ESP32-S3-USB-OTG¶

[中文]

ESP32-S3-USB-OTG is a development board that focuses on USB-OTG function verification and application development. It is based on ESP32-S3 SoC, supports Wi-Fi and BLE 5.0 wireless functions, and supports USB host and USB device functions. It can be used to develop applications such as wireless storage devices, Wi-Fi network cards, LTE MiFi, multimedia devices, virtual keyboards and mice. The development board has the following features:

Onboard ESP32-S3-MINI-1-N8 module, with built-in 8 MB flash
Onboard USB Type-A host and device interface, with built-in USB interface switching circuit
Onboard USB to serial debugging chip (Micro USB interface)
Onboard 1.3-inch LCD color screen, supports GUI
Onboard SD card interface, compatible with SDIO and SPI interfaces
Onboard charging IC, can be connected to lithium battery

The document consists of the following major sections:

Getting Started: Provides a brief overview of ESP32-S3-USB-OTG and necessary hardware and software information.
Hardware Reference: Provides detailed hardware information of ESP32-S3-USB-OTG.
Related Documents: Provides links to related documents.

Getting Started¶

This section describes how to start using ESP32-S3-USB-OTG. It includes introduction to basic information about ESP32-S3-USB-OTG first, and then on how to start using the development board for application development, as well as board packaging and retail information.

Description of Components¶

The ESP32-S3-USB-OTG development board includes the following parts:

Motherboard: ESP32-S3-USB-OTG motherboard is the core of the kit. The motherboard integrates the ESP32-S3-MINI-1 module and provides an interface of the 1.3-inch LCD screen.

The following table starts with the USB_HOST Interface on the left, and introduces the main components in the above figure in an anticlockwise order.

Main components	Description
USB_HOST Interface	USB Type-A female port, used to connect other USB devices.
ESP32-S3-MINI-1 Module	ESP32-S3-MINI-1 is a powerful, generic Wi-Fi + Bluetooth LE MCU module that has a rich set of peripherals. It has strong ability for neural network computing and signal processing. ESP32-S3-MINI-1 comes with a PCB antenna and is pin-to-pin compatible with ESP32-S2-MINI-1.
MENU Button	Menu button.
Micro SD Card Slot	Micro SD card can be inserted. Both four-line SDIO and SPI mode are supported.
USB Switch IC	By setting the level of USB_SEL, you can switch USB peripherals to make them either connected to the USB_DEV interface or the USB_HOST interface. USB_DEV will be connected by default.
Reset Button	Press this button to restart the system.
USB_DEV Interface	USB Type-A male port, can be connected to the USB host, and also used as a lithium battery charge power source.
Power Switch	Switch to ON to use battery power. Switch to OFF to power off battery.
Boot Button	Download button. Holding down Boot and then pressing Reset initiates Firmware Download mode for downloading firmware through the serial port.
DW- Button	Down button.
LCD FPC Connector	Used to connect the 1.3-inch LCD screen.
UP+ Button	Up button.
USB-to-UART Interface	A Micro-USB port used for power supply to the board, for flashing applications to the chip, as well as for communication with the chip via the on-board USB-to-UART bridge.

The following table starts with the Yellow LED on the left, and introduces the main components in the above figure in an anticlockwise order.

Main components	Description
Yellow LED	Driven by GPIO16, set high level to turn on.
Green LED	Driven by GPIO15, set high level to turn on.
Charging LED	During charging, the red light is on, which will be turned off when charged.
Battery Solder Joints	3.6 V lithium battery can be welded to power the motherboard.
Charging Circuit	Used to charge lithium battery.
Free Pins	Idle pins that can be customized.
USB-to-UART Bridge	Single USB-to-UART bridge chip provides transfer rates up to 3 Mbps.

Subboard: ESP32-S3-USB-OTG-SUB mount the 1.3-inch LCD screen

Start Application Development¶

Before powering on the ESP32-S3-USB-OTG, please make sure that the development board is intact.

Required Hardware¶

ESP32-S3-USB-OTG
A USB 2.0 data cable (standard A to Micro-B)
Computer (Windows, Linux or macOS)

Software Setup¶

Please proceed to Get Started, where Section Installation Step by Step will quickly help you set up the development environment and then flash an application example onto your board.

Project Option¶

An example is provided for ESP32-S3-USB-OTG under the folder Examples .

You can configure project options by entering idf.py menuconfig in the example directory.

Contents and Packaging¶

Retail Orders¶

If you order a few samples, each board comes in an individual package in either an antistatic bag or any packaging depending on your retailer.

Which contains the following parts:

Motherboard:
- ESP32-S3-USB-OTG
Subboard:
- ESP32-S3-USB-OTG_SUB
Fastener
- Mounting bolt (x4)
- Screw (x4)
- Nut (x4)

For retail orders, please go to https://www.espressif.com/zh-hans/company/contact/buy-a-sample.

Wholesale Order¶

If purchased in bulk, the development board will be packaged in a large cardboard box.

For wholesale orders, please go to https://www.espressif.com/en/contact-us/sales-questions.

Hardware Reference¶

Block Diagram¶

The block diagram below shows the components of ESP32-S3-USB-OTG and their interconnections.

Please note that the external interface corresponding to the USB_HOST D+ D- signal in the functional block diagram is USB DEV, which means that ESP32-S3 is used as a device to receive signals from other USB hosts. The external interface corresponding to the USB_DEV D+ D- signal is USB HOST, which means that ESP32-S3 acts as a host to control other devices.

Power Supply Options¶

There are three power supply methods for the development board:

Power supply through the Micro_USB interface
- Use the USB cable (standard A to Micro-B) to connect the motherboard to a power supply device, and set battery switch to OFF. Please note that in this power supply mode, only the motherboard and display are powered.
Power supply through the USB_DEV interface
- Set DEV_VBUS_EN to high level, and set the battery switch to OFF. This mode can supply power to the USB HOST interface. The lithium battery will be charged at the same time (if the lithium battery is installed)
Power supply through the battery
- Set BOOST_EN to high level, and set the battery switch to ON. You should solder a 1-Serial lithium battery (3.7 V ~ 4.2 V) to the power solder joint reserved on the back of the motherboard first. This mode can supply power to the USB HOST interface at the same time. The battery interface description is as follows:

USB HOST Interface Power Options¶

The USB HOST interface (Type-A female port) can supply power to the connected USB device. The power supply voltage is 5 V and the maximum current is 500 mA.

There are two power supply methods for the USB HOST interface:
1. Power is supplied through the USB_DEV interface, and the 5 V power is directly from the power source connected to the interface.
2. Power is supplied through the lithium battery, and the 3.6 V ~ 4.2 V voltage of the lithium battery is boosted to 5 V through the Boost circuit. The working status of Boost IC can be controlled by BOOST_EN/GPIO13, set high to enable Boost.

USB HOST interface power supply selection:

BOOST_EN	DEV_VBUS_EN	Power Source
0	1	USB_DEV
1	0	Battery
0	0	No output
1	1	Undefined

500 mA current limiting circuit:
1. The current limiting IC MIC2005A can limit the maximum output current of the USB HOST interface to 500 mA. Please set the IDEV_LIMIT_EN (GPIO17) to high level to enable the current-limiting IC to output voltage.

USB Interface Switch Circuit¶

When USB_SEL (GPIO18) is set to high level, the USB D+/D- Pin (GPIO19, 20) will be connected to USB_DEV D+ D-. Then you can use the USB HOST interface (Type-A female Port) to connect other USB devices.
When USB_SEL (GPIO18) is set to low level, the USB D+/D- Pin (GPIO19, 20) will be connected to USB_HOST D+ D-. Then you can use the USB DEV interface (Type-A male port) to connect to a host like a PC.
USB_SEL is pulled low level by default.

LCD Interface¶

Please note that this interface supports connecting SPI interface screens. The screen controller used by this development board is :dev-kits:` ST7789 <esp32-s3-usb-otg/datasheet/ST7789VW_datasheet.pdf>`, and LCD_BL (GPIO9) can be used to control the screen backlight.

SD Card Interface¶

Please note that the SD card interface is compatible with 1-wire, 4-wire SDIO mode and SPI mode. After being powered on, the card will be in 3.3 V signaling mode. Please send the first CMD0 command to select the bus mode: SD mode or SPI mode.

Charging Circuit¶

Please note that the Type-A male port can be connected to a power adapter that outputs 5 V. When charging the battery, the red indicator LED is on, after fully charged, the red indicator LED is off. When using the charging circuit, please set the battery switch to OFF. The charging current is 212.7 mA.

Pin Layout¶

Function pin:

No.	ESP32-S3-MINI-1 Pin	Description
1	GPIO18	USB_SEL: Used to switch the USB interface. When high level, the USB_HOST interface is enabled. When low level, the USB_DEV interface is enabled.
2	GPIO19	Connect with USB D-.
3	GPIO20	Connect with USB D+.
4	GPIO15	LED_GREEN: the light is lit when set high level.
5	GPIO16	LED_YELLOW: the light is lit when set high level.
6	GPIO0	BUTTON_OK: OK button, low level when pressed.
7	GPIO11	BUTTON_DW: Down button, low level when pressed.
8	GPIO10	BUTTON_UP: UP button, low level when pressed.
9	GPIO14	BUTTON_MENU: Menu button, low level when pressed.
10	GPIO8	LCD_RET: used to reset LCD, low level to reset.
11	GPIO5	LCD_EN: used to enable LCD, low level to enable.
12	GPIO4	LCD_DC: Used to switch data and command status.
13	GPIO6	LCD_SCLK: LCD SPI Clock.
14	GPIO7	LCD_SDA: LCD SPI MOSI.
15	GPIO9	LCD_BL: LCD backlight control.
16	GPIO36	SD_SCK: SD SPI CLK / SDIO CLK.
17	GPIO37	SD_DO: SD SPI MISO / SDIO Data0.
18	GPIO38	SD_D1: SDIO Data1.
19	GPIO33	SD_D2: SDIO Data2.
20	GPIO34	SD_D3: SD SPI CS / SDIO Data3.
21	GPIO1	HOST_VOL: USB_DEV voltage monitoring, ADC1 channel 0.
22	GPIO2	BAT_VOL: Battery voltage monitoring, ADC1 channel 1.
23	GPIO17	LIMIT_EN: Enable current limiting IC, high level enable.
24	GPIO21	0VER_CURRENT: Current overrun signal, high level means overrun.
25	GPIO12	DEV_VBUS_EN: High level to enable DEV_VBUS power supply.
26	GPIO13	BOOST_EN: High level to enable Boost boost circuit.

Extended pin:

No.	ESP32-S3-MINI-1 Pin	Description
1	GPIO45	FREE_1: Idle, can be customized.
2	GPIO46	FREE_2: Idle, can be customized.
3	GPIO48	FREE_3: Idle, can be customized.
4	GPIO26	FREE_4: Idle, can be customized.
5	GPIO47	FREE_5: Idle, can be customized.
6	GPIO3	FREE_6: Idle, can be customized.

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