ESP32S2 Native USB
by Generic
ESP32-S2 board featuring native USB OTG support - perfect for USB device emulation and HID applications.

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Pinout
27 pins| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 1 | A0T1PWM | safe | adc · touch | |
| 2 | 2 | A1T2PWM | safe | adc · touch | |
| 3 | 3 | A2T3PWM | safe | adc · touch | |
| 4 | 4 | A3T4PWM | safe | adc · touch | |
| 5 | 5 | A4T5PWM | safe | adc · touch | |
| 6 | 6 | A5T6PWM | safe | adc · touch | |
| 7 | 7 | A6T7PWM | safe | adc · touch | |
| 8 | 8 | SDAA7T8PWM | safe | adc · touch · i2c | |
| 9 | 9 | SCLA8T9PWM | strapping | adc · touch · i2c | |
| 10 | 10 | A9T10PWM | strapping | adc · touch | |
| 11 | 11 | A10T11PWM | strapping | adc · touch | |
| 12 | 12 | A11T12PWM | strapping | adc · touch | |
| 13 | 13 | A12T13PWM | strapping | adc · touch | |
| 14 | 14 | A13T14PWM | strapping | adc · touch | |
| 15 | 15 | A14PWM | strapping | adc | |
| 16 | 16 | A15PWM | strapping | adc | |
| 17 | 17 | A16DAC1PWM | safe | adc · dac | |
| 18 | 18 | A17DAC2PWM | safe | adc · dac | |
| 19 | 19 | A18PWM | uart | adc | |
| 20 | 20 | A19PWM | uart | adc | |
| 21 | 34 | SSPWM | strapping | spi | |
| 22 | 35 | MOSIPWM | strapping | spi | |
| 23 | 36 | SCKPWM | strapping | spi | |
| 24 | 37 | MISOPWM | strapping | spi | |
| 25 | 43 | TXPWM | uart | uart | |
| 26 | 44 | RXPWM | uart | uart | |
| 27 | - | USB_FW_MSC_SERIAL_NUMBER | safe | - |
Start with these
12 pins with no boot or system involvementFreely 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 |
|---|---|---|---|
| A14 | XTAL_32K_P | If an external 32 kHz crystal is used for RTC, this pin is dedicated to the crystal and cannot be used as GPIO. | Other |
| A15 | XTAL_32K_N | If using an external 32 kHz crystal, this pin is connected to the crystal and should not be used as general I/O. | Other |
Only if you know the tricks
wired to flash or USB - expect a fight| Pin | Label | What to know | Role |
|---|---|---|---|
| SCL | FSPIHD | Typically used as flash/PSRAM IO line in certain configurations; avoid using as GPIO if flash or PSRAM is present. | Flash |
| A9 | FSPICS0 | Often used as flash chip select in some designs; not available for GPIO when controlling flash. | Flash |
| A10 | FSPID | Used for flash data transfer in certain configurations; should be avoided for general use if flash is connected. | Flash |
| A11 | FSPICLK | Used as flash clock line in some boards; not free for GPIO if driving flash. | Flash |
| A12 | FSPIQ | Used for flash data output in certain configurations; avoid using as GPIO if connected to flash. | Flash |
| A13 | FSPIWP | Used as flash write-protect/data line on some modules; not recommended for other usage. | Flash |
| A18 | USB_D- | Used for USB communication; using this pin as general GPIO can interfere with USB functionality. | USB |
| A19 | USB_D+ | Dedicated to USB interface; repurposing as GPIO may disrupt USB connectivity. | USB |
| SS | SPIWP | Connected to SPI flash (write-protect/data line); not recommended for other use. | Flash |
| MOSI | FSPID | Used by internal flash/PSRAM on some ESP32-S2 variants; avoid using as GPIO to prevent conflicts. | Flash |
| SCK | FSPICLK | May be connected to internal flash or used for high-speed SPI; not intended for general GPIO use. | Flash |
| MISO | FSPIQ | Used for internal flash/PSRAM data in some models; should not be repurposed for GPIO. | Flash |
Pinout notes The ESP32S2 Native USB breaks out 27 pins in total: 26 GPIO for your project. For peripherals, I²C is mapped to SDA on GPIO8 and SCL on GPIO9; the SPI bus (…
The ESP32S2 Native USB breaks out 27 pins in total: 26 GPIO for your project.
For peripherals, I²C is mapped to SDA on GPIO8 and SCL on GPIO9; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.
On the analog side there are 20 ADC-capable pins for sensors and battery monitoring, 14 capacitive-touch inputs and 2 true DAC outputs.
If you want zero surprises, A0, A1, A2, A3 and 8 more are free of any such role - the safest first picks. 2 of the exposed pins carry boot-time or system duties on the ESP32-S2 (A14 and A15).
Getting started
flash your first firmware in ~2 minutesBoard: ESP32S2 Dev Module USB CDC On Boot: Enabled Flash Size: 4MB (32Mb) Flash Mode: DIO Partition Scheme: Default 4MB with spiffs (1.2MB APP / 1.5MB SPIFFS) Upload Speed: 921600
// blink the onboard LED
void setup() {
pinMode(1, OUTPUT);
}
void loop() {
digitalWrite(1, HIGH); delay(500);
digitalWrite(1, LOW); delay(500);
}[env:esp32s2usb]
platform = espressif32
board = esp32-s2-saola-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32-s2-saola-1 — or type it after board =.esp32:
board: esp32-s2-saola-1
variant: esp32s2usb
framework:
type: esp-idf
# blink - GPIO1
output:
- platform: gpio
pin: 1
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32-s2-saola-1 (same ids as PlatformIO).esptool.py --chip esp32s2 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x0 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32-S2About this board
At its core is the ESP32-S2 - a single-core Xtensa with native USB-OTG and no Bluetooth.
Onboard you'll find Reset/Boot buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S2 boards.
Resources
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