ESP32-S3-USB-OTG

by Espressif

A development board by Espressif focusing on USB-OTG functionality, suitable for applications like video streaming over Wi-Fi and connecting to wireless USB devices.

Micro-USB Native USB

Buy · $35.00 Pinout

ESP32-S3

MCU

240MHz

clock

8MB

flash

512KB

SRAM

36· 3 ADC

GPIO

BLE 5.0+ WiFi

radio

Pinout

37 pins

View:

Pin	GPIO	Labels	Status	Capabilities
1	0	BUTTON_OK	strapping	-
2	1	A0HOST_VOLTSPWM	safe	adc
3	2	A1BAT_VOLTSPWM	safe	adc
4	3	A2T3PWM	strapping	adc · touch
5	4	LCD_DCPWM	safe	-
6	5	LCD_CSPWM	safe	-
7	6	LCD_CLKPWM	safe	-
8	7	LCD_MOSIPWM	safe	-
9	8	LCD_RSTPWM	safe	-
10	9	LCD_BLPWM	strapping	-
11	10	BUTTON_UPPWM	strapping	-
12	11	BUTTON_DOWNPWM	strapping	-
13	12	DEV_VBUS_ENPWM	strapping	-
14	13	BOOST_ENPWM	strapping	-
15	14	BUTTON_MENUPWM	strapping	-
16	15	LED_GREENPWM	safe	-
17	16	LED_YELLOWPWM	safe	-
18	17	LIMIT_ENPWM	safe	-
19	18	USB_HOST_ENPWM	safe	-
20	19	USB_DNPWM	uart	-
21	20	USB_DPPWM	uart	-
22	21	OVER_CURRENTPWM	safe	-
23	33	SDMMC_D2PWM	strapping	-
24	34	SSSDMMC_D3PWM	strapping	spi
25	35	MOSISDMMC_CMDPWM	strapping	spi
26	36	SCKSDMMC_CLKPWM	strapping	spi
27	37	MISOSDMMC_D0PWM	strapping	spi
28	38	SDMMC_D1PWM	strapping	-
29	39	MTCKPWM	strapping	-
30	40	MTDOPWM	strapping	-
31	41	MTDIPWM	strapping	-
32	42	MTMSPWM	strapping	-
33	43	TXPWM	strapping	uart
34	44	RXPWM	strapping	uart
35	45	SDAPWM	strapping	i2c
36	46	SCL	strapping	i2c
37	-	LCD_MISO	safe	-

Start with these

12 pins with no boot or system involvement

A0HOST_VOLTSA1BAT_VOLTSLCD_DCPWMLCD_CSPWMLCD_CLKPWMLCD_MOSIPWMLCD_RSTPWMLED_GREENPWMLED_YELLOWPWMLIMIT_ENPWMUSB_HOST_ENPWMOVER_CURRENTPWM

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

sampled at boot or shared with debug/serial

Pin	Label	What to know	Role
BUTTON_OK	GPIO0	Must be pulled high (default) or low (to enter UART download mode) at reset. Using it for other functions can interfere with boot mode configuration.	Strapping
A2	GPIO3	Sampled at reset to select JTAG interface (USB Serial/JTAG controller vs. external pins). Improper use can disable external JTAG or alter debug interface.	Strapping
MTCK	MTCK (GPIO39)	Default JTAG debugging TCK pin. If JTAG is needed, this pin must be free; it may also be used internally for PSRAM chip select on certain modules, so avoid repurposing it.	Other
MTDO	MTDO (GPIO40)	Default JTAG TDO output for debugging. Using it as GPIO will interfere with JTAG debugging functionality.	Other
MTDI	MTDI (GPIO41)	Default JTAG TDI input for debugging. Should be reserved for JTAG or left unused if JTAG is to remain available.	Other
MTMS	MTMS (GPIO42)	Default JTAG TMS signal for debugging. Using this pin for other purposes will disable the JTAG interface (unless JTAG is rerouted to USB).	Other
TX	U0TXD (GPIO43)	Used for bootloader output and UART console logs. If repurposed, you will lose the default serial output (and programming via UART0).	Other
RX	U0RXD (GPIO44)	Used for bootloader input (download mode via serial). If repurposed, you cannot use the default UART0 download mode for programming the chip.	Other
SDA	GPIO45	Determines flash/PSRAM power voltage (3.3 V vs 1.8 V) at boot. Must match hardware configuration; using as GPIO can upset flash supply setting.	Strapping
SCL	GPIO46	Must be at a defined level during reset (with GPIO0) to select normal or download boot and UART/USB print mode. This pin is input-only (no output drive), so it should be left for its intended strapping function.	Strapping

Only if you know the tricks

wired to flash or USB - expect a fight

Pin	Label	What to know	Role
LCD_BL	FSPIHD	Connected to external flash (data/hold signal) on most modules. Not recommended for use as GPIO, since it must remain dedicated to flash communication.	Flash
BUTTON_UP	FSPICS0	Used to select the external flash chip. It is required for flash access and cannot be repurposed without losing flash connectivity	Flash
BUTTON_DOWN	FSPID	Used as a data line for flash (and in-package PSRAM). It should not be used as GPIO when the flash/PSRAM is in use.	Flash
DEV_VBUS_EN	FSPICLK	Drives the flash (and PSRAM) clock. This critical signal must be reserved for memory and not used as general GPIO.	Flash
BOOST_EN	FSPIQ	Used as a data line for flash/PSRAM transfers. Not available for other uses when flash/PSRAM is connected.	Flash
BUTTON_MENU	FSPIWP	Connected to external flash (data/write-protect signal). Not recommended as GPIO because it’s reserved for flash operations.	Flash
USB_DN	USB_D-	By default connected to the on-chip USB Serial/JTAG controller. Using it as general GPIO without reconfiguring IO MUX will interfere with USB functionality.	USB
USB_DP	USB_D+	By default connected to the on-chip USB Serial/JTAG controller. Using it as general GPIO without reconfiguring IO MUX will interfere with USB functionality.	USB
SDMMC_D2	FSPIHD	On chips/modules with integrated flash, this IO is wired to the flash hold pin internally. It cannot be reassigned to GPIO without breaking flash access.	Flash
SS	FSPICS0	Wired to the chip select of the internal flash in flash-equipped variants. It must remain low during flash operation, so it’s not available for other use.	Flash
MOSI	FSPID / PSRAM_D0	In modules with octal PSRAM, this pin is connected to the PSRAM data line. It is reserved for memory interface and not free for general GPIO when flash/PSRAM is present.	Flash
SCK	FSPICLK / PSRAM_CLK	In modules with octal PSRAM, this pin drives the PSRAM clock. It must be dedicated to the memory interface, not used as a regular GPIO when that interface is in use.	Flash
MISO	FSPIQ / PSRAM_DQS	In modules with octal PSRAM, this pin is connected to the PSRAM’s DQS signal. It cannot be repurposed without disrupting the PSRAM/flash communication.	Flash
SDMMC_D1	FSPIWP	On flash-equipped chips, this pin is tied to the flash’s WP# (or D3) line. It should be avoided for other use, as it’s needed for flash operations.	Flash

These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.

Pinout notes The ESP32-S3-USB-OTG breaks out 37 pins in total: 36 GPIO for your project. Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO45 and SCL on…

The ESP32-S3-USB-OTG breaks out 37 pins in total: 36 GPIO for your project.

Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO45 and SCL on GPIO46; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.

Beyond plain digital I/O you get 3 ADC-capable pins for sensors and battery monitoring and 1 capacitive-touch inputs.

10 of the exposed pins carry boot-time or system duties on the ESP32-S3 (BUTTON_OK, A2, MTCK and 7 more) - check the guidance above before wiring anything to them. A0, A1, LCD_DC, LCD_CS and 8 more are free of any such role - the safest first picks.

Getting started

flash your first firmware in ~2 minutes

Tool:

Connect over USB

Native USB - no driver, no serial chip. Not detected? Hold BOOT while plugging in.

Flash with your tool

Arduino IDE, PlatformIO, ESPHome or esptool - copy the settings on the right.

Verify it runs

The blink example uses GPIO1 - swap for your board's LED pin if different.

Tools → Board settings Copy

Board:            Esp32 S3 Usb Otg
USB CDC On Boot:  Enabled
Flash Size:       8MB · DIO
Upload Speed:     921600

// blink
pinMode(1, OUTPUT);
digitalWrite(1, LOW);   // on (often inverted)

platformio.ini Copy

[env:esp32s3usbotg]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600

device.yaml Copy

esp32:
  board: esp32-s3-devkitc-1
  variant: esp32s3usbotg
  framework:
    type: esp-idf

# blink - GPIO1
output:
  - platform: gpio
    pin: 1
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out

shell Copy

esptool.py --chip esp32s3 --port /dev/ttyACM0 \
  write_flash 0x0 firmware.bin

Build details: sketch space 1310720 B · data 327680 B · DIO

Good to know

board-specific quirks worth 60 seconds

Specifications

ESP32-S3

Compute

MCU

ESP32-S3

Clock

240 MHz

SRAM · Flash

512 KB · 8MB

Radio

Wi-Fi

802.11 b/g/n

Bluetooth

5.0 LE

Antenna

PCB

I/O

GPIO · ADC

36 · 3

UART · I²C · SPI

3 · 2 · 4

PWM

8 channels

Power

USB

Micro-USB

Serial

Native (CDC)

Boot address

0x0

Display

Screen

LCD · 1.3" · 240x240

Driver

ST7789

Touch

Flashing

Upload · OTA

esptool_py · esp_ota

Flash · Boot mode

DIO · QIO

Sketch · Data

1.25 MB · 320 KB

The ESP32-S3-USB-OTG uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with QIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

Inside sits the ESP32-S3 - a dual-core Xtensa with vector extensions suited to AI workloads.

At $35.00 it's on the expensive side for an ESP32-S3 board - most land around $30.

With 36 GPIO broken out, you get more pins to play with than most ESP32-S3 boards offer.

Around the module: an LCD 1.3" 240x240 display, a microSD slot, status LEDs (Green (GPIO15), Yellow (GPIO16), Charge) and Menu/Up/Down/Boot/Reset buttons.

It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S3 boards.

USB-A female HOST port + USB-A male DEV port for USB-OTG host/device demos
ESP32-S3-MINI-1-N8 (8MB flash, no PSRAM)

Where to buy

prices are typical street prices

ESP32-S3-USB-OTG

$35.00per unit, typical

Resources

ESP32-S3 datasheet espressif.com↗ ESP32-S3-USB-OTG User Guide (Espressif) docs.espressif.com↗

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