Basic AT Commands¶

AT : Tests AT startup.
AT+RST : Restarts a module.
AT+GMR : Checks version information.
AT+GSLP : Enters Deep-sleep mode.
ATE : Configures echoing of AT commands.
AT+RESTORE : Restores the factory default settings of the module.
AT+UART_CUR : Current UART configuration.
AT+UART_DEF : Default UART configuration, saved in flash.
AT+SLEEP : Sets the sleep mode.
AT+SYSRAM : Checks current remaining heap size and minimum heap size.
AT+SYSMSG : Set message format.
AT+RFPOWER : Set RF TX Power.
AT+SYSFLASH : Set User Partitions in Flash.
[ESP32 Only] AT+FS : Filesystem Operations.
AT+SYSROLLBACK : Roll back to the previous firmware.
AT+SYSTIMESTAMP: Set local time stamp.
AT+SYSLOG : Enable or disable the AT error code prompt.
AT+SLEEPWKCFG : Config the light-sleep wakeup source and awake GPIO.
AT+SYSSTORE : Config parameter store mode.

AT—Tests AT Startup¶

Execute Command:

AT

Response:

OK

AT+RST—Restarts the Module¶

Execute Command:

AT+RST  

Response:

OK

AT+GMR—Checks Version Information¶

Execute Command:

AT+GMR  

Response:

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

OK

Parameters:

<AT version info>: information about the AT version.
<SDK version info>: information about the SDK version.
<compile time>: the duration of time for compiling the BIN.

AT+GSLP—Enters Deep-sleep Mode¶

Set Command:

AT+GSLP=<time>  

Response:

<time>

OK

Parameters:

<time>: the duration of the device’s deep sleep. Unit: ms.ESP device will automatically wake up after the deep-sleep for as many milliseconds (ms) as <time> indicates.Upon waking up, the device calls deep sleep wake stub, and then proceeds to load application.

Note:

On ESP8266 platform, in order to timing wake up, it is necessary to connect GPIO16 to RST pin.
Moreover, ESP8266 can be waken up from deep sleep externally by directly triggering RST pin low level pulse.

ATE—AT Commands Echoing¶

Execute Command:

ATE

Response:

OK

Parameters:

ATE0: Switches echo off.
ATE1: Switches echo on.

AT+RESTORE—Restores the Factory Default Settings¶

Execute Command:

AT+RESTORE  

Response:

OK

Note:

The execution of this command will reset all parameters saved in flash, and restore the factory default settings of the module.
The chip will be restarted when this command is executed.

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

Query Command:

AT+UART_CUR?

Response:

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

OK

Note:

Command AT+UART_CUR? will return the actual value of UART configuration parameters, which may have allowable errors compared with the set value because of the clock division.

Set Command:

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

Response:

OK

Parameters:

<baudrate>: UART baud rate
<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 NOT be saved in flash.
The use of flow control requires the support of hardware:
- IO15 is UART0 CTS
- IO14 is UART0 RTS
The range of baud rates supported: 80 ~ 5000000.

Example:

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

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

Query Command:

AT+UART_DEF?

Response:

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

OK

Set Command:

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

Response:

OK

Parameters:

<baudrate>: UART baud rate
<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.
The use of flow control requires the support of hardware:
- IO15 is UART0 CTS
- IO14 is UART0 RTS
The range of baud rates supported: 80 ~ 5000000.

Example:

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

AT+SLEEP—Sets the Sleep Mode¶

Set Command:

AT+SLEEP=<sleep mode>

Response:

OK

Parameters:

<sleep mode>:
- 0: disable the sleep mode.
- 1: Modem-sleep DTIM mode. RF will be periodically closed according to AP DTIM.
- 2: Light-sleep mode. CPU will automatically sleep and RF will be periodically closed according to listen interval set by AT+CWJAP.
- 3: Modem-sleep listen interval mode. RF will be periodically closed according to listen interval set by AT+CWJAP.

Example:

AT+SLEEP=0

Notes:

Light sleep is not available for ESP32S2 currently.

AT+SYSRAM—Checks current remaining heap size and minimum heap size¶

Query 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—Control to use new or old information¶

Query Command:

AT+SYSMSG?
Function:
Query the current system message state. 

Response:

+SYSMSG:<state>
OK  

Set Command:

AT+SYSMSG=<state>
Function:
Control to use new or old information.  

Response:

OK

Parameters:

<state>:

Bit0: Quit transparent transmission0: Quit transparent transmission no information.1: Quit transparent transmission will supply information.
Bit1: Connection information0: Use old connection information.1: Use new connection information.

Bit2: conection status information when in Wi-Fi transparent transmission, Ble SPP and BT SPP0: There is no more prompt information but received data.1: It will print some information if Wi-Fi, socket, ble or bt status is changed, the prompt is as following

  - "CONNECT\r\n" or the message prefixed with "+LINK_CONN:"  
  - "CLOSED\r\n"  
  - "WIFI CONNECTED\r\n"  
  - "WIFI GOT IP\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 set Bit0 to 1 will supply information “+QUITT” when quit transparent transmission.
If set Bit1 to 1 will impact the infomation 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:
// Use new connection info and quit transparent transmission no information AT+SYSMSG=2

AT+SYSFLASH—Set User Partitions in Flash¶

Query Command:

AT+SYSFLASH?
Function:
Check the user partitions in flash. 

Response:

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

Set Command:

AT+SYSFLASH=<operation>,<partition>,<offset>,<length>
Function:
Read/write the user partitions in flash.    

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:

at_customize.bin has to be downloaded, so that the relevant commands can be used. Please refer to the ESP_AT_Customize_Partitions for more details.
Important things to note when erasing user partitions:
- When erasing the targeted user partition in its entirety, parameters <offset> and <length> can be omitted. For example, command AT+SYSFLASH=0,"ble_data" can erase the entire “ble_data” user partition.
- If parameters <offset> and <length> are not omitted when erasing the user partition, 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 actual data, which length is parameter <length>.

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

[ESP32 Only] AT+FS—Filesystem Operations¶

Set 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>: offset, for writing and reading operations only
<length>: data length, for writing and reading operations only

Notes:

at_customize.bin has to be downloaded, so that the relevant commands can be used. The definitions of user partitions are in esp-at/at_customize.csv. Please refer to the ESP32_Customize_Partitions for more details.
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 actual data, which length is 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-Set RF TX Power¶

Query Command:

AT+RFPOWER?
Function: to query the RF TX Power.

Response:

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

Set Command:

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

Response:

OK

Parameters:

<wifi_power>: the unit is 0.25dBm. for example, if set the value is 78, then the actual RF max power value is 78*0.25dBm = 19.5dBm.after configuring it, please confirm the actual value by AT+RFPOWER?
- range: [40, 78] on ESP32 platform and ESP32S2 platform, please refer to the notes below for details
- range: [40, 82] on ESP8266 platform, please refer to the notes below for details
<ble_adv_power>: RF TX Power of BLE advertising, range: [0, 7]
- 0:7dBm
- 1:4dBm
- 2:1dBm
- 3:-2 dBm
- 4:-5 dBm
- 5:-8 dBm
- 6:-11 dBm
- 7:-14 dBm
<ble_scan_power>: RF TX Power of BLE scanning, range: [0, 7], the same as <ble_adv_power>
<ble_conn_power>: RF TX Power of BLE connecting, range: [0, 7], the same as <ble_adv_power>

Notes:

Since the RF TX power is actually divided into several levels, and each level has its own value range, so 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 the query value will not be larger than the set one.
Relationship between set value and actual value, as following,

ESP32 and ESP32S2 platform:

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

ESP8266 platform:

set value	actual value	actual dBm
[33, 48]	33	8
[49, 55]	49	12
[56, 63]	56	14
[64, 67]	64	16
[68, 73]	68	17
[74, 77]	74	18.5
[78, 81]	78	19.5
82	82	20.5

AT+SYSROLLBACK-Roll back to the previous firmware¶

Execute Command:

AT+SYSROLLBACK

Response:

OK

Note:

This command will not upgrade via OTA, only roll back to the firmware which is in the other ota partition.

AT+SYSTIMESTAMP—Set local time stamp.¶

Query Command:

AT+SYSTIMESTAMP?
Function: to query the time stamp.

Response:

+SYSTIMESTAMP:<Unix_timestamp>
OK

Set Command:

AT+SYSTIMESTAMP=<Unix_timestamp>
Function: to set local time stamp. It will be the same as SNTP time when the SNTP time updated.

Response:

OK

Parameters:

<Unix_timestamp>: Unix timestamp, the unit is seconds.

Example:

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

AT+SYSLOG : Enable or disable the AT error code prompt.¶

Query Command:

AT+SYSLOG?  
Function: to query the AT error code prompt for whether it is enabled or disabled.  

Response:

+SYSLOG:<status>  

OK  

Set Command:

AT+SYSLOG=<status>
Function: Enable or disable the AT error code prompt.

Response:

OK

Parameters:

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

Example:If enable AT error code prompt:

AT+SYSLOG=1

OK
AT+FAKE
ERR CODE:0x01090000

ERROR

If disable AT error code prompt:

AT+SYSLOG=0

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

ERROR  

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

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

category: stationary value 0x01
subcategory: error type
extension: error extension information, there are different extension for different subcategory, the detail is defined in components/at/include/esp_at.h

subcategory is defined as follows:

    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 */

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

AT+SLEEPWKCFG—Config the light-sleep wakeup source and awake GPIO.¶

Set Command:

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

Response:

OK

Parameters:

<wakeup source>:
- 0: Wakeup by timer.
- 1: Wakeup by UART. (Only Support ESP32)
- 2: Wakeup by GPIO.
<param1>:
- If the wakeup source is timer, this param is time before wakeup, the units is millisecond.
- If the wakeup source is UART. this param is the Uart number.
- If the wakeup source is GPIO, the param is the GPIO number.
<param2>:
- If the wakeup source is GPIO, the param is the wakeup level, 0: Low level, 1: High level.

Example:

AT+SLEEPWKCFG=0,1000  // Timer wakeup
AT+SLEEPWKCFG=1,1     // Uart1 wakeup, Only Support ESP32
AT+SLEEPWKCFG=2,12,0  // GPIO12 wakeup, low level.

Notes:

GPIO16 as the RTC IO can not be set as GPIO wakeup source on ESP8266 platform for light sleep.

AT+SYSSTORE— Config parameter store mode¶

Query Command:

AT+SYSSTORE?  
Function: to query the AT parameter store mode.  

Response:

+SYSSTORE:<store_mode>  

OK  

Set Command:

AT+SYSSTORE=<store_mode>

Response:

OK

Parameters:

<store_mode>:
- 0: Do not store command configuration into flash.
- 1: Store command configuration into flash.

Affected commands:

AT+SYSMSG  
AT+CWMODE  
AT+CWJAP  
AT+CWSAP
AT+CIPAP  
AT+CIPSTA  
AT+CIPAPMAC  
AT+CIPSTAMAC  
AT+CIPDNS
AT+CIPSSLCCONF
AT+CIPRECONNINTV
AT+CWDHCPS  
AT+CWDHCP  
AT+CWSTAPROTO  
AT+CWAPPROTO  
AT+CWJEAP
AT+CIPETH  
AT+CIPETHMAC  
AT+BLENAME  
AT+BTNAME
AT+BLEADVPARAM
AT+BLEADVDATA
AT+BLEADVDATAEX
AT+BLESCANRSPDATA
AT+BLESCANPARAM
AT+BTSCANMODE
AT+BLECONNPARAM

Note:

* The default value of `store_mode` is 1;  
* `AT+SYSSTORE` only effects on setup command, query command is always got from ram.  

Example:

AT+SYSSTORE=0
AT+CWMODE=1  // Do not store into flash
AT+CWJAP="test","1234567890" // Do not store into flash

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