

AT+BLESECPARAM=<auth_req>,<iocap>,<enc_key_size>,<init_key>,<rsp_key>[,<auth_option>]

Response:

OK

Parameters¶

<auth_req>: authentication request.
- 0: NO_BOND
- 1: BOND
- 4: MITM
- 8: SC_ONLY
- 9: SC_BOND
- 12: SC_MITM
- 13: SC_MITM_BOND
<iocap>: input and output capability.
- 0: DisplayOnly
- 1: DisplayYesNo
- 2: KeyboardOnly
- 3: NoInputNoOutput
- 4: Keyboard display
<enc_key_size>: encryption key size. Range: [7,16]. Unit: byte.
<init_key>: initial key represented in bit combinations.
<rsp_key>: response key represented in bit combinations.
<auth_option>: authentication option of security.
- 0: Select the security level automatically.
- 1: If it cannot follow the preset security level, the connection will disconnect.

Note¶

The bit pattern for parameters <init_key> and <rsp_key> is:
- Bit0: Used to exchange the encryption key in the init key & response key.
- Bit1: Used to exchange the IRK key in the init key & response key.
- Bit2: Used to exchange the CSRK key in the init key & response key.
- Bit3: Used to exchange the link key (only used in the Bluetooth LE & BR/EDR coexist mode) in the init key & response key.

Example¶

AT+BLESECPARAM=1,4,16,3,3,0

AT+BLEENC: Initiate Bluetooth LE Encryption Request¶

Set Command¶

Function:

Start a pairing request

Command:

AT+BLEENC=<conn_index>,<sec_act>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<sec_act>:
- 0: SEC_NONE
- 1: SEC_ENCRYPT
- 2: SEC_ENCRYPT_NO_MITM
- 3: SEC_ENCRYPT_MITM

Note¶

Before running this command, please set the security parameters and connection with remote devices.

Example¶

AT+RESTORE
AT+BLEINIT=2
AT+BLEGATTSSRVCRE
AT+BLEGATTSSRVSTART
AT+BLEADDR?
AT+BLESECPARAM=1,0,16,3,3
AT+BLESETKEY=123456
AT+BLEADVSTART
// Use your Bluetooth LE debugging app as a client to establish a Bluetooth LE connection with the ESP device
AT+BLEENC=0,3

AT+BLEENCRSP: Respond to the Pairing Request from the Peer Device¶

Set Command¶

Function:

Respond to the pairing request from the peer device.

Command:

AT+BLEENCRSP=<conn_index>,<accept>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<accept>:
- 0: reject
- 1: accept

Note¶

After running this command, AT will output the pairing result at the end of the pairing process.

+BLEAUTHCMPL:<conn_index>,<enc_result>

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<enc_result>:
- 0: encryption succeeded
- 1: encryption failed

Example¶

AT+BLEENCRSP=0,1

AT+BLEKEYREPLY: Reply the Key Value to the Peer Device¶

Set Command¶

Function:

Reply a pairing key.

Command:

AT+BLEKEYREPLY=<conn_index>,<key>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<key>: pairing key.

Example¶

AT+BLEKEYREPLY=0,649784

AT+BLECONFREPLY: Reply the Confirm Value to the Peer Device in the Legacy Connection Stage¶

Set Command¶

Function:

Reply a pairing result.

Command:

AT+BLECONFREPLY=<conn_index>,<confirm>

Response:

OK

Parameters¶

<conn_index>: index of Bluetooth LE connection. Range: [0,2].
<confirm>:
- 0: No
- 1: Yes

Example¶

AT+BLECONFREPLY=0,1

AT+BLEENCDEV: Query Bonded Bluetooth LE Encryption Device List¶

Query Command¶

Function:

Query bonded Bluetooth LE encryption device list.

Command:

AT+BLEENCDEV?

Response:

+BLEENCDEV:<enc_dev_index>,<mac_address>
OK

Parameters¶

<enc_dev_index>: index of the bonded devices. This parameter is not necessarily equal to the conn_index parameter in the Bluetooth LE connection list queried by the command AT+BLECONN. Range: [0,14].
<mac_address>: MAC address.

Note¶

ESP-AT allows a maximum of 15 devices to be bonded. If the number of bonded devices exceeds 15, the newly bonded device information will sequentially (from 0 to 14) overwrite the previous device information according to the binding order.

Example¶

AT+BLEENCDEV?

AT+BLEENCCLEAR: Clear Bluetooth LE Encryption Device List¶

Set Command¶

Function:

Remove a device from the security database list with a specific index.

Command:

AT+BLEENCCLEAR=<enc_dev_index>

Response:

OK

Execute Command¶

Function:

Remove all devices from the security database.

Command:

AT+BLEENCCLEAR

Response:

OK

Parameter¶

<enc_dev_index>: index of the bonded devices.

Example¶

AT+BLEENCCLEAR

AT+BLESETKEY: Set Bluetooth LE Static Pair Key¶

Query Command¶

Function:

Query the Bluetooth LE static pair key. If it is not set, AT will return -1.

Command:

AT+BLESETKEY?

Response:

+BLESETKEY:<static_key>
OK

Set Command¶

Function:

Set a Bluetooth LE static pair key for all Bluetooth LE connections.

Command:

AT+BLESETKEY=<static_key>

Response:

OK

Parameter¶

<static_key>: static Bluetooth LE pair key.

Example¶

AT+BLESETKEY=123456

AT+BLEHIDINIT: Bluetooth LE HID Profile Initialization¶

Query Command¶

Function:

Query the initialization status of Bluetooth LE HID profile.

Command:

AT+BLEHIDINIT?

Response:

If Bluetooth LE HID device profile is not initialized, AT will return:

+BLEHIDINIT:0
OK

If Bluetooth LE HID device profile is initialized, AT will return:

+BLEHIDINIT:1
OK

Set Command¶

Function:

Initialize the Bluetooth LE HID profile.

Command:

AT+BLEHIDINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinit Bluetooth LE HID profile
- 1: init Bluetooth LE HID profile

Note¶

The Bluetooth LE HID command cannot be used at the same time with general GATT/GAP commands.

Example¶

AT+BLEHIDINIT=1

AT+BLEHIDKB: Send Bluetooth LE HID Keyboard Information¶

Set Command¶

Function:

Send keyboard information.

Command:

AT+BLEHIDKB=<Modifier_keys>,<key_1>,<key_2>,<key_3>,<key_4>,<key_5>,<key_6>

Response:

OK

Parameters¶

<Modifier_keys>: modifier keys mask
<key_1>: key code 1
<key_2>: key code 2
<key_3>: key code 3
<key_4>: key code 4
<key_5>: key code 5
<key_6>: key code 6

Note¶

For more information about key codes, please refer to the chapter Keyboard/Keypad Page of Universal Serial Bus HID Usage Tables.
To use this command to interact with iOS products, your devices need to pass MFI certification first.

Example¶

AT+BLEHIDKB=0,4,0,0,0,0,0   // input the string "a"

AT+BLEHIDMUS: Send Bluetooth LE HID Mouse Information¶

Set Command¶

Function:

Send mouse information.

Command:

AT+BLEHIDMUS=<buttons>,<X_displacement>,<Y_displacement>,<wheel>

Response:

OK

Parameters¶

<buttons>: mouse button
<X_displacement>: X displacement
<Y_displacement>: Y displacement
<wheel>: wheel

Note¶

For more information about HID mouse, please refer to the section Generic Desktop Page, and Application Usages of Universal Serial Bus HID Usage Tables.
To use this command to interact with iOS products, your devices need to pass MFI certification first.

Example¶

AT+BLEHIDMUS=0,10,10,0

AT+BLEHIDCONSUMER: Send Bluetooth LE HID Consumer Information¶

Set Command¶

Function:

Send consumer information.

Command:

AT+BLEHIDCONSUMER=<consumer_usage_id>

Response:

OK

Parameter¶

<consumer_usage_id>: consumer ID, such as power, reset, help, volume and so on. See chapter Consumer Page (0x0C) of HID Usage Tables for Universal Serial Bus (USB) for more information.

Note¶

To use this command to interact with iOS products, your devices need to pass MFI certification first.

Example¶

AT+BLEHIDCONSUMER=233   // volume up

AT+BLUFI: Start or Stop BluFi¶

Query Command¶

Function:

Query the status of BluFi.

Command:

AT+BLUFI?

Response:

If BluFi is not started, it will return:

+BLUFI:0

OK

If BluFi is started, it will return:

+BLUFI:1

OK

Set Command¶

Function:

Start or stop BluFi.

Command:

AT+BLUFI=<option>[,<auth floor>]

Response:

OK

Parameter¶

<option>:
- 0: stop BluFi
- 1: start BluFi
<auth floor>: Wi-Fi authentication mode floor. ESP-AT will not connect to the AP whose authmode is lower than this floor.
- 0: OPEN (Default)
- 1: WEP
- 2: WPA_PSK
- 3: WPA2_PSK
- 4: WPA_WPA2_PSK
- 5: WPA2_ENTERPRISE
- 6: WPA3_PSK
- 7: WPA2_WPA3_PSK

Note¶

You can only start or stop BluFi when Bluetooth LE is not initialized (AT+BLEINIT=0).

Example¶

AT+BLUFI=1

AT+BLUFINAME: Query/Set BluFi Device Name¶

Query Command¶

Function:

Query the BluFi name.

Command:

AT+BLUFINAME?

Response:

+BLUFINAME:<device_name>
OK

Set Command¶

Function:

Set the BluFi device name.

Command:

AT+BLUFINAME=<device_name>

Response:

OK

Parameter¶

<device_name>: the name of BluFi device.

Notes¶

If you need to set BluFi name, please set it before command AT+BLUFI=1. Otherwise, it will use the default name BLUFI_DEVICE.
The maximum length of BluFi name is 29 bytes.

Example¶

AT+BLUFINAME="BLUFI_DEV"
AT+BLUFINAME?

[ESP32 Only] Classic Bluetooth® AT Commands¶

[中文]

ESP32 AT firmware supports Bluetooth® Core Specification Version 4.2.

[ESP32 Only] AT+BTINIT: Classic Bluetooth initialization.
[ESP32 Only] AT+BTNAME: Query/Set Classic Bluetooth device name.
[ESP32 Only] AT+BTSCANMODE: Set Classic Bluetooth scan mode.
[ESP32 Only] AT+BTSTARTDISC: Start Classic Bluetooth discovery.
[ESP32 Only] AT+BTSPPINIT: Classic Bluetooth SPP profile initialization.
[ESP32 Only] AT+BTSPPCONN: Query/Establish SPP connection.
[ESP32 Only] AT+BTSPPDISCONN: End SPP connection.
[ESP32 Only] AT+BTSPPSTART: Start Classic Bluetooth SPP profile.
[ESP32 Only] AT+BTSPPSEND: Send data to remote Classic Bluetooth SPP device.
[ESP32 Only] AT+BTA2DPINIT: Classic Bluetooth A2DP profile initialization.
[ESP32 Only] AT+BTA2DPCONN: Establish A2DP connection.
[ESP32 Only] AT+BTA2DPDISCONN: End A2DP connection.
[ESP32 Only] AT+BTA2DPSRC: Query/Set the audio file URL.
[ESP32 Only] AT+BTA2DPCTRL: Control the audio play.
[ESP32 Only] AT+BTSECPARAM: Query/Set the Classic Bluetooth security parameters.
[ESP32 Only] AT+BTKEYREPLY: Input the Simple Pair Key.
[ESP32 Only] AT+BTPINREPLY: Input the Legacy Pair PIN Code.
[ESP32 Only] AT+BTSECCFM: Reply the confirm value to the peer device in the legacy connection stage.
[ESP32 Only] AT+BTENCDEV: Query Classic Bluetooth encryption device list.
[ESP32 Only] AT+BTENCCLEAR: Clear Classic Bluetooth encryption device list.
[ESP32 Only] AT+BTCOD: Set class of devices.
[ESP32 Only] AT+BTPOWER: Query/Set power of Classic Bluetooth.

[ESP32 Only] AT+BTINIT: Classic Bluetooth Initialization¶

Query Command¶

Function:

Query the initialization status of Classic Bluetooth.

Command:

AT+BTINIT?

Response:

If Classic Bluetooth is initialized, AT will return:

+BTINIT:1
OK

If Classic Bluetooth is not initialized, AT will return:

+BTINIT:0
OK

Set Command¶

Function:

Initialize or deinitialize Classic Bluetooth.

Command:

AT+BTINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinitialize Classic Bluetooth.
- 1: initialize Classic Bluetooth.

Example¶

AT+BTINIT=1

[ESP32 Only] AT+BTNAME: Query/Set Classic Bluetooth Device Name¶

Query Command¶

Function:

Query the Classic Bluetooth device name.

Command:

AT+BTNAME?

Response:

+BTNAME:<device_name>
OK

Set Command¶

Function:

Set the Classic Bluetooth device name.

Command:

AT+BTNAME=<device_name>

Response:

OK

Parameter¶

<device_name>: the Classic Bluetooth device name. The maximum length is 32.

Notes¶

The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
The default Classic Bluetooth device name is “ESP32_AT”.

Example¶

AT+BTNAME="esp_demo"

[ESP32 Only] AT+BTSCANMODE: Set Classic Bluetooth Scan Mode¶

Set Command¶

Function:

Set the scan mode of Classic Bluetooth.

Command:

AT+BTSCANMODE=<scan_mode>

Response:

OK

Parameter¶

<scan_mode>:
- 0: Neither discoverable nor connectable.
- 1: Connectable but not discoverable.
- 2: Both discoverable and connectable.
- 3: Discoverable but not connectable.

Example¶

AT+BTSCANMODE=2   // both discoverable and connectable

[ESP32 Only] AT+BTSTARTDISC: Start Classic Bluetooth Discovery¶

Set Command¶

Function:

Start Classic Bluetooth discovery.

Command:

AT+BTSTARTDISC=<inq_mode>,<inq_len>,<inq_num_rsps>

Response:

+BTSTARTDISC:<bt_addr>,<dev_name>,<major_dev_class>,<minor_dev_class>,<major_srv_class>,<rssi>

OK

Parameters¶

<inq_mode>:
- 0: general inquiry mode.
- 1: limited inquiry mode.
<inq_len>: inquiry duration. Range: 0x01 ~ 0x30.
<inq_num_rsps>: number of inquiry responses that can be received. If you set it to 0, AT will receive an unlimited number of responses.
<bt_addr>: Classic Bluetooth address.
<dev_name>: device name.
<major_dev_class>:
- 0x0: miscellaneous.
- 0x1: computer.
- 0x2: phone (cellular, cordless, pay phone, modem).
- 0x3: LAN, Network Access Point.
- 0x4: audio/video (headset, speaker, stereo, video display, VCR).
- 0x5: peripheral (mouse, joystick, keyboard).
- 0x6: imaging (printer, scanner, camera, display).
- 0x7: wearable.
- 0x8: toy.
- 0x9: health.
- 0x1F: uncategorized device.
<minor_dev_class>: please refer to Minor Device Class field.
<major_srv_class>:
- 0x0: an invalid value.
- 0x1: Limited Discoverable Mode.
- 0x8: positioning (location identification).
- 0x10: networking, such as LAN, Ad hoc.
- 0x20: rendering, such as printing, speakers.
- 0x40: capturing, such as scanner, microphone.
- 0x80: object transfer, such as v-Inbox, v-Folder.
- 0x100: audio, such as speaker, microphone, headerset service.
- 0x200: telephony, such as cordless telephony, modem, headset service.
- 0x400: information, such as WEB-server, WAP-server.
<rssi>: signal strength.

Example¶

AT+BTINIT=1
AT+BTSCANMODE=2
AT+BTSTARTDISC=0,10,10

[ESP32 Only] AT+BTSPPINIT: Classic Bluetooth SPP Profile Initialization¶

Query Command¶

Function:

Query the initialization status of Classic Bluetooth SPP profile.

Command:

AT+BTSPPINIT?

Response:

If Classic Bluetooth SPP profile is initialized, it will return:

+BTSPPINIT:1
OK

If Classic Bluetooth SPP profile is not initialized, it will return:

+BTSPPINIT:0
OK

Set Command¶

Function:

Initialize or deinitialize Classic Bluetooth SPP profile.

Command:

AT+BTSPPINIT=<init>

Response:

OK

Parameter¶

<init>:
- 0: deinitialize Classic Bluetooth SPP profile.
- 1: initialize Classic Bluetooth SPP profile, the role is master.
- 2: initialize Classic Bluetooth SPP profile, the role is slave.

Example¶

AT+BTSPPINIT=1    // master
AT+BTSPPINIT=2    // slave

[ESP32 Only] AT+BTSPPCONN: Query/Establish SPP Connection¶

Query Command¶

Function:

Query Classic Bluetooth SPP connection.

Command:

AT+BTSPPCONN?

Response:

+BTSPPCONN:<conn_index>,<remote_address>
OK

If the connection has not been established, AT will return:

+BTSPPCONN:-1

Set Command¶

Function:

Establish the Classic Bluetooth SPP connection.

Command:

AT+BTSPPCONN=<conn_index>,<sec_mode>,<remote_address>

Response:

OK

If the connection is established successfully, AT will return:

+BTSPPCONN:<conn_index>,<remote_address>

Otherwise, AT will return:

+BTSPPCONN:<conn_index>,-1

Parameters¶

<conn_index>: index of Classic Bluetooth SPP connection. Only 0 is supported for the single connection right now.
<sec_mode>:
- 0x0000: no security.
- 0x0001: authorization required (only needed for out going connection).
- 0x0036: encryption required.
- 0x3000: Man-In-The-Middle protection.
- 0x4000: Min 16 digit for pin code.
<remote_address>: remote Classic Bluetooth SPP device address.

Example¶

AT+BTSPPCONN=0,0,"24:0a:c4:09:34:23"

[ESP32 Only] AT+BTSPPDISCONN: End SPP Connection¶

Execute Command¶

Function:

End the Classic Bluetooth SPP connection.

Command:

AT+BTSPPDISCONN=<conn_index>

Response:

OK

If the command is successful, it will prompt:

+BTSPPDISCONN:<conn_index>,<remote_address>

If the command is fail, it will prompt:

+BTSPPDISCONN:-1

Parameters¶

<conn_index>: index of Classic Bluetooth SPP connection. Only 0 is supported for the single connection right now.
<remote_address>: remote Classic Bluetooth A2DP device address.

Example¶

AT+BTSPPDISCONN=0

[ESP32 Only] AT+BTSPPSEND: Send Data to Remote Classic Bluetooth SPP Device¶

Execute Command¶

Function:

Enter Classic Bluetooth SPP mode.

Command:

AT+BTSPPSEND

Response:

Set Command¶

Function:

Send data to the remote Classic Bluetooth SPP device.

Command:

AT+BTSPPSEND=<conn_index>,<data_len>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth SPP connection. Only 0 is supported for the single connection right now.
<data_len>: the length of the data which is ready to be sent.

Notes¶

The wrap return is > after this command is executed. Then, the ESP device enters UART Bluetooth passthrough mode. When the packet which only contains +++ is received, the device returns to normal command mode. Please wait for at least one second before sending the next AT command.

Example¶

AT+BTSPPSEND=0,100
AT+BTSPPSEND

[ESP32 Only] AT+BTSPPSTART: Start Classic Bluetooth SPP Profile¶

Execute Command¶

Function:

Start Classic Bluetooth SPP profile.

Command:

AT+BTSPPSTART

Response:

OK

Note¶

During the SPP transmission, AT will not prompt any connection status changes unless bit2 of AT+SYSMSG is 1.

Example¶

AT+BTSPPSTART

[ESP32 Only] AT+BTA2DPINIT: Classic Bluetooth A2DP Profile Initialization¶

Query Command¶

Function:

Query the initialization status of Classic Bluetooth A2DP profile.

Command:

AT+BTA2DPINIT?

Response:

If Classic Bluetooth A2DP profile is initialized, AT will return:

+BTA2DPINIT:<role>

OK

Otherwise, AT will return:

+BTA2DPINIT:0

OK

Set Command¶

Function:

Initialize or deinitialize Classic Bluetooth A2DP profile.

Command:

AT+BTA2DPINIT=<role>

Response:

OK

Parameters¶

<role>: role
- 0: deinitialize Classic Bluetooth A2DP profile.
- 1: source.
- 2: sink.

Example¶

AT+BTA2DPINIT=2

[ESP32 Only] AT+BTA2DPCONN: Query/Establish A2DP Connection¶

Query Command¶

Function:

Query Classic Bluetooth A2DP connection.

Command:

AT+BTA2DPCONN?

Response:

+BTA2DPCONN:<conn_index>,<remote_address>
OK

If the connection has not been established, AT will NOT return the parameter <conn_index> and <remote_address>.

Set Command¶

Function:

Establish the Classic Bluetooth A2DP connection.

Command:

AT+BTA2DPCONN=<conn_index>,<remote_address>

Response:

OK

If the connection is established successfully, it will prompt the message below:

+BTA2DPCONN:<conn_index>,<remote_address>

Otherwise, it will return:

+BTA2DPCONN:<conn_index>,-1

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<remote_address>: remote Classic Bluetooth A2DP device address.

Example¶

AT+BTA2DPCONN=0,0,0,"24:0a:c4:09:34:23"

[ESP32 Only] AT+BTA2DPDISCONN: End A2DP Connection¶

Execute Command¶

Function:

End the Classic Bluetooth A2DP connection.

Command:

AT+BTA2DPDISCONN=<conn_index>

Response:

+BTA2DPDISCONN:<conn_index>,<remote_address>
OK

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<remote_address>: remote Classic Bluetooth A2DP device address.

Example¶

AT+BTA2DPDISCONN=0

[ESP32 Only] AT+BTA2DPSRC: Query/Set the Audio File URL¶

Query Command¶

Function:

Query the audio file URL.

Command:

AT+BTA2DPSRC?

Response:

+BTA2DPSRC:<url>,<type>
OK

Execute Command¶

Function:

Set the audio file URL.

Command:

AT+BTA2DPSRC=<conn_index>,<url>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<url>: the path of the source file. HTTP, HTTPS and FLASH are currently supported.
<type>: the type of audio file, such as “mp3”.

Note¶

Only mp3 format is currently supported.

Example¶

AT+BTA2DPSRC=0,"https://dl.espressif.com/dl/audio/ff-16b-2c-44100hz.mp3"
AT+BTA2DPSRC=0,"flash://spiffs/zhifubao.mp3"

[ESP32 Only] AT+BTA2DPCTRL: Control the Audio Play¶

Execute Command¶

Function:

Control the audio play.

Command:

AT+BTA2DPCTRL=<conn_index>,<ctrl>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth A2DP connection. Only 0 is supported for the single connection right now.
<ctrl>: types of control.
- 0: A2DP Sink, stop play.
- 1: A2DP Sink, start play.
- 2: A2DP Sink, forward.
- 3: A2DP Sink, backward.
- 4: A2DP Sink, fastward start.
- 5: A2DP Sink, fastward stop.
- 0: A2DP Source, stop play.
- 1: A2DP Source, start play.
- 2: A2DP Source, suspend.

Example¶

AT+BTA2DPCTRL=0,1  // start play audio

[ESP32 Only] AT+BTSECPARAM: Query/Set the Classic Bluetooth Security Parameters¶

Query Command¶

Function:

Query Classic Bluetooth security parameters.

Command:

AT+BTSECPARAM?

Response:

+BTSECPARAM:<io_cap>,<pin_type>,<pin_code>
OK

Set Command¶

Function:

Set the Classic Bluetooth security parameters.

Command:

AT+BTSECPARAM=<io_cap>,<pin_type>,<pin_code>

Response:

OK

Parameters¶

<io_cap>: input and output capability.
- 0: DisplayOnly.
- 1: DisplayYesNo.
- 2: KeyboardOnly.
- 3: NoInputNoOutput.
<pin_type>: use variable or fixed PIN.
- 0: variable.
- 1: fixed.
<pin_code>: Legacy Pair PIN Code. Maximum: 16 bytes.

Note¶

If you set the parameter <pin_type> to 0, <pin_code> will be ignored.

Example¶

AT+BTSECPARAM=3,1,"9527"

[ESP32 Only] AT+BTKEYREPLY: Input the Simple Pair Key¶

Execute Command¶

Function:

Input the Simple Pair Key.

Command:

AT+BTKEYREPLY=<conn_index>,<Key>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth connection. Currently, only 0 is supported for the single connection.
<Key>: the Simple Pair Key.

Example¶

AT+BTKEYREPLY=0,123456

[ESP32 Only] AT+BTPINREPLY: Input the Legacy Pair PIN Code¶

Execute Command¶

Function:

Input the Legacy Pair PIN Code.

Command:

AT+BTPINREPLY=<conn_index>,<Pin>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth connection. Currently, only 0 is supported for the single connection.
<Pin>: the Legacy Pair PIN Code.

Example¶

AT+BTPINREPLY=0,"6688"

[ESP32 Only] AT+BTSECCFM: Reply the Confirm Value to the Peer Device in the Legacy Connection Stage¶

Execute Command¶

Function:

Reply the confirm value to the peer device in the legacy connection stage.

Command:

AT+BTSECCFM=<conn_index>,<accept>

Response:

OK

Parameters¶

<conn_index>: index of Classic Bluetooth connection. Currently, only 0 is supported for the single connection.
<accept>: reject or accept.
- 0: reject.
- 1: accept.

Example¶

AT+BTSECCFM=0,1

[ESP32 Only] AT+BTENCDEV: Query Classic Bluetooth Encryption Device List¶

Query Command¶

Function:

Query the bound devices.

Command:

AT+BTENCDEV?

Response:

+BTENCDEV:<enc_dev_index>,<mac_address>
OK

Parameters¶

<enc_dev_index>: index of the bound devices.
<mac_address>: MAC address.

Example¶

AT+BTENCDEV?

[ESP32 Only] AT+BTENCCLEAR: Clear Classic Bluetooth Encryption Device List¶

Set Command¶

Function:

Remove a device from the security database list with a specific index.

Command:

AT+BTENCCLEAR=<enc_dev_index>

Response:

OK

Execute Command¶

Function:

Remove all devices from the security database.

Command:

AT+BLEENCCLEAR

Response:

OK

Parameter¶

<enc_dev_index>: index of the bound devices.

Example¶

AT+BTENCCLEAR

[ESP32 Only] AT+BTCOD: Set Class of Devices¶

Set Command¶

Function:

Set the Classic Bluetooth class of devices.

Command:

AT+BTCOD=<major>,<minor>,<service>

Response:

OK

Parameters¶

<major>: major class.
<minor>: minor class.
<service>: service class.

Example¶

AT+BTCOD=6,32,32   // the printer

[ESP32 Only] AT+BTPOWER: Query/Set TX power of Classic Bluetooth¶

Query Command¶

Function:

Query Classic Bluetooth tx power level.

Command:

AT+BTPOWER?

Response:

+BTPOWER:<min_tx_power>,<max_tx_power>
OK

Set Command¶

Function:

Set the Classic Bluetooth tx power.

Command:

AT+BTPOWER=<min_tx_power>,<max_tx_power>

Response:

OK

Parameters¶

<min_tx_power>: The minimum power level. Range: [0,7].
<max_tx_power>: The maximum power level. Range: [0,7].

Example¶

AT+BTPOWER=5,6   // set Classic Bluetooth tx power.

MQTT AT Commands¶

[中文]

AT+MQTTUSERCFG: Set MQTT user configuration
AT+MQTTCLIENTID: Set MQTT client ID
AT+MQTTUSERNAME: Set MQTT username
AT+MQTTPASSWORD: Set MQTT password
AT+MQTTCONNCFG: Set configuration of MQTT connection
AT+MQTTALPN: Set MQTT Application Layer Protocol Negotiation (ALPN)
AT+MQTTCONN: Connect to MQTT Brokers
AT+MQTTPUB: Publish MQTT Messages in string
AT+MQTTPUBRAW: Publish MQTT messages in binary
AT+MQTTSUB: Subscribe to MQTT topics
AT+MQTTUNSUB: Unsubscribe from MQTT topics
AT+MQTTCLEAN: Close MQTT connections
MQTT AT Error Codes
MQTT AT Notes

AT+MQTTUSERCFG: Set MQTT User Configuration¶

Set Command¶

Function:

Set MQTT User Configuration.

Command:

AT+MQTTUSERCFG=<LinkID>,<scheme>,<"client_id">,<"username">,<"password">,<cert_key_ID>,<CA_ID>,<"path">

Response:

OK

Parameters¶

<LinkID>: currently only supports link ID 0.
<scheme>:
- 1: MQTT over TCP.
- 2: MQTT over TLS (no certificate verify).
- 3: MQTT over TLS (verify server certificate).
- 4: MQTT over TLS (provide client certificate).
- 5: MQTT over TLS (verify server certificate and provide client certificate).
- 6: MQTT over WebSocket (based on TCP).
- 7: MQTT over WebSocket Secure (based on TLS, no certificate verify).
- 8: MQTT over WebSocket Secure (based on TLS, verify server certificate).
- 9: MQTT over WebSocket Secure (based on TLS, provide client certificate).
- 10: MQTT over WebSocket Secure (based on TLS, verify server certificate and provide client certificate).
<client_id>: MQTT client ID. Maximum length: 256 bytes.
<username>: the username to login to the MQTT broker. Maximum length: 64 bytes.
<password>: the password to login to the MQTT broker. Maximum length: 64 bytes.
<cert_key_ID>: certificate ID. Currently, ESP-AT only supports one certificate for ID 0.
<CA_ID>: CA ID. Currently, ESP-AT only supports one CA for ID 0.
<path>: the path of the resource. Maximum length: 32 bytes.

Note¶

The length of the entire AT command should be less than 256 bytes.

AT+MQTTCLIENTID: Set MQTT Client ID¶

Set Command¶

Function:

Set MQTT Client ID.

Command:

AT+MQTTCLIENTID=<LinkID>,<"client_id">

Response:

OK

Parameters¶

<LinkID>: currently only supports link ID 0.
<client_id>: MQTT client ID.

Notes¶

The length of the entire AT command should be less than 256 bytes.
The command AT+MQTTUSERCFG can also set MQTT client ID. The differences between the two commands include:
- You can use AT+MQTTCLIENTID to set a relatively long client ID since there is a limitation on the length of the AT+MQTTUSERCFG command.
- You should set AT+MQTTCLIENTID after setting the AT+MQTTUSERCFG command.

AT+MQTTUSERNAME: Set MQTT Username¶

Set Command¶

Function:

Set MQTT username.

Command:

AT+MQTTUSERNAME=<LinkID>,<"username">

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<username>: the username to login to the MQTT broker.

Notes¶

The length of the entire AT command should be less than 256 bytes.
The command AT+MQTTUSERCFG can also set MQTT username. The differences between the two commands include:
- You can use AT+MQTTUSERNAME to set a relatively long username since there is a limitation on the length of the AT+MQTTUSERCFG command.
- You should set AT+MQTTUSERNAME after setting the command AT+MQTTUSERCFG.

AT+MQTTPASSWORD: Set MQTT Password¶

Set Command¶

Function:

Set MQTT password.

Command:

AT+MQTTPASSWORD=<LinkID>,<"password">

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<password>: the password to login to the MQTT broker.

Notes¶

The length of the entire AT command should be less than 256 bytes.
The command AT+MQTTUSERCFG can also set MQTT password. The differences between the two commands include:
- You can use AT+MQTTPASSWORD to set a relatively long password since there is a limitation on the length of the AT+MQTTUSERCFG command.
- You should set AT+MQTTPASSWORD after setting the command AT+MQTTUSERCFG.

AT+MQTTCONNCFG: Set Configuration of MQTT Connection¶

Set Command¶

Function:

Set configuration of MQTT Connection.

Command:

AT+MQTTCONNCFG=<LinkID>,<keepalive>,<disable_clean_session>,<"lwt_topic">,<"lwt_msg">,<lwt_qos>,<lwt_retain>

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<keepalive>: timeout of MQTT ping. Unit: second. Range [0,7200]. The default value is 0, which will be force-changed to 120 s.
<disable_clean_session>: set MQTT clean session. For more details about this parameter, please refer to the section Clean Session in MQTT Version 3.1.1.
- 0: enable clean session.
- 1: disable clean session.
<lwt_topic>: LWT (Last Will and Testament) message topic. Maximum length: 128 bytes.
<lwt_msg>: LWT message. Maximum length: 64 bytes.
<lwt_qos>: LWT QoS, which can be set to 0, 1, or 2. Default: 0.
<lwt_retain>: LWT retain, which can be set to 0 or 1. Default: 0.

AT+MQTTALPN: Set MQTT Application Layer Protocol Negotiation (ALPN)¶

Set Command¶

Function:

Set MQTT Application Layer Protocol Negotiation (ALPN).

Command:

AT+MQTTALPN=<LinkID>,<alpn_counts>[,<"alpn">][,<"alpn">][,<"alpn">]

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<alpn_counts>: the number of <”alpn”> parameters. Range: [0,5].

0: clean the MQTT ALPN configuration.

[1,5]: set the MQTT ALPN configuration.

<”alpn”>: you can send more than one ALPN in ClientHello to the server.

Notes¶

The length of the entire AT command should be less than 256 bytes.
MQTT ALPN will only be effective if the MQTT connection is based on TLS or WSS.
You should set AT+MQTTALPN after setting the command AT+MQTTUSERCFG.

Example¶

AT+CWMODE=1
AT+CWJAP="ssid","password"
AT+CIPSNTPCFG=1,8,"ntp1.aliyun.com","ntp2.aliyun.com"
AT+MQTTUSERCFG=0,5,"ESP32","espressif","1234567890",0,0,""
AT+MQTTALPN=0,2,"mqtt-ca.cn","mqtt-ca.us"
AT+MQTTCONN=0,"192.168.200.2",8883,1

AT+MQTTCONN: Connect to MQTT Brokers¶

Query Command¶

Function:

Query the MQTT broker that ESP devices are connected to.

Command:

AT+MQTTCONN?

Response:

+MQTTCONN:<LinkID>,<state>,<scheme><"host">,<port>,<"path">,<reconnect>
OK

Set Command¶

Function:

Connect to an MQTT broker.

Command:

AT+MQTTCONN=<LinkID>,<"host">,<port>,<reconnect>

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<host>: MQTT broker domain. Maximum length: 128 bytes.
<port>: MQTT broker port. Maximum: port 65535.
<path>: path. Maximum length: 32 bytes.
<reconnect>:
- 0: MQTT will not reconnect automatically.
- 1: MQTT will reconnect automatically. It takes more resources.
<state>: MQTT state.
- 0: MQTT uninitialized.
- 1: already set AT+MQTTUSERCFG.
- 2: already set AT+MQTTCONNCFG.
- 3: connection disconnected.
- 4: connection established.
- 5: connected, but did not subscribe to any topic.
- 6: connected, and subscribed to MQTT topics.
<scheme>:
- 1: MQTT over TCP.
- 2: MQTT over TLS (no certificate verify).
- 3: MQTT over TLS (verify server certificate).
- 4: MQTT over TLS (provide client certificate).
- 5: MQTT over TLS (verify server certificate and provide client certificate).
- 6: MQTT over WebSocket (based on TCP).
- 7: MQTT over WebSocket Secure (based on TLS, verify no certificate).
- 8: MQTT over WebSocket Secure (based on TLS, verify server certificate).
- 9: MQTT over WebSocket Secure (based on TLS, provide client certificate).
- 10: MQTT over WebSocket Secure (based on TLS, verify server certificate and provide client certificate).

AT+MQTTPUB: Publish MQTT Messages in String¶

Set Command¶

Function:

Publish MQTT messages in string to a defined topic. If you need to publish messages in binary, please use the AT+MQTTPUBRAW command.

Command:

AT+MQTTPUB=<LinkID>,<"topic">,<"data">,<qos>,<retain>

Response:

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<topic>: MQTT topic. Maximum length: 128 bytes.
<data>: MQTT message in string.
<qos>: QoS of message, which can be set to 0, 1, or 2. Default: 0.
<retain>: retain flag.

Notes¶

The length of the entire AT command should be less than 256 bytes.
This command cannot send data \0. If you need to send \0, please use the command AT+MQTTPUBRAW instead.

Example¶

AT+CWMODE=1
AT+CWJAP="ssid","password"
AT+MQTTUSERCFG=0,1,"ESP32","espressif","1234567890",0,0,""
AT+MQTTCONN=0,"192.168.10.234",1883,0
AT+MQTTPUB=0,"topic","\"{\"timestamp\":\"20201121085253\"}\"",0,0

AT+MQTTPUBRAW: Publish MQTT Messages in Binary¶

Set Command¶

Function:

Publish MQTT messages in binary to a defined topic.

Command:

AT+MQTTPUBRAW=<LinkID>,<"topic">,<length>,<qos>,<retain>

Response:

OK
>

The symbol > indicates that AT is ready for receiving serial data, and you can enter the data now. When the requirement of message length determined by the parameter <length> is met, the transmission starts.

If the transmission is successful, AT returns:

+MQTTPUB:OK

Otherwise, it returns:

+MQTTPUB:FAIL

Parameters¶

<LinkID>: only supports link ID 0 currently.
<topic>: MQTT topic. Maximum length: 128 bytes.
<length>: length of MQTT message. The maximum length is limited by available memory.
<qos>: QoS of the published message, which can be set to 0, 1, or 2. Default is 0.
<retain>: retain flag.

AT+MQTTUNSUB: Unsubscribe from MQTT Topics¶

Set Command¶

Function:

Unsubscribe the client from defined topics. This command can be called multiple times to unsubscribe from different topics.

Command:

AT+MQTTUNSUB=<LinkID>,<"topic">

Response:

OK

If the topic has not been subscribed, AT will prompt:

NO UNSUBSCRIBE

OK

Parameters¶

<LinkID>: only supports link ID 0 currently.
<topic>: MQTT topic. Maximum length: 128 bytes.

AT+MQTTCLEAN: Close MQTT Connections¶

Set Command¶

Function:

Close the MQTT connection and release the resource.

Command:

AT+MQTTCLEAN=<LinkID>

Response:

OK

Parameter¶

<LinkID>: only supports link ID 0 currently.

MQTT AT Error Codes ¶

The MQTT Error code will be prompted as ERR CODE:0x<%08x>.

Error Type	Error Code
AT_MQTT_NO_CONFIGURED	0x6001
AT_MQTT_NOT_IN_CONFIGURED_STATE	0x6002
AT_MQTT_UNINITIATED_OR_ALREADY_CLEAN	0x6003
AT_MQTT_ALREADY_CONNECTED	0x6004
AT_MQTT_MALLOC_FAILED	0x6005
AT_MQTT_NULL_LINK	0x6006
AT_MQTT_NULL_PARAMTER	0x6007
AT_MQTT_PARAMETER_COUNTS_IS_WRONG	0x6008
AT_MQTT_TLS_CONFIG_ERROR	0x6009
AT_MQTT_PARAM_PREPARE_ERROR	0x600A
AT_MQTT_CLIENT_START_FAILED	0x600B
AT_MQTT_CLIENT_PUBLISH_FAILED	0x600C
AT_MQTT_CLIENT_SUBSCRIBE_FAILED	0x600D
AT_MQTT_CLIENT_UNSUBSCRIBE_FAILED	0x600E
AT_MQTT_CLIENT_DISCONNECT_FAILED	0x600F
AT_MQTT_LINK_ID_READ_FAILED	0x6010
AT_MQTT_LINK_ID_VALUE_IS_WRONG	0x6011
AT_MQTT_SCHEME_READ_FAILED	0x6012
AT_MQTT_SCHEME_VALUE_IS_WRONG	0x6013
AT_MQTT_CLIENT_ID_READ_FAILED	0x6014
AT_MQTT_CLIENT_ID_IS_NULL	0x6015
AT_MQTT_CLIENT_ID_IS_OVERLENGTH	0x6016
AT_MQTT_USERNAME_READ_FAILED	0x6017
AT_MQTT_USERNAME_IS_NULL	0x6018
AT_MQTT_USERNAME_IS_OVERLENGTH	0x6019
AT_MQTT_PASSWORD_READ_FAILED	0x601A
AT_MQTT_PASSWORD_IS_NULL	0x601B
AT_MQTT_PASSWORD_IS_OVERLENGTH	0x601C
AT_MQTT_CERT_KEY_ID_READ_FAILED	0x601D
AT_MQTT_CERT_KEY_ID_VALUE_IS_WRONG	0x601E
AT_MQTT_CA_ID_READ_FAILED	0x601F
AT_MQTT_CA_ID_VALUE_IS_WRONG	0x6020
AT_MQTT_CA_LENGTH_ERROR	0x6021
AT_MQTT_CA_READ_FAILED	0x6022
AT_MQTT_CERT_LENGTH_ERROR	0x6023
AT_MQTT_CERT_READ_FAILED	0x6024
AT_MQTT_KEY_LENGTH_ERROR	0x6025
AT_MQTT_KEY_READ_FAILED	0x6026
AT_MQTT_PATH_READ_FAILED	0x6027
AT_MQTT_PATH_IS_NULL	0x6028
AT_MQTT_PATH_IS_OVERLENGTH	0x6029
AT_MQTT_VERSION_READ_FAILED	0x602A
AT_MQTT_KEEPALIVE_READ_FAILED	0x602B
AT_MQTT_KEEPALIVE_IS_NULL	0x602C
AT_MQTT_KEEPALIVE_VALUE_IS_WRONG	0x602D
AT_MQTT_DISABLE_CLEAN_SESSION_READ_FAILED	0x602E
AT_MQTT_DISABLE_CLEAN_SESSION_VALUE_IS_WRONG	0x602F
AT_MQTT_LWT_TOPIC_READ_FAILED	0x6030
AT_MQTT_LWT_TOPIC_IS_NULL	0x6031
AT_MQTT_LWT_TOPIC_IS_OVERLENGTH	0x6032
AT_MQTT_LWT_MSG_READ_FAILED	0x6033
AT_MQTT_LWT_MSG_IS_NULL	0x6034
AT_MQTT_LWT_MSG_IS_OVERLENGTH	0x6035
AT_MQTT_LWT_QOS_READ_FAILED	0x6036
AT_MQTT_LWT_QOS_VALUE_IS_WRONG	0x6037
AT_MQTT_LWT_RETAIN_READ_FAILED	0x6038
AT_MQTT_LWT_RETAIN_VALUE_IS_WRONG	0x6039
AT_MQTT_HOST_READ_FAILED	0x603A
AT_MQTT_HOST_IS_NULL	0x603B
AT_MQTT_HOST_IS_OVERLENGTH	0x603C
AT_MQTT_PORT_READ_FAILED	0x603D
AT_MQTT_PORT_VALUE_IS_WRONG	0x603E
AT_MQTT_RECONNECT_READ_FAILED	0x603F
AT_MQTT_RECONNECT_VALUE_IS_WRONG	0x6040
AT_MQTT_TOPIC_READ_FAILED	0x6041
AT_MQTT_TOPIC_IS_NULL	0x6042
AT_MQTT_TOPIC_IS_OVERLENGTH	0x6043
AT_MQTT_DATA_READ_FAILED	0x6044
AT_MQTT_DATA_IS_NULL	0x6045
AT_MQTT_DATA_IS_OVERLENGTH	0x6046
AT_MQTT_QOS_READ_FAILED	0x6047
AT_MQTT_QOS_VALUE_IS_WRONG	0x6048
AT_MQTT_RETAIN_READ_FAILED	0x6049
AT_MQTT_RETAIN_VALUE_IS_WRONG	0x604A
AT_MQTT_PUBLISH_LENGTH_READ_FAILED	0x604B
AT_MQTT_PUBLISH_LENGTH_VALUE_IS_WRONG	0x604C
AT_MQTT_RECV_LENGTH_IS_WRONG	0x604D
AT_MQTT_CREATE_SEMA_FAILED	0x604E
AT_MQTT_CREATE_EVENT_GROUP_FAILED	0x604F
AT_MQTT_URI_PARSE_FAILED	0x6050
AT_MQTT_IN_DISCONNECTED_STATE	0x6051
AT_MQTT_HOSTNAME_VERIFY_FAILED	0x6052

MQTT AT Notes ¶

In general, AT MQTT commands responds within 10 s, except the command AT+MQTTCONN. For example, if the router fails to access the Internet, the command AT+MQTTPUB will respond within 10 s. But the command AT+MQTTCONN may need more time due to packet retransmission in a bad network environment.
If the AT+MQTTCONN is based on a TLS connection, the timeout of each packet is 10 s, and the total timeout will be much longer depending on the handshake packets count.
When the MQTT connection ends, it will prompt the message +MQTTDISCONNECTED:<LinkID>.
When the MQTT connection established, it will prompt the message +MQTTCONNECTED:<LinkID>,<scheme>,<"host">,port,<"path">,<reconnect>.

HTTP AT Commands¶

[中文]

AT+HTTPCLIENT: Send HTTP Client Request
AT+HTTPGETSIZE: Get HTTP Resource Size
AT+HTTPCGET: Get HTTP Resource
AT+HTTPCPOST: Post HTTP data of specified length
AT+HTTPURLCFG: Set/Get long HTTP URL
HTTP AT Error Codes

AT+HTTPCLIENT: Send HTTP Client Request¶

Set Command¶

Command:

AT+HTTPCLIENT=<opt>,<content-type>,<"url">,[<"host">],[<"path">],<transport_type>[,<"data">][,<"http_req_header">][,<"http_req_header">][...]

Response:

+HTTPCLIENT:<size>,<data>

OK

Parameters¶

<opt>: method of HTTP client request.
- 1: HEAD
- 2: GET
- 3: POST
- 4: PUT
- 5: DELETE
<content-type>: data type of HTTP client request.
- 0: application/x-www-form-urlencoded
- 1: application/json
- 2: multipart/form-data
- 3: text/xml
<”url”>: HTTP URL. The parameter can override the <host> and <path> parameters if they are null.
<”host”>: domain name or IP address.
<”path”>: HTTP Path.
<transport_type>: HTTP Client transport type. Default: 1.
- 1: HTTP_TRANSPORT_OVER_TCP
- 2: HTTP_TRANSPORT_OVER_SSL
<”data”>: If <opt> is a POST request, this parameter holds the data you send to the HTTP server. If not, this parameter does not exist, which means there is no need to input a comma to indicate this parameter.
<http_req_header>: you can send more than one request header to the server.

Notes¶

If the length of the entire command containing the URL exceeds 256 bytes, please use the AT+HTTPURLCFG command to preset the URL first, and then set the <”url”> parameter of this command to "".
If the url parameter is not null, HTTP client will use it and ignore the host parameter and path parameter; If the url parameter is omited or null string, HTTP client will use host parameter and path parameter.
In some released firmware, HTTP client commands are not supported (see ESP-AT Firmware Differences), but you can enable it by ./build.py menuconfig > Component config > AT > AT http command support and build the project (see Compile ESP-AT Project).

Example¶

// HEAD Request
AT+HTTPCLIENT=1,0,"http://httpbin.org/get","httpbin.org","/get",1

// GET Request
AT+HTTPCLIENT=2,0,"http://httpbin.org/get","httpbin.org","/get",1

// POST Request
AT+HTTPCLIENT=3,0,"http://httpbin.org/post","httpbin.org","/post",1,"field1=value1&field2=value2"

AT+HTTPGETSIZE: Get HTTP Resource Size¶

Set Command¶

Command:

AT+HTTPGETSIZE=<"url">

Response:

+HTTPGETSIZE:<size>

OK

Parameters¶

<”url”>: HTTP URL. It is a string parameter and should be enclosed with quotes.
<size>: HTTP resource size.

Note¶

If the length of the entire command containing the URL exceeds 256 bytes, please use the AT+HTTPURLCFG command to preset the URL first, and then set the <”url”> parameter of this command to "".
In some released firmware, HTTP client commands are not supported (see ESP-AT Firmware Differences), but you can enable it by ./build.py menuconfig > Component config > AT > AT http command support and build the project (see Compile ESP-AT Project).

Example¶

AT+HTTPGETSIZE="http://www.baidu.com/img/bdlogo.gif"

AT+HTTPCGET: Get HTTP Resource¶

Set Command¶

Command:

AT+HTTPCGET=<"url">[,<tx size>][,<rx size>][,<timeout>]

Response:

+HTTPCGET:<size>,<data>
OK

Parameters¶

<”url”>: HTTP URL. It is a string parameter and should be enclosed with quotes.
<tx size>: HTTP send buffer size. Unit: byte. Default: 2048. Range: [0,10240].
<rx size>: HTTP receive buffer size. Unit: byte. Default: 2048. Range: [0,10240].
<timeout>: Network timeout. Unit: millisecond. Default: 5000. Range: [0,180000].

Note¶

If the length of the entire command containing the URL exceeds 256 bytes, please use the AT+HTTPURLCFG command to preset the URL first, and then set the <”url”> parameter of this command to "".

AT+HTTPCPOST: Post HTTP data of specified length¶

Set Command¶

Command:

AT+HTTPCPOST=<"url">,<length>[,<http_req_header_cnt>][,<http_req_header>..<http_req_header>]

Response:

OK

>

The symbol > indicates that AT is ready for receiving serial data, and you can enter the data now. When the requirement of message length determined by the parameter <length> is met, the transmission starts.

If the transmission is successful, AT returns:

SEND OK

Otherwise, it returns:

SEND FAIL

Parameters¶

<”url”>: HTTP URL. It is a string parameter and should be enclosed with quotes.
<length>: HTTP data length to POST. The maximum length is equal to the system allocable heap size.
<http_req_header_cnt>: the number of <http_req_header> parameters.
[<http_req_header>]: you can send more than one request header to the server.

Note¶

If the length of the entire command containing the URL exceeds 256 bytes, please use the AT+HTTPURLCFG command to preset the URL first, and then set the <”url”> parameter of this command to "".

AT+HTTPURLCFG: Set/Get long HTTP URL¶

Query Command¶

Command:

AT+HTTPURLCFG?

Response:

[+HTTPURLCFG:<url length>,<data>]
OK

Set Command¶

Command:

AT+HTTPURLCFG=<url length>

Response:

OK

>

This response indicates that AT is ready for receiving serial data. You should enter the URL now, and when the URL length reaches the <url length> value, the system returns:

SET OK

Parameters¶

<url length>: HTTP URL length. Unit: byte.
- 0: clean the HTTP URL configuration.
- [8,8192]: set the HTTP URL configuration.
<data>: HTTP URL data.

HTTP AT Error Codes ¶

HTTP Client:

HTTP Client Error Code	Description
0x7000	Failed to Establish Connection
0x7190	Bad Request
0x7191	Unauthorized
0x7192	Payment Required
0x7193	Forbidden
0x7194	Not Found
0x7195	Method Not Allowed
0x7196	Not Acceptable
0x7197	Proxy Authentication Required
0x7198	Request Timeout
0x7199	Conflict
0x719a	Gone
0x719b	Length Required
0x719c	Precondition Failed
0x719d	Request Entity Too Large
0x719e	Request-URI Too Long
0x719f	Unsupported Media Type
0x71a0	Requested Range Not Satisfiable
0x71a1	Expectation Failed

HTTP Server:

HTTP Server Error Code	Description
0x71f4	Internal Server Error
0x71f5	Not Implemented
0x71f6	Bad Gateway
0x71f7	Service Unavailable
0x71f8	Gateway Timeout
0x71f9	HTTP Version Not Supported

HTTP AT:
- The error code of command AT+HTTPCLIENT will be 0x7000+Standard HTTP Error Code (For more details about Standard HTTP/1.1 Error Code, see RFC 2616).
- For example, if AT gets the HTTP error 404 when calling command AT+HTTPCLIENT, it will respond with error code of 0x7194 (hex(0x7000+404)=0x7194).

[ESP32 Only] Ethernet AT Commands¶

[中文]

Prerequisite
[ESP32 Only] AT+CIPETHMAC: Query/Set the MAC address of the ESP Ethernet.
[ESP32 Only] AT+CIPETH: Query/Set the IP address of the ESP Ethernet.

Prerequisite ¶

Before you run any Ethernet AT Commands, please make the following preparations:

Note

This prerequisite takes ESP32-Ethernet-Kit as an example. If you use other modules or development boards, please refer to corresponding datasheets for RX/TX pins.

Change AT UART pins (because default AT UART pins are in conflict with the Ethernet function pins):
- Open factory_param_data.csv file.
- In the row of module WROVER-32, change uart_tx_pin from GPIO22 to GPIO2, uart_rx_pin from GPIO19 to GPIO4, uart_cts_pin from GPIO15 to GPIO1, and uart_rts_pin from GPIO14 to GPIO1 (flow control is optional and is not used here). See How to Set AT Port Pins for more information.
Enable AT ethernet support. See How to Enable ESP-AT Ethernet for more information.
Compile and flash the project onto ESP32-Ethernet-Kit.
Connect your hardware:
- Connect Host MCU (PC with USB to serial converter) to GPIO2 (TX) and GPIO4 (RX) of ESP32-Ethernet-Kit when the flow control function is not enabled.
- Connect ESP32-Ethernet-Kit with Ethernet network.

[ESP32 Only] AT+CIPETHMAC: Query/Set the MAC Address of the ESP Ethernet¶

Query Command¶

Function:

Query the MAC address of the ESP Ethernet.

Command:

AT+CIPETHMAC?

Response:

+CIPETHMAC:<"mac">
OK

Set Command¶

Function:

Set the MAC address of the ESP Ethernet.

Command:

AT+CIPETHMAC=<"mac">

Response:

OK

Parameter¶

<”mac”>: string parameter showing the MAC address of the Ethernet interface.

Notes¶

The default firmware does not support Ethernet AT commands (see ESP-AT Firmware Differences), but you can enable it by ./build.py menuconfig > Component config > AT > AT ethernet support and compile the project (see Compile ESP-AT Project).
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
Please make sure the MAC address of Ethernet interface you set is different from those of other interfaces.
Bit0 of the ESP MAC address CANNOT be 1. For example, a MAC address can be “1a:…” but not “15:…”.
FF:FF:FF:FF:FF:FF and 00:00:00:00:00:00 are invalid MAC addresses and cannot be set.

Example¶

AT+CIPETHMAC="1a:fe:35:98:d4:7b"

[ESP32 Only] AT+CIPETH: Query/Set the IP Address of the the ESP Ethernet¶

Query Command¶

Function:

Query the IP address of the ESP Ethernet.

Command:

AT+CIPETH?

Response:

+CIPETH:ip:<ip>
+CIPETH:gateway:<gateway>
+CIPETH:netmask:<netmask>
OK

Set Command¶

Function:

Set the IP address of the ESP Ethernet.

Command:

AT+CIPETH=<ip>[,<gateway>,<netmask>]

Response:

OK

Parameters¶

<ip>: string parameter showing the IP address of the ESP Ethernet.
[<gateway>]: gateway.
[<netmask>]: netmask.

Notes¶

The default firmware does not support Ethernet AT commands (see ESP-AT Firmware Differences), but you can enable it by ./build.py menuconfig > Component config > AT > AT ethernet support and compile the project (see Compile ESP-AT Project).
The configuration changes will be saved in the NVS area if AT+SYSSTORE=1.
This Set Command correlates with DHCP commands, such as AT+CWDHCP:
- If static IP is enabled, DHCP will be disabled.
- If DHCP is enabled, static IP will be disabled.
- The last configuration overwrites the previous configuration.

Example¶

AT+CIPETH="192.168.6.100","192.168.6.1","255.255.255.0"

Signaling Test AT Commands¶

[中文]

AT+FACTPLCP: Send with long or short PLCP (Physical Layer Convergence Procedure)

AT+FACTPLCP: Send with Long or Short PLCP¶

Set Command¶

Command:

AT+FACTPLCP=<enable>,<tx_with_long>

Response:

OK

Parameters¶

<enable>: Enable or disable manual configuration.
- 0: Disable manual configuration. The default value for the parameter <tx_with_long> will be used.
- 1: Enable manual configuration. The type of PLCP that AT sends depends on <tx_with_long>.
<tx_with_long>: Send with long PLCP or short PLCP.
- 0: Send with short PLCP (default).
- 1: Send with long PLCP.

Web Server AT Commands¶

[中文]

AT+WEBSERVER: Enable/disable Wi-Fi connection configuration via Web server.

AT+WEBSERVER: Enable/disable Wi-Fi connection configuration via Web server¶

Set Command¶

Command:

AT+WEBSERVER=<enable>,<server_port>,<connection_timeout>

Response:

OK

Parameters¶

<enable>: Enable or disable Web server.
- 0: Disable the Web server and release related resources.
- 1: Enable Web server, which means that you can use WeChat or a browser to configure Wi-Fi connection information.
<server_port>: The Web server port number.
<connection_timeout>: The timeout for the every connection. Unit: second. Range:[21,60].

Notes¶

There are two ways to provide the HTML files needed by the Web server. One is to use FAT file system, and you need to enable AT FS command at this time. The other one is to use embedded files to store HTML files (default setting).
Please make sure that the maximum number of open sockets is not less than 12, you may change the number by ./build.py menuconfig > Component config > LWIP > Max bumber of open sockets and compile the project (see Compile ESP-AT Project).
The default firmware does not support Web server AT commands (see ESP-AT Firmware Differences), but you can enable it by ./build.py menuconfig > Component config > AT > AT WEB Server command support and compile the project (see Compile ESP-AT Project).
ESP-AT supports captive portals in ESP32 and ESP32-C series of devices. See example.
For more examples, please refer to Web Server AT Example.
The command implementation is open-source. See the source code in at/src/at_web_server_cmd.c.
Please refer to How to Implement OTA Upgrade for more OTA commands.

Example¶

// Enable the Web server with port 80, and the timeout for the every connection is 50 seconds
AT+WEBSERVER=1,80,50

// Disable the Web server
AT+WEBSERVER=0

Driver AT Commands¶

[中文]

AT+DRVADC: Read ADC channel value.
AT+DRVPWMINIT: Initialize PWM driver.
AT+DRVPWMDUTY: Set PWM duty.
AT+DRVPWMFADE: Set PWM fade.
AT+DRVI2CINIT: Initialize I2C master driver.
AT+DRVI2CRD: Read I2C data.
AT+DRVI2CWRDATA: Write I2C data.
AT+DRVI2CWRBYTES: Write no more than 4 bytes I2C data.
AT+DRVSPICONFGPIO: Configure SPI GPIO.
AT+DRVSPIINIT: Initialize SPI master driver.
AT+DRVSPIRD: Read SPI data.
AT+DRVSPIWR: Write SPI data.

AT+DRVADC: Read ADC Channel Value¶

Set Command¶

Command:

AT+DRVADC=<channel>,<atten>

Response:

+DRVADC:<raw data>

OK

Parameters¶

<channel>: ADC1 channel.
- For ESP32 devices, the range is [0,7].
  
  CHANNEL
  
  GPIO
  
  0
  
  GPIO36
  
  1
  
  GPIO37
  
  2
  
  GPIO38
  
  3
  
  GPIO39
  
  4
  
  GPIO32
  
  5
  
  GPIO33
  
  6
  
  GPIO34
  
  7
  
  GPIO35
- For ESP32-C3 devices, the range is [0,4].
  
  CHANNEL
  
  GPIO
  
  0
  
  GPIO0
  
  1
  
  GPIO1
  
  2
  
  GPIO2
  
  3
  
  GPIO3
  
  4
  
  GPIO4
<atten>: attenuation.
- For ESP32 devices:
  - 0: 0 dB attenuation, effective measurement range is [100, 950] mV.
  - 1: 2.5 dB attenuation, effective measurement range is [100, 1250] mV.
  - 2: 6 dB attenuation, effective measurement range is [150, 1750] mV.
  - 3: 11 dB attenuation, effective measurement range is [150, 2450] mV.
- For ESP32-C3 devices:
  - 0: 0 dB attenuation, effective measurement range is [0, 750] mV.
  - 1: 2.5 dB attenuation, effective measurement range is [0, 1050] mV.
  - 2: 6 dB attenuation, effective measurement range is [0, 1300] mV.
  - 3: 11 dB attenuation, effective measurement range is [0, 2500] mV.
<raw data>: ADC channel value.

Notes¶

ESP-AT only supports ADC1.
ESP32 and ESP32-C3 support 12-bit width.
For details on how to convert the channel value into voltage, please refer to ADC Conversion for ESP32 devices and ADC Conversion for ESP32-C3 devices.

Example¶

// For ESP32, 0 dB attenuation, effective measurement range is [100, 950] mV
// The returned 2048 means the voltage is 2048 / 4095 * 950 = 475.12 mV
AT+DRVADC=0,0
+DRVADC:2048

OK

// For ESP32-C3, 0 dB attenuation, effective measurement range is [0, 750] mV
// The returned 2048 means the voltage is 2048 / 4095 * 750 = 375.09 mV
AT+DRVADC=0,0
+DRVADC:2048

OK

AT+DRVPWMINIT: Initialize PWM Driver¶

Set Command¶

Command:

AT+DRVPWMINIT=<freq>,<duty_res>,<ch0_gpio>[,...,<ch3_gpio>]

Response:

OK

Parameters¶

<freq>: LEDC timer frequency. Unit: Hz. Range: 1 Hz ~ 8 MHz.
<duty_res>: LEDC channel duty resolution. Range: 0 ~ 20 bits.
<chx_gpio>: LEDC output GPIO number of channel x. For example, if you want to use GPIO16 as channel 0, set <ch0_gpio> to 16.

Notes¶

AT can support a maximum of 4 channels.
The number of channels that you initialize using this command will determine how many channels you can set using other PWM commands, including AT+DRVPWMDUTY and AT+DRVPWMFADE. For example, if you initialize two channels, you can only change the two channels’ PWM duty using command AT+DRVPWMDUTY.
The frequency and the duty resolution are interdependent. See Supported Range of Frequency and Duty Resolutions for more details.

Example¶

AT+DRVPWMINIT=5000,13,17,16,18,19  // set 4 channels; frequency: 5 kHz; duty resolution: 13 bits
AT+DRVPWMINIT=10000,10,17          // only use channel 0, frequency: 10 kHz; duty resolution: 10 bits; other PMW commands can only set one channel

AT+DRVPWMDUTY: Set PWM Duty¶

Set Command¶

Command:

AT+DRVPWMDUTY=<ch0_duty>[,...,<ch3_duty>]

Response:

OK

Parameter¶

<duty>: LEDC channel duty. Range: [0,2 ^{duty_resolution}].

Notes¶

AT can support a maximum of 4 channels.
If you do not want to set <duty> for a specific channel, just omit it.

Example¶

AT+DRVPWMDUTY=255,512   // set channel 0 to duty 255, set channel 1 to duty 512
AT+DRVPWMDUTY=,,0       // set channel 2 to duty 0

AT+DRVPWMFADE: Set PWM Fade¶

Set Command¶

Command:

AT+DRVPWMFADE=<ch0_target_duty>,<ch0_fade_time>[,...,<ch3_target_duty>,<ch3_fade_time>]

Response:

OK

Parameters¶

<target_duty>: target duty of fading. Range: [0, 2 ^{duty_resolution}–1].
<fade_time>: the maximum time of fading. Unit: millisecond.

Notes¶

AT can support a maximum of 4 channels.
If you do not want to set <target_duty> and <fade_time> for a specific channel, just omit them.

Example¶

AT+DRVPWMFADE=,,0,1000           // use one second to change channel 1 duty to 0
AT+DRVPWMFADE=1024,1000,0,2000,  // use one second time to change channel 0 duty to 1024, two seconds to change channel 1 duty to 0

AT+DRVI2CINIT: Initialize I2C Master Driver¶

Set Command¶

Command:

AT+DRVI2CINIT=<num>,<scl_io>,<sda_io>,<clock>

Response:

OK

Parameters¶

<num>: I2C port number. Range: 0 ~ 1. If the following parameters are not set, AT will deinitialize the I2C port.
<scl_io>: GPIO number for I2C SCL signal.
<sda_io>: GPIO number for I2C SDA signal.
<clock>: I2C clock frequency for master mode. Unit: Hz. Maximum: 1 MHz.

Note¶

This command only supports I2C masters.

Example¶

AT+DRVI2CINIT=0,25,26,1000  // initialize I2C0; GPIO25 is SCL; GPIO26 is SDA; I2C clock is 1 kHz
AT+DRVI2CINIT=0             // deinitialize I2C0

AT+DRVI2CRD: Read I2C Data¶

Set Command¶

Command:

AT+DRVI2CRD=<num>,<address>,<length>

Response:

+DRVI2CRD:<read data>
OK

Parameters¶

<num>: I2C port number. Range: 0 ~ 1.
<address>: I2C slave device address.
- 7-bit address: 0 ~ 0x7F.
- 10-bit address: The first seven bits of the first byte are the combination 1111 0XX of which the last two bits (XX) are the two Most Significant Bits (MSBs) of the 10-bit address. For example, if the 10-bit address is 0x2FF (b’1011111111), the input address should be 0x7AFF (b’111101011111111).
<length>: I2C data length. Range: 1 ~ 2048.
<read data>: I2C data.

Note¶

I2C transmission timeout is one second.

Example¶

AT+DRVI2CRD=0,0x34,1     // I2C0 reads one byte data from address 0x34
AT+DRVI2CRD=0,0x7AFF,1   // I2C0 reads one byte data from 10-bit address 0x2FF

// I2C0 reads address 0x34, register address 0x27, read 2 bytes
AT+DRVI2CWRBYTES=0,0x34,1,0x27     // I2C0 first writes device address 0x34, register address 0x27
AT+DRVI2CRD=0,0x34,2               // I2C0 reads 2 bytes

AT+DRVI2CWRDATA: Write I2C Data¶

Set Command¶

Command:

AT+DRVI2CWRDATA=<num>,<address>,<length>

Response:

OK
>

This response indicates that you should enter the data you want to write. When the requirement of data length is met, the data transmission starts.

If the data is transmitted successfully, AT returns:

OK

If the data transmission fails, AT returns:

ERROR

Parameters¶

<num>: I2C port number. Range: 0 ~ 1.
<address>: I2C slave device address.
- 7-bit address: 0 ~ 0x7F.
- 10-bit address: The first seven bits of the first byte are the combination 1111 0XX of which the last two bits (XX) are the two Most Significant Bits (MSBs) of the 10-bit address. For example, if the 10-bit address is 0x2FF (b’1011111111), the input address should be 0x7AFF (b’111101011111111).
<length>: I2C data length. Range: 1 ~ 2048.

Note¶

I2C transmission timeout is one second.

Example¶

AT+DRVI2CWRDATA=0,0x34,10   // I2C0 writes 10 bytes data to address 0x34

AT+DRVI2CWRBYTES: Write No More Than 4 Bytes I2C Data¶

Set Command¶

Command:

AT+DRVI2CWRBYTES=<num>,<address>,<length>,<data>

Response:

OK

Parameters¶

<num>: I2C port number. Range: 0 ~ 1.
<address>: I2C slave device address.
- 7-bit address: 0 ~ 0x7F.
- 10-bit address: The first seven bits of the first byte are the combination 1111 0XX of which the last two bits (XX) are the two Most Significant Bits (MSBs) of the 10-bit address. For example, if the 10-bit address is 0x2FF (b’1011111111), the input address should be 0x7AFF (b’111101011111111).
<length>: the length of the I2C data you want to write. Range: 1 ~ 4 bytes.
<data>: the data of <length> long. Range: 0 ~ 0xFFFFFFFF.

Note¶

I2C transmission timeout is one second.

Example¶

AT+DRVI2CWRBYTES=0,0x34,2,0x1234     // I2C0 writes 2 bytes data 0x1234 to address 0x34
AT+DRVI2CWRBYTES=0,0x7AFF,2,0x1234   // I2C0 writes 2 bytes data 0x1234 to 10-bit address 0x2FF

// I2C0 writes address 0x34; register address: 0x27; data: c0xFF
AT+DRVI2CWRBYTES=0,0x34,2,0x27FF

AT+DRVSPICONFGPIO: Configure SPI GPIO¶

Set Command¶

Command:

AT+DRVSPICONFGPIO=<mosi>,<miso>,<sclk>,<cs>

Response:

OK

Parameters¶

<mosi>: GPIO pin for Master Out Slave In signal.
<miso>: GPIO pin for Master In Slave Out signal, or -1 if not used.
<sclk>: GPIO pin for SPI Clock signal.
<cs>: GPIO pin for slave selection signal, or -1 if not used.

AT+DRVSPIINIT: Initialize SPI Master Driver¶

Set Command¶

Command:

AT+DRVSPIINIT=<clock>,<mode>,<cmd_bit>,<addr_bit>,<dma_chan>[,bits_msb]

Response:

OK

Parameters¶

<clock>: Clock speed, divisors of 80 MHz. Unit: Hz. Maximum: 40 MHz.
<mode>: SPI mode. Range: 0 ~ 3.
<cmd_bit>: Default amount of bits in command phase. Range: 0 ~ 16.
<addr_bit>: Default amount of bits in address phase. Range: 0 ~ 64.
<dma_chan>: Either channel 1 or 2, or 0 in the case when no DMA is required.
<bits_msb>: SPI data format:
- Bit0:
  - 0: Transmit MSB first (default).
  - 1: Transmit LSB first.
- Bit1:
  - 0: Receive data MSB first (default).
  - 1: Receive data LSB first.

Note¶

You should configure SPI GPIO before SPI initialization.

Example¶

AT+DRVSPIINIT=102400,0,0,0,0,3 // SPI clock: 100 kHz; mode: 0; both command and address bits are 0; not use DMA; transmit and receive LSB first
OK
AT+DRVSPIINIT=0   // delete SPI Driver
OK

AT+DRVSPIRD: Read SPI Data¶

Set Command¶

Command:

AT+DRVSPIRD=<data_len>[,<cmd>,<cmd_len>][,<addr>,<addr_len>]

Response:

+DRVSPIRD:<read data>
OK

Parameters¶

<data_len>: length of SPI data you want to read. Range: 1 ~ 4092 bytes.
<cmd>: command data. The length of the data is set in <cmd_len>.
<cmd_len>: command length in this transaction. Range: 0 ~ 2 bytes.
<addr>: command address. The length of the address is set in <addr_len>.
<addr_len>: The address length in this transaction. Range: 0 ~ 4 bytes.

Note¶

If you don’t use DMA, the maximum <data_len> you can set is 64 bytes each time.

Example¶

AT+DRVSPIRD=2  // read 2 bytes data
+DRVI2CREAD:ffff
OK

AT+DRVSPIRD=2,0x03,1,0x001000,3  // read 2 bytes data; <cmd> is 0x03; <cmd_len> is 1 byte; <addr> is 0x1000; <addr_len> is 3 bytes
+DRVI2CREAD:ffff
OK

AT+DRVSPIWR: Write SPI Data¶

Set Command¶

Command:

AT+DRVSPIWR=<data_len>[,<cmd>,<cmd_len>][,<addr>,<addr_len>]

Response:

When <data_len> is larger than 0, AT returns:

OK
>

This response indicates that you should enter the data you want to write. When the requirement of data length is met, the data transmission starts.

If the data is transmitted successfully, AT returns:

OK

When <data_len> is equal to 0, which means AT transmits commands and addresses only, and no SPI data, AT returns:

OK

Parameters¶

<data_len>: SPI data length. Range: 0 ~ 4092.
<cmd>: command data. The length of the data is set in <cmd_len>.
<cmd_len>: command length in this transaction. Range: 0 ~ 2 bytes.
<addr>: command address. The length of the address is set in <addr_len>.
<addr_len>: The address length in this transaction. Range: 0 ~ 4 bytes.

Note¶

If you don’t use DMA, the maximum <data_len> you can set is 64 bytes each time.

Example¶

AT+DRVSPIWR=2  // write 2 bytes data
OK
>              // begin receiving serial data
OK

AT+DRVSPIWR=0,0x03,1,0x001000,3  // write 0 byte data; <cmd> is 0x03; <cmd_len> is 1 byte; <addr> is 0x1000; <addr_len> is 3 bytes
OK

User AT Commands¶

[中文]

AT+USERRAM: Operate user’s free RAM.
AT+USEROTA: Upgrade the firmware according to the specified URL.

AT+USERRAM: Operate user’s free RAM¶

Query Command¶

Function:

Query the current available user’s RAM size.

Command:

AT+USERRAM?

Response:

+USERRAM:<size>
OK

Set Command¶

Function:

Operate user’s free RAM

Command:

AT+USERRAM=<operation>,<size>[,<offset>]

Response:

+USERRAM:<length>,<data>    // esp-at returns this response only when the operator is ``read``

OK

Parameters¶

<operation>:
- 0: release user’s RAM
- 1: malloc user’s RAM
- 2: write user’s RAM
- 3: read user’s RAM
- 4: clear user’s RAM
<size>: the size to malloc/read/write
<offset>: the offset to read/write. Default: 0

Notes¶

Please malloc the RAM size before you perform any other operations.
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>.
If the operator is read and the length is bigger than 1024, ESP-AT will reply multiple times in the same format, each reply can carry up to 1024 bytes of data, and eventually end up with \r\nOK\r\n.

Example¶

// malloc 1 KB user's RAM
AT+USERRAM=1,1024

// write 500 bytes to RAM (offset: 0)
AT+USERRAM=2,500

// read 64 bytes from RAM offset 100
AT+USERRAM=3,64,100

// free the user's RAM
AT+USERRAM=0

AT+USEROTA: Upgrade the Firmware According to the Specified URL¶

ESP-AT upgrades firmware at runtime by downloading the new firmware from a specific URL.

Set Command¶

Function:

Upgrade to the firmware version specified by the URL.

Command:

AT+USEROTA=<url len>

Response:

OK

>

This response indicates that AT is ready for receiving URL. You should enter the URL, and when the URL length reaches the <url len> value, the system returns:

Recv <url len> bytes

After AT outputs the above information, the upgrade process starts. If the upgrade process is complete, the system return:

OK

If the parameter is wrong or firmware upgrades fails, the system returns:

ERROR

Parameters¶

<url len>: URL length. Maximum: 8192 bytes.

Note¶

The speed of the upgrade depends on the network status.
If the upgrade fails due to unfavorable network conditions, AT will return ERROR. Please wait for some time before retrying.
After you upgrade the AT firmware, you are suggested to call the command AT+RESTORE to restore the factory default settings.
AT+USEROTA supports HTTP and HTTPS.
After AT outputs the > character, the special characters in the URL does not need to be escaped through the escape character, and it does not need to end with a new line(CR-LF).
When the URL is HTTPS, SSL verification is not recommended. If SSL verification is required, you need to generate your own PKI files and download them into the corresponding partition, and then load the certificates in the code implemented by the AT+USEROTA command. Please refer to How to Generate PKI Files for PKI files. For AT+USEROTA command, ESP-AT project provides an example of USEROTA.
Please refer to How to Implement OTA Upgrade for more OTA commands.

Example¶

AT+USEROTA=36

OK

>
Recv 36 bytes

OK

It is strongly recommended to read the following sections for some common information on AT commands before you dive into the details of each command.

AT Command Types
AT Commands with Configuration Saved in the Flash
AT Messages

AT Command Types ¶

Generic AT command has four types:

Type	Command Format	Description
Test Command	AT+<CommandName>=?	Query the Set Commands’ internal parameters and their range of values.
Query Command	AT+<CommandName>?	Return the current value of parameters.
Set Command	AT+<CommandName>=<…>	Set the value of user-defined parameters in commands, and run these commands.
Execute Command	AT+<CommandName>	Run commands with no user-defined parameters.

Not all AT commands support all of the four types mentioned above.
Currently, only strings and integer numbers are supported as input parameters in AT commands.
Angle brackets < > designate parameters that can not be omitted.
Square brackets [ ] designate optional parameters that can be omitted. The default value of the parameter will be used instead when you omit it. Below are examples of entering the command AT+CWJAP with some parameters omitted.
```
AT+CWJAP="ssid","password"
AT+CWJAP="ssid","password","11:22:33:44:55:66"
```
If the parameter you want to omit is followed by a parameter(s), you must give a , to indicate it.
```
AT+CWJAP="ssid","password",,1
```
String values need to be included in double quotation marks.
```
AT+CWSAP="ESP756290","21030826",1,4
```
Escape character syntax is needed if a string contains special characters, such as ,, ", or \:
- \\: escape the backslash itself
- \,: escape comma which is not used to separate each parameter
- \": escape double quotation mark which is not used to mark string input
- \<any>: escape <any> character means that drop backslash symbol and only use <any> character
Escape is needed in AT commands only, not elsewhere. For example, when AT command port prints > and wait for your input, the input does not need to be escaped.
```
AT+CWJAP="comma\,backslash\\ssid","1234567890"
AT+MQTTPUB=0,"topic","\"{\"sensor\":012}\"",1,0
```
The default baud rate of AT command is 115200.
The length of each AT command should be no more than 256 bytes.
AT commands end with a new-line (CR-LF), so the serial tool should be set to “New Line Mode”.
Definitions of AT command error codes are provided in AT API Reference:

AT Commands with Configuration Saved in the Flash ¶

Configuration settings entered by the following AT Commands will always be saved in the flash NVS Area, so they can be automatically restored on reset:

AT+UART_DEF: AT+UART_DEF=115200,8,1,0,3
AT+SAVETRANSLINK: AT+SAVETRANSLINK=1,"192.168.6.10",1001
AT+CWAUTOCONN: AT+CWAUTOCONN=1

Saving of configuration settings by several other commands can be switched on or off with AT+SYSSTORE command, which is mentioned in the Note section of these commands.

AT Messages ¶

There are two types of ESP-AT messages returned from the ESP-AT command port:

ESP-AT Response Messages (passive)

Each ESP-AT command input returns response messages to tell the sender the result of the ESP-AT command. The last message in the response is either OK or ERROR.

ESP-AT Response Messages¶
AT Response Messages	Description
OK	AT command process done and return OK
ERROR	AT command error or error occurred during the execution
SEND OK	Data has been sent to the protocol stack (specific to AT+CIPSEND and AT+CIPSENDEX command). It doesn’t mean that the data has been sent to the opposite end
SEND FAIL	Error occurred during sending the data to the protocol stack (specific to AT+CIPSEND and AT+CIPSENDEX command
SET OK	The URL has been set successfully (specific to AT+HTTPURLCFG command)
+<Command Name>:`...`	Response to the sender that describes AT command process results in details

ESP-AT Message Reports (active)

ESP-AT will report important state changes or messages in the system.

ESP-AT Message Reports¶
ESP-AT Message Report	Description
ready	The ESP-AT firmware is ready
busy p…	Busy processing. The system is in process of handling the previous command, thus CANNOT accept the new input
ERR CODE:`<0x%08x>`	Error code for different commands
Will force to restart!!!	Module restart right now
smartconfig type:`<xxx>`	Smartconfig type
Smart get wifi info	Smartconfig has got the SSID and PASSWORD information
+SCRD:`<length>`,``<reserved data>``	ESP-Touch v2 has got the reserved information
smartconfig connected wifi	Smartconfig done. ESP-AT has connected to the Wi-Fi
WIFI CONNECTED	Wi-Fi station interface has connected to an AP
WIFI GOT IP	Wi-Fi station interface has got the IPv4 address
WIFI GOT IPv6 LL	Wi-Fi station interface has got the IPv6 LinkLocal address
WIFI GOT IPv6 GL	Wi-Fi station interface has got the IPv6 Global address
WIFI DISCONNECT	Wi-Fi station interface has disconnected from an AP
+ETH_CONNECTED	Ethernet interface has connected
+ETH_GOT_IP	Ethernet interface has got the IPv4 address
+ETH_DISCONNECTED	Ethernet interface has disconnected
[<conn_id>,]CONNECT	A network connection of which ID is `<conn_id>` is established (ID=0 by default)
[<conn_id>,]CLOSED	A network connection of which ID is `<conn_id>` ends (ID=0 by default)
+LINK_CONN	Detailed connection information of TCP/UDP/SSL
+STA_CONNECTED: <sta_mac>	A station has connected to the Wi-Fi softAP interface of ESP-AT
+DIST_STA_IP: <sta_mac>,<sta_ip>	The Wi-Fi softAP interface of ESP-AT distributes an IP address to the station
+STA_DISCONNECTED: <sta_mac>	A station disconnected from the Wi-Fi softAP interface of ESP-AT
>	ESP-AT is waiting for more data to be received
Recv `<xxx>` bytes	ESP-AT has already received `<xxx>` bytes from the ESP-AT command port
+IPD	ESP-AT received the data from the network
SEND Canceled	Cancel to send in Wi-Fi normal sending mode
Have `<xxx>` Connections	Has reached the maximum connection counts for server
+QUITT	ESP-AT quits from the Wi-Fi Passthrough Mode
NO CERT FOUND	No valid device certificate found in custom partition
NO PRVT_KEY FOUND	No valid private key found in custom partition
NO CA FOUND	No valid CA certificate found in custom partition
+MQTTCONNECTED	MQTT connected to the broker
+MQTTDISCONNECTED	MQTT disconnected from the broker
+MQTTSUBRECV	MQTT received the data from the broker
+MQTTPUB:FAIL	MQTT failed to publish data
+MQTTPUB:OK	MQTT publish data done
+BLECONN	A Bluetooth LE connection established
+BLEDISCONN	A Bluetooth LE connection ends
+READ	A read operation from Bluetooth LE connection
+WRITE	A write operation from Bluetooth LE connection
+NOTIFY	A notification from Bluetooth LE connection
+INDICATE	An indication from Bluetooth LE connection
+BLESECNTFYKEY	Bluetooth LE SMP key
+BLESECREQ:<conn_index>	Received encryption request which index is <conn_index>
+BLEAUTHCMPL:<conn_index>,<enc_result>	Bluetooth LE SMP pairing completed

AT Command Examples¶

[中文]

TCP/IP AT Examples¶

[中文]

This document provides detailed command examples to illustrate how to utilize TCP/IP AT Commands on ESP devices.

ESP device as a TCP client in single connection
ESP device as a TCP server in multiple connections
UDP transmission with fixed remote IP address and port
UDP transmission with changeable remote IP address and port
ESP device as an SSL client in single connection
ESP device as an SSL server in multiple connections
ESP device as an SSL client to create a single connection with two-way authentication
ESP device as an SSL server to create multiple connection with two-way authentication
UART Wi-Fi passthrough transmission when the ESP device works as a TCP client in single connection
UART Wi-Fi passthrough transmission when the ESP device works as a softAP in UDP transparent transmission

ESP device as a TCP client in single connection ¶

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Connect the PC to the same router which ESP device is connected to.

Use a network tool on the PC to create a TCP server. For example, the TCP server on PC is 192.168.3.102, and the port is 8080.
ESP device is connected to the TCP server as a client over TCP. The server’s IP address is 192.168.3.102, and the port is 8080.

Command:
```
AT+CIPSTART="TCP","192.168.3.102",8080
```
Response:
```
CONNECT

OK
```
Send 4 bytes of data.

Command:
```
AT+CIPSEND=4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following message.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data.

Assume that the TCP server sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,4:test
```

ESP device as a TCP server in multiple connections ¶

When ESP device works as a TCP server, multiple connections should be enabled by AT+CIPMUX=1 command, because in most cases more than one client needs to be connected to the ESP server.

Below is an example showing how a TCP server is established when ESP device works in the softAP mode. If ESP device works as a station, you can set up a server in the same way mentioned above after connecting ESP device to the router.

Set the Wi-Fi mode to softAP.

Command:
```
AT+CWMODE=2
```
Response:
```
OK
```
Enable multiple connections.

Command:
```
AT+CIPMUX=1
```
Response:
```
OK
```

Set softAP.

Command:

AT+CWSAP="ESP32_softAP","1234567890",5,3

Response:

OK

Query softAP information.

Command:
```
AT+CIPAP?
```
Response:
```
AT+CIPAP?
+CIPAP:ip:"192.168.4.1"
+CIPAP:gateway:"192.168.4.1"
+CIPAP:netmask:"255.255.255.0"

OK
```
Note:
- The address you obtained may be different from that in the above response.
Set up a TCP server, the default port is 333.

Command:
```
AT+CIPSERVER=1
```
Response:
```
OK
```
Connect the PC to the ESP device softAP.
Use a network tool on PC to create a TCP client and connect it to the TCP server that ESP device has created.
Send 4 bytes of data to connection link 0.

Command:
```
AT+CIPSEND=0,4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following messages.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data from connection link 0.

Assume that the TCP server sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,0,4:test
```
Close TCP connection.

Command:
```
AT+CIPCLOSE=0
```
Response:
```
0,CLOSED

OK
```

UDP transmission with fixed remote IP address and port ¶

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Connect the PC to the same router which ESP device is connected to.

Use a network tool on the PC to create UDP transmission. For example, the PC’s IP address is 192.168.3.102, and the port is 8080.
Enable multiple connections.

Command:
```
AT+CIPMUX=1
```
Response:
```
OK
```
Create a UDP transmission. The connection link is 4, the remote host’s IP address is 192.168.3.102, the remote port is 8080, the local port is 1112, and the mode is 0.

Important

In UDP transmission, whether the remote IP address and port are fixed or not is determined by the mode parameter of AT+CIPSTART. If the parameter is 0, a specific connection link ID will be given to ensure that the remote IP address and port are fixed and the data sender and receiver will not be replaced by other devices.

Command:
```
AT+CIPSTART=4,"UDP","192.168.3.102",8080,1112,0
```
Response:
```
4,CONNECT

OK
```
Note:
- "192.168.3.102" and 8080 are the remote IP address and port of UDP transmission on the remote side, i.e., the UDP configuration set by PC.
- 1112 is the local port number of ESP device. You can define this port number, or else, a random port will be used.
- 0 means that the remote IP address and port are fixed and cannot be changed. For example, when there is another PC creating a UDP entity and sending data to ESP device port 1112, ESP device will still receive the data from UDP port 1112, and if the AT command AT+CIPSEND=4,X is used, the data will still be sent to the first PC end. However, if the parameter is not set as 0, the data will be sent to the new PC.
Send 7 bytes of data to connection link 4.

Command:
```
AT+CIPSEND=4,7
```
Response:
```
OK

>
```
Input 7 bytes, for example, abcdefg, then AT will respond the following messages.
```
Recv 7 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data from connection link 4.

Assume that the PC sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,4,4:test
```
Close UDP connection link 4.

Command:
```
AT+CIPCLOSE=4
```
Response:
```
4,CLOSED

OK
```

UDP transmission with changeable remote IP address and port ¶

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Connect the PC to the same router which ESP device is connected to.

Use a network tool on the PC to create UDP transmission. For example, the PC’s IP address is 192.168.3.102, and the port is 8080.
Enable single connections.

Command:
```
AT+CIPMUX=0
```
Response:
```
OK
```
Create a UDP transmission. The remote host’s IP address is 192.168.3.102, the remote port is 8080, the local port is 1112, and the mode is 2.

Command:
```
AT+CIPSTART="UDP","192.168.3.102",8080,1112,2
```
Response:
```
CONNECT

OK
```
Note:
- "192.168.3.102" and 8080 are the remote IP address and port of UDP transmission on the remote side, i.e., the UDP configuration set by PC.
- 1112 is the local port number of ESP device. You can define this port number, or else, a random port will be used.
- 2 means the opposite terminal of UDP transmission can be changed. The remote IP address and port will be automatically changed to those of the last UDP connection to ESP device.
Send 4 bytes of data.

Command:
```
AT+CIPSEND=4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following messages.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Send data to any other UDP terminal. For example, you can send 4 bytes of data with the remote host’s IP address as 192.168.3.103 and the remote port as 1000.

If you want to send data to any other UDP terminal, please designate the IP address and port of the target terminal in the command.

Command:
```
AT+CIPSEND=4,"192.168.3.103",1000
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following messages.
```
Recv 4 bytes

SEND OK
```
Receive 4 bytes of data.

Assume that the PC sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,4:test
```
Close UDP connection.

Command:
```
AT+CIPCLOSE
```
Response:
```
CLOSED

OK
```

ESP device as an SSL client in single connection ¶

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Connect the PC to the same router which ESP device is connected to.

Use the OpenSSL command on the PC to create an SSL server. For example, the SSL server on PC is 192.168.3.102, and the port is 8070.

Command:

openssl s_server -cert /home/esp-at/components/customized_partitions/raw_data/server_cert/server_cert.crt -key /home/esp-at/components/customized_partitions/raw_data/server_key/server.key -port 8070

Response:

ACCEPT

Connect the ESP device to the SSL server as a client over SSL. The server’s IP address is 192.168.3.102, and the port is 8070.

Command:
```
AT+CIPSTART="SSL","192.168.3.102",8070
```
Response:
```
CONNECT

OK
```
Send 4 bytes of data.

Command:
```
AT+CIPSEND=4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following message.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data.

Assume that the SSL server sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,4:test
```

ESP device as an SSL server in multiple connections ¶

When ESP device works as an SSL server, multiple connections should be enabled by AT+CIPMUX=1 command, because in most cases more than one client needs to be connected to the ESP server.

Below is an example showing how an SSL server is established when ESP device works in the softAP mode. If ESP device works as a station, after connecting to the router, follow the steps for establishing a connection to an SSL server in this example.

Set the Wi-Fi mode to softAP.

Command:
```
AT+CWMODE=2
```
Response:
```
OK
```
Enable multiple connections.

Command:
```
AT+CIPMUX=1
```
Response:
```
OK
```

Configure the ESP softAP.

Command:

AT+CWSAP="ESP32_softAP","1234567890",5,3

Response:

OK

Query softAP information.

Command:
```
AT+CIPAP?
```
Response:
```
AT+CIPAP?
+CIPAP:ip:"192.168.4.1"
+CIPAP:gateway:"192.168.4.1"
+CIPAP:netmask:"255.255.255.0"

OK
```
Note:
- The address you obtained may be different from that in the above response.
Set up an SSL server.

Command:
```
AT+CIPSERVER=1,8070,"SSL"
```
Response:
```
OK
```
Connect the PC to the ESP device softAP.
Use the OpenSSL command on PC to create an SSL client and connect it to the SSL server that ESP device has created.

Command:
```
openssl s_client -host 192.168.4.1 -port 8070
```
Response on the ESP device:
```
CONNECT
```
Send 4 bytes of data to connection link 0.

Command:
```
AT+CIPSEND=0,4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following messages.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data from connection link 0.

Assume that the SSL server sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,0,4:test
```
Close SSL connection.

Command:
```
AT+CIPCLOSE=0
```
Response:
```
0,CLOSED

OK
```

ESP device as an SSL client to create a single connection with two-way authentication ¶

The certificate used in the example is the default certificate in esp-at. You can also generate and flash your own the certificate, then you need replace the SSL server certificate path below with your certificate path. To obtain the SSL certificate, please refer to tools/README.md for how to generate the certificate bin and esp-at/module_config/module_name/at_customize.csv for where to flash it.

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Set the SNTP server.

Command:
```
AT+CIPSNTPCFG=1,8,"cn.ntp.org.cn","ntp.sjtu.edu.cn"
```
Response:
```
OK
```
Note:
- You can set the SNTP server according to your country’s time zone.
Query the SNTP time.

Command:
```
AT+CIPSNTPTIME?
```
Response:
```
+CIPSNTPTIME:Mon Oct 18 20:12:27 2021
OK
```
Note:
- You can check whether the SNTP time matches the real-time time to determine whether the SNTP server you set takes effect.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Connect the PC to the same router which ESP device is connected to.

Use the OpenSSL command on the PC to create an SSL server. For example, the SSL server on PC is 192.168.3.102, and the port is 8070.

Command:

openssl s_server -CAfile /home/esp-at/components/customized_partitions/raw_data/server_ca/server_ca.crt -cert /home/esp-at/components/customized_partitions/raw_data/server_cert/server_cert.crt -key /home/esp-at/components/customized_partitions/raw_data/server_key/server.key -port 8070 -verify_return_error -verify_depth 1 -Verify 1

Response on the ESP device:

CONNECT

Note:

The certificate path in the command can be adjusted according to the location of your certificate.

The ESP device sets up the SSL client two-way authentication configuration.

Command:
```
AT+CIPSSLCCONF=3,0,0
```
Response:
```
OK
```
Connect the ESP device to the SSL server as a client over SSL. The server’s IP address is 192.168.3.102, and the port is 8070.

Command:
```
AT+CIPSTART="SSL","192.168.3.102",8070
```
Response:
```
CONNECT

OK
```
Send 4 bytes of data.

Command:
```
AT+CIPSEND=4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following message.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data.

Assume that the SSL server sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,4:test
```

ESP device as an SSL server to create multiple connection with two-way authentication ¶

When ESP device works as an SSL server, multiple connections should be enabled by AT+CIPMUX=1 command, because in most cases more than one client needs to be connected to the ESP server.

Below is an example showing how an SSL server is established when ESP device works in the station mode. If ESP device works as a softAP, refer to the example of ESP device as an SSL server in multiple connections.

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Enable multiple connections.

Command:
```
AT+CIPMUX=1
```
Response:
```
OK
```
Set up an SSL server.

Command:
```
AT+CIPSERVER=1,8070,"SSL",1
```
Response:
```
OK
```
Connect the PC to the ESP device softAP.

Use the OpenSSL command on PC to create an SSL client and connect it to the SSL server that ESP device has created.

Command:

openssl s_client -CAfile /home/esp-at/components/customized_partitions/raw_data/client_ca/client_ca_00.crt -cert /home/esp-at/components/customized_partitions/raw_data/client_cert/client_cert_00.crt -key /home/esp-at/components/customized_partitions/raw_data/client_key/client_key_00.key -host 192.168.3.112 -port 8070

Response on the ESP device:

0,CONNECT

Send 4 bytes of data to connection link 0.

Command:
```
AT+CIPSEND=0,4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following messages.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data from connection link 0.

Assume that the SSL server sends 4 bytes of data (data is test), the system will prompt:
```
+IPD,0,4:test
```
Close SSL connection.

Command:
```
AT+CIPCLOSE=0
```
Response:
```
0,CLOSED

OK
```
Close SSL server.

Command:
```
AT+CIPSERVER=0
```
Response:
```
OK
```

UART Wi-Fi passthrough transmission when the ESP device works as a TCP client in single connection ¶

Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Query the device’s IP address.

Command:
```
AT+CIPSTA?
```
Response:
```
+CIPSTA:ip:"192.168.3.112"
+CIPSTA:gateway:"192.168.3.1"
+CIPSTA:netmask:"255.255.255.0"

OK
```
Note:
- The query results you obtained may be different from those in the above response.
Connect the PC to the same router which ESP device is connected to.

Use a network tool on the PC to create a TCP server. For example, the TCP server on PC is 192.168.3.102, and the port is 8080.
Connect the ESP device to the TCP server as a TCP client over TCP. The server’s IP address is 192.168.3.102, and the port is 8080.

Command:
```
AT+CIPSTART="TCP","192.168.3.102",8080
```
Response:
```
CONNECT

OK
```
Enable the UART Wi-Fi transmission mode.

Command:
```
AT+CIPMODE=1
```
Response:
```
OK
```
Send data in Passthrough Mode.

Command:
```
AT+CIPSEND
```
Response:
```
OK

>
```
Stop sending data.

When receiving a packet that contains only +++, the UART Wi-Fi passthrough transmission process will be stopped. Then please wait at least 1 second before sending next AT command. Please be noted that if you input +++ directly by typing, the +++ may not be recognised as three consecutive + because of the prolonged typing duration. For more details, please refer to [Passthrough Mode Only] +++.

Important

The aim of ending the packet with +++ is to exit transparent transmission and to accept normal AT commands, while TCP still remains connected. However, you can also use command AT+CIPSEND to go back into transparent transmission.
Exit the UART Wi-Fi passthrough mode.

Command:
```
AT+CIPMODE=0
```
Response:
```
OK
```
Close TCP connection.

Command:
```
AT+CIPCLOSE
```
Response:
```
CLOSED

OK
```

UART Wi-Fi passthrough transmission when the ESP device works as a softAP in UDP transparent transmission ¶

Set the Wi-Fi mode to softAP.

Command:
```
AT+CWMODE=2
```
Response:
```
OK
```

Set softAP.

Command:

AT+CWSAP="ESP32_softAP","1234567890",5,3

Response:

OK

Connect the PC to the ESP device softAP.
Create a UDP endpoint.

Use a network tool on PC to create a UDP endpoint. For example, the PC’s IP address is 192.168.4.2 and the port is 8080.
Create a UDP transmission between ESP32 and the PC with a fixed remote IP address and port. The remote host’s IP address is 192.168.4.2, the remote port is 8080, the local port is 2233, and the mode is 0.

Command:
```
AT+CIPSTART="UDP","192.168.4.2",8080,2233,0
```
Response:
```
CONNECT

OK
```
Enable the UART Wi-Fi transmission mode.

Command:
```
AT+CIPMODE=1
```
Response:
```
OK
```
Send data in Passthrough Mode.

Command:
```
AT+CIPSEND
```
Response:
```
OK

>
```
Stop sending data.

When receiving a packet that contains only +++, the UART Wi-Fi passthrough transmission process will be stopped. Then please wait at least 1 second before sending next AT command. Please be noted that if you input +++ directly by typing, the +++ may not be recognised as three consecutive + because of the prolonged typing duration. For more details, please refer to [Passthrough Mode Only] +++.

Important

The aim of ending the packet with +++ is to exit transparent transmission and to accept normal AT commands, while TCP still remains connected. However, you can also use command AT+CIPSEND to go back into transparent transmission.
Exit the UART Wi-Fi passthrough mode.

Command:
```
AT+CIPMODE=0
```
Response:
```
OK
```
Close TCP connection.

Command:
```
AT+CIPCLOSE
```
Response:
```
CLOSED

OK
```

Bluetooth LE AT Examples¶

[中文]

This document provides an introduction and detailed command examples to illustrate how to utilize Bluetooth® Low Energy AT Commands on ESP devices.

Introduction
Bluetooth LE client reads and write services
Bluetooth LE server read and write services
Encrypt Bluetooth LE connection
Establish SPP connection between two ESP32 development boards and transmit data in UART-Bluetooth LE Passthrough Mode
Establish SPP connection between ESP32 and mobile phone and transmit data in UART-Bluetooth LE passthrough mode

Introduction ¶

ESP-AT currently only supports Bluetooth LE 4.2 protocol specification, and the description in this document is only for Bluetooth LE 4.2 protocol specification. Please refer to Core Specification 4.2 for more details.

Bluetooth LE protocol architecture¶

Bluetooth LE protocol stack is divided into several layers from bottom to top: Physical Layer (PHY), Link Layer (LL), Host Controller Interface (HCI), Logical Link Control and Adaptation Protocol Layer (L2CAP), Attribute Protocol (ATT), Security Manager Protocol (SMP), Generic Attribute Profile (GATT), Generic Access Profile (GAP).

PHY: the PHY layer is responsible for transmitting and receiving packets of information on the physical channel. Bluetooth LE uses 40 RF channels. Frequency Range: 2402 MHz to 2480 MHz.
LL: the LL layer is responsible for the creation, modification and release of logical links (and, if required, their associated logical transports), as well as the update of parameters related to physical links between devices. It controls the Link Layer state machine in one of the five states of standby, advertising, scanning, initiating and connected.
HCI: the HCI layer provides a standardized interface to host and controller. This layer can be implemented by software API or controlled by hardware interfaces UART, SPI and USB.
L2CAP: the L2CAP layer is responsible for protocol multiplexing capability, segmentation, and reassembly operation for data exchanged between the host and the protocol stack.
ATT: the ATT layer implements the peer-to-peer protocol between an attribute server and an attribute client. The ATT client sends commands, requests, and confirmations to the ATT server. The ATT server sends responses, notifications and indications to the client.
SMP: the SMP layer is the peer-to-peer protocol used to generate encryption keys and identity keys. The SMP also manages storage of the encryption keys and identity keys and is responsible for generating random addresses and resolving random addresses to known device identities.
GATT: the GATT layer represents the functionality of the attribute server and, optionally, the attribute client. The profile describes the hierarchy of services, characteristics and attributes used in the attribute server. The layer provides interfaces for discovering, reading, writing and indicating of service characteristics and attributes.
GAP: the GAP represents the base functionality common to all Bluetooth devices such as modes and access procedures used by the transports, protocols and application profiles. GAP services include device discovery, connection modes, security, authentication, association models and service discovery.

Bluetooth LE role division¶

There are different roles in different levels of the Bluetooth LE protocol architecture. These divisions are not affected by each other.

LL: devices can be divided into master and slave, the slave advertises, and the master initiates a connection.
GAP: GAP defines four specific roles: broadcaster, observer, peripheral, and central.
GATT: devices can be divided into server and client.

Important

The Bluetooth LE server and Bluetooth LE client described in this document are both GATT layer roles.
At present, ESP-AT supports the existence of Bluetooth LE server and Bluetooth LE client at the same time.
No matter ESP-AT is initialized as Bluetooth LE server or Bluetooth LE client, the maximum number of devices connected at the same time is 3.

GATT is actually an attribute transmission protocol, which can be regarded as an application layer protocol for attribute transmission. The structure of this attribute is very simple. It is composed of services, each service is composed of different numbers of characteristics, and each characteristic is composed of many other elements.

GATT server and GATT client roles exist after the Bluetooth LE connection is established. The GATT server stores the data transported over the Attribute Protocol and accepts Attribute Protocol requests, commands and confirmations from the GATT client. In short, the end that provides data is called GATT server, and the end that accesses data is called GATT client.

Important

The ESP32 Bluetooth LE server needs to download a ble_data.bin into flash to provide Bluetooth LE services.
- To learn how to generate a ble_data.bin, please refer to Customize Bluetooth LE Services Tools.
- The download address of the ble_data.bin is the address of ble_data in at_customize.csv, or described in build/download.config.

Bluetooth LE client reads and write services ¶

Below is an example of using two ESP32 development boards, one as a Bluetooth LE server (only as Bluetooth LE server role), the other one as a Bluetooth LE client (only as Bluetooth LE client role). The example shows how to use Bluetooth LE functions with AT commands.

Important

In the following steps, the operations starting with ESP32 Bluetooth LE server only need to be executed at ESP32 Bluetooth LE server, and the operations starting with ESP32 Bluetooth LE client only need to be executed at ESP32 Bluetooth LE client.

Bluetooth LE initialization.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLEINIT=1
```
Response:
```
OK
```
ESP32 Bluetooth LE server gets Bluetooth LE address.

Command:
```
AT+BLEADDR?
```
Response:
```
+BLEADDR:"24:0a:c4:d6:e4:46"
OK
```
Note:
- The address you obtain may be different from that in the above response. Keep yours handy as you will need it in one of the following steps.
ESP32 Bluetooth LE server creates services.

Command:
```
AT+BLEGATTSSRVCRE
```
Response:
```
OK
```
ESP32 Bluetooth LE server starts services.

Command:
```
AT+BLEGATTSSRVSTART
```
Response:
```
OK
```

ESP32 Bluetooth LE server discovers characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

+BLEGATTSCHAR:"char",1,1,0xC300,0x02
+BLEGATTSCHAR:"desc",1,1,1,0x2901
+BLEGATTSCHAR:"char",1,2,0xC301,0x02
+BLEGATTSCHAR:"desc",1,2,1,0x2901
+BLEGATTSCHAR:"char",1,3,0xC302,0x08
+BLEGATTSCHAR:"desc",1,3,1,0x2901
+BLEGATTSCHAR:"char",1,4,0xC303,0x04
+BLEGATTSCHAR:"desc",1,4,1,0x2901
+BLEGATTSCHAR:"char",1,5,0xC304,0x08
+BLEGATTSCHAR:"char",1,6,0xC305,0x10
+BLEGATTSCHAR:"desc",1,6,1,0x2902
+BLEGATTSCHAR:"char",1,7,0xC306,0x20
+BLEGATTSCHAR:"desc",1,7,1,0x2902
+BLEGATTSCHAR:"char",1,8,0xC307,0x02
+BLEGATTSCHAR:"desc",1,8,1,0x2901
+BLEGATTSCHAR:"char",2,1,0xC400,0x02
+BLEGATTSCHAR:"desc",2,1,1,0x2901
+BLEGATTSCHAR:"char",2,2,0xC401,0x02
+BLEGATTSCHAR:"desc",2,2,1,0x2901

OK

ESP32 Bluetooth LE server starts advertising, then the ESP32 Bluetooth LE client starts scanning and lasts for 3 s.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLESCAN=1,3
```
Response:
```
OK
+BLESCAN:"5b:3b:6c:51:90:49",-87,02011a020a0c0aff4c001005071c3024dc,,1
+BLESCAN:"c4:5b:be:93:ec:66",-84,0201060303111809095647543147572d58020a03,,0
+BLESCAN:"24:0a:c4:d6:e4:46",-29,,,0
```
Note:
- The scan results you obtain may be different from those in the above response.
Establish the Bluetooth LE connection.

ESP32 Bluetooth LE client:

Command:
```
AT+BLECONN=0,"24:0a:c4:d6:e4:46"
```
Response:
```
+BLECONN:0,"24:0a:c4:d6:e4:46"

OK
```
Note:
- When entering the above command, replace the address with your ESP Bluetooth LE server address.
- If the Bluetooth LE connection is established successfully, message +BLECONN:0,"24:0a:c4:d6:e4:46 will be prompted.
- If the Bluetooth LE connection is broken, message +BLECONN:0,-1 will be prompted.
ESP32 Bluetooth LE client discovers services.

Command:
```
AT+BLEGATTCPRIMSRV=0
```
Response:
```
 +BLEGATTCPRIMSRV:0,1,0x1801,1
 +BLEGATTCPRIMSRV:0,2,0x1800,1
 +BLEGATTCPRIMSRV:0,3,0xA002,1
 +BLEGATTCPRIMSRV:0,4,0xA003,1

OK
```
Note:
- When discovering services, the ESP32 Bluetooth LE client will get two more default services (UUID: 0x1800 and 0x1801) than what the ESP32 Bluetooth LE server will get. So, for the same service, the <srv_index> received by the ESP32 Bluetooth LE client equals the <srv_index> received by the ESP32 Bluetooth LE server + 2. For example, for service 0xA002, the <srv_index> queried on the ESP32 Bluetooth LE client is 3, if the ESP32 Bluetooth LE server is queried through the command AT+BLEGATTSSRV?, then <srv_index> is 1.

ESP32 Bluetooth LE client discovers characteristics.

Command:

AT+BLEGATTCCHAR=0,3

Response:

+BLEGATTCCHAR:"char",0,3,1,0xC300,0x02
+BLEGATTCCHAR:"desc",0,3,1,1,0x2901
+BLEGATTCCHAR:"char",0,3,2,0xC301,0x02
+BLEGATTCCHAR:"desc",0,3,2,1,0x2901
+BLEGATTCCHAR:"char",0,3,3,0xC302,0x08
+BLEGATTCCHAR:"desc",0,3,3,1,0x2901
+BLEGATTCCHAR:"char",0,3,4,0xC303,0x04
+BLEGATTCCHAR:"desc",0,3,4,1,0x2901
+BLEGATTCCHAR:"char",0,3,5,0xC304,0x08
+BLEGATTCCHAR:"char",0,3,6,0xC305,0x10
+BLEGATTCCHAR:"desc",0,3,6,1,0x2902
+BLEGATTCCHAR:"char",0,3,7,0xC306,0x20
+BLEGATTCCHAR:"desc",0,3,7,1,0x2902
+BLEGATTCCHAR:"char",0,3,8,0xC307,0x02
+BLEGATTCCHAR:"desc",0,3,8,1,0x2901

OK

ESP32 Bluetooth LE client reads a characteristic.

Command:
```
AT+BLEGATTCRD=0,3,1
```
Response:
```
+BLEGATTCRD:0,1,0

OK
```
Note:
- Please note that the target characteristic’s property has to support the read operation.
- If the ESP32 Bluetooth LE client reads the characteristic successfully, message +READ:0,"7c:df:a1:b3:8d:de" will be prompted on the ESP32 Bluetooth LE Server side.
ESP32 Bluetooth LE client writes a characteristic.

Command:
```
AT+BLEGATTCWR=0,3,3,,2
```
Response:
```
>
```
The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the writing starts.
```
OK
```
Note:
- If the ESP32 Bluetooth LE client writes the characteristic successfully, message +WRITE:<conn_index>,<srv_index>,<char_index>,[<desc_index>],<len>,<value> will be prompted on the ESP32 Bluetooth LE server side.
Indicate a characteristic.

ESP32 Bluetooth LE client:

Command:
```
AT+BLEGATTCWR=0,3,7,1,2
```
Response:
```
>
```
The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the writing starts.

To receive data from ESP32 Bluetooth LE server (through the notify or the indicate method), the ESP32 Bluetooth LE client needs to register with the server in advance. Write the value 0x0001 to use the notify method, and 0x0002 to use the indicate method. This example writes the 0x0002 to use the indicate method.
```
OK
```
Note:
- If the ESP32 Bluetooth LE client writes the descriptor successfully, message +WRITE:<conn_index>,<srv_index>,<char_index>,<desc_index>,<len>,<value> will be prompted on the ESP32 Bluetooth LE server side.
ESP32 Bluetooth LE server:

Command:
```
AT+BLEGATTSIND=0,1,7,3
```
Response:
```
>
```
The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <length> is met, the indication starts.
```
OK
```
Note:
- If the ESP32 Bluetooth LE client receives the indication, message +INDICATE:<conn_index>,<srv_index>,<char_index>,<len>,<value> will be prompted.
- For the same service, the <srv_index> on the ESP32 Bluetooth LE client side equals the <srv_index> on the ESP32 Bluetooth LE server side + 2.
- For the permissions of the characteristics in the services, please refer to How to Customize Bluetooth® LE Services.

Bluetooth LE server read and write services ¶

Below is an example of using two ESP32 development boards, one as a Bluetooth LE server (only as Bluetooth LE server role), the other one as a Bluetooth LE client (only as Bluetooth LE client role). The example shows how to establish a Bluetooth LE connection, as well as the read and write characteristics of the server and client settings, and notification characteristics.

Important

In the step, the operations starting with ESP32 Bluetooth LE server only need to be executed at ESP32 Bluetooth LE server, and the operations starting with ESP32 Bluetooth LE client only need to be executed at ESP32 Bluetooth LE client.

Bluetooth LE initialization.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLEINIT=1
```
Response:
```
OK
```
ESP32 Bluetooth LE server creates services.

Command:
```
AT+BLEGATTSSRVCRE
```
Response:
```
OK
```
ESP32 Bluetooth LE server starts services.

Command:
```
AT+BLEGATTSSRVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE server gets its MAC address.

Command:
```
AT+BLEADDR?
```
Response:
```
+BLEADDR:"24:0a:c4:d6:e4:46"
OK
```
Note:
- The address you obtain may be different from that in the above response. Keep yours handy as you will need it in one of the following steps.

Set Bluetooth LE advertising data.

Command:

AT+BLEADVDATA="0201060A09457370726573736966030302A0"

Response:

OK

ESP32 Bluetooth LE server starts advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE client creates services.

Command:
```
AT+BLEGATTSSRVCRE
```
Response:
```
OK
```
ESP32 Bluetooth LE client starts services.

Command:
```
AT+BLEGATTSSRVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE client gets Bluetooth LE address.

Command:
```
AT+BLEADDR?
```
Response:
```
+BLEADDR:"24:0a:c4:03:a7:4e"
OK
```
Note:
- The address you obtain may be different from that in the above response. Keep yours handy as you will need it in one of the following steps.

ESP32 Bluetooth LE client enables a scanning for three seconds.

Command:

AT+BLESCAN=1,3

Response:

OK
+BLESCAN:"5b:3b:6c:51:90:49",-87,02011a020a0c0aff4c001005071c3024dc,,1
+BLESCAN:"c4:5b:be:93:ec:66",-84,0201060303111809095647543147572d58020a03,,0
+BLESCAN:"24:0a:c4:d6:e4:46",-29,,,0

Note:

The scan results you obtain may be different from those in the above response.

Establish the Bluetooth LE connection.

ESP32 Bluetooth LE client:

Command:
```
AT+BLECONN=0,"24:0a:c4:d6:e4:46"
```
Response:
```
+BLECONN:0,"24:0a:c4:d6:e4:46"

OK
```
Note:
- When entering the above command, replace the address with your ESP Bluetooth LE server address.
- If the Bluetooth LE connection is established successfully, message +BLECONN:0,"24:0a:c4:d6:e4:46 will be prompted.
- If the Bluetooth LE connection is broken, message +BLECONN:0,-1 will be prompted.
ESP32 Bluetooth LE server:

Command:
```
AT+BLECONN=0,"24:0a:c4:03:a7:4e"
```
Response:
```
+BLECONN:0,"24:0a:c4:03:a7:4e"

OK
```
Note:
- When entering the above command, replace the address with your ESP Bluetooth LE server address.
- If the Bluetooth LE connection is established successfully, the message OK will be prompted and the message +BLECONN:0,"24:0a:c4:03:a7:4e will not be prompted.
- If the Bluetooth LE connection is broken, the message ERROR will be prompted and the message +BLECONN:0,-1 will not be prompted.

ESP32 Bluetooth LE client discovers local services.

Command:

AT+BLEGATTSSRV?

Response:

+BLEGATTSSRV:1,1,0xA002,1
+BLEGATTSSRV:2,1,0xA003,1

OK

ESP32 Bluetooth LE client discovers local characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

+BLEGATTSCHAR:"char",1,1,0xC300,0x02
+BLEGATTSCHAR:"desc",1,1,1,0x2901
+BLEGATTSCHAR:"char",1,2,0xC301,0x02
+BLEGATTSCHAR:"desc",1,2,1,0x2901
+BLEGATTSCHAR:"char",1,3,0xC302,0x08
+BLEGATTSCHAR:"desc",1,3,1,0x2901
+BLEGATTSCHAR:"char",1,4,0xC303,0x04
+BLEGATTSCHAR:"desc",1,4,1,0x2901
+BLEGATTSCHAR:"char",1,5,0xC304,0x08
+BLEGATTSCHAR:"char",1,6,0xC305,0x10
+BLEGATTSCHAR:"desc",1,6,1,0x2902
+BLEGATTSCHAR:"char",1,7,0xC306,0x20
+BLEGATTSCHAR:"desc",1,7,1,0x2902
+BLEGATTSCHAR:"char",1,8,0xC307,0x02
+BLEGATTSCHAR:"desc",1,8,1,0x2901
+BLEGATTSCHAR:"char",2,1,0xC400,0x02
+BLEGATTSCHAR:"desc",2,1,1,0x2901
+BLEGATTSCHAR:"char",2,2,0xC401,0x02
+BLEGATTSCHAR:"desc",2,2,1,0x2901

OK

ESP32 Bluetooth LE server discovers primary services.

Command:
```
AT+BLEGATTCPRIMSRV=0
```
Response:
```
 +BLEGATTCPRIMSRV:0,1,0x1801,1
 +BLEGATTCPRIMSRV:0,2,0x1800,1
 +BLEGATTCPRIMSRV:0,3,0xA002,1
 +BLEGATTCPRIMSRV:0,4,0xA003,1

OK
```
Note:
- When discovering services, the ESP32 Bluetooth LE server will get two more default services (UUID: 0x1800 and 0x1801) than what the ESP32 Bluetooth LE client will get. So, for the same service, the <srv_index> received by the ESP32 Bluetooth LE server equals the <srv_index> received by the ESP32 Bluetooth LE client + 2. For example, for service 0xA002, the <srv_index> queried on the ESP32 Bluetooth LE client is 3, if the ESP32 Bluetooth LE server is queried through the command AT+BLEGATTSSRV?, then <srv_index> is 1.

ESP32 Bluetooth LE server discovers primary characteristics.

Command:

AT+BLEGATTCCHAR=0,3

Response:

+BLEGATTCCHAR:"char",0,3,1,0xC300,0x02
+BLEGATTCCHAR:"desc",0,3,1,1,0x2901
+BLEGATTCCHAR:"char",0,3,2,0xC301,0x02
+BLEGATTCCHAR:"desc",0,3,2,1,0x2901
+BLEGATTCCHAR:"char",0,3,3,0xC302,0x08
+BLEGATTCCHAR:"desc",0,3,3,1,0x2901
+BLEGATTCCHAR:"char",0,3,4,0xC303,0x04
+BLEGATTCCHAR:"desc",0,3,4,1,0x2901
+BLEGATTCCHAR:"char",0,3,5,0xC304,0x08
+BLEGATTCCHAR:"char",0,3,6,0xC305,0x10
+BLEGATTCCHAR:"desc",0,3,6,1,0x2902
+BLEGATTCCHAR:"char",0,3,7,0xC306,0x20
+BLEGATTCCHAR:"desc",0,3,7,1,0x2902
+BLEGATTCCHAR:"char",0,3,8,0xC307,0x02
+BLEGATTCCHAR:"desc",0,3,8,1,0x2901

OK

ESP32 Bluetooth LE client sets characteristics.

Select the service characteristic that supports the write operation (characteristic) to set the characteristic.

Command:
```
AT+BLEGATTSSETATTR=1,8,,1
```
Response:
```
>
```
Command:
```
Write 1 byte ``9``
```
Response:
```
OK
```
ESP32 Bluetooth LE server reads characteristics.

Command:
```
AT+BLEGATTCRD=0,3,8,
```
Response:
```
+BLEGATTCRD:0,1,9

OK
```
ESP32 Bluetooth LE client write characteristics.

Select the service characteristic that supports the write operation to write the characteristics.

Command:
```
AT+BLEGATTCWR=0,3,6,1,2
```
Response:
```
>
```
Command:
```
Write 2 bytes ``12``
```
Response:
```
OK
```
Note:
- If the Bluetooth LE server successfully writes the service characteristic value, the Bluetooth LE client will prompt +WRITE:0,1,6,1,2,12.
ESP32 Bluetooth LE client notify characteristics.

Command:
```
AT+BLEGATTSNTFY=0,1,6,10
```
Response:
```
>
```
Command:
```
Write 10 bytes ``1234567890``
```
Response:
```
OK
```
Note:
- If the ESP32 Bluetooth LE client’s notify characteristic is successfully sent to the server, the Bluetooth LE server +NOTIFY:0,3,6,10,1234567890 will be prompt.

Encrypt Bluetooth LE connection ¶

Below is an example of using two ESP32 development boards, one as a Bluetooth LE server (only as Bluetooth LE server role), the other one as a Bluetooth LE client (only as Bluetooth LE client role). The example shows how to encrypt Bluetooth LE connection.

Important

In the following steps, the operations starting with ESP32 Bluetooth LE server only need to be executed at ESP32 Bluetooth LE server, and the operations starting with ESP32 Bluetooth LE client only need to be executed at ESP32 Bluetooth LE client.
Encryption and bonding are two different concepts. bonding is just a long-term key stored locally after successful encryption.
ESP-AT allows a maximum of 10 devices to be bonded.

Bluetooth LE initialization.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLEINIT=1
```
Response:
```
OK
```
ESP32 Bluetooth LE server gets Bluetooth LE address.

Command:
```
AT+BLEADDR?
```
Response:
```
+BLEADDR:"24:0a:c4:d6:e4:46"
OK
```
Note:
- The address you obtain may be different from that in the above response. Keep yours handy as you will need it in one of the following steps.
ESP32 Bluetooth LE server creates services.

Command:
```
AT+BLEGATTSSRVCRE
```
Response:
```
OK
```
ESP32 Bluetooth LE server starts services.

Command:
```
AT+BLEGATTSSRVSTART
```
Response:
```
OK
```

ESP32 Bluetooth LE server discovers characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

+BLEGATTSCHAR:"char",1,1,0xC300,0x02
+BLEGATTSCHAR:"desc",1,1,1,0x2901
+BLEGATTSCHAR:"char",1,2,0xC301,0x02
+BLEGATTSCHAR:"desc",1,2,1,0x2901
+BLEGATTSCHAR:"char",1,3,0xC302,0x08
+BLEGATTSCHAR:"desc",1,3,1,0x2901
+BLEGATTSCHAR:"char",1,4,0xC303,0x04
+BLEGATTSCHAR:"desc",1,4,1,0x2901
+BLEGATTSCHAR:"char",1,5,0xC304,0x08
+BLEGATTSCHAR:"char",1,6,0xC305,0x10
+BLEGATTSCHAR:"desc",1,6,1,0x2902
+BLEGATTSCHAR:"char",1,7,0xC306,0x20
+BLEGATTSCHAR:"desc",1,7,1,0x2902
+BLEGATTSCHAR:"char",1,8,0xC307,0x02
+BLEGATTSCHAR:"desc",1,8,1,0x2901
+BLEGATTSCHAR:"char",2,1,0xC400,0x02
+BLEGATTSCHAR:"desc",2,1,1,0x2901
+BLEGATTSCHAR:"char",2,2,0xC401,0x02
+BLEGATTSCHAR:"desc",2,2,1,0x2901

OK

ESP32 Bluetooth LE server starts advertising, then the ESP32 Bluetooth LE client starts scanning and lasts for 3 s.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLESCAN=1,3
```
Response:
```
OK
+BLESCAN:"5b:3b:6c:51:90:49",-87,02011a020a0c0aff4c001005071c3024dc,,1
+BLESCAN:"c4:5b:be:93:ec:66",-84,0201060303111809095647543147572d58020a03,,0
+BLESCAN:"24:0a:c4:d6:e4:46",-29,,,0
```
Note:
- The scan results you obtain may be different from those in the above response.
Establish the Bluetooth LE connection.

ESP32 Bluetooth LE client:

Command:
```
AT+BLECONN=0,"24:0a:c4:d6:e4:46"
```
Response:
```
+BLECONN:0,"24:0a:c4:d6:e4:46"

OK
```
Note:
- When entering the above command, replace the address with your ESP Bluetooth LE server address.
- If the Bluetooth LE connection is established successfully, message +BLECONN:0,"24:0a:c4:d6:e4:46 will be prompted.
- If the Bluetooth LE connection is broken, message +BLECONN:0,-1 will be prompted.
ESP32 Bluetooth LE client discovers services.

Command:
```
AT+BLEGATTCPRIMSRV=0
```
Response:
```
 +BLEGATTCPRIMSRV:0,1,0x1801,1
 +BLEGATTCPRIMSRV:0,2,0x1800,1
 +BLEGATTCPRIMSRV:0,3,0xA002,1
 +BLEGATTCPRIMSRV:0,4,0xA003,1

OK
```
Note:
- When discovering services, the ESP32 Bluetooth LE client will get two more default services (UUID: 0x1800 and 0x1801) than what the ESP32 Bluetooth LE server will get. So, for the same service, the <srv_index> received by the ESP32 Bluetooth LE client equals the <srv_index> received by the ESP32 Bluetooth LE server + 2. For example, for service 0xA002, the <srv_index> queried on the ESP32 Bluetooth LE client is 3, if the ESP32 Bluetooth LE server is queried through the command AT+BLEGATTSSRV?, then <srv_index> is 1.

ESP32 Bluetooth LE client discovers characteristics.

Command:

AT+BLEGATTCCHAR=0,3

Response:

+BLEGATTCCHAR:"char",0,3,1,0xC300,0x02
+BLEGATTCCHAR:"desc",0,3,1,1,0x2901
+BLEGATTCCHAR:"char",0,3,2,0xC301,0x02
+BLEGATTCCHAR:"desc",0,3,2,1,0x2901
+BLEGATTCCHAR:"char",0,3,3,0xC302,0x08
+BLEGATTCCHAR:"desc",0,3,3,1,0x2901
+BLEGATTCCHAR:"char",0,3,4,0xC303,0x04
+BLEGATTCCHAR:"desc",0,3,4,1,0x2901
+BLEGATTCCHAR:"char",0,3,5,0xC304,0x08
+BLEGATTCCHAR:"char",0,3,6,0xC305,0x10
+BLEGATTCCHAR:"desc",0,3,6,1,0x2902
+BLEGATTCCHAR:"char",0,3,7,0xC306,0x20
+BLEGATTCCHAR:"desc",0,3,7,1,0x2902
+BLEGATTCCHAR:"char",0,3,8,0xC307,0x02
+BLEGATTCCHAR:"desc",0,3,8,1,0x2901

OK

Set Bluetooth LE encryption parameters. Set auth_req to SC_MITM_BOND, server’s iocap to KeyboardOnly, client’s iocap to KeyboardDisplay, key_size to 16, init_key to 3, rsp_key to 3.

ESP32 Bluetooth LE server:

Command:
```
AT+BLESECPARAM=13,2,16,3,3
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLESECPARAM=13,4,16,3,3
```
Response:
```
OK
```
Note:
- In this example, ESP32 Bluetooth LE server enters the pairing code and ESP32 Bluetooth LE client displays the pairing code.
- ESP-AT supports Legacy Pairing and Secure Connections encryption methods, but the latter has a higher priority. If the peer also supports Secure Connections, then Secure Connections will be used for encryption.
ESP32 Bluetooth LE client initiates encryption request.

Command:
```
AT+BLEENC=0,3
```
Response:
```
OK
```
Note:

If the ESP32 Bluetooth LE server successfully receives the encryption request, message +BLESECREQ:0 will be prompted on the ESP32 Bluetooth LE server side.
ESP32 Bluetooth LE server responds to the pairing request.

Command:
```
AT+BLEENCRSP=0,1
```
Response:
```
OK
```
Note:
- If the ESP32 Bluetooth LE client successfully receives the pairing response, a 6-digit pairing code will generate on the ESP32 Bluetooth LE client side.
- In this example, message +BLESECNTFYKEY:0,793718 will be prompted on the ESP32 Bluetooth LE client side. Pairing code is 793718.
ESP32 Bluetooth LE server replies pairing code.

Command:
```
AT+BLEKEYREPLY=0,793718
```
Response:
```
OK
```
After running this command, there will be corresponding messages prompt on both the ESP32 Bluetooth LE server and the ESP32 Bluetooth LE client.

ESP32 Bluetooth LE server:
```
+BLESECKEYTYPE:0,16
+BLESECKEYTYPE:0,1
+BLESECKEYTYPE:0,32
+BLESECKEYTYPE:0,2
+BLEAUTHCMPL:0,0
```
ESP32 Bluetooth LE client:
```
+BLESECNTFYKEY:0,793718
+BLESECKEYTYPE:0,2
+BLESECKEYTYPE:0,16
+BLESECKEYTYPE:0,1
+BLESECKEYTYPE:0,32
+BLEAUTHCMPL:0,0
```
You can ignore the message starting with +BLESECKEYTYPE. In terms of the second parameter in the message +BLEAUTHCMPL:0,0, 0 means encryption is successful, and 1 means encryption fails.

Establish SPP connection between two ESP32 development boards and transmit data in UART-Bluetooth LE Passthrough Mode ¶

Below is an example of using two ESP32 development boards, one as a Bluetooth LE server (only as Bluetooth LE server role), the other one as a Bluetooth LE client (only as Bluetooth LE client role). The example shows how to build Bluetooth LE SPP (Serial Port Profile, UART-Bluetooth LE passthrough mode) with AT commands.

Important

In the following steps, the operations starting with ESP32 Bluetooth LE server only need to be executed at ESP32 Bluetooth LE server, and the operations starting with ESP32 Bluetooth LE client only need to be executed at ESP32 Bluetooth LE client.

Bluetooth LE initialization.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
ESP32 Bluetooth LE client:

Command:
```
AT+BLEINIT=1
```
Response:
```
OK
```
ESP32 Bluetooth LE server creates services.

Command:
```
AT+BLEGATTSSRVCRE
```
Response:
```
OK
```
ESP32 Bluetooth LE server starts services.

Command:
```
AT+BLEGATTSSRVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE server gets Bluetooth LE address.

Command:
```
AT+BLEADDR?
```
Response:
```
+BLEADDR:"24:0a:c4:d6:e4:46"
OK
```
Note:
- The address you obtain may be different from that in the above response. Keep yours handy as you will need it in one of the following steps.

Set Bluetooth LE advertising data.

Command:

AT+BLEADVDATA="0201060A09457370726573736966030302A0"

Response:

OK

ESP32 Bluetooth LE server starts advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```

ESP32 Bluetooth LE client enables a scanning for three seconds.

Command:

AT+BLESCAN=1,3

Response:

OK
+BLESCAN:"24:0a:c4:d6:e4:46",-78,0201060a09457370726573736966030302a0,,0
+BLESCAN:"45:03:cb:ac:aa:a0",-62,0201060aff4c001005441c61df7d,,1
+BLESCAN:"24:0a:c4:d6:e4:46",-26,0201060a09457370726573736966030302a0,,0

Note:

The scan results you obtain may be different from those in the above response.

Establish the Bluetooth LE connection.

ESP32 Bluetooth LE client:

Command:
```
AT+BLECONN=0,"24:0a:c4:d6:e4:46"
```
Response:
```
+BLECONN:0,"24:0a:c4:d6:e4:46"

OK
```
Note:
- When entering the above command, replace the address your ESP Bluetooth LE server address.
- If the Bluetooth LE connection is established successfully, message +BLECONN:0,"24:0a:c4:d6:e4:46 will be prompted.
- If the Bluetooth LE connection is broken, message +BLECONN:0,-1 will be prompted.

ESP32 Bluetooth LE server discovers local services.

Command:

AT+BLEGATTSSRV?

Response:

+BLEGATTSSRV:1,1,0xA002,1
+BLEGATTSSRV:2,1,0xA003,1

OK

ESP32 Bluetooth LE server discovers local characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

+BLEGATTSCHAR:"char",1,1,0xC300,0x02
+BLEGATTSCHAR:"desc",1,1,1,0x2901
+BLEGATTSCHAR:"char",1,2,0xC301,0x02
+BLEGATTSCHAR:"desc",1,2,1,0x2901
+BLEGATTSCHAR:"char",1,3,0xC302,0x08
+BLEGATTSCHAR:"desc",1,3,1,0x2901
+BLEGATTSCHAR:"char",1,4,0xC303,0x04
+BLEGATTSCHAR:"desc",1,4,1,0x2901
+BLEGATTSCHAR:"char",1,5,0xC304,0x08
+BLEGATTSCHAR:"char",1,6,0xC305,0x10
+BLEGATTSCHAR:"desc",1,6,1,0x2902
+BLEGATTSCHAR:"char",1,7,0xC306,0x20
+BLEGATTSCHAR:"desc",1,7,1,0x2902
+BLEGATTSCHAR:"char",1,8,0xC307,0x02
+BLEGATTSCHAR:"desc",1,8,1,0x2901
+BLEGATTSCHAR:"char",2,1,0xC400,0x02
+BLEGATTSCHAR:"desc",2,1,1,0x2901
+BLEGATTSCHAR:"char",2,2,0xC401,0x02
+BLEGATTSCHAR:"desc",2,2,1,0x2901

OK

ESP32 Bluetooth LE client discovers services.

Command:
```
AT+BLEGATTCPRIMSRV=0
```
Response:
```
 +BLEGATTCPRIMSRV:0,1,0x1801,1
 +BLEGATTCPRIMSRV:0,2,0x1800,1
 +BLEGATTCPRIMSRV:0,3,0xA002,1
 +BLEGATTCPRIMSRV:0,4,0xA003,1

OK
```
Note:
- When discovering services, the ESP32 Bluetooth LE client will get two more default services (UUID: 0x1800 and 0x1801) than what the ESP32 Bluetooth LE server will get. So, for the same service, the <srv_index> received by the ESP32 Bluetooth LE client equals the <srv_index> received by the ESP32 Bluetooth LE server + 2. For example, for service 0xA002, the <srv_index> queried on the ESP32 Bluetooth LE client is 3, if the ESP32 Bluetooth LE server is queried through the command AT+BLEGATTSSRV?, then <srv_index> is 1.

ESP32 Bluetooth LE client discovers characteristics.

Command:

AT+BLEGATTCCHAR=0,3

Response:

+BLEGATTCCHAR:"char",0,3,1,0xC300,0x02
+BLEGATTCCHAR:"desc",0,3,1,1,0x2901
+BLEGATTCCHAR:"char",0,3,2,0xC301,0x02
+BLEGATTCCHAR:"desc",0,3,2,1,0x2901
+BLEGATTCCHAR:"char",0,3,3,0xC302,0x08
+BLEGATTCCHAR:"desc",0,3,3,1,0x2901
+BLEGATTCCHAR:"char",0,3,4,0xC303,0x04
+BLEGATTCCHAR:"desc",0,3,4,1,0x2901
+BLEGATTCCHAR:"char",0,3,5,0xC304,0x08
+BLEGATTCCHAR:"char",0,3,6,0xC305,0x10
+BLEGATTCCHAR:"desc",0,3,6,1,0x2902
+BLEGATTCCHAR:"char",0,3,7,0xC306,0x20
+BLEGATTCCHAR:"desc",0,3,7,1,0x2902
+BLEGATTCCHAR:"char",0,3,8,0xC307,0x02
+BLEGATTCCHAR:"desc",0,3,8,1,0x2901

OK

ESP32 Bluetooth LE client Configures Bluetooth LE SPP.

Set a characteristic that enables writing permission to TX channel for sending data. Set another characteristic that supports notification or indication to RX channel for receiving data.

Command:
```
AT+BLESPPCFG=1,3,5,3,7
```
Response:
```
OK
```
ESP32 Bluetooth LE client enables Bluetooth LE SPP.

Command:
```
AT+BLESPP
```
Response:
```
OK

>
```
This response indicates that AT has entered Bluetooth LE SPP mode and can send and receive data.

Note:
- After the ESP32 Bluetooth LE client enables Bluetooth LE SPP, data received from serial port will be transmitted to the Bluetooth LE server directly.
ESP32 Bluetooth LE server Configures Bluetooth LE SPP.

Set a characteristic that supports notification or indication to TX channel for sending data. Set another characteristic that enables writing permission to RX channel for receiving data.

Command:
```
AT+BLESPPCFG=1,1,7,1,5
```
Response:
```
OK
```
ESP32 Bluetooth LE server enables Bluetooth LE SPP.

Command:
```
AT+BLESPP
```
Response:
```
OK

>
```
This response indicates that AT has entered Bluetooth LE SPP mode and can send and receive data.

Note:
- After the ESP32 Bluetooth LE server enables Bluetooth LE SPP, the data received from serial port will be transmitted to the Bluetooth LE client directly.
- If the ESP32 Bluetooth LE client does not enable Bluetooth LE SPP first, or uses other device as Bluetooth LE client, then the Bluetooth LE client needs to listen to the notification or indication first. For example, if the ESP32 Bluetooth LE client does not enable Bluetooth LE SPP first, then it should use command AT+BLEGATTCWR=0,3,7,1,1 to enable listening function first, so that the ESP32 Bluetooth LE server can transmit successfully.
- For the same service, the <srv_index> on the ESP32 Bluetooth LE client side equals the <srv_index> on the ESP32 Bluetooth LE server side + 2.

Establish SPP connection between ESP32 and mobile phone and transmit data in UART-Bluetooth LE passthrough mode ¶

The example shows how to establish SPP connection between an ESP32 development board (only serving as the Bluetooth LE server role) and a mobile phone (only serve as the Bluetooth LE client role) and how to transmit data between them in UART-Bluetooth LE passthrough mode.

Important

In the following steps, the operations starting with ESP32 Bluetooth LE server only need to be executed at ESP32 Bluetooth LE server, and those Bluetooth LE client only need to be executed at the Bluetooth debugging assistant of the mobile phone.

First, you need to download the Bluetooth LE debugging assistant on the mobile phone, such as nRF Connect app (Android) and LightBlue (iOS).
Bluetooth LE initialization.

ESP32 Bluetooth LE server:

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
ESP32 Bluetooth LE server creates services.

Command:
```
AT+BLEGATTSSRVCRE
```
Response:
```
OK
```
ESP32 Bluetooth LE server starts services.

Command:
```
AT+BLEGATTSSRVSTART
```
Response:
```
OK
```
ESP32 Bluetooth LE server gets its MAC address.

Command:
```
AT+BLEADDR?
```
Response:
```
+BLEADDR:"24:0a:c4:d6:e4:46"
OK
```
Note:
- The address you obtain may be different from that in the above response. Keep yours handy as you will need it in one of the following steps.

Set Bluetooth LE advertising data.

Command:

AT+BLEADVDATA="0201060A09457370726573736966030302A0"

Response:

OK

ESP32 Bluetooth LE server starts advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
Establish the Bluetooth LE connection.

Open the nRF debugging assistant on your mobile phone, and open SCAN to start scanning. When you find the MAC address of the ESP32 Bluetooth LE server, click CONNECT. Then, ESP32 should print the log similar to +BLECONN:0,"60:51:42:fe:98:aa", which indicates that Bluetooth LE connection has been established.

ESP32 Bluetooth LE server discovers local services.

Command:

AT+BLEGATTSSRV?

Response:

+BLEGATTSSRV:1,1,0xA002,1
+BLEGATTSSRV:2,1,0xA003,1

OK

ESP32 Bluetooth LE server discovers local characteristics.

Command:

AT+BLEGATTSCHAR?

Response:

+BLEGATTSCHAR:"char",1,1,0xC300,0x02
+BLEGATTSCHAR:"desc",1,1,1,0x2901
+BLEGATTSCHAR:"char",1,2,0xC301,0x02
+BLEGATTSCHAR:"desc",1,2,1,0x2901
+BLEGATTSCHAR:"char",1,3,0xC302,0x08
+BLEGATTSCHAR:"desc",1,3,1,0x2901
+BLEGATTSCHAR:"char",1,4,0xC303,0x04
+BLEGATTSCHAR:"desc",1,4,1,0x2901
+BLEGATTSCHAR:"char",1,5,0xC304,0x08
+BLEGATTSCHAR:"char",1,6,0xC305,0x10
+BLEGATTSCHAR:"desc",1,6,1,0x2902
+BLEGATTSCHAR:"char",1,7,0xC306,0x20
+BLEGATTSCHAR:"desc",1,7,1,0x2902
+BLEGATTSCHAR:"char",1,8,0xC307,0x02
+BLEGATTSCHAR:"desc",1,8,1,0x2901
+BLEGATTSCHAR:"char",2,1,0xC400,0x02
+BLEGATTSCHAR:"desc",2,1,1,0x2901
+BLEGATTSCHAR:"char",2,2,0xC401,0x02
+BLEGATTSCHAR:"desc",2,2,1,0x2901

OK

Bluetooth LE client discovers services.

Click UnKnown Service of UUID:0xA002 on the mobile phone nRF debugging assistant client.
ESP32 Bluetooth LE client discovers characteristics.

In the next-level option of UnKnown Service of UUID:0xA002 of the mobile phone nRF debugging assistant client, click the right button of the service feature whose Properties is NOTIFY or INDICATE (here ESP-AT default Properties The service characteristics of NOTIFY or INDICATE are 0xC305 and 0xC306) and start to listen for the service characteristics of NOTIFY or INDICATE.
ESP32 Bluetooth LE server configures Bluetooth LE SPP.

Set a characteristic that supports notification or indication to TX channel for sending data. Set another characteristic that enables writing permission to RX channel for receiving data.

Command:
```
AT+BLESPPCFG=1,1,7,1,5
```
Response:
```
OK
```
ESP32 Bluetooth LE server enables Bluetooth LE SPP.

Command:
```
AT+BLESPP
```
Response:
```
OK

>
```
This response indicates that AT has entered Bluetooth LE SPP mode and can send and receive data.
Bluetooth LE client sends data.

In the nRF debugging assistant client, select the 0xC304 service characteristic value and send the data test to the ESP32 Bluetooth LE server. Then, the ESP32 Bluetooth LE server can receive the test.
ESP32 Bluetooth LE server sends data.

The ESP32 Bluetooth LE server sends test, and then the nRF debugging assistant client can receive test.

MQTT AT Examples¶

[中文]

This document provides detailed command examples to illustrate how to utilize MQTT AT Commands on ESP devices.

MQTT over TCP (with a local MQTT broker)(suitable for a small amount of data)
MQTT over TCP (with a local MQTT broker)(suitable for large amounts of data)
MQTT over TLS (with a local MQTT broker)
MQTT over WSS

Important

The examples described in this document are based on the situation that Wi-Fi has been connected.

MQTT over TCP (with a local MQTT broker)(suitable for a small amount of data)¶

Below is an example of using two ESP32 development boards, one as a MQTT publisher (only as MQTT publisher role), the other one as a MQTT subscriber (only as MQTT subscriber role).

The example shows how to establish MQTT connections over TCP. You need to first create a local MQTT broker. For example, the MQTT broker’s IP address is 192.168.3.102, and the port is 8883.

Important

In the step, the operations starting with ESP32 MQTT publisher only need to be executed at ESP32 MQTT publisher, and the operations starting with ESP32 MQTT subscriber only need to be executed at ESP32 MQTT subscriber. If the operation is not specified on which side it is executed, it needs to be executed on both the publisher side and the subscriber side.

Set MQTT user configuration.

ESP32 MQTT publisher:

Command:

AT+MQTTUSERCFG=0,1,"publisher","espressif","123456789",0,0,""

Response:

OK

ESP32 MQTT subscriber:

Command:

AT+MQTTUSERCFG=0,1,"subscriber","espressif","123456789",0,0,""

Response:

OK

Connect to MQTT brokers.

Command:
```
AT+MQTTCONN=0,"192.168.3.102",8883,1
```
Response:
```
+MQTTCONNECTED:0,1,"192.168.3.102","8883","",1

OK
```
Note:
- The MQTT broker domain or MQTT broker IP address you enter may be different from those in the above command.
Subscribe to MQTT topics.

ESP32 MQTT subscriber:

Command:
```
AT+MQTTSUB=0,"topic",1
```
Response:
```
OK
```
Publish MQTT messages in string.

ESP32 MQTT publisher:

Command:
```
AT+MQTTPUB=0,"topic","test",1,0
```
Response:
```
OK
```
Note:
- If the ESP32 MQTT publisher successfully publishes the message, following message will be prompted on the ESP32 MQTT subscriber.
```
+MQTTSUBRECV:0,"topic",4,test
```
Close MQTT connections.

Command:
```
AT+MQTTCLEAN=0
```
Response:
```
OK
```

MQTT over TCP (with a local MQTT broker)(suitable for large amounts of data)¶

Below is an example of using two ESP32 development boards, one as a MQTT publisher (only as MQTT publisher role), the other one as a MQTT subscriber (only as MQTT subscriber role).

The example shows how to establish MQTT connections over TCP. You need to first create a local MQTT broker. For example, the MQTT broker’s IP address is 192.168.3.102, and the port is 8883.

If the amount of data you publish is relatively large, and the length of a single AT command has exceeded the threshold of 256, it is recommended that you use the AT+MQTTPUBRAW command.

Important

In the step, the operations starting with ESP32 MQTT publisher only need to be executed at ESP32 MQTT publisher, and the operations starting with ESP32 MQTT subscriber only need to be executed at ESP32 MQTT subscriber. If the operation is not specified on which side it is executed, it needs to be executed on both the publisher side and the subscriber side.

Set MQTT user configuration.

ESP32 MQTT publisher:

Command:

AT+MQTTUSERCFG=0,1,"publisher","espressif","123456789",0,0,""

Response:

OK

ESP32 MQTT subscriber:

Command:

AT+MQTTUSERCFG=0,1,"subscriber","espressif","123456789",0,0,""

Response:

OK

Connect to MQTT brokers.

Command:
```
AT+MQTTCONN=0,"192.168.3.102",8883,1
```
Response:
```
+MQTTCONNECTED:0,1,"192.168.3.102","8883","",1

OK
```
Note:
- The MQTT broker domain or MQTT broker IP address you enter may be different from those in the above command.
Subscribe to MQTT topics.

ESP32 MQTT subscriber:

Command:
```
AT+MQTTSUB=0,"topic",1
```
Response:
```
OK
```

Publish MQTT messages in string.

Assume the data you want to publish is as follows, length is 427 bytes.

{"headers": {"Accept": "application/json","Accept-Encoding": "gzip, deflate","Accept-Language": "en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7","Content-Length": "0","Host": "httpbin.org","Origin": "http://httpbin.org","Referer": "http://httpbin.org/","User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36","X-Amzn-Trace-Id": "Root=1-6150581e-1ad4bd5254b4bf5218070413"}}

ESP32 MQTT publisher:

Command:

AT+MQTTPUBRAW=0,"topic",427,0,0

Response:

OK

>

This response indicates that AT is ready for receiving serial data. You should enter the data, and when the data length reaches the <length> value, the transmission of data starts.

+MQTTPUB:OK

Note:

After AT outputs the > character, the special characters in the data does not need to be escaped through the escape character, and it does not need to end with a new line(CR-LF).

If the ESP32 MQTT publisher successfully publishes the message, following message will be prompted on the ESP32 MQTT subscriber.

+MQTTSUBRECV:0,"topic",427,{"headers": {"Accept": "application/json","Accept-Encoding": "gzip, deflate","Accept-Language": "en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7","Content-Length": "0","Host": "httpbin.org","Origin": "http://httpbin.org","Referer": "http://httpbin.org/","User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36","X-Amzn-Trace-Id": "Root=1-6150581e-1ad4bd5254b4bf5218070413"}}

Close MQTT connections.

Command:
```
AT+MQTTCLEAN=0
```
Response:
```
OK
```

MQTT over TLS (with a local MQTT broker)¶

Below is an example of using two ESP32 development boards, one as a MQTT publisher (only as MQTT publisher role), the other one as a MQTT subscriber (only as MQTT subscriber role).

The example shows how to establish MQTT connections over TLS. You need to first create a local MQTT broker. For example, the MQTT broker’s IP address is 192.168.3.102, and port is 8883.

Important

In the step, the operations starting with ESP32 MQTT publisher only need to be executed at ESP32 MQTT publisher, and the operations starting with ESP32 MQTT subscriber only need to be executed at ESP32 MQTT subscriber. If the operation is not specified on which side it is executed, it needs to be executed on both the publisher side and the subscriber side.

Set the time zone and the SNTP server.

Command:
```
AT+CIPSNTPCFG=1,8,"ntp1.aliyun.com"
```
Response:
```
OK
```
Query the SNTP time.

Command:
```
AT+CIPSNTPTIME?
```
Response:
```
+CIPSNTPTIME:Thu Sep  2 18:57:03 2021
OK
```
Note:
- The time you obtained may be different from that in the above response.
- Please make sure that the SNTP time must be a real and valid time and cannot be the time in 1970 or before.
- The purpose of setting the time is to verify the validity period of the certificates during TLS authentication.

Set MQTT user configuration.

ESP32 MQTT publisher:

Command:

AT+MQTTUSERCFG=0,4,"publisher","espressif","123456789",0,0,""

Response:

OK

ESP32 MQTT subscriber:

Command:

AT+MQTTUSERCFG=0,4,"subscriber","espressif","123456789",0,0,""

Response:

OK

Set configuration of MQTT connection.

Command:
```
AT+MQTTCONNCFG=0,0,0,"lwtt","lwtm",0,0
```
Response:
```
OK
```
Connect to MQTT brokers.

Command:
```
AT+MQTTCONN=0,"192.168.3.102",8883,1
```
Response:
```
+MQTTCONNECTED:0,4,"192.168.3.102","8883","",1

OK
```
Note:
- The MQTT broker domain or MQTT broker IP address you enter may be different from those in the above command.
Subscribe to MQTT topics.

ESP32 MQTT subscriber:

Command:
```
AT+MQTTSUB=0,"topic",1
```
Response:
```
OK
```
Publish MQTT messages in string.

ESP32 MQTT publisher:

Command:
```
AT+MQTTPUB=0,"topic","test",1,0
```
Response:
```
OK
```
Note:
- If the ESP32 MQTT publisher successfully publishes the message, following message will be prompted on the ESP32 MQTT subscriber.
```
+MQTTSUBRECV:0,"topic",4,test
```
Close MQTT connections.

Command:
```
AT+MQTTCLEAN=0
```
Response:
```
OK
```

MQTT over WSS ¶

Below is an example of using two ESP32 development boards, one as a MQTT publisher (only as MQTT publisher role), the other one as a MQTT subscriber (only as MQTT subscriber role).

The example shows how to establish MQTT connections over WSS and how to communicate with a MQTT broker. For example, the MQTT broker’s domain name is test.mosquitto.org, and the port is 8081.

Important

In the step, the operations starting with ESP32 MQTT publisher only need to be executed at ESP32 MQTT publisher, and the operations starting with ESP32 MQTT subscriber only need to be executed at ESP32 MQTT subscriber. If the operation is not specified on which side it is executed, it needs to be executed on both the publisher side and the subscriber side.

Set the time zone and the SNTP server.

Command:
```
AT+CIPSNTPCFG=1,8,"ntp1.aliyun.com"
```
Response:
```
OK
```
Query the SNTP time.

Command:
```
AT+CIPSNTPTIME?
```
Response:
```
+CIPSNTPTIME:Thu Sep  2 18:57:03 2021
OK
```
Note:
- The time you obtained may be different from that in the above response.
- Please make sure that the SNTP time must be a real and valid time and cannot be the time in 1970 or before.
- The purpose of setting the time is to verify the validity period of the certificates during TLS authentication.

Set MQTT user configuration.

ESP32 MQTT publisher:

Command:

AT+MQTTUSERCFG=0,7,"publisher","espressif","1234567890",0,0,""

Response:

OK

ESP32 MQTT subscriber:

Command:

AT+MQTTUSERCFG=0,7,"subscriber","espressif","1234567890",0,0,""

Response:

OK

Connect to MQTT brokers.

Command:
```
AT+MQTTCONN=0,"test.mosquitto.org",8081,1
```
Response:
```
+MQTTCONNECTED:0,7,"test.mosquitto.org","8081","/",1

OK
```
Note:
- The MQTT broker domain or MQTT broker IP address you enter may be different from those in the above command.
Subscribe to MQTT topics.

ESP32 MQTT subscriber:

Command:
```
AT+MQTTSUB=0,"topic",1
```
Response:
```
OK
```
Publish MQTT messages in string.

ESP32 MQTT publisher:

Command:
```
AT+MQTTPUB=0,"topic","test",1,0
```
Response:
```
OK
```
Note:
- If the ESP32 MQTT publisher successfully publishes the message, following message will be prompted on the ESP32 MQTT subscriber.
```
+MQTTSUBRECV:0,"topic",4,test
```
Close MQTT connections.

Command:
```
AT+MQTTCLEAN=0
```
Response:
```
OK
```

[ESP32 Only] Ethernet AT Examples¶

[中文]

This document provides an introduction and detailed command examples to illustrate how to utilize [ESP32 Only] Ethernet AT Commands on ESP devices.

Establish a TCP connection on Ethernet network

Important

Before you run any Ethernet AT commands, please make sure you have followed the Prerequisite.
The examples described in this document are based on the situation that network cable has been plugged in.

Establish a TCP connection on Ethernet network ¶

Enable multiple connections.

Command:
```
AT+CIPMUX=1
```
Response:
```
OK
```
Create a TCP server.

Command:
```
AT+CIPSERVER=1,8081
```
Response:
```
OK
```
Obtain the IP address of the server.

Command:
```
AT+CIPETH?
```
Response:
```
+CIPETH:ip:192.168.105.24
+CIPETH:gateway:192.168.105.1
+CIPETH:netmask:255.255.255.0
OK
```
Note:
- The address you obtain may be different from that in the above response.
Use a network tool on PC to create a TCP client and connect to the TCP server by the step 2, which IP address is 192.168.105.24, port is 8081.
Send 4 bytes of data to transmission link 0 in Normal Transmission Mode.

Command:
```
AT+CIPSEND=0,4
```
Response:
```
OK

>
```
Input 4 bytes, for example, test, then AT will respond the following messages.
```
Recv 4 bytes

SEND OK
```
Note:
- If the number of bytes input exceeds the length (n) set by AT+CIPSEND, the system will reply busy p..., and send the first n bytes. After sending the first n bytes, the system will reply SEND OK.
Receive 4 bytes of data from transmission link 0 in Normal Transmission Mode.

Assume that the TCP server received 4 bytes of data (data is test), the system would be prompt as:
```
+IPD,0,4:test
```
Close TCP connection.

Command:
```
AT+CIPCLOSE=0
```
Response:
```
0,CLOSED

OK
```
Delete the TCP server.

Command:
```
AT+CIPSERVER=0
```
Response:
```
OK
```
Note:
- The AT+CIPSERVER=0 command will only shutdown the server, but will keep the existing connection. If you want to close all client connections to the server at the same time, please execute the command AT+CIPSERVER=0,1.

Web Server AT Example¶

[中文]

This document mainly introduces the use of AT web server, mainly involving the following applications:

Wi-Fi Provisioning Using a Browser
OTA Firmware Upgrade Using a Browser
Wi-Fi Provisioning Using a WeChat Applet
OTA Firmware Upgrade Using a WeChat Applet
[ESP32][ESP32-C Series] Using Captive Portal

Note

The default firmware does not support web server AT commands, please refer to Web Server AT Commands to enable the web server.

Wi-Fi Provisioning Using a Browser ¶

Introduction¶

With the web server, mobile phone or PC is able to control ESP device’s Wi-Fi provisioning service. You can use a mobile phone or computer to connect to the SoftAP of the ESP device, open the web pages via browser, start provisioning service, and then the ESP device can connect to the target router as you set.

Introduction to Operation Steps¶

The whole process can be divided into the following three steps:

Use STA Device to Connect to ESP Device
Use the Browser to Send Wi-Fi Connection Information
Get the Result of Wi-Fi Connection

Use STA Device to Connect to ESP Device ¶

Firstly, ESP device needs to be configured to softAP + STA mode, and creates a web server to wait for Wi-Fi provisioning messages. In this case, a mobile phone or a PC can connect to the ESP softAP as a station. The corresponding AT commands are as follows:

Clear the previous Wi-Fi provisioning information.
- Command
```
AT+RESTORE
```
Set the Wi-Fi mode to Station+SoftAP.
- Command
```
AT+CWMODE=3
```
Set the configuration of an ESP SoftAP. (For example, set the default connection ssid to “pos_softap”, Wi-Fi without password.)
- Command
```
AT+CWSAP="pos_softap","",11,0,3
```
Enable multiple connections.
- Command
```
AT+CIPMUX=1
```
Create a web server, port: 80, connection timeout: 25 s (default maximum is 60 s).
- Command
```
AT+WEBSERVER=1,80,25
```

After starting the web sever according to the above commands, you can turn on the Wi-Fi connection function on your STA device, and connect it to the softAP of the ESP device:

connects_to_the_ESP_AP — The browser connects to the ESP AP¶

Use the Browser to Send Wi-Fi Connection Information ¶

After your STA device connected to the ESP softAP, it can send Wi-Fi connection information to ESP in an HTTP request. Please note that if your target AP is the hotspot of the device which opens the web pages, you may not receive the Wi-Fi connection result. You can enter the default IP address of the web server in the browser (the default IP is 192.168.4.1, or you can query the current SoftAP IP address by command AT+CIPAP?), open the Wi-Fi provisioning interface, and enter the ssid and password of the router to be connected, click “Connect” to let ESP device start connecting to the router:

opens_the_Wi-Fi_configuration_interface — The browser opens the Wi-Fi provisioning interface¶

Or you can click the drop-down box of SSID to list all APs nearby, select the target AP and enter the password, and then click “Connect” to let the ESP device start connecting to the router:

Schematic_diagram_of_browser_obtaining_Wi-Fi_AP_list — Schematic diagram of browser obtaining Wi-Fi AP list¶

Get the Result of Wi-Fi Connection ¶

After the Wi-Fi connection is established successfully, the web page will be displayed as follows:

Browser_Wi-Fi_configuration_is_successful — Wi-Fi connection is established successfully¶

Note 1: After the Wi-Fi connection is established successfully, the webpage will be closed automatically. If you want to continue to access the webpage, please re-enter the IP address of the ESP device and reopen the webpage.

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information
WIFI CONNECTED       // meaning that ESP device is connecting
WIFI GOT IP          // meaning that ESP device connect successfully to the destination rounter
+WEBSERVERRSP:2      // meaning that STA device has received Wi-Fi connection result, and web resources can be released

If the ESP device fails to connect to the router, the web page will display:

ESP_device_connects_fail — ESP device fails to connect to the router¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information, but failed to connect to the rounter.

Troubleshooting¶

Note 1: The network configuration page received a prompt “Connection failed”. Please check whether the Wi-Fi AP of the ESP module is correctly turned on, and the relevant configuration of the AP, and confirm that the correct AT command has been entered to successfully enable the web server.

OTA Firmware Upgrade Using a Browser ¶

Introduction¶

After the browser opens the web page of the web server, you can choose to enter the OTA upgrade page to upgrade the firmware of the ESP device through the web page.

Open the OTA Configuration Page ¶

As shown in the figure, click on the “OTA” option in the lower right corner of the web page, and after opening the OTA configuration page, you can view the current firmware version and AT Core version:

Note 1: The configuration interface can only be opened when the STA device is connected to the AP of the ESP device, or the STA device accessing the OTA configuration page is connected to the ESP device in the same subnet.

Note 2: The “current app version” displayed on the webpage is the version number of the application. You can change the version number through ./build.py menuconfig –> Component config –> AT –> AT firmware version (see Compile ESP-AT Project). In this case, you can manage your application firmware version.

Select and Send the New Firmware ¶

As shown in the figure, click the “Browse” button on the page and select the new firmware to be sent:

Select_the_new_version_of_firmware_to_be_sent — Select the new version of firmware to be sent¶

Note 1: Before sending the new firmware, the system will check the selected firmware. The suffix of the firmware name must be .bin, and its size should not exceed 2M.

Get the Result of OTA ¶

As shown in the figure, if the ESP device OTA successfully, it will prompt “OTA Succeeded”:

The_new_firmware_was_sent_successfully — The new firmware was sent successfully¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:3      // meaning that ESP device begin to receive ota data
+WEBSERVERRSP:4      // meaning that ESP device has received all firmware data, and you can choose to restart the ESP device to apply the new firmware

If the received firmware data verification fails, the following message will be received on the serial port:

+WEBSERVERRSP:3      // meaning that ESP device begin to receive ota data
+WEBSERVERRSP:5      // meaning that the received OTA data verification failed. You can choose to reopen the OTA configuration interface and follow the above steps to restart the firmware upgrade

Wi-Fi Provisioning Using a WeChat Applet ¶

Introduction¶

The WeChat applet can automatically connect to the WiFi AP of the ESP device, and then send the ssid and password required by the ESP device to connect to the network.

Introduction to Operation Steps¶

The whole process can be divided into the following four steps:

Configure ESP Device Parameters
Load WeChat Applet
Target AP Selection
Use the WeChat Applet to Send Wi-Fi Connection Information

Configure ESP Device Parameters ¶

Firstly, ESP device needs to be configured to softAP + STA mode, and creates a web server to wait for Wi-Fi provisioning messages. In this case, a mobile phone or a PC can connect to the ESP softAP as a station. The corresponding AT commands are as follows:

Clear the previous Wi-Fi provisioning information.
- Command
```
AT+RESTORE
```
Set the Wi-Fi mode to Station+SoftAP.
- Command
```
AT+CWMODE=3
```
Set the configuration of an ESP SoftAP. (For example, set the default connection ssid to “pos_softap”, and password to “espressif”.)
- Command
```
AT+CWSAP="pos_softap","espressif",11,3,3
```

Note

By default, the WeChat applet initiates a connection to the SoftAP whose ssid is pos_softap and password is espressif. Please make sure to set the parameters of the ESP device according to the above configuration.

Enable multiple connections.
- Command
```
AT+CIPMUX=1
```
Create a web server, port: 80, connection timeout: 40 s (default maximum is 60 s).
- Command
```
AT+WEBSERVER=1,80,40
```

Load WeChat Applet ¶

Open the mobile phone WeChat, scan the following QR code:

Get_the_QR_code_of_the_applet — Get the QR code of the applet¶

Open the WeChat applet and enter the Wi-Fi provisioning interface:

Wi-Fi_configuration_interface — Wi-Fi provisioning interface¶

Target AP Selection ¶

After loading the WeChat applet, there are two situations according to different target AP:

Situation 1. If your target AP is the hotspot of the mobile phone which running the WeChat applet, please select the “Local phone hotspot” option box on the WeChat applet page.

Situation 2. If your target AP is just another AP, not as the special situation one as above, then please do not select the “Local phone hotspot” option box.

Use the WeChat Applet to Send Wi-Fi Connection Information ¶

The target AP to be accessed is not the hotspot provided by the mobile phone which loading the WeChat applet.¶

Here, take connecting to a router as an example, the process of Wi-Fi Connection configuration is introduced:

1.Turn on the mobile Wi-Fi and connect to the router:

connect_to_the_rounter — connect to the rounter¶

2.Open the WeChat applet, you can see that the applet page has automatically displayed the ssid of the current router as “FAST_FWR310_02”.

get_rounter_info — The applet obtains the information of the router to be connected¶

Note: If the ssid of the connected router is not displayed on the current page, please click “Re-enter applet” in the following figure to refresh the current page:

Re-enter_the_applet — Re-enter the applet¶

3.After entering the password of the router, click “Connect”.

wechat_rounter_connecting — The applet starts the ESP device to connect to the router¶

4.After the Wi-Fi connection is established successfully, the web page will be displayed as follows:

wechat_rounter_connect_success — The applet Wi-Fi provisioning is successful¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information
WIFI CONNECTED       // meaning that ESP device is connecting
WIFI GOT IP          // meaning that ESP device connect successfully to the destination rounter
+WEBSERVERRSP:2      // meaning that STA device has received Wi-Fi connection result, and web resources can be released

5.If the ESP device fails to connect to the router, the page will display:

wechat_rounter_connect_fail — The applet Wi-Fi provisioning is failed¶

At the same time, the following messages will be returned from the ESP-AT command port:

+WEBSERVERRSP:1      // meaning that ESP device has received Wi-Fi connection information, but failed to connect to the rounter.

The target AP to be accessed is the hotspot provided by the mobile phone which loading the WeChat applet.¶

If the target AP to be accessed is the hotspot provided by the mobile phone which loading the WeChat applet, it is not necessary to enter the ssid, but only needs to enter the password of the AP, and turn on the mobile AP in time according to the prompts.

1.Select the “Local phone hotspot” option box on the WeChat applet page, enter the password of the local hotspot, and click “Connect”.

wechat_enter_local_password — Enter the password of the AP¶

2.After receiving the prompt “Connecting to the mobile phone hotspot”, please check that the local mobile phone hotspot is turned on. At this time, the ESP device will automatically scan the surrounding hotspots and initiate a connection.

wechat_start_connect — Start to connect to the AP¶

3.The display of the WiFi connection results on the applet page and the data output from the serial port are the same as the above-mentioned “The target AP to be accessed is not the hotspot provided by the mobile phone which loading the WeChat applet.”, please refer to the above.

Troubleshooting¶

Note 1: The Wi-Fi provisioning page received a prompt “Data transmission failed”. Please check whether the Wi-Fi AP of the ESP device is correctly turned on, and the relevant configuration of the AP, and confirm that the correct AT command has been entered to successfully enable the web server.

Note 2: The Wi-Fi provisioning page receives a prompt “Failed to connect to the AP”. Please check whether the Wi-Fi connection function of the mobile phone is turned on, check whether the Wi-Fi AP of the ESP device is correctly turned on, and whether the ssid and password of the AP are configured according to the above steps.

Note 3: The Wi-Fi provisioning page receives a prompt “The Wi-Fi provisioning saved by the system expired”. Please manually connect the ESP device AP with a mobile phone, and confirm that the ssid and password of the ESP module have been configured according to the above steps.

OTA Firmware Upgrade Using a WeChat Applet ¶

The WeChat applet support online firmware upgrade , please refer to the above-described Configure ESP Device Parameters specific steps performed ESP device configuration (if the configuration has been completed, do not repeat configuration). Once configured, the device performs OTA firmware upgrade processes is similar as OTA Firmware Upgrade Using a Browser .

[ESP32][ESP32-C Series] Using Captive Portal ¶

Introduction¶

Captive Portal is commonly used to present a specified page to newly connected devices of a Wi-Fi or wired network. For more information about Captive Portal, please refer to Captive Portal Wiki .

Note

The default firmware does not support web server Captive Portal, you may enable it by ./build.py menuconfig > Component config > AT > AT WEB Server command support > AT WEB captive portal support and build the project (see Compile ESP-AT Project). In addition, enabling this feature may cause page skipping when using wechat applet for Wi-Fi provisioning or OTA firmware upgrade. It is recommended that this feature be enabled only when accessing at web using browser.

Introduction to Operation Steps¶

After Enable Captive Portal support, please refer to Use STA Device to Connect to ESP Device to complete the configuration of the ESP device, and then connect to the AP of the ESP device:

auth_pages — Connect to the AP with Captive Portal enabled¶

As shown in the figure above, after the Station device is connected to the AP of the ESP device with the Captive Portal function enabled, it will prompt “requires login/authentication”, and then the browser will automatically open and jump to the main interface of AT Web. If it cannot be redirected automatically, please follow the instructions of the Station device, click “Authentication” or click the name of the “pos_softap” hotspot in the figure above to manually trigger the Captive Portal to automatically open the browser and enter the main interface of AT Web.

Troubleshooting¶

Note 1: Both Station device and AP device support the Captive Portal function to ensure the normal use of this function. Therefore, if the device is connected to the AP of the ESP device, but it does not prompt “Login/Authentication”, it may be that the Station device does not support this function. In this case, please refer to the specific steps of Use the Browser to Send Wi-Fi Connection Information above to open the main interface of AT Web.

HTTP AT Examples¶

[中文]

This document provides detailed command examples to illustrate how to utilize HTTP AT Commands on ESP devices.

The HEAD method of HTTP client
The GET method of HTTP client
The POST method of HTTP client (suitable for POST small amount of data)
The POST method of HTTP client (recommended method)
The PUT method of HTTP client
The DELETE method of HTTP client

Important

Currently ESP-AT only supports some HTTP client functions.

The HEAD method of HTTP client ¶

In this example, the HTTP server is http://httpbin.org.

Restore factory default settings of the module.

Command:
```
AT+RESTORE
```
Response:
```
OK
```
Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.

Send an HTTP HEAD request. Set opt to 1 (HEAD method), url to http://httpbin.org/get and transport_type to 1 (HTTP_TRANSPORT_OVER_TCP).

Command:

AT+HTTPCLIENT=1,0,"http://httpbin.org/get",,,1

Response:

+HTTPCLIENT:35, Date: Sun, 26 Sep 2021 06:59:13 GMT
+HTTPCLIENT:30, Content-Type: application/json
+HTTPCLIENT:19, Content-Length: 329
+HTTPCLIENT:22, Connection: keep-alive
+HTTPCLIENT:23, Server: gunicorn/19.9.0
+HTTPCLIENT:30, Access-Control-Allow-Origin: *
+HTTPCLIENT:38, Access-Control-Allow-Credentials: true

OK

Note:

The HTTP header information you obtain may be different from those in the above response.

The GET method of HTTP client ¶

This example describes how to download an image file in JPG format. The image link is https://www.espressif.com/sites/all/themes/espressif/images/about-us/solution-platform.jpg.

Restore factory default settings of the module.

Command:
```
AT+RESTORE
```
Response:
```
OK
```
Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.

Send an HTTP GET request. Set opt to 2 (GET method), url to https://www.espressif.com/sites/all/themes/espressif/images/about-us/solution-platform.jpg and transport_type to 2 (HTTP_TRANSPORT_OVER_SSL).

Command:

AT+HTTPCLIENT=2,0,"https://www.espressif.com/sites/all/themes/espressif/images/about-us/solution-platform.jpg",,,2

Response:

+HTTPCLIENT:512,<0xff><0xd8><0xff><0xe2><0x0c>XICC_PROFILE<break>
<0x01><0x01><break>
<break>
<0x0c>HLino<0x02><0x10><break>
<break>
mntrRGB XYZ <0x07><0xce><break>
<0x02><break>
...
+HTTPCLIENT:512,<0xeb><0xe2>v<0xcb><0x98>-<0xf8><0x8a><0xae><0xf3><0xc8><0xb6><0xa8><0x86><0x02>j<0x06><0xe2>
"<0xaa>*p<0x7f>2",h<0x12>N<0xa5><0x1e><0xd2>bp<0xea><0x1e><0xf5><0xa3>x<0xa6>J<0x14>Ti<0xc3>m<0x1a>m<0x94>T<0xe1>I<0xb6><0x90><0xdc>_<0x11>QU;<0x94><0x97><0xcb><0xdd><0xc7><0xc6><0x85><0xd7>U<0x02><0xc9>W<0xa4><0xaa><0xa1><0xa1><0x08>hB<0x1a><0x10><0x86><0x84>!<0xa1><0x08>hB<0x1a><0x10><0x9b><0xb9>K<0xf5>5<0x95>5-=<0x8a><0xcb><0xce><0xe0><0x91><0xf0>m<0xa9><0x04>C<0xde>k<0xe7><0xc2>v<H|<0xaf><0xb8>L<0x91>=<0xda>_<0x94><0xde><0xd0><0xa9><0xc0><0xdd>8<0x9a>B<0xaa><0x1a><0x10><0x86><0x84>$<0xf4><0xd6><0xf2><0xa3><0x92><0xe7><0xa8>I<0xa3>b<0x1f>)<0xe1>z<0xc4>y<0xae><0xca><0xed><0xec><0x1e>|^<0xd7>E<0xa2>_<0x13><0x9e>;{|<0xb5>Q<0x97><0xa5>P<0xdf><0xa1>#3vn<0x1b><0xc3>-<0x92><0xe2>dIn<0x9c><0xb8>
<0xc7><0xa9><0xc6>(<0xe0><0xd3>i-<0x9e>@<0xbb><0xcc><0x88><0xd5>K<0xe3><0xf0>O<0x9f>Km<0xb3>h<0xa8>omR<0xfe><0x8b><0xf9><0xa4><0xa6><0xff><break>
aU<0xdf><0xf3><0xa3>:A<0xe2>UG<0x04>k<0xaa>*<0xa1><0xa1><0x0b><0xca><0xec><0xd8>Q<0xfb><0xbc>yqY<0xec><0xfb>?<0x16>CM<0xf6>|}<0xae><0xf3><0x1e><0xdf>%<0xf8><0xe8><0xb1>B<0x8f>[<0xb3>><0x04><0xec><0xeb>f<0x06><0x1c><0xe8><0x92><0xc9><0x8c><0xb0>I<0xd1><0x8b>%<0x99><0x04><0xd0><0xbb>s<0x8b>xj<0xe2>4f<0xa0><0x8e>+E<0xda><0xab><0xc7>=<0xab><0xc7><0xb9>xz1f<0xba><0xfd>_e6<0xff><break>
(w<0xa7>b<0xe3>m<0xf0>|<0x82><0xc9><0xfb><0x8b><0xac>r<0x95><0x94><0x96><0xd9>i<0xe9>RVA<0x91><0x83><0x8b>M'<0x86><0x8f><0xa3>A<0xd8><0xd8>"r"<0x8a><0xa8><0x9e>zl=<0xcd><0x16><0x07>D<0xa2><0xd0>u(<0xc2><0x8b><0x0b><0xc4><0xf1><0x87><0x9c><0x93><0x8f><0xe3><0xd5>U<0x12>]<0x8e><0x91>]<0x91><0x06>#l<0xbe><0xf4>t0?<0xd7><0x85><GEM<0xb1>%<0xee>UUT<0xe7><0xdf><0xa0><0xb9><0xce><0xe2>U@<0x03><0x82>S<0xe9>*<0xa8>hB<0x1a><0x10><0xa1><0xaf>V<0x19>U<0x9d><0xb3>x<0xa6><0xc7><0xe2><0x86><0x8e>d[<0x89>e<0x05>l<0x80>H<0x91>#<0xd2><0x8c><0xe1>j<0x1b>rH<0x04><0x89><0x98><0xd3>lZW]q><0xc2><';<0x93><0xb4><0xf5>&<0x9d><0xa0>^Wp<0xa9>6`<0xe2>T<0xa2><0xc2><0xb1>*<0xbc><0x13><0x13><0xa0><0xc4>)<0x83><0xb6><0xbe><0x86><0xb9><0x88>-<0x1a>

OK

The POST method of HTTP client (suitable for POST small amount of data)¶

In this example, the HTTP server is http://httpbin.org and the data type is application/json.

Restore factory default settings of the module.

Command:
```
AT+RESTORE
```
Response:
```
OK
```
Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.

Send an HTTP POST request. Set opt to 3 (POST method), url to http://httpbin.org/post, content-type to 1 (application/json) and transport_type to 1 (HTTP_TRANSPORT_OVER_TCP).

Command:

AT+HTTPCLIENT=3,1,"http://httpbin.org/post",,,1,"{\"form\":{\"purpose\":\"test\"}}"

Response:

+HTTPCLIENT:282,{
  "args": {},
  "data": "{\"form\":{\"purpose\":\"test\"}}",
  "files": {},
  "form": {},
  "headers": {
    "Content-Length": "27",
    "Content-Type": "application/json",
    "Host": "httpbin.org",
    "User-Agent": "ESP32 HTTP Client/1.0",
    "X-Amzn-Trace-Id": "Root=
+HTTPCLIENT:173,1-61503a3f-4b16b71918855b97614c5dfb"
  },
  "json": {
    "form": {
      "purpose": "test"
    }
  },
  "origin": "20.187.154.207",
  "url": "http://httpbin.org/post"
}


OK

Note:

The results you obtain may be different from those in the above response.

The POST method of HTTP client (recommended method)¶

If the amount of data you post is relatively large, and the length of a single AT command has exceeded the threshold of 256, it is recommended that you use the AT+HTTPCPOST command.

In this example, the HTTP server is http://httpbin.org and the data type is application/json.

Restore factory default settings of the module.

Command:
```
AT+RESTORE
```
Response:
```
OK
```
Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.

Post HTTP data of specified length. The command specifies that the number of HTTP header fields is 2, which are connection field and content-type field respectively. connection is keep-alive and content-type is application/json.

Assume the JSON data you want to post is as follows, length is 472 bytes.

{"headers": {"Accept": "application/json","Accept-Encoding": "gzip, deflate","Accept-Language": "en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7","Content-Length": "0","Host": "httpbin.org","Origin": "http://httpbin.org","Referer": "http://httpbin.org/","User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36","X-Amzn-Trace-Id": "Root=1-6150581e-1ad4bd5254b4bf5218070413"}}

Command:

AT+HTTPCPOST="http://httpbin.org/post",427,2,"connection: keep-alive","content-type: application/json"

Response:

OK

>

This response indicates that AT is ready for receiving serial data. You should enter the data, and when the data length reaches the <length> value, the transmission of data starts.

+HTTPCPOST:281,{
  "args": {},
  "data": "{\"headers\": {\"Accept\": \"application/json\",\"Accept-Encoding\": \"gzip, deflate\",\"Accept-Language\": \"en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7\",\"Content-Length\": \"0\",\"Host\": \"httpbin.org\",\"Origin\": \"http://httpbin.org\",\"Referer\": \"htt
+HTTPCPOST:512,p://httpbin.org/\",\"User-Agent\": \"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36\",\"X-Amzn-Trace-Id\": \"Root=1-6150581e-1ad4bd5254b4bf5218070413\"}}",
  "files": {},
  "form": {},
  "headers": {
    "Content-Length": "427",
    "Content-Type": "application/json",
    "Host": "httpbin.org",
    "User-Agent": "ESP32 HTTP Client/1.0",
    "X-Amzn-Trace-Id": "Root=1-61505e76-278b5c267aaf55842bd58b32"
  },
  "json": {
    "headers": {

+HTTPCPOST:512,"Accept": "application/json",
      "Accept-Encoding": "gzip, deflate",
      "Accept-Language": "en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7",
      "Content-Length": "0",
      "Host": "httpbin.org",
      "Origin": "http://httpbin.org",
      "Referer": "http://httpbin.org/",
      "User-Agent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36",
      "X-Amzn-Trace-Id": "Root=1-6150581e-1ad4bd5254b4bf5218070413"
    }
  },
  "origin": "20.187.154
+HTTPCPOST:45,.207",
  "url": "http://httpbin.org/post"
}


SEND OK

Note:

After AT outputs the > character, the special characters in the HTTP body does not need to be escaped through the escape character, and it does not need to end with a new line(CR-LF).

The PUT method of HTTP client ¶

In this example, the HTTP server is http://httpbin.org. PUT request supports Query String Parameters mode.

Restore factory default settings of the module.

Command:
```
AT+RESTORE
```
Response:
```
OK
```
Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.

Send an HTTP PUT request. Set opt to 4 (PUT method), url to http://httpbin.org/put, and transport_type to 1 (HTTP_TRANSPORT_OVER_TCP).

Command:

AT+HTTPCLIENT=4,0,"http://httpbin.org/put?user=foo",,,1

Response:

+HTTPCLIENT:282,{
  "args": {
    "user": "foo"
  },
  "data": "",
  "files": {},
  "form": {},
  "headers": {
    "Content-Length": "0",
    "Content-Type": "application/x-www-form-urlencoded",
    "Host": "httpbin.org",
    "User-Agent": "ESP32 HTTP Client/1.0",
    "X-Amzn-Trace-Id": "R
+HTTPCLIENT:140,oot=1-61503d41-1dd8cbe0056190f721ab1912"
  },
  "json": null,
  "origin": "20.187.154.207",
  "url": "http://httpbin.org/put?user=foo"
}


OK

Note:

The results you obtain may be different from those in the above response.

The DELETE method of HTTP client ¶

In this example, the HTTP server is http://httpbin.org. The DELETE method is used to delete resources on a server. The exact use of DELETE requests depends on the server implementation.

Restore factory default settings of the module.

Command:
```
AT+RESTORE
```
Response:
```
OK
```
Set the Wi-Fi mode to station.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to the router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.

Send an HTTP DELETE request. Set opt to 5 (DELETE method), url to http://httpbin.org/delete, and transport_type to 1 (HTTP_TRANSPORT_OVER_TCP).

Command:

AT+HTTPCLIENT=5,0,"https://httpbin.org/delete",,,1

Response:

+HTTPCLIENT:282,{
  "args": {},
  "data": "",
  "files": {},
  "form": {},
  "headers": {
    "Content-Length": "0",
    "Content-Type": "application/x-www-form-urlencoded",
    "Host": "httpbin.org",
    "User-Agent": "ESP32 HTTP Client/1.0",
    "X-Amzn-Trace-Id": "Root=1-61504289-468a41
+HTTPCLIENT:114,737b0d251672acec9d"
  },
  "json": null,
  "origin": "20.187.154.207",
  "url": "https://httpbin.org/delete"
}


OK

Note:

The results you obtain may be different from those in the above response.

[ESP32 Only] Classic Bluetooth AT Examples¶

[中文]

This document provides detailed command examples to illustrate how to utilize [ESP32 Only] Classic Bluetooth® AT Commands on ESP devices.

Establish SPP connection between phone (or PC) and ESP32 in Normal Transmission mode with IO capability set to NoInputNoOutput
Establish SPP connection between phone (or PC) and ESP32 in Passthrough mode with IO capability set to NoInputNoOutput
Establish SPP connection between phone (or PC) and ESP32 with IO capability set to KeyboardOnly
Establish SPP connection between two ESP32 development boards
Establish A2DP connection and enable A2DP Sink to play music
Query and clear Classic Bluetooth encryption device list

Important

The default firmware does not support Classic Bluetooth commands, please refer to How to Enable ESP-AT Classic Bluetooth to enable Classic Bluetooth commands.

Establish SPP connection between phone (or PC) and ESP32 in Normal Transmission mode with IO capability set to NoInputNoOutput ¶

In this example, mobile phone or PC is master and ESP32 is slave. The example shows how to establish SPP connection.

Classic Bluetooth initialization.

Command:
```
AT+BTINIT=1
```
Response:
```
OK
```
Classic Bluetooth SPP profile initialization, and the role is set to slave.

Command:
```
AT+BTSPPINIT=2
```
Response:
```
OK
```
Set Classic Bluetooth device name.

Command:
```
AT+BTNAME="EXAMPLE"
```
Response:
```
OK
```
Set Classic Bluetooth scan mode to discoverable and connectable.

Command:
```
AT+BTSCANMODE=2
```
Response:
```
OK
```
Set Classic Bluetooth security parameters. Set io_cap to NoInputNoOutput, pin_type to fixed, pin_code to 9527.

Command:
```
AT+BTSECPARAM=3,1,"9527"
```
Response:
```
OK
```
Start Classic Bluetooth SPP profile.

Command:
```
AT+BTSPPSTART
```
Response:
```
OK
```
The mobile phone or PC initiates the connection.

The mobile phone or PC should be able to find the Bluetooth device with name “EXAMPLE”. If the mobile phone or PC initiates a connection and the connection is established successfully, ESP32 will prompt:
```
+BTSPPCONN:0,"e0:24:81:47:90:bc"
```
Note:
- The address you obtained may be different from that in the above response.
Send 4 bytes of data.

Command:
```
AT+BTSPPSEND=0,4
```
Response:
```
>
```
The symbol > indicates that AT is ready for receiving serial data and you can enter data now. When the requirement of data length determined by the parameter <data_len> is met, the writing starts.

Input 4 bytes, for example, test, then AT will respond the following message.
```
OK
```
Note:
- If the number of bytes inputted are more than the length (n) set by AT+BTSPPSEND, the system will reply busy p..., and send the first n bytes. And after sending the first n bytes, the system will reply OK.
- After AT outputs the > character, the special characters in the data does not need to be escaped through the escape character, and it does not need to end with a new line (CR-LF).
Receive 4 bytes of data.

Assume that mobile phone or PC sends 4 bytes of data (data is test), the system will prompt:
```
+BTDATA:4,test
```
Terminate Classic Bluetooth SPP connection.

Command:
```
AT+BTSPPDISCONN=0
```
Response:
```
+BTSPPDISCONN:0,"e0:24:81:47:90:bc"

OK
```
Note:
- The address you obtained may be different from that in the above response.

Establish SPP connection between phone (or PC) and ESP32 in Passthrough mode with IO capability set to NoInputNoOutput ¶

In this example, mobile phone or PC is master and ESP32 is slave. The example shows how to establish SPP connection.

Classic Bluetooth initialization.

Command:
```
AT+BTINIT=1
```
Response:
```
OK
```
Classic Bluetooth SPP profile initialization, and the role is set to slave.

Command:
```
AT+BTSPPINIT=2
```
Response:
```
OK
```
Set Classic Bluetooth device name.

Command:
```
AT+BTNAME="EXAMPLE"
```
Response:
```
OK
```
Set Classic Bluetooth scan mode to discoverable and connectable.

Command:
```
AT+BTSCANMODE=2
```
Response:
```
OK
```
Set Classic Bluetooth security parameters. Set io_cap to NoInputNoOutput, pin_type to fixed, pin_code to 9527.

Command:
```
AT+BTSECPARAM=3,1,"9527"
```
Response:
```
OK
```
Start Classic Bluetooth SPP profile.

Command:
```
AT+BTSPPSTART
```
Response:
```
OK
```
The mobile phone or PC initiates the connection.

The mobile phone or PC should be able to find the Bluetooth device with name “EXAMPLE”. If the mobile phone or PC initiates a connection and the connection is established successfully, ESP32 will prompt:
```
+BTSPPCONN:0,"e0:24:81:47:90:bc"
```
Note:
- The address you obtained may be different from that in the above response.
Send data in Passthrough Mode.

Command:
```
AT+BTSPPSEND
```
Response:
```
OK

>
```
This response indicates that AT has entered Passthrough Mode.

Note:
- After the AT enters Passthrough Mode, data received from serial port will be transmitted to the mobile phone or PC.
Stop sending data.

When receiving a packet that contains only +++, the Passthrough Mode will be stopped. Then please wait at least 1 second before sending next AT command. Please be noted that if you input +++ directly by typing, the +++ may not be recognised as three consecutive + because of the prolonged typing duration. For more details, please refer to AT+BTSPPSEND.

Important

The aim of ending the packet with +++ is to exit Passthrough Mode and to accept normal AT commands. However, you can also use command AT+BTSPPSEND to go back into Passthrough Mode.
Terminate Classic Bluetooth SPP connection.

Command:
```
AT+BTSPPDISCONN=0
```
Response:
```
+BTSPPDISCONN:0,"e0:24:81:47:90:bc"

OK
```
Note:
- The address you obtained may be different from that in the above response.

Establish SPP connection between phone (or PC) and ESP32 with IO capability set to KeyboardOnly ¶

The process is basically the same as in the Establish SPP connection between phone (or PC) and ESP32 in Normal Transmission mode with IO capability set to NoInputNoOutput. The only difference lies in security parameters settings.

Classic Bluetooth initialization.

Command:
```
AT+BTINIT=1
```
Response:
```
OK
```
Classic Bluetooth SPP profile initialization, and the role is set to slave.

Command:
```
AT+BTSPPINIT=2
```
Response:
```
OK
```
Set Classic Bluetooth device name.

Command:
```
AT+BTNAME="EXAMPLE"
```
Response:
```
OK
```
Set Classic Bluetooth scan mode to discoverable and connectable.

Command:
```
AT+BTSCANMODE=2
```
Response:
```
OK
```
Set Classic Bluetooth security parameters. Set io_cap to KeyboardOnly, pin_type to variable, pin_code to 9527.

Command:
```
AT+BTSECPARAM=2,0,"9527"
```
Response:
```
OK
```
Start Classic Bluetooth SPP profile.

Command:
```
AT+BTSPPSTART
```
Response:
```
OK
```
The mobile phone or PC initiates the connection.

The mobile phone or PC can initiate a connection and generate a PIN code, then you can enter the PIN code on the ESP32.
```
AT+BTKEYREPLY=0,676572
```
If the connection is established successfully, the system will prompt:
```
+BTSPPCONN:0,"e0:24:81:47:90:bc"
```
Note:
- The PIN code you entered may be different from those in the above command. Please use the real PIN instead.
- The address you obtained may be different from that in the above response.
Terminate Classic Bluetooth SPP connection.

Command:
```
AT+BTSPPDISCONN=0
```
Response:
```
+BTSPPDISCONN:0,"e0:24:81:47:90:bc"

OK
```
Note:
- The address you obtained may be different from that in the above response.

Establish SPP connection between two ESP32 development boards ¶

Below is an example of using two ESP32 development boards, one as master, the other one as slave.

Important

In the following steps, the operations starting with Master only need to be executed at master, and the operations starting with Slave only need to be executed at slave. If the operation is not specified on which side it is executed, it needs to be executed on both the master side and the slave side.

Classic Bluetooth initialization.

Command:
```
AT+BTINIT=1
```
Response:
```
OK
```
Classic Bluetooth SPP profile initialization.

Master:

Command:
```
AT+BTSPPINIT=1
```
Response:
```
OK
```
Slave:

Command:
```
AT+BTSPPINIT=2
```
Response:
```
OK
```
Set Classic Bluetooth device name.

Slave:

Command:
```
AT+BTNAME="EXAMPLE"
```
Response:
```
OK
```
Set Classic Bluetooth scan mode to discoverable and connectable.

Slave:

Command:
```
AT+BTSCANMODE=2
```
Response:
```
OK
```
Set Classic Bluetooth security parameters. Set io_cap to NoInputNoOutput, pin_type to fixed, pin_code to 9527.

Slave:

Command:
```
AT+BTSECPARAM=3,1,"9527"
```
Response:
```
OK
```
Start Classic Bluetooth SPP profile.

Slave:

Command:
```
AT+BTSPPSTART
```
Response:
```
OK
```

Start Classic Bluetooth discovery. Set inquiry duration to 10 s, number of inquiry responses to 10.

Master:

Command:

AT+BTSTARTDISC=0,10,10

Response:

+BTSTARTDISC:"10:f6:05:f9:bc:4f",realme V11 5G,0x2,0x3,0x2d0,-34
+BTSTARTDISC:"24:0a:c4:d6:e4:46",EXAMPLE,,,,-27
+BTSTARTDISC:"10:f6:05:f9:bc:4f",realme V11 5G,0x2,0x3,0x2d0,-33
+BTSTARTDISC:"24:0a:c4:d6:e4:46",EXAMPLE,,,,-25
+BTSTARTDISC:"ac:d6:18:47:0c:ae",,0x2,0x3,0x2d0,-72
+BTSTARTDISC:"24:0a:c4:d6:e4:46",EXAMPLE,,,,-26
+BTSTARTDISC:"10:f6:05:f9:bc:4f",,0x2,0x3,0x2d0,-41
+BTSTARTDISC:"24:0a:c4:2c:a8:a2",,,,,-50
+BTSTARTDISC:"24:0a:c4:d6:e4:46",EXAMPLE,,,,-26
+BTSTARTDISC:"10:f6:05:f9:bc:4f",realme V11 5G,0x2,0x3,0x2d0,-39
+BTSTARTDISC:"24:0a:c4:d6:e4:46",EXAMPLE,,,,-23
+BTSTARTDISC:"10:f6:05:f9:bc:4f",realme V11 5G,0x2,0x3,0x2d0,-36
+BTSTARTDISC:"10:f6:05:f9:bc:4f",realme V11 5G,0x2,0x3,0x2d0,-41
+BTSTARTDISC:"b4:a5:ac:16:14:8c",,0x2,0x3,0x2d0,-57
+BTSTARTDISC:"24:0a:c4:2c:a8:a2"
+BTSTARTDISC:"b4:a5:ac:16:14:8c"

OK

Note:

The discovery results you obtain may be different from those in the above response.

Establish SPP connection.

Master:

Command:
```
AT+BTSPPCONN=0,0,"24:0a:c4:d6:e4:46"
```
Response:
```
+BTSPPCONN:0,"24:0a:c4:d6:e4:46"

OK
```
Note:
- When entering the above command, replace the address with slave address.
- If the SPP connection is established successfully, message +BTSPPCONN:0,"30:ae:a4:80:06:8e" will be prompted on the slave.
Terminate Classic Bluetooth SPP connection.

Slave:

Command:
```
AT+BTSPPDISCONN=0
```
Response:
```
+BTSPPDISCONN:0,"30:ae:a4:80:06:8e"

OK
```
Note:
- Both master and slave can actively terminate the SPP connection.
- If the SPP connection is ended successfully, message +BTSPPDISCONN:0,"24:0a:c4:d6:e4:46" will be prompted on the master.

Establish A2DP connection and enable A2DP Sink to play music ¶

Important

To use A2DP Sink, you need to add the code of the I2S part by yourself. For the code to initialize the I2S part, please refer to a2dp sink example.
The driver code of the decoder chip part also needs to be added by yourself or use an off-the-shelf development board.

Classic Bluetooth initialization.

Command:
```
AT+BTINIT=1
```
Response:
```
OK
```
Classic Bluetooth A2DP profile initialization, and the role is set to sink.

Command:
```
AT+BTA2DPINIT=2
```
Response:
```
OK
```
Set Classic Bluetooth device name.

Command:
```
AT+BTNAME="EXAMPLE"
```
Response:
```
OK
```
Set Classic Bluetooth scan mode to discoverable and connectable.

Command:
```
AT+BTSCANMODE=2
```
Response:
```
OK
```
Establish connection.

The source role should be able to find the Bluetooth device with name “EXAMPLE”. In this example, you can use your mobile phone to initiate a connection. If the connection is established successfully, ESP32 will prompt:
```
+BTA2DPCONN:0,"e0:24:81:47:90:bc"
```
Note:
- The address you obtained may be different from that in the above response.
Start playing music.

Command:
```
AT+BTA2DPCTRL=0,1
```
Response:
```
OK
```
Note:
- For more types of control, please refer to AT+BTA2DPCTRL.
Stop playing music.

Command:
```
AT+BTA2DPCTRL=0,0
```
Response:
```
OK
```
Note:
- For more types of control, please refer to AT+BTA2DPCTRL.

Terminate A2DP connection.

Command:

AT+BTA2DPDISCONN=0

Response:

OK
+BTA2DPDISCONN:0,"e0:24:81:47:90:bc"

Query and clear Classic Bluetooth encryption device list ¶

Get the encryption device list.

Command:
```
AT+BTENCDEV?
```
Response:
```
+BTA2DPDISCONN:0,"e0:24:81:47:90:bc"
OK
```
Note:
- If no device has been successfully bound before, AT will only prompt OK.
Clear Classic Bluetooth encryption device list.

There are two ways to clear encryption device list.
1. Remove a device from the encryption device list with a specific index.
  
  Command:
```
AT+BTENCCLEAR=0
```
  Response:
```
OK
```
2. Remove all devices from the encryption device list.
  
  Command:
```
AT+BTENCCLEAR
```
  Response:
```
OK
```

Sleep AT Examples¶

[中文]

This document provides an introduction and detailed command examples to illustrate how to utilize AT commands to set sleep modes on ESP32 and ESP32-C3 series of products.

Introduction
Set Modem-sleep mode in Wi-Fi mode
Set Light-sleep mode in Wi-Fi mode
Set Modem-sleep mode in Bluetooth LE advertising mode
Set Modem-sleep mode in Bluetooth LE connection mode
Set Light-sleep mode in Bluetooth LE advertising mode
Set Light-sleep mode in Bluetooth LE connection mode
Set Deep-sleep mode

Introduction ¶

With the use of advanced power-management technologies, ESP32 and ESP32-C3 series can switch between different power modes. Currently, ESP-AT supports the following four power consumption modes (for more sleep modes, please refer to the datasheet):

Active Mode: CPU and chip radio are powered on. The chip can receive, transmit, or listen.
Modem-sleep Mode: The CPU is operational and the clock speed can be reduced. Wi-Fi baseband, Bluetooth LE baseband, and radio are disabled, but Wi-Fi and Bluetooth LE connection can remain active.
Light-sleep Mode: The CPU is paused. Any wake-up events (MAC, host, RTC timer, or external interrupts) will wake up the chip. Wi-Fi and Bluetooth LE connection can remain active.
Deep-sleep Mode: CPU and most peripherals are powered down. Only the RTC memory is powered on.

By default, ESP32 and ESP32-C3 will enter Active mode after system reset. When the CPU does not need to work all the time, such as waiting for external activities to wake up, the system can enter low-power modes.

For current consumption of ESP32 and ESP32-C3, please refer to ESP32 Series Datasheet and ESP32-C3 Series Datasheet.

Note

Setting ESP32 and ESP32-C3 to sleep modes in Wi-Fi mode and Bluetooth LE mode will be described separately.
In single Wi-Fi mode, only station mode supports Modem-sleep mode and Light-sleep mode.
For Light-sleep mode in Bluetooth LE mode, please ensure that there is an external 32 KHz crystal oscillator. If there is no external 32 KHz crystal oscillator, ESP-AT will work as the Modem-sleep mode.

Measurement Method¶

In order to avoid some unnecessary interference during the power consumption test process, it is recommended to use the Espressif modules that integrate the chip for the test.

Refer to the following for hardware connection.

ESP32 series

ESP32-C3 series

Set Modem-sleep mode in Wi-Fi mode ¶

Set the Wi-Fi mode to station mode.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to an router.

Command:
```
AT+CWJAP="espressif","1234567890"
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Set the sleep mode to Modem-sleep mode.

Command:
```
AT+SLEEP=1
```
Response:
```
OK
```

Note

RF will be periodically closed according to AP DTIM (routers generally set DTIM to 1).
When the CPU frequency of ESP32 is 80 MHz and the module is in single Wi-Fi mode, the average current in Modem-sleep mode is about 21 mA.
When the CPU frequency of ESP32-C3 is 160 MHz and the module is in single Wi-Fi mode, the average current in Modem-sleep mode is about 20 mA.

Set Light-sleep mode in Wi-Fi mode ¶

Set the Wi-Fi mode to station mode.

Command:
```
AT+CWMODE=1
```
Response:
```
OK
```
Connect to an router. Set listen interval to 3.

Command:
```
AT+CWJAP="espressif","1234567890",,,,3
```
Response:
```
WIFI CONNECTED
WIFI GOT IP

OK
```
Note:
- The SSID and password you entered may be different from those in the above command. Please replace the SSID and password with those of your router settings.
Set the sleep mode to Light-sleep mode.

Command:
```
AT+SLEEP=2
```
Response:
```
OK
```

Note

CPU will automatically sleep and RF will be periodically closed according to listen interval set by AT+CWJAP.
When the module of ESP32 is in single Wi-Fi mode, the average current in Light-sleep mode is about 0.8 mA.
When the module of ESP32-C3 is in single Wi-Fi mode, the average current in Light-sleep mode is about 130 uA.

Set Modem-sleep mode in Bluetooth LE advertising mode ¶

Initialize the role of Bluetooth LE as server.

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
Set parameters of Bluetooth LE advertising. Set Bluetooth LE advertising interval to 1 s.

Command:
```
AT+BLEADVPARAM=1600,1600,0,0,7,0,0,"00:00:00:00:00:00"
```
Response:
```
OK
```
Start Bluetooth LE advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
Disable Wi-Fi.

Command:
```
AT+CWMODE=0
```
Response:
```
OK
```
Set the sleep mode to Modem-sleep mode.

Command:
```
AT+SLEEP=1
```
Response:
```
OK
```

Note

When the CPU frequency of ESP32 is 80 MHz and the module in single Bluetooth LE advertising mode, the average current in Modem-sleep mode is about 23 mA.
When the CPU frequency of ESP32-C3 is 160 MHz and the module in single Bluetooth LE advertising mode, the average current in Modem-sleep mode is about 20 mA.

Set Modem-sleep mode in Bluetooth LE connection mode ¶

Initialize the role of Bluetooth LE as server.

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
Start Bluetooth LE advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
Waiting for connection.

If the connection is established successfully, AT will prompt:
```
+BLECONN:0,"47:3f:86:dc:e4:7d"
+BLECONNPARAM:0,0,0,6,0,500
+BLECONNPARAM:0,0,0,24,0,500

OK
```
Note:
- In this example, Bluetooth LE client address is 47:3f:86:dc:e4:7d.
- For prompt information (+BLECONN and +BLECONNPARAM), please refer to AT+BLECONN and AT+BLECONNPARAM for more details.
Update parameters of Bluetooth LE connection. Set Bluetooth LE connection interval to 1 s.

Command:
```
AT+BLECONNPARAM=0,800,800,0,500
```
Response:
```
OK
```
If the connection parameters are updated successfully, AT will output:
```
+BLECONNPARAM:0,800,800,800,0,500
```
Note:
- For prompt information (+BLECONNPARAM), please refer to AT+BLECONNPARAM for more details.
Disable Wi-Fi.

Command:
```
AT+CWMODE=0
```
Response:
```
OK
```
Set the sleep mode to Modem-sleep mode.

Command:
```
AT+SLEEP=1
```
Response:
```
OK
```

Note

When the CPU frequency of ESP32 is 80 MHz and the module in single Bluetooth LE connection mode, the average current in Modem-sleep mode is about 23 mA.
When the CPU frequency of ESP32-C3 is 160 MHz and the module in single Bluetooth LE connection mode, the average current in Modem-sleep mode is about 20 mA.

Set Light-sleep mode in Bluetooth LE advertising mode ¶

Initialize the role of Bluetooth LE as server.

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
Set parameters of Bluetooth LE advertising. Set Bluetooth LE advertising interval to 1 s.

Command:
```
AT+BLEADVPARAM=1600,1600,0,0,7,0,0,"00:00:00:00:00:00"
```
Response:
```
OK
```
Start Bluetooth LE advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
Disable Wi-Fi.

Command:
```
AT+CWMODE=0
```
Response:
```
OK
```
Set the sleep mode to Light-sleep mode.

Command:
```
AT+SLEEP=2
```
Response:
```
OK
```

Note

When the module of ESP32 in single Bluetooth LE advertising mode, the average current in Light-sleep mode is about 0.8 mA.
When the module of ESP32-C3 in single Bluetooth LE advertising mode, the average current in Light-sleep mode is about 130 uA.

Set Light-sleep mode in Bluetooth LE connection mode ¶

Initialize the role of Bluetooth LE as server.

Command:
```
AT+BLEINIT=2
```
Response:
```
OK
```
Start Bluetooth LE advertising.

Command:
```
AT+BLEADVSTART
```
Response:
```
OK
```
Waiting for connection.

If the connection is established successfully, AT will prompt:
```
+BLECONN:0,"47:3f:86:dc:e4:7d"
+BLECONNPARAM:0,0,0,6,0,500
+BLECONNPARAM:0,0,0,24,0,500

OK
```
Note:
- In this example, Bluetooth LE client address is 47:3f:86:dc:e4:7d.
- For prompt information (+BLECONN and +BLECONNPARAM), please refer to AT+BLECONN and AT+BLECONNPARAM for more details.
Update parameters of Bluetooth LE connection. Set Bluetooth LE connection interval to 1 s.

Command:
```
AT+BLECONNPARAM=0,800,800,0,500
```
Response:
```
OK
```
If the connection parameters are updated successfully, AT will output:
```
+BLECONNPARAM:0,800,800,800,0,500
```
Note:
- For prompt information (+BLECONNPARAM), please refer to AT+BLECONNPARAM for more details.
Disable Wi-Fi.

Command:
```
AT+CWMODE=0
```
Response:
```
OK
```
Set the sleep mode to Light-sleep mode.

Command:
```
AT+SLEEP=2
```
Response:
```
OK
```

Note

When the module of ESP32 in single Bluetooth LE connection mode, the average current in Light-sleep mode is about 0.8 mA.
When the module of ESP32-C3 in single Bluetooth LE connection mode, the average current in Light-sleep mode is about 130 uA.

Set Deep-sleep mode ¶

Set the sleep mode to Deep-sleep mode. Set the deep-sleep time to 3600000 ms.

Command:
```
AT+GSLP=3600000
```
Response:
```
OK
```
Note:
- When the time is up, the device automatically wakes up, calls Deep-sleep wake stub, and then proceeds to load the application.
- For Deep-sleep mode, the only wake-up method is timed wake-up.

Note

When the module of ESP32 in Deep-sleep mode, the average current in Deep-sleep mode is about 10 uA.
When the module of ESP32-C3 in Deep-sleep mode, the average current in Deep-sleep mode is about 5 uA.

How to Compile and Develop Your Own AT Project¶

[中文]

Compile ESP-AT Project¶

[中文]

This document details how to build your own ESP-AT project and flash the generated firmware into your ESP devices, including ESP32, and ESP32-C3. It comes in handy when the official released fimware cannot meet your needs, for example, to customize the AT port pins, Bluetooth LE services, and partitions, and so on.

The structure of this document is as follows:

Overview: Overview of the steps to build an ESP-AT project.
ESP32 and ESP32-C3 Series: Details steps to build a project for ESP32, and ESP32-C3 series.

Overview¶

Before compiling an ESP-AT project, you need first get started with ESP-IDF and set up the environment for ESP-IDF, because ESP-AT is based on ESP-IDF.

After the environment is ready, install the tools and ESP-AT SDK. Then, connect your ESP device to PC. Use ./build.py menuconfig to set up some configuration for the project. Build the project and flash the generated bin files onto your ESP device.

Note

Please pay attention to possible conflicts of pins. If choosing AT through HSPI, you can get the information of the HSPI pin by ./build.py menuconfig –> Component config –> AT –> AT hspi settings.

ESP32 and ESP32-C3 Series¶

This section describes how to compile an ESP-AT project for ESP32 and ESP32-C3 series.

Get Started with ESP-IDF¶

Get started with ESP-IDF before compiling an ESP-AT project, because ESP-AT is developed based on ESP-IDF, and the supported version varies from series to series:

ESP-IDF Versions for Different Series¶
Project	IDF Version	IDF Documentation Version
ESP32 ESP-AT	release/v4.2	ESP-IDF Get Started Guide v4.2
ESP32-C3 ESP-AT	release/v4.3	ESP-IDF Get Started Guide v4.3

First, set up the development environment for ESP-IDF according to Step 1 to 4 of ESP-IDF Get Started Guide (click the corresponding link in the table above to navigate to the documentation).

Then, start a simple project of hello_world according to Step 5 to 10 of ESP-IDF Get Started Guide to make sure your environment works and familiarize yourself with the process of starting a new project based on ESP-IDF. It is not a must, but you are strongly recommended to do so.

After finishing all the ten steps (if not, at least the first four steps), you can move onto the following steps that are ESP-AT specific.

Note

Please do not set IDF_PATH during the process, otherwise, you would encounter some unexpected issues when compiling ESP-AT projects later.

Get ESP-AT¶

To compile an ESP-AT project, you need the software libraries provided by Espressif in the ESP-AT repository.

To get ESP-AT, navigate to your installation directory and clone the repository with git clone, following instructions below specific to your operating system.

Linux or macOS

cd ~/esp
git clone --recursive https://github.com/espressif/esp-at.git

Windows
- For ESP32 series of modules, it is recommended that you run ESP-IDF 4.2 CMD as an administrator first.
- For ESP32-C3 series of modules, it is recommended that you run ESP-IDF 4.3 CMD as an administrator first.
```
cd %userprofile%\esp
git clone --recursive https://github.com/espressif/esp-at.git
```

If you are located in China or have difficulties to access GitHub, you can also use git clone https://gitee.com/EspressifSystems/esp-at.git to get ESP-AT, which may be faster.

ESP-AT will be downloaded into ~/esp/esp-at on Linux or macOS, or %userprofile%\esp\esp-at on Windows.

Note

This guide uses the directory ~/esp on Linux or macOS, or %userprofile%\esp on Windows as an installation folder for ESP-AT. You can use any directory, but you will need to adjust paths for the commands respectively. Keep in mind that ESP-AT does not support spaces in paths.

Connect Your Device¶

Connect your device to the PC with a USB cable to download firmware and log output. See Hardware Connection for more information. Note that you do not need to set up the “AT command/response” connection if you do not send AT commands and receive AT responses during the compiling process. You can change default port pins referring to How to Set AT Port Pins.

Configure¶

In this step, you will clone the esp-idf folder into the esp-at folder, set up the development environment in the newly cloned folder, and configure your project.

Navigate to ~/esp/esp-at directory.
Run the project configuration utility menuconfig to configure.

./build.py menuconfig

Select the following configuration options for your ESP device if it is your first time.

Select the Platform name for your ESP device. For example, select PLATFORM_ESP32 for ESP32 series of products, PLATFORM_ESP32C3 for ESP32-C3 series of products. Platform name is defined in factory_param_data.csv .

Select the Module name for your ESP device. For example, select WROOM-32 for the ESP32-WROOM-32D module. Module name is defined in factory_param_data.csv .

Enable or disable silence mode. If enabled, it will remove some logs and reduce the firmware size. Generally, it should be disabled.

The above three option items will not appear if the file build/module_info.json exists. So please delete it if you want to reconfigure the module information.

Now, the esp-idf folder is created in esp-at folder. This esp-idf is different from that in Get Started with ESP-IDF.

If you encounter any of the cases below, please proceed with the next step to set up the develop environment in the esp-at/esp-idf.
The terminal prompt an error message like the following:
The following Python requirements are not satisfied:
...
Please follow the instructions found in the "Set up the tools" section of ESP-IDF Get Started Guide.
If you have compiled an ESP-AT project for an ESP series before and want to switch to another series, you must run rm -rf esp-idf to remove the old esp-idf and then proceed with the next step.

Your esp-idf is upgraded.

Set up the development environment in the esp-at/esp-idf.

Set up the tools in the folder if it is the first time you compile the ESP-AT project. See Step 3 of ESP-IDF Get Started Guide.

Set up environment variables in the folder every time you compile an ESP-AT project. See Step 4 of ESP-IDF Get Started Guide.
Install pyyaml and xlrd packages with pip in the folder if you have not done it.
python -m pip install pyyaml xlrd

If the previous steps have been done correctly, the following menu appears after you run ./build.py menuconfig:

You are using this menu to set up project-specific configuration, e.g. changing AT port pins, enabling Classic Bluetooth function, etc. If you made no changes, it will run with the default configuration.

Build the Project¶

Build the project by running:

./build.py build

If Bluetooth feature is enabled, the firmware size will be much larger. Please make sure it does not exceed the ota partition size.
After compiled, the combined factory bin will be created in build/factory. See ESP-AT Firmware Differences for more information.

Flash onto the Device¶

Flash the firmware that you just compiled onto your ESP device by running:

./build.py -p (PORT) flash

Note that you need to replace PORT with your ESP device’s serial port name.
Or you can follow the printed instructions to download the bin files into flash. Note that you also need to replace the PORT.
If the ESP-AT bin fails to boot and prints “ota data partition invalid”, you should run ./build.py erase_flash to erase the entire flash, and then re-flash the AT firmware.

How to Set AT Port Pins¶

[中文]

This document introduces how to modify AT port pins in the firmware for ESP32 and ESP32-C3 series of products. By default, ESP-AT uses two UART interfaces as AT ports: one is to output logs (named as log port below) and the other to send AT commands and receive responses (named as command port below).

To modify the AT port pins of your ESP device, you should:

clone the ESP-AT project;
modify the pins either in the menuconfig utility or the factory_param_data.csv table;
compile the project to generate the new bin in build/customized_partitions/factory_param.bin;
flash the new bin to your device.

This document focuses on modifying the pins. Click the links above for details of other steps. Below is the document structure:

ESP32 Series
ESP32-C3 Series

Note

To use other interfaces as the AT command port, please refer to AT through SDIO , AT through SPI , or AT through socket for more details.

ESP32 Series¶

The log port and command port pins of ESP32 AT firmware can be user-defined to other pins. Refer to ESP32 Technical Reference Manual for the pins you can use.

Modify Log Port Pins¶

By default, the ESP32 AT firmware provided by Espressif uses the following UART0 pins to output log:

TX: GPIO1
RX: GPIO3

When compiling your ESP-AT project, you can modify them to other pins with the menuconfig utitlity:

./build.py menuconfig –> Component config –> Common ESP-related –> UART for console output
./build.py menuconfig –> Component config –> Common ESP-related –> UART TX on GPIO#
./build.py menuconfig –> Component config –> Common ESP-related –> UART RX on GPIO#

Modify Command Port Pins¶

By default, UART1 is used to send AT commands and receive AT responses, and its pins are defined in Column uart_port, uart_tx_pin, uart_rx_pin, uart_cts_pin, and uart_rts_pin of the factory_param_data.csv .

You can change them directly in your factory_param_data.csv table:

Open your local factory_param_data.csv file.
Locate the row of your module.
Set uart_port as needed.
Set uart_tx_pin and uart_rx_pin as needed.
Set uart_cts_pin and uart_rts_pin to be -1 if you do not use the hardware flow control function.
Save the table.

ESP32-C3 Series¶

The log port and command port pins of ESP32-C3 AT firmware can be user-defined to other pins. ESP32-C3 Technical Reference Manual for the pins you can use.

Modify Log Port Pins¶

By default, the ESP32-C3 AT firmware provided by Espressif uses the following UART0 pins to output log:

TX: GPIO21
RX: GPIO20

When compiling your ESP-AT project, you can modify them to other pins with the menuconfig utitlity:

./build.py menuconfig –> Component config –> Common ESP-related –> UART for console output
./build.py menuconfig –> Component config –> Common ESP-related –> UART TX on GPIO#
./build.py menuconfig –> Component config –> Common ESP-related –> UART RX on GPIO#

Modify Command Port Pins¶

By default, UART1 is used to send AT commands and receive AT responses, and its pins are defined in Column uart_port, uart_tx_pin, uart_rx_pin, uart_cts_pin, and uart_rts_pin of the factory_param_data.csv .

You can change them directly in your factory_param_data.csv table:

Open your local factory_param_data.csv file.
Locate the row of your module.
Set uart_port as needed.
Set uart_tx_pin and uart_rx_pin as needed.
Set uart_cts_pin and uart_rts_pin to be -1 if you do not use the hardware flow control function.
Save the table.

How to add user-defined AT commands¶

[中文]

This document details how to add a user-defined AT command based on the ESP-AT project. It uses the AT+TEST command as an example to show the sample code for each step.

Customizing a basic and well-functioned command requires at least the two steps below:

Define AT Commands
Register AT Commands

This step checks how the newly defined command works out.

Give it a try

The remaining steps are for relatively complex AT commands and are optional depending on your needs.

Define Return Values
Access Command Parameters
Omit Command Parameters
Block Command Execution
Access Input Data from AT Command Port

The source code of AT command set is not open-source, and is provided in the form of library file . It is also the basis to parse user-defined AT commands.

Define AT Commands¶

Before defining any AT command, you should first decide on the name and type of the command.

Command naming rules:

It should start with the + character.
Alphabetic characters (A~Z, a~z), numeric characters (0~9), and some other characters (!, %, -, ., /, :, _) are supported. See AT Command Types for more information.

Command types:

Each AT command can have up to four types: Test Command, Query Command, Set Command, and Execute Command. See AT Command Types for more information.

Then, define desired type of command. Assuming that AT+TEST supports all the four types. Below is the sample code to define each type.

Test Command:

uint8_t at_test_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is test cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Query Command:

uint8_t at_query_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is query cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Set Command:

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t para_int_1 = 0;
    uint8_t *para_str_2 = NULL;
    uint8_t num_index = 0;
    uint8_t buffer[64] = {0};

    if (esp_at_get_para_as_digit(num_index++, &para_int_1) != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    }

    if (esp_at_get_para_as_str(num_index++, &para_str_2) != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    }

    snprintf((char *)buffer, 64, "this cmd is setup cmd and cmd num is: %u\r\n", para_num);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    memset(buffer, 0, 64);
    snprintf((char *)buffer, 64, "first parameter is: %d\r\n", para_int_1);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    memset(buffer, 0, 64);
    snprintf((char *)buffer, 64, "second parameter is: %s\r\n", para_str_2);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Execute Command:

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is execute cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    return ESP_AT_RESULT_CODE_OK;
}

Finally, call esp_at_cmd_struct to define the name and type(s) that your AT command supports. The sample code below defined the name +TEST (omitting AT) and all the four types.

static esp_at_cmd_struct at_custom_cmd[] = {
    {"+TEST", at_test_cmd_test, at_query_cmd_test, at_setup_cmd_test, at_exe_cmd_test},
};

If you do not want to define a particular type, set it to NULL.

Register AT Commands¶

Call API esp_at_custom_cmd_array_regist() to register your AT command. Below is the sample code to register AT+TEST:

esp_at_custom_cmd_array_regist(at_custom_cmd, sizeof(at_custom_cmd) / sizeof(at_custom_cmd[0]));

Note

esp_at_custom_cmd_array_regist is recommended to be added to the at_custom_init() in app_main().

Give it a try¶

If you have finished the above two steps, the command should work after you build the ESP-AT project and flash the firmware to your device. Give it a try!

Below is how AT+TEST works out.

Test Command:

AT+TEST=?

Response:

AT+TEST=?
this cmd is test cmd: +TEST

OK

Query Command:

AT+TEST?

Response:

AT+TEST?
this cmd is query cmd: +TEST

OK

Set Command:

AT+TEST=1,"espressif"

Response:

AT+TEST=1,"espressif"
this cmd is setup cmd and cmd num is: 2
first parameter is: 1
second parameter is: espressif

OK

Execute Command:

AT+TEST

Response:

AT+TEST
this cmd is execute cmd: +TEST

OK

Define Return Values¶

ESP-AT has defined return values in esp_at_result_code_string_index. See AT Messages for more return values.

In addition to output return values through the return mode, you can also use API esp_at_response_result() to output the execution result of the command. ESP_AT_RESULT_CODE_SEND_OK and ESP_AT_RESULT_CODE_SEND_FAIL can be used with the API in code.

For example, when you send data to the server or MCU with the Execute Command of AT+TEST, you can use esp_at_response_result() to output the sending result, and the return mode to output the command execution result. Below is the sample code:

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is execute cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    // user-defined operation of sending data to server or MCU
    send_data_to_server();

    // output SEND OK
    esp_at_response_result(ESP_AT_RESULT_CODE_SEND_OK);

    return ESP_AT_RESULT_CODE_OK;
}

How it works out:

AT+TEST
this cmd is execute cmd: +TEST

SEND OK

OK

Access Command Parameters¶

ESP-AT provides two APIs to access command parameters:

esp_at_get_para_as_digit() obtains digital parameters.
esp_at_get_para_as_str() obtains string parameters.

See Set Command for an example.

Omit Command Parameters¶

This section describes how to provide optional command parameters:

Omit the First or Middle Parameter
Omit the Last Parameter

Omit the First or Middle Parameter¶

Let’s say you want to make <param_2> and <param_3> of AT+TEST optional. <param_2> is a digital parameter, and <param_3> a string parameter.

AT+TEST=<param_1>[,<param_2>][,<param_3>],<param_4>

Below is the sample code to achieve it:

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t para_int_1 = 0;
    int32_t para_int_2 = 0;
    uint8_t *para_str_3 = NULL;
    uint8_t *para_str_4 = NULL;
    uint8_t num_index = 0;
    uint8_t buffer[64] = {0};
    esp_at_para_parse_result_type parse_result = ESP_AT_PARA_PARSE_RESULT_OK;

    snprintf((char *)buffer, 64, "this cmd is setup cmd and cmd num is: %u\r\n", para_num);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    parse_result = esp_at_get_para_as_digit(num_index++, &para_int_1);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "first parameter is: %d\r\n", para_int_1);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_digit(num_index++, &para_int_2);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OMITTED) {
        if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
            return ESP_AT_RESULT_CODE_ERROR;
        } else {
            // sample code
            // user needs to customize the operation
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "second parameter is: %d\r\n", para_int_2);
            esp_at_port_write_data(buffer, strlen((char *)buffer));
        }
    } else {
        // sample code
        // the second parameter is omitted
        // user needs to customize the operation
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "second parameter is omitted\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_str(num_index++, &para_str_3);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OMITTED) {
        if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
            return ESP_AT_RESULT_CODE_ERROR;
        } else {
            // sample code
            // user needs to customize the operation
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "third parameter is: %s\r\n", para_str_3);
            esp_at_port_write_data(buffer, strlen((char *)buffer));
        }
    } else {
        // sample code
        // the third parameter is omitted
        // user needs to customize the operation
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "third parameter is omitted\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_str(num_index++, &para_str_4);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "fourth parameter is: %s\r\n", para_str_4);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    return ESP_AT_RESULT_CODE_OK;
}

Note

If the string parameter input is "", it is not omitted.

Omit the Last Parameter¶

Let’s say you want to make the string parameter <param_3> of AT+TEST optional, which is also the last parameter.

AT+TEST=<param_1>,<param_2>[,<param_3>]

There are two cases of omission:

AT+TEST=<param_1>,<param_2>
AT+TEST=<param_1>,<param_2>,

Below is the sample code to achieve it:

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t para_int_1 = 0;
    uint8_t *para_str_2 = NULL;
    uint8_t *para_str_3 = NULL;
    uint8_t num_index = 0;
    uint8_t buffer[64] = {0};
    esp_at_para_parse_result_type parse_result = ESP_AT_PARA_PARSE_RESULT_OK;

    snprintf((char *)buffer, 64, "this cmd is setup cmd and cmd num is: %u\r\n", para_num);
    esp_at_port_write_data(buffer, strlen((char *)buffer));

    parse_result = esp_at_get_para_as_digit(num_index++, &para_int_1);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "first parameter is: %d\r\n", para_int_1);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    parse_result = esp_at_get_para_as_str(num_index++, &para_str_2);
    if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    } else {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "second parameter is: %s\r\n", para_str_2);
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    if (num_index == para_num) {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "third parameter is omitted\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    } else {
        parse_result = esp_at_get_para_as_str(num_index++, &para_str_3);
        if (parse_result != ESP_AT_PARA_PARSE_RESULT_OMITTED) {
            if (parse_result != ESP_AT_PARA_PARSE_RESULT_OK) {
                return ESP_AT_RESULT_CODE_ERROR;
            } else {
                // sample code
                // user needs to customize the operation
                memset(buffer, 0, 64);
                snprintf((char *)buffer, 64, "third parameter is: %s\r\n", para_str_3);
                esp_at_port_write_data(buffer, strlen((char *)buffer));
            }
        } else {
            // sample code
            // the third parameter is omitted
            // user needs to customize the operation
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "third parameter is omitted\r\n");
            esp_at_port_write_data(buffer, strlen((char *)buffer));
        }
    }

    return ESP_AT_RESULT_CODE_OK;
}

Note

If the string parameter input is "", it is not omitted.

Block Command Execution¶

Sometimes you want to block the execution of one command to wait for another execution result, and the system may return different values according to the result.

Generally, this kind of command needs to synchronize the results of other tasks.

semaphore is recommended to handle synchronization.

The sample code is as follows:

xSemaphoreHandle at_operation_sema = NULL;

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    uint8_t buffer[64] = {0};

    snprintf((char *)buffer, 64, "this cmd is execute cmd: %s\r\n", cmd_name);

    esp_at_port_write_data(buffer, strlen((char *)buffer));

    // sample code
    // users don't have to create semaphores here
    at_operation_sema = xSemaphoreCreateBinary();
    assert(at_operation_sema != NULL);

    // block command execution
    // wait for another execution result
    // other tasks can call xSemaphoreGive to release the semaphore
    xSemaphoreTake(at_operation_sema, portMAX_DELAY);

    return ESP_AT_RESULT_CODE_OK;
}

Access Input Data from AT Command Port¶

ESP-AT supports accessing input data from AT Command port. It provides two APIs for this purpose.

esp_at_port_enter_specific() sets the callback function which will be called by AT port after receiving the input data.
esp_at_port_exit_specific() deletes the callback function set by esp_at_port_enter_specific.

Approaches to access the data vary depending on whether the data length has been specified or not.

Input Data of Specified Length¶

Assuming that you have specified the data length in <param_1> as follows:

AT+TEST=<param_1>

Below is the sample to access the input data of <param_1> length from AT Command Port:

static xSemaphoreHandle at_sync_sema = NULL;

void wait_data_callback(void)
{
    xSemaphoreGive(at_sync_sema);
}

uint8_t at_setup_cmd_test(uint8_t para_num)
{
    int32_t specified_len = 0;
    int32_t received_len = 0;
    int32_t remain_len = 0;
    uint8_t *buf = NULL;
    uint8_t buffer[64] = {0};

    if (esp_at_get_para_as_digit(0, &specified_len) != ESP_AT_PARA_PARSE_RESULT_OK) {
        return ESP_AT_RESULT_CODE_ERROR;
    }

    buf = (uint8_t *)malloc(specified_len);
    if (buf == NULL) {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "malloc failed\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    // sample code
    // users don't have to create semaphores here
    if (!at_sync_sema) {
        at_sync_sema = xSemaphoreCreateBinary();
        assert(at_sync_sema != NULL);
    }

    // output input prompt ">"
    esp_at_port_write_data((uint8_t *)">", strlen(">"));

    // set the callback function which will be called by AT port after receiving the input data
    esp_at_port_enter_specific(wait_data_callback);

    // receive input data
    while(xSemaphoreTake(at_sync_sema, portMAX_DELAY)) {
        received_len += esp_at_port_read_data(buf + received_len, specified_len - received_len);

        if (specified_len == received_len) {
            esp_at_port_exit_specific();

            // get the length of the remaining input data
            remain_len = esp_at_port_get_data_length();
            if (remain_len > 0) {
                // sample code
                // if the remaining data length > 0, the actual input data length is greater than the specified received data length
                // users can customize the operation to process the remaining data
                // here is just a simple print out of the remaining data
                esp_at_port_recv_data_notify(remain_len, portMAX_DELAY);
            }

            // sample code
            // output received data
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "\r\nreceived data is: ");
            esp_at_port_write_data(buffer, strlen((char *)buffer));

            esp_at_port_write_data(buf, specified_len);

            break;
        }
    }

    free(buf);

    return ESP_AT_RESULT_CODE_OK;
}

So, if you set AT+TEST=5 and the input data is 1234567890, the ESP-AT output is as follows.

AT+TEST=5
>67890
received data is: 12345
OK

Input Data of Unspecified Length¶

This scenario is similar to the Wi-Fi Passthrough Mode. You do not specify the data length.

AT+TEST

Assuming that ESP-AT ends the execution of the command and returns the execution result, the sample code is as follows:

#define BUFFER_LEN (2048)
static xSemaphoreHandle at_sync_sema = NULL;

void wait_data_callback(void)
{
    xSemaphoreGive(at_sync_sema);
}

uint8_t at_exe_cmd_test(uint8_t *cmd_name)
{
    int32_t received_len = 0;
    int32_t remain_len = 0;
    uint8_t *buf = NULL;
    uint8_t buffer[64] = {0};


    buf = (uint8_t *)malloc(BUFFER_LEN);
    if (buf == NULL) {
        memset(buffer, 0, 64);
        snprintf((char *)buffer, 64, "malloc failed\r\n");
        esp_at_port_write_data(buffer, strlen((char *)buffer));
    }

    // sample code
    // users don't have to create semaphores here
    if (!at_sync_sema) {
        at_sync_sema = xSemaphoreCreateBinary();
        assert(at_sync_sema != NULL);
    }

    // output input prompt ">"
    esp_at_port_write_data((uint8_t *)">", strlen(">"));

    // set the callback function which will be called by AT port after receiving the input data
    esp_at_port_enter_specific(wait_data_callback);

    // receive input data
    while(xSemaphoreTake(at_sync_sema, portMAX_DELAY)) {
        memset(buf, 0, BUFFER_LEN);

        received_len = esp_at_port_read_data(buf, BUFFER_LEN);
        // check whether to exit the mode
        // the exit condition is the "+++" string received
        if ((received_len == 3) && (strncmp((const char *)buf, "+++", 3)) == 0) {
            esp_at_port_exit_specific();

            // sample code
            // if the remaining data length > 0, it means that there is still data left in the buffer to be processed
            // users can customize the operation to process the remaining data
            // here is just a simple print out of the remaining data
            remain_len = esp_at_port_get_data_length();
            if (remain_len > 0) {
                esp_at_port_recv_data_notify(remain_len, portMAX_DELAY);
            }

            break;
        } else if (received_len > 0) {
            // sample code
            // users can customize the operation to process the received data
            // here is just a simple print received data
            memset(buffer, 0, 64);
            snprintf((char *)buffer, 64, "\r\nreceived data is: ");
            esp_at_port_write_data(buffer, strlen((char *)buffer));

            esp_at_port_write_data(buf, strlen((char *)buf));
        }
    }

    free(buf);

    return ESP_AT_RESULT_CODE_OK;
}

So, if the first input data is 1234567890, and the second input data is +++, the ESP-AT output is as follows:

AT+TEST
>
received data is: 1234567890
OK

How to Improve ESP-AT Throughput Performance¶

[中文]

By default, UART is used for communication between ESP-AT and the host MCU, so the maximum throughput speed will not exceed its default configuration, that is, 115200 bps. If users want ESP-AT to achieve high throughput, it is necessary to understand this document and choose the appropriate configuration method. Taking ESP32 as an example, this document introduces how to improve the throughput performance of ESP-AT.

Note

This document describes general methods to improve TCP/UDP/SSL throughput performance when ESP-AT is in Passthrough Mode.

Users could choose one of the following methods to improve throughput performance:

[Simple] Quick Configuration
[Recommended] Understand Data Stream and Make the Precise Configuration

[Simple] Quick Configuration¶

1. Configure system, LWIP, Wi-Fi parameters

Copy the following code snippet and append to tail of module_config/module_esp32_default/sdkconfig.defaults file. For other ESP series devices, please modify the sdkconfig.defaults file in the corresponding folder.

# System
CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE=4096
CONFIG_FREERTOS_UNICORE=n
CONFIG_FREERTOS_HZ=1000
CONFIG_ESP32_DEFAULT_CPU_FREQ_240=y
CONFIG_ESP32_DEFAULT_CPU_FREQ_MHZ=240
CONFIG_ESPTOOLPY_FLASHMODE_QIO=y
CONFIG_ESPTOOLPY_FLASHFREQ_80M=y

# LWIP
CONFIG_LWIP_TCP_SND_BUF_DEFAULT=65534
CONFIG_LWIP_TCP_WND_DEFAULT=65534
CONFIG_LWIP_TCP_RECVMBOX_SIZE=12
CONFIG_LWIP_UDP_RECVMBOX_SIZE=12
CONFIG_LWIP_TCPIP_RECVMBOX_SIZE=64

# Wi-Fi
CONFIG_ESP32_WIFI_STATIC_RX_BUFFER_NUM=16
CONFIG_ESP32_WIFI_DYNAMIC_RX_BUFFER_NUM=64
CONFIG_ESP32_WIFI_DYNAMIC_TX_BUFFER_NUM=64
CONFIG_ESP32_WIFI_TX_BA_WIN=32
CONFIG_ESP32_WIFI_RX_BA_WIN=32
CONFIG_ESP32_WIFI_AMPDU_TX_ENABLED=y
CONFIG_ESP32_WIFI_AMPDU_RX_ENABLED=y

2. Enlarge UART buffer size

Copy the following code snippet and replace the uart_driver_install() line of at_uart_task.c file.
uart_driver_install(esp_at_uart_port, 1024 * 16, 1024 * 16, 100, &esp_at_uart_queue, 0);

3. Delete, Build, Flash, Run

rm -rf build sdkconfig
./build.py build
./build.py flash monitor

4. Increase UART baud rate before entering passthrough mode

A typical ESP-AT commands sequence is as follows:

AT+CWMODE=1
AT+CWJAP="ssid","password"
AT+UART_CUR=3000000,8,1,0,3
AT+CIPSTART="TCP","192.168.105.13",3344
AT+CIPSEND
// data transmission

This simple and quick configuration method can improve the throughput to a certain extent, but sometimes it might not meet the expectations of users. In addition, some configurations may not hit the bottleneck of throughput. Higher configurations may sacrifice memory resources or power consumption. Therefore, users could also familiarize themselves with the following recommended method and make the precise configuration.

[Recommended] Understand Data Stream and Make the Precise Configuration¶

The factors that generally affect ESP-AT throughput are illustrated in the following figure:

As shown by the arrows in the figure:

The Data stream sent by ESP-AT is (TX): S1 -> S2 -> S3 -> S4 -> S5 -> S6 -> S7 -> S8
The Data stream received by ESP-AT is (RX): R8 -> R7 -> R6 -> R5 -> R4 -> R3 -> R2 -> R1

The data stream of throughput is similar to water flow. In order to improve throughput, it is necessary to consider optimizing between nodes with low data flow rate rather than making additional configuration between nodes with expected data flow rate, so as to avoid unnecessary waste of resources. In actual products, usually, users only need to improve the throughput of one data stream. So here, users need to configure it according to the following instructions.

Note

The following configurations are based on sufficient available memory. Users can query the available memory through the AT command: AT+SYSRAM.

1. G0 throughput optimization

G0 is a part of the system that can be optimized. The recommended configuration is as follows:

CONFIG_ESP_SYSTEM_EVENT_TASK_STACK_SIZE=4096
CONFIG_FREERTOS_UNICORE=n
CONFIG_FREERTOS_HZ=1000
CONFIG_ESP32_DEFAULT_CPU_FREQ_240=y
CONFIG_ESP32_DEFAULT_CPU_FREQ_MHZ=240
CONFIG_ESPTOOLPY_FLASHMODE_QIO=y
CONFIG_ESPTOOLPY_FLASHFREQ_80M=y

2. S1, R1 throughput optimization

Generally, S1 and R1 are the key to the throughput of ESP-AT. Because UART is used for communication between ESP-AT and the host MCU by default, and the baud rate is 115200. On the hardware, the baud rate upper limit is 5 Mbps. Therefore, if the throughput is expected to be less than 5 Mbps, the user can use the default UART as the communication medium with the host MCU, and the following optimization methods can be carried out.

2.1 Enlarge UART buffer size

Copy the following code snippet and replace the uart_driver_install() line of at_uart_task.c file.
Improve UART TX throughput
uart_driver_install(esp_at_uart_port, 1024 * 16, 8192, 100, &esp_at_uart_queue, 0);
Improve UART RX throughput
uart_driver_install(esp_at_uart_port, 2048, 1024 * 16, 100, &esp_at_uart_queue, 0);
Improve UART TX and RX throughput
uart_driver_install(esp_at_uart_port, 1024 * 16, 1024 * 16, 100, &esp_at_uart_queue, 0);

2.2 Increase UART baud rate before entering passthrough mode

A typical ESP-AT commands sequence is as follows:

AT+CWMODE=1
AT+CWJAP="ssid","password"
AT+UART_CUR=3000000,8,1,0,3
AT+CIPSTART="TCP","192.168.105.13",3344
AT+CIPSEND
// data transmission

Note

The user needs to ensure that the UART of the host MCU can support such a high rate, and the UART connection between the host MCU and ESP-AT is as short as possible.

Note

If the user expects the throughput rate to be greater than or close to 5 Mbps, then SPI, SDIO, Socket or other methods can be considered. Please refer to:

3. S2, R2, R3, S3 throughput optimization

Generally, S2, R2, R3, S3 are not the bottleneck of ESP-AT throughput. Because AT core transfers data between UART buffer and the transport layer of communication protocol, where has minimal and non-time-consuming application logic, there is no need to optimize them.

4. S4, R4, S5, R5, S6, R6 throughput optimization

If UART is used for communication between ESP-AT and host MCU, S4, R4, S5, R5, S6, R6 need not be optimized. If other transmission media are used, S4, R4, S5, R5, S6, R6 should be a factor affecting throughput.

S4, R4, S5, R5, S6, R6 is the data stream between the transport layer, network layer and data link layer of the communication protocol. Users need to read How to improve Wi-Fi performance in ESP-IDF to understand the principle and make reasonable configuration. These configurations can be configured in ./build.py menuconfig.

Improve throughput of S4 -> S5 -> S6: TX direction

Improve throughput of R6 -> R5 -> R4: RX direction

5. S6, R6 throughput optimization

S6 and R6 are the data link layers of the communication protocol. ESP32 can use Wi-Fi or ethernet as the transmission medium. In addition to the optimization methods described above, Wi-Fi throughput optimization may also need users’ attention:

Improve RF Power

The default RF power is usually not the bottleneck of throughput. Users could query and set RF power through AT command: AT+RFPOWER.

Set 802.11 b/g/n protocol

The default Wi-Fi mode is 802.11 b/g/n protocol. Users could query and set 802.11 b/g/n protocol through AT command: AT+CWSTAPROTO. The configuration is bidirectional. Therefore, it is recommended that the Wi-Fi mode of AP is configured as 802.11 b/g/n protocol and the bandwidth mode of AP is configured as HT20/HT40 (20/40 MHz) mode.

6. S7, R7, S8, R8 throughput optimization

Generally, S7, R7, S8, R8 are not the scope of ESP-AT throughput optimization because this is related to the actual network bandwidth, network routing, physical distance, etc.

How to Generate Factory Parameter Bin¶

[中文]

This document explains how to generate a customized ESP-AT factory parameter bin file (factory_MODULE_NAME.bin) for your module. For example, you may want to self-define the country code, RF restriction, or UART pins in your ESP-AT firmware. The two tables below allow you to define such parameters.

factory_param_type.csv
factory_param_data.csv

The following describes how to generate a customized factory parameter bin by modifying the two tables.

Add a Customized Module
Add a Customized Parameter
Modify Factory Parameter Data on an Existing Module

factory_param_type.csv¶

The factory_param_type.csv table lists all the parameters that you can define as well as the offset, type, and size of each parameter. It is located in customized_partitions/raw_data/factory_param/factory_param_type.csv.

The table below provides some information about each parameter.

param_name	Note
description	Additional information of the module, which is prompted when you are building the ESP-AT project.
magic_flag	The value must be `0xfcfc`.
version	The version of factory parameter management for internal use. The current version is `3`. It is not recommended to modify it.
reserved1	Reserved.
tx_max_power	Wi-Fi maximum tx power for ESP32 and ESP32-C3: [40,84]. See ESP32 and ESP32-C3 tx power setting range for details.
uart_port	The UART port that is used to send AT commands and receive AT responses.
start_channel	Wi-Fi start channel.
channel_num	The total channel number of Wi-Fi.
country_code	Country code.
uart_baudrate	UART baudrate.
uart_tx_pin	UART tx pin.
uart_rx_pin	UART rx pin.
uart_cts_pin	UART cts pin; it should be set to -1 if not used.
uart_rts_pin	UART rts pin; it should be set to -1 if not used.
tx_control_pin	For some boards, the tx pin needs to be separated from MCU when power on; it should be set to -1 if not used.
rx_control_pin	For some boards, the rx pin needs to be separated from MCU when power on; it should be set to -1 if not used.
reserved2	Reserved.
platform	The platform (or called chip series) that the current firmware runs on.
module_name	The module that the current firmware runs on.

factory_param_data.csv¶

This factory_param_data.csv table holds the values for all the parameters defined in factory_param_type.csv. It covers the modules of ESP32 and ESP32-C3 series. You can customize your factory parameter bin by modifying the values in the table. It is located in customized_partitions/raw_data/factory_param/factory_param_data.csv.

Add a Customized Module¶

This section demonstrates how to add a customized module in factory_param_data.csv and generate the factory parameter bin for it with an example. Assuming that you want to generate the factory parameter bin for an ESP32 module named as MY_MODULE, its country code is JP, Wi-Fi channel is from 1 to 14, and other parameters stay the same with WROOM-32 module of PLATFORM_ESP32, you can do as follows:

Modify factory_param_data.csv
Modify esp_at_module_info Structure
Recompile the Project and Select the Customized Module

Modify factory_param_data.csv ¶

Set all parameter values for MY_MODULE in the factory_param_data.csv table.

Firstly, insert a row at the bottom of the table, and then enter the following parameter values:

param_name: value
platform: PLATFORM_ESP32
module_name: MY_MODULE
description: MY_DESCRIPTION
magic_flag: 0xfcfc
version: 3
reserved1: 0
tx_max_power: 78
uart_port: 1
start_channel: 1
channel_num: 14
country_code: JP
uart_baudrate: 115200
uart_tx_pin: 17
uart_rx_pin: 16
uart_cts_pin: 15
uart_rts_pin: 14
tx_control_pin: -1
rx_control_pin: -1

The modified factory_param_data.csv file is as follows.

platform,module_name,description,magic_flag,version,reserved1,tx_max_power,uart_port,start_channel,channel_num,country_code,uart_baudrate,uart_tx_pin,uart_rx_pin,uart_cts_pin,uart_rts_pin,tx_control_pin,rx_control_pin
PLATFORM_ESP32,WROOM-32,,0xfcfc,3,0,78,1,1,13,CN,115200,17,16,15,14,-1,-1
...
PLATFORM_ESP32,MY_MODULE,MY_DESCRIPTION,0xfcfc,3,0,78,1,1,14,JP,115200,17,16,15,14,-1,-1

Modify `esp_at_module_info` Structure ¶

Add customized module information in the esp_at_module_info structure in at/src/at_default_config.c.

The esp_at_module_info structure provides OTA upgrade verification token:

typedef struct {
    char* module_name;
    char* ota_token;
    char* ota_ssl_token;
} esp_at_module_info_t;

If you do not want to use OTA features, member 2 ota_token and member 3 ota_ssl_token should be set to NULL. Member 1 module_name must correspond to the field module_name in the factory_param_data.csv file.

The modified esp_at_module_info structure is as follows:

static const esp_at_module_info_t esp_at_module_info[] = {
#if defined(CONFIG_IDF_TARGET_ESP32)
    {"WROOM-32",        CONFIG_ESP_AT_OTA_TOKEN_WROOM32,       CONFIG_ESP_AT_OTA_SSL_TOKEN_WROOM32 },        // default:ESP32-WROOM-32
    {"WROOM-32",        CONFIG_ESP_AT_OTA_TOKEN_WROOM32,       CONFIG_ESP_AT_OTA_SSL_TOKEN_WROOM32 },        // ESP32-WROOM-32
    {"WROVER-32",       CONFIG_ESP_AT_OTA_TOKEN_WROVER32,      CONFIG_ESP_AT_OTA_SSL_TOKEN_WROVER32 },       // ESP32-WROVER
    {"PICO-D4",         CONFIG_ESP_AT_OTA_TOKEN_ESP32_PICO_D4, CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_PICO_D4},   // ESP32-PICO-D4
    {"SOLO-1",          CONFIG_ESP_AT_OTA_TOKEN_ESP32_SOLO_1,  CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_SOLO_1 },   // ESP32-SOLO-1
    {"MINI-1",          CONFIG_ESP_AT_OTA_TOKEN_ESP32_MINI_1,  CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_MINI_1 },   // ESP32-MINI-1
    {"ESP32-D2WD",      NULL,  NULL },   // ESP32-D2WD
    {"ESP32_QCLOUD",    CONFIG_ESP_AT_OTA_TOKEN_ESP32_QCLOUD,   CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32_QCLOUD },  // ESP32-QCLOUD
    {"MY_MODULE",       CONFIG_ESP_AT_OTA_TOKEN_MY_MODULE,      CONFIG_ESP_AT_OTA_SSL_TOKEN_MY_MODULE },     // MY_MODULE
#endif

#if defined(CONFIG_IDF_TARGET_ESP32C3)
    {"MINI-1",         CONFIG_ESP_AT_OTA_TOKEN_ESP32C3_MINI,        CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32C3_MINI },
    {"ESP32C3_QCLOUD", CONFIG_ESP_AT_OTA_TOKEN_ESP32C3_MINI_QCLOUD, CONFIG_ESP_AT_OTA_SSL_TOKEN_ESP32C3_MINI_QCLOUD },
#endif
};

Macro CONFIG_ESP_AT_OTA_TOKEN_MY_MODULE and macro CONFIG_ESP_AT_OTA_SSL_TOKEN_MY_MODULE are defined in the header file at/private_include/at_ota_token.h.

#if defined(CONFIG_IDF_TARGET_ESP32)
...
#define CONFIG_ESP_AT_OTA_TOKEN_MY_MODULE       CONFIG_ESP_AT_OTA_TOKEN_DEFAULT

...
#define CONFIG_ESP_AT_OTA_SSL_TOKEN_MY_MODULE       CONFIG_ESP_AT_OTA_SSL_TOKEN_DEFAULT

Recompile the Project and Select the Customized Module ¶

After adding the customized module information, recompile the whole project according to Compile ESP-AT Project and select the customized module when configuring the project:

Platform name:
PLATFORM_ESP32
PLATFORM_ESP32C3
choose(range[1,2]):1

Module name:
WROOM-32
WROVER-32
PICO-D4
SOLO-1
MINI-1 (description: ESP32-U4WDH chip inside)
ESP32-D2WD (description: 2MB flash, No OTA)
ESP32_QCLOUD (description: QCLOUD TX:17 RX:16)
MY_MODULE (description: MY_DESCRIPTION)
choose(range[1,8]):8

You can find the factory parameter bin generated in esp-at/build/customized_partitions folder after the build is completed.

Add a Customized Parameter¶

This section demonstrates how to add a customized parameter with an example. Assuming that you want to add the parameter date for MY_MODULE and set it to 20210603, you should do as follows:

Modify factory_param_type.csv
Modify factory_param_data.csv
Process a Customized Parameter
Recompile the Project

Modify factory_param_type.csv ¶

Define the parameter date in the factory_param_type.csv.

Firstly, insert a row at the end of the table, and then set the name, offset, type, and size of the parameter:

param_name	offset	type	size
description	-1	String	0
…	…	…	…
`date`	`88`	`String`	`9`

Modify factory_param_data.csv ¶

In the factory_param_data.csv, insert a column named as date to the right of the last column, then set its value to 20210603 for MY_MODULE.

The modified CSV table is as follows:

platform,module_name,description,magic_flag,version,reserved1,tx_max_power,uart_port,start_channel,channel_num,country_code,uart_baudrate,uart_tx_pin,uart_rx_pin,uart_cts_pin,uart_rts_pin,tx_control_pin,rx_control_pin,date
PLATFORM_ESP32,WROOM-32,,0xfcfc,3,0,78,1,1,13,CN,115200,17,16,15,14,-1,-1
...
PLATFORM_ESP32,MY_MODULE,MY_DESCRIPTION,0xfcfc,3,0,78,1,1,14,JP,115200,17,16,15,14,-1,-1,20210603

Process a Customized Parameter ¶

You can customize processing functions to process the customized parameter date. This section is just a simple output:

static void esp_at_factory_parameter_date_init(void)
{
    const esp_partition_t * partition = esp_at_custom_partition_find(0x40, 0xff, "factory_param");
    char* data = NULL;
    char* str_date = NULL;

    if (!partition) {
        printf("factory_parameter partition missed\r\n");
        return;
    }

    data = (char*)malloc(ESP_AT_FACTORY_PARAMETER_SIZE); // Notes
    assert(data != NULL);
    if(esp_partition_read(partition, 0, data, ESP_AT_FACTORY_PARAMETER_SIZE) != ESP_OK){
        free(data);
        return;
    }

    if ((data[0] != 0xFC) || (data[1] != 0xFC)) { // check magic flag, should be 0xfc 0xfc
        return;
    }

    // sample code
    // users can customize the operation of processing date
    // here is just a simple print out of the date parameter
    str_date = &data[88];   // date field offset address
    printf("date is %s\r\n", str_date);

    free(data);

    return;
}

Recompile the Project ¶

Recompile the whole project according to Compile ESP-AT Project.

You can find the factory parameter bin generated in esp-at/build/customized_partitions folder after the build is completed.

Modify Factory Parameter Data on an Existing Module¶

Assuming that you need to modify the factory parameter data of an existing module in factory_param_data.csv, you choose one of the following options:

Recompile the Whole Project
Only Recompile the Factory Parameter Bin
Directly Modify Factory Parameter Bin

Recompile the Whole Project ¶

Open the factory_param_data.csv and modify the parameters as needed.

Recompile the ESP-AT project according to Compile ESP-AT Project to generate the factory parameter bin in esp-at/build/customized_partitions folder.

Only Recompile the Factory Parameter Bin ¶

Firstly, clone the entire ESP-AT project.

Secondly, navigate to the root directory of ESP-AT project, enter the following command, and replace some parameters:

python tools/factory_param_generate.py --platform PLATFORM --module MODULE --define_file DEFINE_FILE --module_file MODULE_FILE --bin_name BIN_NAME --log_file LOG_FILE

Replace PLATFORM with the platform of your module. It must correspond to the platform in the factory_param_data.csv.
Replace MODULE with your module name. It must correspond to the module_name in the factory_param_data.csv.
Replace DEFINE_FILE with the relative path of factory_param_type.csv.
Replace MODULE_FILE with the relative path of factory_param_data.csv.
Replace BIN_NAME with factory parameter bin file name.
Replace LOG_FILE with the file name stored the module name.

Below is the example command for MY_MODULE:

python tools/factory_param_generate.py --platform PLATFORM_ESP32 --module MY_MODULE --define_file components/customized_partitions/raw_data/factory_param/factory_param_type.csv --module_file components/customized_partitions/raw_data/factory_param/factory_param_data.csv --bin_name ./factory_param.bin --log_file ./factory_parameter.log

After the above command is executed, the three files will be generated in the current directory:

factory_param.bin
factory_parameter.log
factory_param_MY_MODULE.bin

Download the new factory_param_MY_MODULE.bin into flash. ESP-AT provides esptool.py to do it. Execute the following command under the root directory of ESP-AT project and replace some parameters:

python esp-idf/components/esptool_py/esptool/esptool.py -p PORT -b BAUD --before default_reset --after hard_reset --chip auto  write_flash --flash_mode dio --flash_size detect --flash_freq 40m ADDRESS FILEDIRECTORY

Replace PORT with the port name
Replace BAUD with baud rate
Replace ADDRESS with the start address in flash. ESP-AT has strict requirements on the ADDRESS parameter. The address of factory parameter bin varies from firmware to firmware. Please refer to the table below:

factory parameter bin download addresses¶

Platform

Firmware

Address

PLATFORM_ESP32

All firmware

0x30000

PLATFORM_ESP32C3

MINI-1 Bin

0x31000

PLATFORM_ESP32C3

QCLOUD Bin

0x30000
Replace FILEDIRECTORY with the relative path of the factory parameter bin.

Below is the example command to flash the generated factory parameter bin to MY_MODULE:

python esp-idf/components/esptool_py/esptool/esptool.py -p /dev/ttyUSB0 -b 921600 --before default_reset --after hard_reset --chip auto  write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x30000 ./factory_param_MY_MODULE.bin

Directly Modify Factory Parameter Bin ¶

Open the factory parameter bin with a binary tool, and directly modify the parameters in the corresponding position according to the parameters offset in factory_param_type.csv.

Download the new factory_param.bin into flash (see Downloading Guide).

How to Customize Bluetooth® LE Services¶

[中文]

This document describes how to customize Bluetooth LE services on your ESP device with the Bluetooth LE service source file provided by ESP-AT.

Bluetooth LE Service Source File
Customize Bluetooth LE Services

The Bluetooth LE services are defined as a multivariate array of GATT structures, and the array contains at least one primary service whose attribute type is defined as 0x2800. Each service always consists of a service definition and several characteristics. Each characteristic always consists of a value and optional descriptors. Please refer to Part Generic Attribute Profile (GATT) of Bluetooth Core Specification for more information.

Bluetooth LE Service Source File ¶

The ESP-AT project creates Bluetooth LE services based on its Bluetooth LE service source file. It is located in components/customized_partitions/raw_data/ble_data/example.csv. The table below shows the default source file.

index	uuid_len	uuid	perm	val_max_len	val_cur_len	value
0	16	0x2800	0x01	2	2	A002
1	16	0x2803	0x01	1	1	2
2	16	0xC300	0x01	1	1	30
3	16	0x2901	0x11	1	1	30
…	…	…	…	…	…	…

Below are descriptions of the table above.

perm field describes the permission. Its definition in the ESP-AT project is as follows:

/* relate to BTA_GATT_PERM_xxx in bta/bta_gatt_api.h */
/**
* @brief Attribute permissions
*/
#define    ESP_GATT_PERM_READ                  (1 << 0)   /* bit 0 -  0x0001 */    /* relate to BTA_GATT_PERM_READ in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_READ_ENCRYPTED        (1 << 1)   /* bit 1 -  0x0002 */    /* relate to BTA_GATT_PERM_READ_ENCRYPTED in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_READ_ENC_MITM         (1 << 2)   /* bit 2 -  0x0004 */    /* relate to BTA_GATT_PERM_READ_ENC_MITM in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_WRITE                 (1 << 4)   /* bit 4 -  0x0010 */    /* relate to BTA_GATT_PERM_WRITE in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_WRITE_ENCRYPTED       (1 << 5)   /* bit 5 -  0x0020 */    /* relate to BTA_GATT_PERM_WRITE_ENCRYPTED in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_WRITE_ENC_MITM        (1 << 6)   /* bit 6 -  0x0040 */    /* relate to BTA_GATT_PERM_WRITE_ENC_MITM in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_WRITE_SIGNED          (1 << 7)   /* bit 7 -  0x0080 */    /* relate to BTA_GATT_PERM_WRITE_SIGNED in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_WRITE_SIGNED_MITM     (1 << 8)   /* bit 8 -  0x0100 */    /* relate to BTA_GATT_PERM_WRITE_SIGNED_MITM in bta/bta_gatt_api.h */
#define    ESP_GATT_PERM_READ_AUTHORIZATION    (1 << 9)   /* bit 9 -  0x0200 */
#define    ESP_GATT_PERM_WRITE_AUTHORIZATION   (1 << 10)  /* bit 10 - 0x0400 */

The first line of table is the service definition with a UUID of 0xA002.
The second line is the declaration of a characteristic. UUID 0x2803 means the characteristic declaration. The value 2 sets the permission. The length of permission is 8 bits, and each bit represents permission for an operation. 1 indicates that the operation is supported, and 0 indicates not supported.

Bit

Permission

0

BROADCAST

1

READ

2

WRITE WITHOUT RESPONSE

3

WRITE

4

NOTIFY

5

INDICATE

6

AUTHENTICATION SIGNED WRITES

7

EXTENDED PROPERTIES
The third line defines a characteristic of the service. UUID of this line is the characteristic’s UUID, and value is the characteristic’s value.
The fourth line defines a descriptor of the characteristic (optional).

For more information about UUID, please refer to Bluetooth Special Interest Group (SIG) Assigned Numbers.

If you use the default source file on your ESP device without any modification and establish a Bluetooth LE connection, you will get the following result after querying the server service on the client side.

Customize Bluetooth LE Services ¶

If you want to customize the Bluetooth LE services, follow the steps below.

Modify the Bluetooth LE Service Source File
Generate ble_data.bin
Download ble_data.bin

Modify the Bluetooth LE Service Source File ¶

You can define more than one service. For example, if you want to define three services (Server_A, Server_B and Server_C), these three services need to be arranged in order. Since the definition of each service is similar, here we define one service as an example, and then you can define others one by one accordingly.

Add the service definition.

In this example, we define a primary service with a value of 0xFF01.

index

uuid_len

uuid

perm

val_max_len

val_cur_len

value

31

16

0x2800

0x01

2

2

FF01
Add the characteristic declaration and characteristic value.

In this example, we define a readable and writable characteristic with UUID 0xC300, and set its value to 0x30.

index

uuid_len

uuid

perm

val_max_len

val_cur_len

value

32

16

0x2803

0x11

1

1

0A

33

16

0xC300

0x11

1

1

30
Add the characteristic descriptor (optional).

In this example, we add client characteristic configuration. Its value 0x0000 represents notifications and indications are disabled.

index

uuid_len

uuid

perm

val_max_len

val_cur_len

value

34

16

0x2902

0x11

2

2

0000

After the above steps, the customized Bluetooth LE service has been defined as follows.

index	uuid_len	uuid	perm	val_max_len	val_cur_len	value
31	16	0x2800	0x01	2	2	FF01
32	16	0x2803	0x11	1	1	0A
33	16	0xC300	0x11	1	1	30
34	16	0x2902	0x11	2	2	0000

Generate ble_data.bin ¶

You can generate ble_data.bin in either of the following ways:

Recompile the ESP-AT project to generate ble_data.bin. See Build the Project for more information.
Execute the BLEService.py script to generate ble_data.bin

The path of BLEService.py is tools/BLEService.py. You can execute the following command in the root directory of ESP-AT to generate ble_data.bin.
```
python ./tools/BLEService.py components/customized_partitions/raw_data/ble_data/example.csv
```

Download ble_data.bin ¶

You can download ble_data.bin in either of the following ways, corresponding to the ways to generate bin files in the Generate ble_data.bin section.

Download recompiled ESP-AT firmware. See Flash onto the Device for more information.
Download ble_data.bin only. This way only updates the ble_data area in the device.

You can execute the following command in the root directory of ESP-AT to download ble_data.bin.
```
esptool.py --chip auto --port PORTNAME --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB ADDRESS ble_data.bin
```
Replace PORTNAME with your port name and replace ADDRESS with download ble_data.bin address. The ble_data.bin has different addresses in different modules.
- ESP32: 0x21000
- ESP32-C3: 0x1F000
- ESP32-C3 QCLOUD: 0x21000

After the download is complete, re-establish the Bluetooth LE connection. Query the server service on the client side as follows:

How to Customize Partitions¶

[中文]

This document describes how to customize the partitions in your ESP device by modifying the at_customize.csv table provided by ESP-AT. There are two partition tables: the primary partition and the secondary partition table.

The primary partition table partitions_at.csv is for system usage, based on which the partitions_at.bin file is generated. If the primary partition table goes wrong, the system will fail to startup. Therefore, it is not recommended to modify the partitions_at.csv.

ESP-AT provides a secondary partition table at_customize.csv that you can customize to store self-defined blocks of data. It is based on the primary partition table.

To modify the partition in your ESP device, please follow the first three steps. The fourth section illustrates the three steps with an example.

Modify at_customize.csv
Generate at_customize.bin
Flash at_customize.bin into ESP Device
Example

Modify at_customize.csv¶

Find the at_customize.csv for your module with reference to the following table.

at_customize.csv paths¶
Platform	Module	Paths
ESP32	WROOM-32 PICO-D4 SOLO-1 MINI-1	module_esp32_default/at_customize.csv
ESP32	WROVER-32	module_wrover-32/at_customize.csv
ESP32	ESP32-D2WD	module_esp32-d2wd/at_customize.csv
ESP32	ESP32_QCLOUD	module_esp32_qcloud/at_customize.csv
ESP32-C3	MINI-1	module_esp32c3_default/at_customize.csv
ESP32-C3	ESP32C3_QCLOUD	module_esp32c3_qcloud/at_customize.csv

Then, follow the rules below when modifying at_customize.csv.

Do not change the Name and Type of the user partitions that have already been defined in it, while SubType, Offset, and Size can be changed.
If you need to add a new user partition, please check if it has already been defined in the ESP-IDF (esp_partition.h) first.
- If yes, you should keep the Type value the same as that of ESP-IDF.
- If no, please set the Type to 0x40.
A user partition’s Name should not be longer than 16 bytes.
The default size of the entire at_customize partition is defined in the partitions_at.csv table. Please do not exceed the range when adding new user partitions.

Generate at_customize.bin¶

After having modified the at_customize.csv, you can either recompile the ESP-AT project to generate the at_customize.bin file, or use the python script gen_esp32part.py.

If you use the script, execute the following command under the root directory of ESP-AT project and replace INPUT and OUTPUT:

python esp-idf/components/partition_table/gen_esp32part.py <INPUT> [OUTPUT]

Replace INPUT with the path to at_customize.csv or the binary file to parse.
Replace OUTPUT with the path to output converted binary or CSV file. Stdout will be used if omitted.

Flash at_customize.bin into ESP Device¶

Download the at_customize.bin into flash. Please refer to Flash AT Firmware into Your Device for how to flash bin files into ESP and the following table for the download address for your module.

at_customize.bin download address of modules¶
Platform	Module	Address	Size
ESP32	WROOM-32 WROVER-32 PICO-D4 SOLO-1 MINI-1 ESP32-D2WD ESP32_QCLOUD	0x20000	0xE0000
ESP32-C3	MINI-1	0x1E000	0x42000
ESP32-C3	ESP32C3_QCLOUD	0x20000	0xE0000

There are cases where at_customize.bin must be downloaded to flash in order to use certain AT commands:

AT+SYSFLASH: Query/Set User Partitions in Flash
AT+FS: Filesystem Operations
SSL server relevant commands
BLE server relevant commands

Example¶

The section demonstrates how to add a 4 KB partition named test into the ESP32-WROOM-32 module.

Firstly, find the at_customize.csv table for ESP32-WROOM-32 and set the Name, Type, Subtype, Offset, and Size of the new partition:

# Name,Type,SubType,Offset,Size
... ...
test,0x40,15,0x3D000,4K
fatfs,data,fat,0x70000,576K

Secondly, recompile the ESP-AT project, or execute the python script in the ESP-AT root directory to generate at_customize.bin.

python esp-idf/components/partition_table/gen_esp32part.py -q ./module_config/module_esp32_default/at_customize.csv at_customize.bin

Then, the at_customize.bin will be generated in the ESP-AT root directory.

Thirdly, download the at_customize.bin to flash.

Execute the following command under the root directory of ESP-AT project and replace PORT and BAUD.

python esp-idf/components/esptool_py/esptool/esptool.py -p PORT -b BAUD --before default_reset --after hard_reset --chip auto  write_flash --flash_mode dio --flash_size detect --flash_freq 40m 0x20000 ./at_customize.bin

Replace PORT with your port name.
Replace BAUD with the baud rate.

How to Enable ESP-AT Classic Bluetooth¶

[中文]

By default, Classic Bluetooth AT commands are disabled in the ESP32 series AT firmware. If you want to use them on ESP32 devices, please follow the steps below. The commands supported by AT are classified into three categories, general Bluetooth commands, SPP commands, and A2DP commands and each category may be enabled and disabled separately.

Clone the ESP-AT project.
Run the configuration utility by executing ./build.py menuconfig (Linux or macOS) or build.py menuconfig (Windows).
Enable the commands you need.

Enable general Bluetooth commands.

Component config -> AT -> AT bt command support.

Enable SPP commands.

Component config -> AT -> AT bt command support -> AT bt spp command support.

Enable A2DP commands.

Component config -> AT -> AT bt command support -> AT bt a2dp command support.

Compile the project to generate the new firmware in build/esp-at.bin.
Flash the new firmware to your device.

How to Enable ESP-AT Ethernet¶

[中文]

Overview¶

This document is intended to help you enable ESP-AT Ethernet. After that, a simple test will show you how to confirm whether the enablement is successful.

Step 1. Configure and Flash¶

./build.py menuconfig -> Component config -> AT -> AT ethernet support to enable the Ethernet interface.
./build.py menuconfig -> Component config -> AT -> Ethernet PHY to choose the PHY model. For more details see PHY Configuration.
Recompile the esp-at project (see Compile ESP-AT Project), download AT bin into flash.

PHY Configuration¶

Use ./build.py menuconfig to set the PHY model. These configuration items will vary depending on the hardware configuration you are using.

The default configuration is correct for Espressif’s Ethernet board with TP101 PHY. ESP32 AT supports up to four Ethernet PHY: LAN8720, IP101, DP83848 and RTL8201. TLK110 PHY is no longer supported because TI stoped production. If you want to use other PHY, follow the ESP32-Ethernet-Kit V1.2 Getting Started Guide to design.

Step 2. Connect the Board and Test¶

Now connect the board to the router via a ethernet cable, the board will automatically send a DHCP request and try to obtain an IP address. If the device obtains the IP address successfully, you can use the PC connected to the router to ping the board.

How to Add Support for a Module¶

[中文]

The ESP-AT project supports multiple modules, and provides configuration for them in the factory_param_data.csv table and the files in the module_config folder. See the table below for the supported platforms (chip series) and modules, as well as locations of the default configuration files.

default configuration files¶
Platform	Module	Default
ESP32	WROOM-32 PICO-D4 SOLO-1 MINI-1	module_config/module_esp32_default/sdkconfig.defaults module_config/module_esp32_default/sdkconfig_silence.defaults
ESP32	WROVER-32	module_config/module_wrover-32/sdkconfig.defaults module_config/module_wrover-32/sdkconfig_silence.defaults
ESP32	ESP32-D2WD	module_config/module_esp32-d2wd/sdkconfig.defaults module_config/module_esp32-d2wd/sdkconfig_silence.defaults
ESP32	ESP32_QCLOUD	module_config/module_esp32_qcloud/sdkconfig.defaults module_config/module_esp32_qcloud/sdkconfig_silence.defaults
ESP32-C3	MINI-1	module_config/module_esp32c3_default/sdkconfig.defaults module_config/module_esp32c3_default/sdkconfig_silence.defaults
ESP32-C3	ESP32C3_QCLOUD	module_config/module_esp32c3_qcloud/sdkconfig.defaults module_config/module_esp32c3_qcloud/sdkconfig_silence.defaults

Note

When the silence mode in ./build.py menuconfig is 0, the default sdkconfig corresponding to the module is sdkconfig.defaults.
When the silence mode in ./build.py menuconfig is 1, the default sdkconfig corresponding to the module is sdkconfig_silence.defaults.

If you want to add support for an ESP module in your ESP-AT project, you need to modify those configuration files. The “ESP module” here means:

Modules that the ESP-AT project has not supported yet, including those of supported platform and not supported platform. However, adding support for the latter requires extra huge work, thus not recommended and not explained in this document.
Modules that the ESP-AT project supports, but you want to modify the default configuration.

The document uses an example to explain how to add support for an ESP module in the ESP-AT project. The example module is ESP32-WROOM-32 that uses SDIO instead of the default UART interface.

Add Module to factory_param_data.csv¶

Open your local factory_param_data.csv , insert a new row at the end, set the parameters as needed. In the example, we set platform to PLATFORM_ESP32, module_name to WROOM32-SDIO, as well as other parameters as follows (see factory_param_type.csv for what each parameter represents):

platform: PLATFORM_ESP32
module_name: WROOM32-SDIO
description:
magic_flag: 0xfcfc
version: 3
reserved1: 0
tx_max_power: 78
uart_port: 1
start_channel: 1
channel_num: 13
country_code: CN
uart_baudrate: -1
uart_tx_pin: -1
uart_rx_pin: -1
uart_cts_pin: -1
uart_rts_pin: -1
tx_control_pin: -1
rx_control_pin: -1

Modify esp_at_module_info Structure¶

Refer to Modify esp_at_module_info Structure for details.

Configure the Module¶

Firstly, enter module_config folder, and create a new folder to store all the configuration files for your module. Note that the folder name should be in lower case. Then, add the configuration files in the new folder: IDF_VERSION, at_customize.csv, partitions_at.csv, sdkconfig.defaults, and sdkconfig_silence.defaults.

In this example, we copy the module_esp32_default folder as well as the files within it and rename it as module_wroom32-sdio. The copied IDF_VERSION, at_customize.csv, and partitions_at.csv do not need any modification in our case. We only need to modify the sdkconfig.defaults and sdkconfig_silence.defaults:

Modify the two files to use the partition table in the module_wroom32-sdio folder as follows:

CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="module_config/module_wroom32-sdio/partitions_at.csv"
CONFIG_PARTITION_TABLE_FILENAME="module_config/module_wroom32-sdio/partitions_at.csv"
CONFIG_AT_CUSTOMIZED_PARTITION_TABLE_FILE="module_config/module_wroom32-sdio/at_customize.csv"

Modify the two files to use the SDIO configuration and remove the UART configuration as follows:
- Remove the UART configuration
```
CONFIG_AT_BASE_ON_UART=n
```
- Add the SDIO configuration
```
CONFIG_AT_BASE_ON_SDIO=y
```

After finishing the above steps, you can recompile the ESP-AT project to generate the firmware for your module. In this example, we choose PLATFORM_ESP32 and WROOM32-SDIO when configuring the project to generate the firmware for it.

ESP32 SDIO AT Guide¶

[中文]

Introduction¶

ESP32 SDIO AT uses SDIO rather than UART as the communication interface between ESP32 (SDIO slave) and the host MCU.

SDIO can use either 1-bit or 4-bit data transfer mode.

For 1-bit mode at least 4 pins are required: CMD, CLK, DAT0, DAT1; where DAT1 runs as the interrupt pin.
For 4-bit mode, two more pins (DAT2 and DAT3) are needed.

The SDIO slave pins are as below:

CLK is GPIO14
CMD is GPIO15
DAT0 is GPIO2
DAT1 is GPIO4
DAT2 is GPIO12 (for 4-bit mode only)
DAT3 is GPIO13 (for 4-bit mode only)

Implement SDIO AT¶

Before testing SDIO AT communication, please configure ESP32 hardware according to SD Pull-up Requirements, otherwise, exceptions may occur during SDIO communication.

SDIO Slave¶

By default, the ESP-AT project uses UART as the the communication interface. When ESP32 serves as the SDIO slave, please go to ./build.py menuconfig -> Component config -> AT -> communicate method for AT command -> AT via SDIO to switch to the SDIO interface. Then, recompile the ESP-AT project, flash and run the new bin.

SDIO MCU¶

ESP-AT provides the at_sdio_host example for ESP32 or STM32 serving as the SDIO host. For ESP32 serving as the host, you can use the esp-idf of the AT project to compile and flash; for STM32, as the provided solution is based on STM32F103ZET, please use Keil5 to compile and flash as the application.

For other devices working as SDIO hosts, you can develop based on the above example.

SDIO Data Transimission¶

SDIO Host¶

Initialize the SDIO host
- The SDIO host initialization is mainly the initialization of the SDIO protocol, including setting 1-bit or 4-bit transfer mode, SDIO frequency, and SD mode.
Negotiate SDIO communication
- Negotiate SDIO parameters with the slave according to the SDIO specification. Please note that if the host and slave reboot at the same time, the host must wait until the slave startup is done to start the negotiation. Usually, the host needs to add a delay at boot time to achieve it.
Receive data
- When the SDIO host detects an interrupt from DAT1 and determines that the slave sends new packets, the host will read those data by CMD53.
Send data
- In SDIO AT demo, the data inputs from a serial port. When the SDIO host gets the data, it will transfer it to the slave through SDIO by CMD53.
- Please note that if the sending time out, there may be something wrong with the slave, please re-initiate both the host and slave.
- After AT+RST or AT+RESTORE is called, both the host and slave should be initialized again.

SDIO Slave¶

When the SDIO slave receives data from the SDIO host, it will inform the AT core and give the data to the AT core to handle. After the AT core finishes the work, the slave will send data to the host as feedback.

Initialize the SDIO slave
- Call sdio_slave_initialize to initialize the SDIO slave driver.
- Call sdio_slave_recv_register_buf to register receiving buffer. To make it faster to receive data, you can register multiple buffers.
- Call sdio_slave_recv_load_buf to load the receiving buffer to receive data.
- Call sdio_slave_set_host_intena to set host interrupts, of which the SDIO_SLAVE_HOSTINT_SEND_NEW_PACKET is used to notify that a new packet is sent from the host.
- Call sdio_slave_start to start SDIO hardware transmission.
Send data
- Since the SDIO slave data transmission is via DMA, you need to copy the data from AT core to the memory which DMA can read firstly. Call sdio_slave_transmit to send the data.
Receive data
- To speed up the data transmission, after receiving data by sdio_slave_recv, a circular linked list is used to transmit the received data to the AT core.

SPI AT Guide¶

This document mainly introduces the implementation and use of SPI AT, mainly involving the following aspects:

Overview
How to Use SPI AT?
SPI AT Throughput

Note

This document mainly introduces the implementation and use of SPI AT for ESP32-C and ESP32-S series. Due to hardware limit, it is not recommended to implement SPI AT on ESP32 series. Instead, use SDIO SPI AT on ESP32 series.

Overview ¶

SPI AT is based on ESP-AT project and uses SPI protocol for data communication. When SPI AT is used, MCU works as SPI master and ESP AT device works as SPI slave. Both sides of communication exchange data based on AT command through SPI protocol.

Why SPI AT?¶

ESP-AT project uses UART protocol for data communication by default, but UART protocol is not applicable in some application scenarios that need high-speed data transmission. In this case, the SPI protocol which supports a higher transmission rate is a better choice.

How to enable SPI AT?¶

You can configure and enable SPI AT through the following steps:

./build.py menuconfig -> Component config -> AT -> communicate method for AT command -> AT through HSPI to enable SPI AT.
./build.py menuconfig -> Component config -> AT -> communicate method for AT command -> AT SPI Data Transmission Mode to choose the SPI data transmission mode.
./build.py menuconfig -> Component config -> AT -> communicate method for AT command -> AT SPI GPIO settings to change the default pin assignments for SPI AT.
./build.py menuconfig -> Component config -> AT -> communicate method for AT command -> AT SPI driver settings to choose the SPI slave mode, and config the buffer size for data transmission.
Recompile the esp-at project(see Compile ESP-AT Project), download AT bin into flash.

The Default Pin Assignment¶

The following pin assignments are used by default:

The Default Pins for SPI AT¶
Signal	GPIO Number (ESP32-C3)
SCLK	6
MISO	2
MOSI	7
CS	10
HANDSHAKE	3
GND	GND
QUADWP (qio/qout):sup:1	8
QUADHD (qio/qout):sup:1	9

Note 1: QUADWP and QUADHD signals are only used for 4-bit (qio/qout) transactions.

You can change the default pin assignments by ./build.py menuconfig > Component config > AT > communicate method for AT command > AT through HSPI > AT SPI GPIO settings and compile the project (see Compile ESP-AT Project).

How to Use SPI AT?¶

When SPI AT is used, ESP device works in SPI half-duplex mode as a slave. Usually, when SPI protocol works in half-duplex mode, it is the SPI master that starts the read/write operation. However, when AT command is used for data interaction, ESP device (slave) is required to actively report some information. Therefore, we add a handshake line between SPI master and slave to realize the purpose. The specific methods of using handshake line are as follows:

When master sends AT commands to slave via SPI, the workflow with an extra handshake line is as follows:
1. The master sends a request for data transmission to the slave, and then waits for the signal sent by the slave to the handshake line to allow data transmission.
2. After the master detects the permission signal sent by the slave on the handshake line, it starts to send data.
3. After sending the data, the master notifies slave that the data transmission is finished.
When slave sends AT responses to master via SPI, the workflow with an extra handshake line is as follows:
1. The slave sends a signal through the handshake line to inform the master to start receiving data.
2. The master receives data and notifies slave that the data transmission is finished after receiving all data.

Communication Formats¶

The communication format used by SPI AT is CMD+ADDR+DUMMY+DATA (Read or Write). When using SPI AT, some communication messages used by SPI master are described as follows:

The message used by the master to send data to slave:

Master write data to slave¶
CMD (1 byte)	ADDR (1 byte)	DUMMY (1 byte)	DATA (Up to 4092 bytes)
0x3	0x0	0x0	data_buffer

The message used by the master to inform the slave all data has been sent:

Master write data done¶
CMD (1 byte)	ADDR (1 byte)	DUMMY (1 byte)	DATA
0x7	0x0	0x0	null

The message used by the master to receive data from the slave:

Master read data from slave¶
CMD (1 byte)	ADDR (1 byte)	DUMMY (1 byte)	DATA (Up to 4092 bytes)
0x4	0x0	0x0	data_buffer

The message used by the master to inform the slave all data has been received:

Master read data done¶
CMD (1 byte)	ADDR (1 byte)	DUMMY (1 byte)	DATA
0x8	0x0	0x0	null

The message used by the master to send a request to send data:

Master request to send data¶
CMD (1 byte)	ADDR (1 byte)	DUMMY (1 byte)	DATA (4 bytes)
0x1	0x0	0x0	data_info

The 4-byte length data_info contains the information about the packet to be sent. The specific format is as follows:

0~15 bits: the length of the data that the master want to send to the slave.
16~23 bits: the sequence number of the packet sent by the master to the slave.
24~31 bits: the magic num, and default value is 0xFE.

After receiving the signal from the handshake line, the master can send the message to query the read or write status of the slave:

Master query the read/write status of the slave¶
CMD (1 byte)	ADDR (1 byte)	DUMMY (1 byte)	DATA (4 bytes)
0x2	0x4	0x0	slave_status

After sending the query request, the slave’s status returned will be stored in the 4-byte length slave_status, the specific format is as follows:

0~15 bits: the length of the data the slave want to sent to the master. This field is valid only when the slave is readable.
16~23 bits: the sequence number of the packet to been sent. The maximum sequence number is 0xFF, and if the number is reached, the sequence number is incremented by 1 from 0.
24~31 bits: the slave status(readable/writable).

SPI AT Workflow¶

The workflows mainly includes two aspects:

When master sends AT commands to slave, the workflow is as follows:

| SPI master |                            | SPI slave |
       |                                        |
       |   -------step 1: request to send---->  |
       |                                        |
       |   <------step 2: GPIO interrupt------  |
       |                                        |
       |   -------step 3: read slave status-->  |
       |                                        |
       |   -------step 4: send data---------->  |
       |                                        |
       |   -------step 5: send done---------->  |

The specific description of each step is as follows:

step 1. The master sends a request for data transmission to the slave. step 2. The slave receives the request from the master. If the master is allowed to send data, the slave sets the status register, and then triggers the GPIO interrupt on the master through the handshake line. step 3. After receiving the interrupt, master will query the status register of slave. If the query result shows that the slave is in the writable state, the master starts to send data. step 4. The master send data to the slave. step 5. After sending the data, the master notifies slave that the data transmission is finished.

When master receives AT responses from slave, the workflow is as follows:

| SPI master |                            | SPI slave |
       |                                        |
       |   <------step 1: GPIO interrupt------  |
       |                                        |
       |   -------step 2: read slave status-->  |
       |                                        |
       |   <------step 3: send data-----------  |
       |                                        |
       |   -------step 4: receive done------->  |

The specific description of each step is as follows:

step 1. The slave sets the status register, and then triggers the GPIO interrupt on the master through the handshake line. step 2. After receiving the interrupt, master will query the status register of slave. If the query result shows that the slave is in the readable state, the master starts to receive data. step 3. The master receives the data send by the slave. step 4. After receiving all data, the master notifies the slave that the data transmission is finished.

Sample Code of SPI AT Master¶

A code example of SPI AT master can be found under the directory :example:` AT ESP32 SPI Master Example <at_spi_master/spi/esp32_c_series>`.

SPI AT Throughput ¶

Introduction of the Test¶

An ESP32-DevKitC development board is been used as SPI master. The application runs in the board can be found under the directory at_spi_master/spi/esp32_c_series of the ESP-AT project. Some related configurations are described below:

Hardware configuration: The frequency of CPU is 240 MHz, flash SPI mode is in QIO mode with 40 MHz.
Software configuration: The ESP-IDF version is v4.3. The size of streambuffer is 8192 bytes.

An ESP32-C3-DevKitC development board is been used as SPI slave. Please refer to Compile ESP-AT Project to build your own ESP-AT project and flash the generated binary files into the board. The board works in the TCP passthrough mode, and some related configurations are described below:

Hardware configuration: The frequency of CPU is 160 MHz.
Software configuration: The size of streambuffer is 8192 bytes, the sdkconfig is sdkconfig.defaults.esp32c3.

Reference Results¶

The table below shows the throughput results we got in a shield box.

SPI AT Wi-Fi TCP Throughput¶
Clock	SPI mode	master->slave	slave->master
10 M	Standard	0.95 MByte/s	1.00 MByte/s
10 M	Dual	1.37 MByte/s	1.29 MByte/s
10 M	Quad	1.43 MByte/s	1.31 MByte/s
20 M	Standard	1.41 MByte/s	1.30 MByte/s
20 M	Dual	1.39 MByte/s	1.30 MByte/s
20 M	Quad	1.39 MByte/s	1.30 MByte/s
40 M	Standard	1.37 MByte/s	1.30 MByte/s
40 M	Dual	1.40 MByte/s	1.31 MByte/s
40 M	Quad	1.48 MByte/s	1.31 MByte/s

Note 1: When SPI clock frequency is high, due to the limitation of upper network components, the communication rate of Dual or Quad mode is not significantly improved compared with Standard mode.

Note 2: For more information about SPI communication, please refer to the Technical Reference Manuals.

How to Implement OTA Upgrade¶

[中文]

This document introduces how to implement OTA upgrade on ESP32 and ESP32-C3 series of modules. Currently, ESP-AT provides the following three OTA commands targeting at different scenarios. You could choose one command according to your needs.

AT+USEROTA

AT+CIUPDATE

AT+WEBSERVER

The structure of this document is as follows:

Comparison Among OTA Commands and Their Application Scenarios
Perform OTA Upgrade with ESP-AT OTA Commands

Comparison Among OTA Commands and Their Application Scenarios¶

AT+USEROTA ¶

This command implements OTA upgrade through a URL. You can upgrade to the firmware placed on the HTTP server. Currently, the command only supports the upgrade of app partitions. For more information on this command, please refer to AT+USEROTA for more details.

Since this command is a user-defined command, you can modify the implementation of this command by modifying the at/src/at_user_cmd.c source code.

The application scenarios of this command are as follows:

You have your own HTTP server.

You need to specify the URL.

Important

If the firmware you upgrade is not officially released by Espressif, you may no longer be able to use AT+CIUPDATE command to upgrade after the upgrade is complete, unless you create your own device according to OTA Upgrade with AT+CIUPDATE.

AT+CIUPDATE ¶

This command uses iot.espressif.cn as the default HTTP server. It can upgrade both the app partition and the user-defined partitions that are defined in the at_customize.csv. If you are using the version released by Espressif, it will only upgrade to the version released by Espressif. For more information on this command, please refer to AT+CIUPDATE for more details.

To upgrade the customized bin file with this command, please select one of the following ways.

replace iot.espressif.cn with the your own HTTP server and implement the interactive process. For how to implement your own AT+CIUPDATE command, please refer to at/src/at_ota_cmd.c.

create a devices on iot.espressif.cn and upload customized AT firmware on it. (The premise is that the firmware running in the module already corresponds to the device you created on the Espressif server.) For more information, please refer to OTA Upgrade with AT+CIUPDATE.

The application scenarios of this command are as follows:

You only use the firmware released by Espressif, and only want to upgrade to the firmware released by Espressif.

You want to upgrade the customized bin file, but do not have an HTTP server.

You have your own HTTP server. In addition to the app partition, you also want to upgrade the user-defined partitions in at_customize.csv.

AT+WEBSERVER ¶

This command upgrades AT firmware with a browser or WeChat applet. Currently, this command only supports the upgrade of app partitions. Before starting the upgrade, please enable the web server command and copy the AT firmware to the computer or mobile phone in advance. For more information, you can refer to AT+WEBSERVER and Web Server AT Example.

To implement your own HTML page, please refer to the example of fs_image/index.html. To implement your own AT+WEBSERVER command, please refer to the example of at/src/at_web_server_cmd.c.

The application scenarios of this command are as follows:

You need a more convenient and faster OTA upgrade that does not rely on network status.

Important

If the firmware you upgrade is not officially released by Espressif, you may no longer be able to use AT+CIUPDATE command to upgrade after the upgrade is complete, unless you create your own device according to OTA Upgrade with AT+CIUPDATE.

Perform OTA Upgrade with ESP-AT OTA Commands¶

OTA Upgrade with AT+USEROTA¶

Please refer to AT+USEROTA: for more details.

OTA Upgrade with AT+CIUPDATE¶

To upgrade the customized bin file with AT+CIUPDATE command, the first thing to do is to upload the bin file to the iot.espressif.cn and obtain the token value. The following steps describe how to create a device on iot.espressif.cn and upload the bin file to it.

Open the website http://iot.espressif.cn or https://iot.espressif.cn.

Open iot.espressif.cn website¶
Click “Join” in the upper right corner of the webpage, and enter your name, email address, and password.

Join iot.espressif.cn website¶

Note

The Join function is currently not open to new users. If you want to use it, please contact Espressif.

Click on “Device” in the upper left corner of the webpage, and click on “Create” to create a device.

Click on “Device”¶

Click on “Create”¶
A key is generated when the device is successfully created, as the figure below shows.

A key has been generated¶
Use the key to compile your own OTA bin file. The process of configuring the AT OTA token key is as follows:

Configuring the AT OTA token key - Step 1¶

Configuring the AT OTA token key - Step 2 and 3¶
Note
- If using SSL OTA, the option “The SSL token for AT OTA” also needs to be configured.
Click on “Product” to enter the webpage, as shown below. Click on the device created. Enter version and corename under “ROM Deploy”. Rename the bin file in Step 5 as “ota.bin” and save the configuration.

Enter version and corename¶
Note
- If you want to upgrade the user-defined partition defined in the at_customize.csv, just replace ota.bin with the bin of the user-defined partition.
- For the field corename, the purpose of this field is only to help you distinguish bin files.
Click on the ota.bin to save it as the current version.

Save the current version of ota.bin¶
Run the command AT+USEROTA on the ESP device. If the network is connected, OTA upgrade will begin.

Important

When setting the name of bin files uploaded to the iot.espressif.cn, please follow the rules below:
- If you upgrade app partitions, set the bin file name to ota.bin.
- If you upgrade a user-defined partition, set the bin file name as the Name field in the at_customize.csv. For example, if you upgrade factory_Param partition, please set it to factory_ param.bin.
ESP-AT stores the new firmware in a spare OTA partition. In this way, even if OTA fails due to unexpected reasons, the original ESP-AT firmware can still run. But for user-defined partitions, because ESP-AT has no backup measures, please upgrade it carefully.
If you intend to upgrade only customized bin file at the beginning, please set the OTA token to your own token value when the initial version is released.

OTA Upgrade with AT+WEBSERVER¶

Please refer to AT+WEBSERVER and Web Server AT Example for more details.

How to Update the ESP-IDF Version¶

[中文]

ESP-AT firmware is based on the Espressif IoT Development Framework (ESP-IDF), and each version of ESP-AT firmware corresponds to a specific ESP-IDF version. It is strongly recommended to use the default ESP-IDF version of the ESP-AT project, and NOT recommended to update it, because the inconsistency between the underlying ESP-IDF versions of libesp_*_at_core.a and the ESP-AT project may cause incorrect operation of the firmware.

However, in some special cases, a minor updated ESP-IDF version may be also able to work with the ESP-AT project. In case you should update it, this document can be a reference.

The ESP-IDF version that a specific ESP-AT firmware corresponds to is recorded in the IDF_VERSION files, which are distributed in different module folders under the module_config folder. The file describes the branch, commit ID, and repository URL of the ESP-IDF that a module firmware is based on.

For example, the IDF_VERSION of the WROOM-32 module of PLATFORM_ESP32 platform is located at module_config/module_esp32_default/IDF_VERSION.

If you want to update the ESP-IDF version for your ESP-AT firmware, please follow the steps:

Find the IDF_VERSION file for your module.
Update the branch, commit ID, repository as needed.
Delete the original esp-idf under the esp-at root directory, so that the ESP-IDF of the version specified in IDF_VERSION will be cloned first in the next compilation.
Recompile the ESP-AT project.

Note that when the ESP-AT version and the ESP-IDF version do not match, the following error will be reported when compiling:

Please wait for the update to complete, which will take some time

ESP-AT Firmware Differences¶

[中文]

This document compares the differences among AT firmwares of a certain ESP series in terms of the supported commands set, hardware, and supported modules.

ESP32 Series¶

This section describes the differences among AT firmwares of ESP32 series, including

ESP32-WROOM-32_AT_Bin (referred to as WROOM Bin in this section);
ESP32-WROVER-32_AT_Bin (referred to as WROOM Bin in this section);
ESP32-PICO-D4_AT_Bin (referred to as PICO-D4 Bin in this section);
ESP32-SOLO-1_AT_Bin (referred to as SOLO-1 Bin in this section);
ESP32-MINI-1_AT_Bin (referred to as MINI-1 Bin in this section);
ESP32-D2WD_AT_Bin (referred to as D2WD Bin in this section);
ESP32-QLOUD_AT_Bin (referred to as QCLOUD Bin in this section).

Supported Command Set¶

The table lists which command set is supported by default in the official AT firmware applicable to ESP32 series of modules (marked with ), which is not supported by default but can be supported after configuration of the ESP-AT project (marked with ), and which is not supported at all (marked with ). Note that the command set that is not shown in this table is not supported either. Applicable firmware that has not been officially released requires compilation by yourself. Those self-compiled firmware cannot be upgraded OTA from Espressif official server.

Command Set	WROOM Bin	WROVER Bin	PICO-D4 Bin	SOLO-1 Bin	MINI-1 Bin	D2WD Bin	QCLOUD Bin
base
user
wifi
net
MDNS
WPS
smartconfig
ping
MQTT
http
ble
ble hid
blufi
bt spp
bt a2dp
ethernet
FS
driver
WPA2
WEB
OTA
qcloud IoT

Hardware Differences¶

Hardware	WROOM Bin	WROVER Bin	PICO-D4 Bin	SOLO-1 Bin	MINI-1 Bin	D2WD Bin	QCLOUD Bin
Flash	4 MB	4 MB	4 MB	4 MB	4 MB	2 MB	4 MB
PSRAM		8 MB
UART Pins 1	TX: 17 RX: 16 CTS: 15 RTS: 14	TX: 22 RX: 19 CTS: 15 RTS: 14	TX: 22 RX: 19 CTS: 15 RTS: 14	TX: 17 RX: 16 CTS: 15 RTS: 14	TX: 22 RX: 19 CTS: 15 RTS: 14	TX: 22 RX: 19 CTS: 15 RTS: 14	TX: 17 RX: 16 CTS: 15 RTS: 14

1: UART pins can be customized. See How to Set AT Port Pins for details.

Supported Modules¶

The table lists the ESP modules or chips that each AT firmware supports.

Module/Chip	WROOM Bin	WROVER Bin	PICO-D4 Bin	SOLO-1 Bin	MINI-1 Bin	D2WD Bin	QCLOUD Bin
ESP32-WROOM-32E
ESP32-WROOM-32UE
ESP32-WROOM-32D
ESP32-WROOM-32U
ESP32-WROOM-32
ESP32-WROOM-32SE
ESP32-WROVER-E
ESP32-WROVER-IE
ESP32-WROVER-B
ESP32-WROVER-IB
ESP32-WROVER
ESP32-WROVER-I
ESP32-SOLO-1
ESP32-D2WD
ESP32-MINI-1
ESP32-PICO-D4

ESP32-C3 Series¶

This section describes the differences among the ESP32-C3 Series of AT firmware, including

ESP32-C3-MINI-1_AT_Bin (referred to as MINI-1 Bin in this section);
ESP32-C3-QCLOUD_AT_BIN (referred to as QCLOUD Bin in this section).

Supported Command Set¶

The table lists which command set is supported by default in the official AT firmware applicable to ESP32-C3 series of modules (marked with ), which is not supported by default but can be supported after configuration of the ESP-AT project (marked with ), and which is not supported at all (marked with ). Note that the command set that is not shown in this table is not supported either. Applicable firmware that has not been officially released requires compilation by yourself. Those self-compiled firmware cannot be upgraded OTA from Espressif official server.

Command Set	MINI-1 Bin	QCLOUD Bin
base
user
wifi
net
MDNS
WPS
smartconfig
ping
MQTT
http
FS
driver
WPA2
WEB
OTA
qcloud IoT

Hardware Differences¶

Hardware	MINI-1	QCLOUD
Flash	4 MB	4 MB
PSRAM
UART Pins 2	TX: 7 RX: 6 CTS: 5 RTS: 4	TX: 7 RX: 6 CTS: 5 RTS: 4

2: UART pins can be customized. See How to Set AT Port Pins for details.

Firmware Supported Modules¶

The table lists the ESP modules or chips that each AT firmware supports.

Module/Chip	MINI-1 Bin	QCLOUD Bin
ESP32-C3-MINI-1

How to Download the Latest Temporary Version of AT Firmware from GitHub¶

[中文]

As ESP-AT enables CI (Continuous Integration) on GitHub, temporary versions of ESP-AT firmware is generated every time when the code is pushed to GitHub.

Note

The temporary version of AT firmware is only for testing, and Espressif is not responsible for it. You need to test and save the firmware by yourself.

The following steps guide you on how to download the latest temporary version of AT firmware from GitHub. Before you start, please sign in your GitHub account, as you need login permission to download firmware.

Open the website https://github.com/espressif/esp-at.

ESP-AT GitHub Home Page¶
Click “Actions” to enter the “Actions” page.

Click Actions¶

Actions Page¶
Click the latest workflow and enter the latest workflow page.

Click the Latest Workflow¶

Latest Workflow Page¶

If you want to download the temporary firmware of the specified branch, click “Branch” to enter the workflow page of the specified branch.

Click the Branch¶
Scroll the page to the end, select the corresponding module on the Artifacts page.

Artifacts Page¶
Click to download the temporary version of AT firmware for modules.

Note

If you do not find the firmware of the corresponding module on the Artifacts page, you can refer to ESP-AT Firmware Differences to select a similar firmware to download.

Customize Bluetooth LE Services Tools¶

[中文]

ESP-AT provides python script BLEService.py to convert customized Bluetooth LE services into ble_data.bin. For more information on customizing Bluetooth LE services, please refer to How to Customize Bluetooth® LE Services.

Generate Bin File
Download or Update Bin File

Generate Bin File ¶

Select one of the following ways to generate ble_data.bin.

Script Generation
Generation During Compilation

Script Generation ¶

The path of BLEService.py is tools/BLEService.py. You can get help information of the script through the -h option. You can also generate ble_data.bin directly through the following commands.

python <SCRIPT_PATH> [-t TARGET_FILE_NAME] <source_file>

SCRIPT_PATH: the path the script. If you’re in “tools” folder of ESP-AT project, SCRIPT_PATH is BLEService.py.
TARGET_FILE_NAME: the target file which you want to save the generated bin (absolute address or relative address of the target file); if not specified, it will generate ATBleService.bin in the same directory with source_file.
source_file: the source file which you defines your Bluetooth LE GATT services (absolute address or relative address of the source file).

For example, you can execute the following directory to generate ble_data.bin in the tools directory:

python BLEService.py -t ble_data.bin ../components/customized_partitions/raw_data/ble_data/example.csv

Generation During Compilation ¶

The storage path of Bluetooth LE GATT service files in ESP-AT is components/customized_partitions/raw_data/ble_data/example.csv.

For how to customize Bluetooth LE services, you can refer to How to Customize Bluetooth® LE Services.

For how to compile ESP-AT project, you can refer to Compile ESP-AT Project.

Download or Update Bin File ¶

The script BLEService.py is only responsible for converting example.csv file to bin file. You can download bin files to the corresponding flash partition in the following ways:

Download bin file with tools

Windows

Please download Flash Download Tools for Windows.

For more details about the Tools, please see readme.pdf or the doc folder in the zip folder.
Linux or macOS

Please use esptool.py.

You can refer to How to Customize Bluetooth® LE Services for more details.
esptool.py --chip auto --port PORTNAME --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB ADDRESS FILEDIRECTORY
Replace PORTNAME with your port name. Replace ADDRESS with the the download address. Replace FILEDIRECTORY with the file directory of the bin.

Update bin file with commands

AT+SYSFLASH

Taking ESP32 module as an example, you can execute the following command to upgrade the ble_data partition. Please refer to AT+SYSFLASH for more details.

Query user partitions in flash
Command:
AT+SYSFLASH?
Response:
+SYSFLASH:"ble_data",64,1,0x21000,0x3000
+SYSFLASH:"server_cert",64,2,0x24000,0x2000
+SYSFLASH:"server_key",64,3,0x26000,0x2000
+SYSFLASH:"server_ca",64,4,0x28000,0x2000
+SYSFLASH:"client_cert",64,5,0x2a000,0x2000
+SYSFLASH:"client_key",64,6,0x2c000,0x2000
+SYSFLASH:"client_ca",64,7,0x2e000,0x2000
+SYSFLASH:"factory_param",64,8,0x30000,0x1000
+SYSFLASH:"wpa2_cert",64,9,0x31000,0x2000
+SYSFLASH:"wpa2_key",64,10,0x33000,0x2000
+SYSFLASH:"wpa2_ca",64,11,0x35000,0x2000
+SYSFLASH:"mqtt_cert",64,12,0x37000,0x2000
+SYSFLASH:"mqtt_key",64,13,0x39000,0x2000
+SYSFLASH:"mqtt_ca",64,14,0x3b000,0x2000
+SYSFLASH:"fatfs",1,129,0x70000,0x90000

OK
Erase ble_data sector
Command:
AT+SYSFLASH=0,"ble_data"
Response:
OK
Update ble_data sector
Command:
AT+SYSFLASH=1,"ble_data",0,6487
Response:
>
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>. When the write operation is completed, the system will prompt the following information.
OK
AT+CIUPDATE

For example, you can execute the following command to upgrade the ble_data partition (The premise is that you must use the Wi-Fi function). Please refer to AT+CIUPDATE for more details.

Important

If you want to update the ble_data partition in this way, you must implement your own OTA device, please refer to How to Implement OTA Upgrade.
AT+CIUPDATE=1,"v2.2.0.0","ble_data"

Note

You must ensure that the download address is correct, otherwise the ESP-AT firmware may not work. The simplest way to view the download address is to execute the command AT+SYSFLASH?.

How to Generate PKI Files¶

[中文]

ESP-AT provides python script AtPKI.py to convert SSL server certificates, SSL client certificates, MQTT certificates, and WPA2 certificates files (including CA, cert, and private key files) into bin files.

Certificate Bin Files Format
Generate Certificate Bin Files
Download or Update Certificate Bin Files

Certificate Bin Files Format ¶

In addition to converting the certificate file into a bin file, the script AtPKI.py adds some additional information to the bin file.

When converting a single certificate file, the script will add 12 bytes in little-endian format to the header and 4 bytes aligned at the end.

Field

Description

magic code (2 bytes)

0xF1 0xF1

list size (2 bytes)

the number of certificate files

length (4 bytes)

remaining file size = total file size - magic code size - list size - length size

type (1 bytes)

ca: 0x01

certificate: 0x02

key: 0x03

ID (1 bytes)

used to match certificate files

content len (2 bytes)

the size of the certificate file converted to the bin file

Taking the client_cert.bin generated in the Generate Certificate Bin Files section as an example, the 12 bytes in little-endian format at the beginning of the file are:

Field

Description

magic code (2 bytes)

0xF1 0xF1

list size (2 bytes)

0x02 0x00

length (4 bytes)

0x20 0x09 0x00 0x00

type (1 bytes)

0x02

ID (1 bytes)

0x00

content len (2 bytes)

0x8C 0x04

When converting multiple certificate files, the script AtPKI.py inserts 4 bytes at the beginning of every file except the first one. The 4 bytes in little-endian format at the beginning of the file are:

Field

Description

type (1 bytes)

ca: 0x01

certificate: 0x02

key: 0x03

ID (1 bytes)

used to match certificate files

content len (2 bytes)

the size of the certificate file converted to the bin file

Taking the client_cert.bin generated in the Generate Certificate Bin Files section as an example, the 4 bytes in little-endian format at the beginning of the file are:

Field

Description

type (1 bytes)

certificate: 0x02

ID (1 bytes)

0x01

content len (2 bytes)

0x8C 0x04

Generate Certificate Bin Files ¶

Select one of the following ways to generate certificate bin files.

Script Generation
Generation During Compilation

Script Generation ¶

The path of AtPKI.py is tools/AtPKI.py. You can get help information of the script through the -h option. You can also generate bin files directly through the following commands.

python <SCRIPT_PATH> generate_bin [-b OUTPUT_BIN_NAME] <PKI_LIST> <source_file>

SCRIPT_PATH: the path the script. If you’re in “tools” folder of ESP-AT project, SCRIPT_PATH is AtPKI.py.
OUTPUT_BIN_NAME: the target file which you want to save the generated bin (absolute address or relative address of the target file); if -b OUTPUT_BIN_NAME is omitted, it will generate PKI.bin in the current directory.
PKI_LIST: must be equal to one of ca, cert, key.
source_file: the certificate source file which you want to convert (absolute address or relative address of the source file).

Taking the SSL client certificate files of ESP-AT as an example, you can execute the following command to generate client_cert.bin in the tools directory:

python AtPKI.py generate_bin -b ./client_cert.bin  cert ../components/customized_partitions/raw_data/client_cert/client_cert_00.crt cert ../components/customized_partitions/raw_data/client_cert/client_cert_01.crt

Generation During Compilation ¶

The storage path of certificate files in ESP-AT is components/customized_partitions/raw_data.

Taking the SSL client certificate files of ESP-AT as an example. If you want to generate your own SSL client certificates files, you must replace the CA certificate in the client_ca directory with your own CA certificate, the cert certificate in the client_cert directory with your own cert certificate, and the private key in the client_ key directory with your own private key.

If you have multiple sets of certificate files, please place them in the corresponding directory according to your certificate chain. It is recommended that you end the file name with a number to ensure the parsing order of the certificate files.

After replacement, You can refer to Compile ESP-AT Project to compile the ESP-AT project.

Download or Update Certificate Bin Files ¶

The script AtPKI.py is only responsible for converting the certificate files to bin files. You can download bin files to the corresponding flash partition in one of the following ways:

Download with Tools¶

Windows

Please download Flash Download Tools for Windows.

For more details about the Tools, please see readme.pdf or the doc folder in the zip folder.
Linux or macOS

Please use esptool.py.

You can execute the following command in the root directory of ESP-AT to download bin files.
```
esptool.py --chip auto --port PORTNAME --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size 4MB ADDRESS FILEDIRECTORY
```
Replace PORTNAME with your port name. Replace ADDRESS with the the download address. Replace FILEDIRECTORY with the file directory of the bin.

Update with Commands¶

AT+SYSFLASH

Taking ESP32 module as an example, you can execute the following command to upgrade the client_cert partition. Please refer to AT+SYSFLASH for more details.

Query user partitions in flash

Command:

AT+SYSFLASH?

Response:

+SYSFLASH:"ble_data",64,1,0x21000,0x3000
+SYSFLASH:"server_cert",64,2,0x24000,0x2000
+SYSFLASH:"server_key",64,3,0x26000,0x2000
+SYSFLASH:"server_ca",64,4,0x28000,0x2000
+SYSFLASH:"client_cert",64,5,0x2a000,0x2000
+SYSFLASH:"client_key",64,6,0x2c000,0x2000
+SYSFLASH:"client_ca",64,7,0x2e000,0x2000
+SYSFLASH:"factory_param",64,8,0x30000,0x1000
+SYSFLASH:"wpa2_cert",64,9,0x31000,0x2000
+SYSFLASH:"wpa2_key",64,10,0x33000,0x2000
+SYSFLASH:"wpa2_ca",64,11,0x35000,0x2000
+SYSFLASH:"mqtt_cert",64,12,0x37000,0x2000
+SYSFLASH:"mqtt_key",64,13,0x39000,0x2000
+SYSFLASH:"mqtt_ca",64,14,0x3b000,0x2000
+SYSFLASH:"fatfs",1,129,0x70000,0x90000

OK

Erase client_cert sector

Command:
AT+SYSFLASH=0,"client_cert"
Response:
OK

Update client_cert sector

Command:
AT+SYSFLASH=1,"client_cert",0,2344
Response:
>
If the operator is write, wrap return > after the write command, then you can send the data that you want to write. The length should be parameter <length>. When the write operation is completed, the system will prompt the following information.
OK

AT+CIUPDATE

For example, you can execute the following command to upgrade the client_ca partition. Please refer to AT+CIUPDATE for more details.

Important

If you want to update the client_ca partition in this way, you must implement your own OTA device, please refer to How to Implement OTA Upgrade.
```
AT+CIUPDATE=1,"v2.2.0.0","client_ca"
```

Note

You must ensure that the download address is correct, otherwise the ESP-AT firmware may not work. The simplest way to view the download address is to execute the command AT+SYSFLASH?.

AT API Reference¶

Header File¶

at/include/esp_at_core.h

Functions¶

void esp_at_module_init(uint32_t netconn_max, const uint8_t *custom_version)¶

This function should be called only once, before any other AT functions are called.

Parameters

netconn_max: the maximum number of the link in the at module
custom_version: version information by custom

esp_at_para_parse_result_type esp_at_get_para_as_digit(int32_t para_index, int32_t *value)¶

Parse digit parameter from command string.

Return

ESP_AT_PARA_PARSE_RESULT_OK : succeed
ESP_AT_PARA_PARSE_RESULT_FAIL : fail
ESP_AT_PARA_PARSE_RESULT_OMITTED : this parameter is OMITTED

Parameters

para_index: the index of parameter
value: the value parsed

esp_at_para_parse_result_type esp_at_get_para_as_str(int32_t para_index, uint8_t **result)¶

Parse string parameter from command string.

Return

ESP_AT_PARA_PARSE_RESULT_OK : succeed
ESP_AT_PARA_PARSE_RESULT_FAIL : fail
ESP_AT_PARA_PARSE_RESULT_OMITTED : this parameter is OMITTED

Parameters

para_index: the index of parameter
result: the pointer that point to the result.

void esp_at_port_recv_data_notify_from_isr(int32_t len)¶

Calling the esp_at_port_recv_data_notify_from_isr to notify at module that at port received data. When received this notice,at task will get data by calling get_data_length and read_data in esp_at_device_ops. This function MUST be used in isr.

Parameters

len: data length

bool esp_at_port_recv_data_notify(int32_t len, uint32_t msec)¶

Calling the esp_at_port_recv_data_notify to notify at module that at port received data. When received this notice,at task will get data by calling get_data_length and read_data in esp_at_device_ops. This function MUST NOT be used in isr.

Return

true : succeed
false : fail

Parameters

len: data length
msec: timeout time,The unit is millisecond. It waits forever,if msec is portMAX_DELAY.

void esp_at_transmit_terminal_from_isr(void)¶: terminal transparent transmit mode,This function MUST be used in isr.

void esp_at_transmit_terminal(void)¶: terminal transparent transmit mode,This function MUST NOT be used in isr.

bool esp_at_custom_cmd_array_regist(const esp_at_cmd_struct *custom_at_cmd_array, uint32_t cmd_num)¶

regist at command set, which defined by custom,

Parameters

custom_at_cmd_array: at command set
cmd_num: command number

void esp_at_device_ops_regist(esp_at_device_ops_struct *ops)¶

regist device operate functions set,

Parameters

ops: device operate functions set

bool esp_at_custom_net_ops_regist(int32_t link_id, esp_at_custom_net_ops_struct *ops)¶

bool esp_at_custom_ble_ops_regist(int32_t conn_index, esp_at_custom_ble_ops_struct *ops)¶

void esp_at_custom_ops_regist(esp_at_custom_ops_struct *ops)¶

regist custom operate functions set interacting with AT,

Parameters

ops: custom operate functions set

uint32_t esp_at_get_version(void)¶

get at module version number,

Return: at version bit31~bit24: at main version bit23~bit16: at sub version bit15~bit8 : at test version bit7~bit0 : at custom version

void esp_at_response_result(uint8_t result_code)¶

response AT process result,

Parameters

result_code: see esp_at_result_code_string_index

int32_t esp_at_port_write_data(uint8_t *data, int32_t len)¶

write data into device,

Return

>= 0 : the real length of the data written
others : fail.

Parameters

data: data buffer to be written
len: data length

int32_t esp_at_port_read_data(uint8_t *data, int32_t len)¶

read data from device,

Return

>= 0 : the real length of the data read from device
others : fail

Parameters

data: data buffer
len: data length

bool esp_at_port_wait_write_complete(int32_t timeout_msec)¶

wait for transmitting data completely to peer device,

Return

true : succeed,transmit data completely
false : fail

Parameters

timeout_msec: timeout time,The unit is millisecond.

int32_t esp_at_port_get_data_length(void)¶

get the length of the data received,

Return

>= 0 : the length of the data received
others : fail

bool esp_at_base_cmd_regist(void)¶: regist at base command set. If not,you can not use AT base command

bool esp_at_user_cmd_regist(void)¶: regist at user command set. If not,you can not use AT user command

bool esp_at_wifi_cmd_regist(void)¶: regist at wifi command set. If not,you can not use AT wifi command

bool esp_at_net_cmd_regist(void)¶: regist at net command set. If not,you can not use AT net command

bool esp_at_mdns_cmd_regist(void)¶: regist at mdns command set. If not,you can not use AT mdns command

bool esp_at_driver_cmd_regist(void)¶: regist at driver command set. If not,you can not use AT driver command

bool esp_at_wps_cmd_regist(void)¶: regist at wps command set. If not,you can not use AT wps command

bool esp_at_smartconfig_cmd_regist(void)¶: regist at smartconfig command set. If not,you can not use AT smartconfig command

bool esp_at_ping_cmd_regist(void)¶: regist at ping command set. If not,you can not use AT ping command

bool esp_at_http_cmd_regist(void)¶: regist at http command set. If not,you can not use AT http command

bool esp_at_mqtt_cmd_regist(void)¶: regist at mqtt command set. If not,you can not use AT mqtt command

bool esp_at_ble_cmd_regist(void)¶: regist at ble command set. If not,you can not use AT ble command

bool esp_at_ble_hid_cmd_regist(void)¶: regist at ble hid command set. If not,you can not use AT ble hid command

bool esp_at_blufi_cmd_regist(void)¶: regist at blufi command set. If not,you can not use AT blufi command

bool esp_at_bt_cmd_regist(void)¶: regist at bt command set. If not,you can not use AT bt command

bool esp_at_bt_spp_cmd_regist(void)¶: regist at bt spp command set. If not,you can not use AT bt spp command

bool esp_at_bt_a2dp_cmd_regist(void)¶: regist at bt a2dp command set. If not,you can not use AT bt a2dp command

bool esp_at_fs_cmd_regist(void)¶: regist at fs command set. If not,you can not use AT fs command

bool esp_at_eap_cmd_regist(void)¶: regist at WPA2 Enterprise AP command set. If not,you can not use AT EAP command

bool esp_at_eth_cmd_regist(void)¶: regist at ethernet command set. If not,you can not use AT ethernet command

bool esp_at_custom_cmd_line_terminator_set(uint8_t *terminator)¶

Set AT command terminator, by default, the terminator is “\r\n” You can change it by calling this function, but it just supports one character now.

Return

true : succeed,transmit data completely
false : fail

Parameters

terminator: the line terminator

uint8_t *esp_at_custom_cmd_line_terminator_get(void)¶

Get AT command line terminator,by default, the return string is “\r\n”.

Return: the command line terminator

const esp_partition_t *esp_at_custom_partition_find(esp_partition_type_t type, esp_partition_subtype_t subtype, const char *label)¶

Find the partition which is defined in at_customize.csv.

Return

pointer to esp_partition_t structure, or NULL if no partition is found. This pointer is valid for the lifetime of the application

Parameters

type: the type of the partition
subtype: the subtype of the partition
label: Partition label

void esp_at_port_enter_specific(esp_at_port_specific_callback_t callback)¶

Set AT core as specific status, it will call callback if receiving data. for example:

static void wait_data_callback (void)
{
    xSemaphoreGive(sync_sema);
}

void process_task(void* para)
{
    vSemaphoreCreateBinary(sync_sema);
    xSemaphoreTake(sync_sema,portMAX_DELAY);
    esp_at_port_write_data((uint8_t *)">",strlen(">"));
    esp_at_port_enter_specific(wait_data_callback);
    while(xSemaphoreTake(sync_sema,portMAX_DELAY)) {
        len = esp_at_port_read_data(data, data_len);
        // TODO:
    }
}

Parameters

callback: which will be called when received data from AT port

void esp_at_port_exit_specific(void)¶: Exit AT core as specific status.

const uint8_t *esp_at_get_current_cmd_name(void)¶: Get current AT command name.

Structures¶

struct esp_at_cmd_struct¶

esp_at_cmd_struct used for define at command

Public Members

char *at_cmdName¶: at command name

uint8_t (*at_testCmd)(uint8_t *cmd_name)¶: Test Command function pointer

uint8_t (*at_queryCmd)(uint8_t *cmd_name)¶: Query Command function pointer

uint8_t (*at_setupCmd)(uint8_t para_num)¶: Setup Command function pointer

uint8_t (*at_exeCmd)(uint8_t *cmd_name)¶: Execute Command function pointer

struct esp_at_device_ops_struct¶

esp_at_device_ops_struct device operate functions struct for AT

Public Members

int32_t (*read_data)(uint8_t *data, int32_t len)¶: read data from device

int32_t (*write_data)(uint8_t *data, int32_t len)¶: write data into device

int32_t (*get_data_length)(void)¶: get the length of data received

bool (*wait_write_complete)(int32_t timeout_msec)¶: wait write finish

struct esp_at_custom_net_ops_struct¶

esp_at_custom_net_ops_struct custom socket callback for AT

Public Members

int32_t (*recv_data)(uint8_t *data, int32_t len)¶: callback when socket received data

void (*connect_cb)(void)¶: callback when socket connection is built

void (*disconnect_cb)(void)¶: callback when socket connection is disconnected

struct esp_at_custom_ble_ops_struct¶

esp_at_custom_ble_ops_struct custom ble callback for AT

Public Members

int32_t (*recv_data)(uint8_t *data, int32_t len)¶: callback when ble received data

void (*connect_cb)(void)¶: callback when ble connection is built

void (*disconnect_cb)(void)¶: callback when ble connection is disconnected

struct esp_at_custom_ops_struct¶

esp_at_ops_struct some custom function interacting with AT

Public Members

void (*status_callback)(esp_at_status_type status)¶: callback when AT status changes

void (*pre_deepsleep_callback)(void)¶: callback before enter deep sleep

void (*pre_restart_callback)(void)¶: callback before restart

Macros¶

at_min(x, y)¶

at_max(x, y)¶

ESP_AT_ERROR_NO(subcategory, extension)¶

ESP_AT_CMD_ERROR_OK¶: No Error

ESP_AT_CMD_ERROR_NON_FINISH¶: terminator character not found (“\r\n” expected)

ESP_AT_CMD_ERROR_NOT_FOUND_AT¶: Starting “AT” not found (or at, At or aT entered)

ESP_AT_CMD_ERROR_PARA_LENGTH(which_para)¶: parameter length mismatch

ESP_AT_CMD_ERROR_PARA_TYPE(which_para)¶: parameter type mismatch

ESP_AT_CMD_ERROR_PARA_NUM(need, given)¶: parameter number mismatch

ESP_AT_CMD_ERROR_PARA_INVALID(which_para)¶: the parameter is invalid

ESP_AT_CMD_ERROR_PARA_PARSE_FAIL(which_para)¶: parse parameter fail

ESP_AT_CMD_ERROR_CMD_UNSUPPORT¶: the command is not supported

ESP_AT_CMD_ERROR_CMD_EXEC_FAIL(result)¶: the command execution failed

ESP_AT_CMD_ERROR_CMD_PROCESSING¶: processing of previous command is in progress

ESP_AT_CMD_ERROR_CMD_OP_ERROR¶: the command operation type is error

Type Definitions¶

typedef void (*esp_at_port_specific_callback_t)(void)¶: AT specific callback type.

Enumerations¶

enum esp_at_status_type¶

esp_at_status some custom function interacting with AT

Values:

ESP_AT_STATUS_NORMAL = 0x0¶: Normal mode.Now mcu can send AT command

ESP_AT_STATUS_TRANSMIT¶: Transparent Transmition mode

enum esp_at_module¶

module number,Now just AT module

Values:

ESP_AT_MODULE_NUM = 0x01¶: AT module

enum esp_at_error_code¶

subcategory number

Values:

ESP_AT_SUB_OK = 0x00¶: OK

ESP_AT_SUB_COMMON_ERROR = 0x01¶: reserved

ESP_AT_SUB_NO_TERMINATOR = 0x02¶: terminator character not found (“\r\n” expected)

ESP_AT_SUB_NO_AT = 0x03¶: Starting “AT” not found (or at, At or aT entered)

ESP_AT_SUB_PARA_LENGTH_MISMATCH = 0x04¶: parameter length mismatch

ESP_AT_SUB_PARA_TYPE_MISMATCH = 0x05¶: parameter type mismatch

ESP_AT_SUB_PARA_NUM_MISMATCH = 0x06¶: parameter number mismatch

ESP_AT_SUB_PARA_INVALID = 0x07¶: the parameter is invalid

ESP_AT_SUB_PARA_PARSE_FAIL = 0x08¶: parse parameter fail

ESP_AT_SUB_UNSUPPORT_CMD = 0x09¶: the command is not supported

ESP_AT_SUB_CMD_EXEC_FAIL = 0x0A¶: the command execution failed

ESP_AT_SUB_CMD_PROCESSING = 0x0B¶: processing of previous command is in progress

ESP_AT_SUB_CMD_OP_ERROR = 0x0C¶: the command operation type is error

enum esp_at_para_parse_result_type¶

the result of AT parse

Values:

ESP_AT_PARA_PARSE_RESULT_FAIL = -1¶: parse fail,Maybe the type of parameter is mismatched,or out of range

ESP_AT_PARA_PARSE_RESULT_OK = 0¶: Successful

ESP_AT_PARA_PARSE_RESULT_OMITTED¶: the parameter is OMITTED.

enum esp_at_result_code_string_index¶

the result code of AT command processing

Values:

ESP_AT_RESULT_CODE_OK = 0x00¶: “OK”

ESP_AT_RESULT_CODE_ERROR = 0x01¶: “ERROR”

ESP_AT_RESULT_CODE_FAIL = 0x02¶: “ERROR”

ESP_AT_RESULT_CODE_SEND_OK = 0x03¶: “SEND OK”

ESP_AT_RESULT_CODE_SEND_FAIL = 0x04¶: “SEND FAIL”

ESP_AT_RESULT_CODE_IGNORE = 0x05¶: response nothing, just change internal status

ESP_AT_RESULT_CODE_PROCESS_DONE = 0x06¶: response nothing, just change internal status

ESP_AT_RESULT_CODE_OK_AND_INPUT_PROMPT = 0x07¶

ESP_AT_RESULT_CODE_MAX¶

Header File¶

at/include/esp_at.h

Functions¶

const char *esp_at_get_current_module_name(void)¶: get current module name

const char *esp_at_get_module_name_by_id(uint32_t id)¶: get module name by index

uint32_t esp_at_get_module_id(void)¶: get current module id

void esp_at_board_init(void)¶: init peripheral and default parameters in factory_param.bin

bool esp_at_web_server_cmd_regist(void)¶: regist WiFi config via web command. If not,you can not use web server to config wifi connect

Macros¶

ESP_AT_PORT_TX_WAIT_MS_MAX¶

ESP_AT_FACTORY_PARAMETER_SIZE¶

Customized AT Commands and Firmware¶

Tencent Cloud IoT AT Commands and Firmware¶

Tencent Cloud IoT AT Command Set¶

Please refer to [Chinese version]. The English version is not provided since the firmware and commands are applicable to the Chinese market (Tencent).

Tencent Cloud IoT AT Firmware¶

ESP32¶

TODO

ESP32-C3¶

TODO

AT FAQ¶

[中文]

AT Firmware
AT Commands and Responses
Hardware
Performance
Other

AT Firmware ¶

There is no released firmware for my module. Where can I get the firmware for it?¶

If there is no released fimware for your module in the AT Binary Lists chapter, please consider the following options:

Use the firmware for the module that has the same hardware configuration as yours (see ESP-AT Firmware Differences for which module has the same configuration).
Create a factory parameter bin and compile the firmware for your module by yourself.

How to get the source code of AT firmware?¶

ESP-AT firmware is partially open-source. See esp-at for the open-source repository.

How to download the AT firmware on Espressif’s official website?¶

Download the flash tool: Flash Download Tools.

See AT Downloading Guide for the download address.

How to combine all the bin files compiled by ESP-AT?¶

You can use the combine button of the Flash Download Tools.

Why is the error “flash read err,1000” printed on the serial port after powering up the newly purchased ESP32-WROVE-E module? How to use AT commands for this module?¶

The ESP32-WROVER-E module is shipped without AT firmware, so the error “flash read err” appears.

If you want to use the AT command function of ESP32-WROVER-E, please refer to the following links to get the firmware and flash it.

Download firmware;

Connect hardware;

Flash firmware.

Does the AT firmware shipped in modules support flow control?¶

Hardware flow control is supported, but software flow control is not.

To enable or disable hardware flow control, run AT+UART_CUR or AT+UART_DEF.

See Hardware connection for more details.

I am new to ESP-AT firmware. Which AT firmware version shall I choose for ESP8266, NONOS or RTOS?¶

It is recommended to use the RTOS version, which is being actively maintained now. NONOS is an older AT version.

The two versions are quite different in terms of logic. Besides, RTOS supports more features and fixes the bugs that exist in NONOS version. RTOS version is now and will be our focus in the long run. We will fix bugs more timely and constantly add new features in this version.

Please download RTOS AT bin.

AT Commands and Responses ¶

What is the reason why AT prompts busy?¶

The “busy” prompt indicates that the previous command is being executed, and the system cannot respond to the current input. The processing mechanism of the AT commands is serial, i.e. one command at a time.

Any input through serial ports is considered to be a command input, so the system will also prompt “busy” or “ERROR” when there is any extra invisible character input.

Serial input AT+GMR (change character CR LF) (space character), because AT+GMR (change character CR LF) is already a complete AT command, the system will execute the command. At this time, if the system has not completed the AT+GMR operation, it has received the following space character, which will be regarded as a new command input, and the system will prompt “busy”. But if the system has completed the AT+GMR operation, and then receives the following space character, the space character will be regarded as an error command, and the system will prompt “ERROR”.

After the MCU sends AT+CIPSEND and receives the busy p.. response, the MCU needs to resend the data. Because busy p.. represents the previous command is being executed, the current input is invalid. It is recommended to wait for the response of the last AT command before the MCU sends a new command again.

Why does the ESP-AT firmware always return the following message after the I powered up the device and sent the first command?¶

ERR CODE:0x010b0000
busy p...
This message means that the previous command is being executed.

Normally only “busy p…” is displayed. The ERR CODE is displayed because the error code prompt is enabled.

If you receive this message after sending the first command on power-up, the possible reasons are: the command is followed by the unnecessary newline/space/other symbols; or two or more AT commands are sent in succession.

What commands are supported by the default ESP-AT firmware on different modules, and from which version are they supported?¶

To learn what commands are supported by the default ESP-AT firmware on different modules, please refer to ESP-AT Firmware Differences and How to understand the differences of each type of module.

To learn from which version a command is supported and what issues are fixed in each version, please refer to release notes.

When the host MCU sends an AT command to the ESP32 device (AT firmware version: V2.1.0.0), there is no response. What is the reason?¶

A terminator (“ATrn”) must be added after an AT command when the host MCU sending AT commands to an ESP32 device. Please see Check Whether AT Works.

Do AT commands support ESP-WIFI-MESH?¶

Currently, AT commands do not support ESP-WIFI-MESH.

Does AT support websocket commands?¶

Not supported in the default firmware.

It can be implemented by custom commands. See websocket and How to add user-defined AT commands for more information.

Can AT command set Bluetooth LE transmit power?¶

Yes, the AT+RFPOWER command can set Bluetooth LE transmit power. ESP32 and ESP32-C3 Wi-Fi and Bluetooth LE share the same antenna.

Is it possible to set the ESP32-WROOM-32 module to HID keyboard mode with AT commands?¶

Yes, please refer to Bluetooth LE AT Commands.

How to support commands that are not supported by the default firmware but can be supported after configuring and compiling the ESP-AT project?¶

For example, if you need to support the Bluetooth function on the ESP32-WROOM series, configure and compile the firmware by yourself. Open the Bluetooth function in menuconfig when compiling: ./build.py menuconfig > Component config > AT > [*]AT bt command support.

How to handle special characters in AT commands?¶

Please refer to the escape character syntax described in the AT Command Types section.

Can the serial port baudrate be modified in AT Commands? (Default: 115200)¶

Yes, you can use either of the two ways below to modify it:

Use the command AT+UART_CUR or AT+UART_DEF.

Re-compile the AT firmware: establish the compiling environment and change the UART baudrate.

After ESP32 enters the passthrough mode using AT commands, can ESP32 give a message if the connected hotspot is disconnected?¶

Yes, you can configure it with AT+SYSMSG, i.e., set AT+SYSMSG=4. In this way, the serial port will report “WIFI DISCONNECTrn” when the connected hotspot is disconnected.

Note that this command is added after AT v2.1.0. It is not available for v2.1.0 and earlier versions.

How to set ADV broadcast parameters after it exceeds 32 bytes?¶

The AT+BLEADVDATA command supports up to 32 bytes of ADV broadcast parameters. If you need to set a bigger parameter, please use command AT+BLESCANRSPDATA.

After I migrate from ESP8266 NONOS AT to RTOS AT (v2.0.0.0 and above), flash the firmware successfully, and start up AT, why no “ready” is returned?¶

AT communication pins of the ESP8266 RTOS version have been changed to GPIO13 and GPIO15.

See Hardware connection for more details.

Hardware ¶

How big is the chip flash required for ESP-AT firmware on different modules?¶

For ESP32 and ESP32-C3 series modules, please refer to ESP-AT Firmware Differences.

For ESP8266 series modules, please refer to How to understand the differences of each type of module.

How does the ESP32 AT communicate through the UART0 port?¶

The default AT firmware communicates through the UART1 port. If you want to communicate through UART0, please download and compile the ESP-AT project.

Refer to Compile ESP-AT Project to set up the compiling environment;

Modify the module’s UART pins in your factory_param_data.csv , i.e. change uart_tx_pin to GPIO1, and uart_tx_pin to GPIO3;

Configure your esp-at project: ./build.py menuconfig > Component config > Common ESP-related > UART for console output(Custom) > Uart peripheral to use for console output(0-1)(UART1) > (1)UART TX on GPIO# (NEW) > (3)UART TX on GPIO# (NEW).

How to view the error log of AT firmware?¶

For ESP32, the error log is output through the download port. By default, UART0 is GPIO1 and GPIO3.

For ESP32-C3, the error log is output through the download port. By default, UART0 is GPIO21 and GPIO20.

For ESP8266, it is output from UART1 TX, which is GPIO2 by default.

See Hardware Connection for more details.

The UART1 communication pin used by ESP-AT on the ESP32 module is inconsistent with the default UART1 pin described in the ESP32 module’s datasheet?¶

ESP32 supports IO matrix. When compiling ESP-AT, you can configure UART1 pins in menuconfig, so they may be inconsistent with the pins described in the module datasheet.

See factory_param_data.csv for more details.

Performance ¶

How long does it take for the AT to connect to Wi-Fi?¶

In an office scenario, the connection time is 5 seconds. However, in actual practice, Wi-Fi connection time depends on the router performance, network environment, module antenna performance, etc.

The maximum timeout time can be set by the <jap_timeout> parameter of AT+CWJAP.

Is it possible to change the TCP send window size in AT firmware?¶

Currently, it cannot be changed by AT commands, but you can configure and compile the ESP-AT project to generate a new firmware.

You can configure the menuconfig parameter: Component config > LWIP > TCP > Default send buffer size.

How to test and optimize the throughput of ESP32 AT?¶

Many factors are affecting the AT throughput test. It is recommended to use the iperf example in esp-idf for testing. While testing, please use the passthrough mode, adjust the data length to 1460 bytes, and send data continuously.

If the test rate does not meet your requirements, please refer to How to Improve ESP-AT Throughput Performance.

What is the maximum rate of ESP32 AT default firmware Bluetooth LE UART transparent transmission?¶

In an open office environment, when the serial port baud rate is 2000000, the average transmission rate of ESP-AT Bluetooth is 0.56 Mbps, and the average transmission rate of ESP-AT Bluetooth LE is 0.101 Mbps.

Other ¶

What interfaces of ESP chips can be used to transmit AT commands?¶

ESP8266 can transmit AT commands through UART. ESP32 can transmit AT commands through SDIO, SPI, and UART. ESP32-C3 can transmit AT commands through SPI and UART.

The default firmware uses UART for transmission. If you need SDIO or SPI interface to transmit AT commands, you can configure it through ./build.py menuconfig -> Component config -> AT when compiling the ESP-AT project by yourself.

See AT through SDIO , AT through SPI , or AT through socket for more details.

How to use the Ethernet function of the ESP32 AT?¶

The Ethernet function is disable in AT default firmware, if you need to enable the Ethernet function, please refer to How to Enable ESP-AT Ethernet.

How does ESP-AT conduct BQB certification?¶

Please contact Espressif for solutions.

How do I specify the TLS protocol version for ESP32 AT?¶

When compiling the esp-at project, you can disable the unwanted versions in the ./build.py menuconfig -> Component config -> mbedTLS.

How to modify the number of TCP connections in AT?¶

At present, the maximum number of TCP connections of the AT default firmware is 5.

The ESP32 AT supports a maximum of 16 TCP connections, which can be configured in menuconfig as follows:

./build.py menuconfig—> Component config—> AT—> (16)AT socket maximum connection number

./build.py menuconfig—> LWIP—> (16)Max number of open sockets

The ESP8266 AT supports a maximum of 5 TCP connections, which can be configured in menuconfig as follows:

./build.py menuconfig—> Component config—> AT—> (5)AT socket maximum connection number

./build.py menuconfig—> LWIP—> (10)Max number of open sockets

Index of Abbreviations¶

A2DP

Advanced Audio Distribution Profile

高级音频分发框架

ADC

Analog-to-Digital Converter

模拟数字转换器

ALPN

Application Layer Protocol Negotiation

应用层协议协商

AT

AT stands for “attention”.

AT 是 attention 的缩写。

AT command port

The port that is used to send AT commands and receive responses. More details are in the AT port introduction.

AT 命令端口

也称为 AT 命令口，用于发送 AT 命令和接收响应的端口。更多介绍请参考 AT 端口。

AT log port

The port that is used to output log. More details are in the AT port introduction.

AT 日志端口

也称为 AT 日志口，用于输出 AT 日志的端口。更多介绍请参考 AT 端口。

AT port

AT port is the general name of AT log port (that is used to output log) and AT command port (that is used to send AT commands and receive responses). Please refer to Hardware Connection for default AT port pins and How to Set AT Port Pins for how to customize them.

AT 端口

AT 端口是 AT 日志端口（用于输出日志）和 AT 命令端口（用于发送 AT 命令和接收响应）的总称。请参考 Hardware Connection 了解默认的 AT 端口管脚，参考 How to Set AT Port Pins 了解如何自定义 AT 端口管脚。

Bluetooth LE

Bluetooth Low Energy

低功耗蓝牙

BluFi

Wi-Fi network configuration function via Bluetooth channel

BluFi 是一款基于蓝牙通道的 Wi-Fi 网络配置功能

Command Mode

Default operating mode of AT. In the command mode, any character received by the AT command port will be treated as an AT command, and AT returns the command execution result to the AT command port. AT enters Data Mode from Command Mode in the following cases.

After sending the AT+CIPSEND set command successfully and returns >.
After sending the AT+CIPSEND execute command successfully and returns >.
After sending the AT+CIPSENDL set command successfully and returns >.
After sending the AT+CIPSENDEX set command successfully and returns >.
After sending the AT+SAVETRANSLINK set command successfully and sending the AT+RST command and restart the module.
After sending the AT+BTSPPSEND execute command successfully and returns >.
After sending the AT+BLESPP execute command successfully and returns >.

In the data mode, send the +++ command, AT will exit from Data Mode and enter the Command Mode.

命令模式

AT 的默认工作模式。在命令模式下，AT 命令端口收到的任何字符都会被当作 AT 命令进行处理，同时 AT 会在命令端口回复命令执行结果。 AT 在下列情况下，会从命令模式进入数据模式。

发送 AT+CIPSEND 设置命令成功，回复 > 之后
发送 AT+CIPSEND 执行命令成功，回复 > 之后
发送 AT+CIPSENDL 设置命令成功，回复 > 之后
发送 AT+CIPSENDEX 设置命令成功，回复 > 之后
发送 AT+SAVETRANSLINK 设置命令成功，再发送 (AT+RST) 命令，模组重启之后
发送 AT+BTSPPSEND 执行命令成功，回复 > 之后
发送 AT+BLESPP 执行命令成功，回复 > 之后

在数据模式下，发送 +++ 命令，会从数据模式退出，进入命令模式。

Data Mode

In the data mode, any character received by the AT command port will be treated as data (except for special +++) instead of the AT command, and these data will be sent to the opposite end without modification. AT enters Data Mode from Command Mode in the following cases.

After sending the AT+CIPSEND set command successfully and returns >.
After sending the AT+CIPSEND execute command successfully and returns >.
After sending the AT+CIPSENDL set command successfully and returns >.
After sending the AT+CIPSENDEX set command successfully and returns >.
After sending the AT+SAVETRANSLINK set command successfully and sending the AT+RST command and restart the module.
After sending the AT+BTSPPSEND execute command successfully and returns >.
After sending the AT+BLESPP execute command successfully and returns >.

In the data mode, send the +++ command, AT will exit from Data Mode and enter the Command Mode.

数据模式

在数据模式下，AT 命令端口收到的任何字符都会被当作数据（除了特殊的 +++），而不是 AT 命令，这些数据会无修改的发往对端。 AT 在下列情况下，会从命令模式进入数据模式。

发送 AT+CIPSEND 设置命令成功，回复 > 之后
发送 AT+CIPSEND 执行命令成功，回复 > 之后
发送 AT+CIPSENDL 设置命令成功，回复 > 之后
发送 AT+CIPSENDEX 设置命令成功，回复 > 之后
发送 AT+SAVETRANSLINK 设置命令成功，再发送 AT+RST 命令，模组重启之后
发送 AT+BTSPPSEND 执行命令成功，回复 > 之后
发送 AT+BLESPP 执行命令成功，回复 > 之后

在数据模式下，发送 +++ 命令，会从数据模式退出，进入命令模式。

DHCP

Dynamic Host Configuration Protocol

动态主机配置协议

DNS

Domain Name System

域名系统

DTIM

Delivery Traffic Indication Map

延迟传输指示映射

GATTC

Generic Attributes client

GATT 客户端

GATTS

Generic Attributes server

GATT 服务器

HID

Human Interface Device

人机接口设备

I2C

Inter-Integrated Circuit

集成电路总线

ICMP

Intemet Control Message Protocol

因特网控制报文协议

LWT

Last Will and Testament

遗嘱

MAC

Media Access Control

MAC 地址

mDNS

Multicast Domain Name System

多播 DNS

MSB

Most Significant Bit

最高有效位

MTU

maximum transmission unit

最大传输单元

NVS

Non-Volatile Storage

非易失性存储器

Normal Transmission Mode

Default Transmission Mode

In normal transmission mode, users can send AT commands. For examples, users can send MCU data received by AT command port to the opposite end of transmission by AT+CIPSEND; and the data received from the opposite end of transmission will also be returned to MCU through AT command port with additional prompt: +IPD.

During a normal transmission, if the connection breaks, ESP devices will give a prompt and will not attempt to reconnect.

More details are in Transmission Mode Shift Diagram.

普通传输模式

默认传输模式

在普通传输模式下，用户可以发送 AT 命令。例如，用户可以通过 AT+CIPSEND 命令，发送 AT 命令口收到的 MCU 数据到传输对端。从传输对端收到的数据，会通过 AT 命令口返回给 MCU，同时会附带 +IPD 信息。

普通传输模式时，如果连接断开，ESP 不会重连，并提示连接断开。

更多介绍请参考 Transmission Mode Shift Diagram。

Passthrough Mode

Also called as “Passthrough Sending & Receiving Mode”.

In passthrough mode, users cannot send AT commands except special +++ command. All MCU data received by AT command port will be sent to the opposite end of transmission without any modification; and the data received from the opposite end of transmission will also be returned to MCU through AT command port without any modification.

During the Wi-Fi passthrough transmission, if the connection breaks, ESP devices will keep trying to reconnect until +++ is input to exit the passthrough transmission.

More details are in Transmission Mode Shift Diagram.

透传模式

也称为 “透传发送接收模式”。

在透传模式下，用户不能发送其它 AT 命令，除了特别的 +++ 命令。AT 命令口收到的所有的 MCU 数据都将无修改地，发送到传输对端。从传输对端收到的数据也会通过 AT 命令口无修改地，返回给 MCU。

Wi-Fi 透传模式传输时，如果连接断开，ESP 会不停地尝试重连，此时单独输入 +++ 退出透传，则停止重连。

更多介绍请参考 Transmission Mode Shift Diagram。

Transmission Mode Shift Diagram

More details are in the following introduction.

Normal Transmission Mode (普通传输模式)
Passthrough Receiving Mode (透传接收模式)
Passthrough Mode (透传模式)
AT+CIPMODE
AT+CIPSEND
+++
AT+SAVETRANSLINK

Passthrough Receiving Mode

The temporary mode between Normal Transmission Mode and Passthrough Mode.

In passthrough receiving mode, AT cannot send any data to the opposite end of transmission; but the data received from the opposite end of transmission can be returned to MCU through AT command port without any modification. More details are in Transmission Mode Shift Diagram.

透传接收模式

在普通传输模式和透传模式之间的一个临时模式。

在透传接收模式，AT 不能发送数据到传输对端；但 AT 可以收到来自传输对端的数据，通过 AT 命令口无修改地返回给 MCU。更多介绍请参考 Transmission Mode Shift Diagram。

PBC

Push Button Configuration

按钮配置

PCI Authentication

Payment Card Industry Authentication. In ESP-AT project, it refers to all Wi-Fi authentication modes except OPEN and WEP.

PCI 认证，在 ESP-AT 工程中指的是除 OPEN 和 WEP 以外的 Wi-Fi 认证模式。

PKI

A public key infrastructure (PKI) is a set of roles, policies, hardware, software and procedures needed to create, manage, distribute, use, store and revoke digital certificates and manage public-key encryption.

More details are in Public Key Infrastructure.

公开密钥基础建设。公开密钥基础建设（PKI）是一组由硬件、软件、参与者、管理政策与流程组成的基础架构，其目的在于创造、管理、分配、使用、存储以及撤销数字证书。

更多介绍请参考公开密钥基础建设。

PLCP

Physical Layer Convergence Procedure

PLCP 协议，即物理层会聚协议

PMF

protected management frame

受保护的管理帧

PSK

Pre-shared Key

预共享密钥

PWM

Pulse-Width Modulation

脉冲宽度调制

QoS

Quality of Service

服务质量

RTC

Real Time Controller. A group of circuits in SoC that keeps working in any chip mode and at any time.

实时控制器，为 SoC 中的一组电路，在任何芯片模式下都能随时保持工作。

SMP

Security Manager Protocol

安全管理协议

SNI

Server Name Indication

服务器名称指示

SNTP

Simple Network Time Protocol

简单网络时间协议

SPI

Serial Peripheral Interface

串行外设接口

SPP

Serial Port Profile

SPP 协议，即串口协议

SSL

Secure Sockets Layer

SSL 协议，即安全套接字协议

TLS

Transport Layer Security

TLS 协议，即传输层安全性协议

URC

Unsolicited Result Code

非请求结果码，一般为模组给 MCU 的串口返回

UTC

Coordinated Universal Time

协调世界时

UUID

universally unique identifier

通用唯一识别码

WEP

Wired-Equivalent Privacy

WEP 加密方式，即有线等效加密

WPA

Wi-Fi Protected Access

Wi-Fi 保护访问

WPA2

Wi-Fi Protected Access II

Wi-Fi 保护访问 II

WPS

Wi-Fi Protected Setup

Wi-Fi 保护设置

About¶

[中文]

This is documentation of ESP-AT, a solution developed by Espressif to quickly and easily interface with ESP products.

Espressif Wi-Fi and Bluetooth chipsets are often used as add-on modules to seamlessly integrate wireless connectivity features into new and existing products. In an effort to facilitate this and cut down on engineering costs, Espressif Systems has developed AT firmware as well as a rich set of AT commands that can be used to interface with Espressif products.

The AT firmware allows for rapid integration by providing:

In-built TCP/IP stack and data buffering
Easy integration with resource-constrained host platforms
Easy-to-parse command-response protocols
Customized, user-defined AT commands

Index

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CHANNEL	GPIO
0	GPIO36
1	GPIO37
2	GPIO38
3	GPIO39
4	GPIO32
5	GPIO33
6	GPIO34
7	GPIO35

Bit	Permission
0	BROADCAST
1	READ
2	WRITE WITHOUT RESPONSE
3	WRITE
4	NOTIFY
5	INDICATE
6	AUTHENTICATION SIGNED WRITES
7	EXTENDED PROPERTIES