Adafruit Feather ESP32-S2
ESP32-S2 Feather board with USB-C and STEMMA QT - ideal for secure, battery-powered IoT projects.
Adafruit Feather ESP32-S2 Pinout
25 pins · 2.54 mm pitch
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 1 | NEOPIXEL_NUMPWM | safe | - | |
| 2 | 3 | SDAPWM | safe | i2c | |
| 3 | 4 | SCLPWM | safe | i2c | |
| 4 | 5 | T5PWM | safe | touch | |
| 5 | 6 | T6PWM | safe | touch | |
| 6 | 7 | I2C_POWERPIN_I2C_POWERPWM | safe | - | |
| 7 | 8 | A5T8PWM | safe | adc · touch | |
| 8 | 9 | T9PWM | strapping | touch | |
| 9 | 10 | T10PWM | strapping | touch | |
| 10 | 11 | T11PWM | strapping | touch | |
| 11 | 12 | T12PWM | strapping | touch | |
| 12 | 13 | LED_BUILTINT13PWM | strapping | touch | |
| 13 | 14 | A4T14PWM | strapping | adc · touch | |
| 14 | 15 | A3PWM | strapping | adc | |
| 15 | 16 | A2PWM | strapping | adc | |
| 16 | 17 | A1DAC1PWM | safe | adc · dac | |
| 17 | 18 | A0DAC2PWM | safe | adc · dac | |
| 18 | 21 | NEOPIXEL_POWERPWM | safe | - | |
| 19 | 33 | PIN_NEOPIXELPWM | strapping | - | |
| 20 | 35 | MOSIPWM | strapping | spi | |
| 21 | 36 | SCKPWM | strapping | spi | |
| 22 | 37 | MISOPWM | strapping | spi | |
| 23 | 38 | RXPWM | uart | uart | |
| 24 | 39 | TXPWM | strapping | uart | |
| 25 | 42 | SSPWM | strapping | spi |
Start with these
11 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
10 pins · 5 things to knowT9GPIO9T10GPIO10T11GPIO11T12GPIO12LED_BUILTINGPIO13A4GPIO14 General-purpose SPI2 (FSPI) IO MUX pins Other
IO MUX pin of the general-purpose SPI2 (FSPI) bus, not of the in-package flash - that sits on GPIO26-32. The datasheet does not restrict it, so it is only taken if your board wires flash, an SD card or a display to FSPI.
- T9General-purpose SPI2 (FSPI) IO MUX pin - hold/data line (FSPIHD)
- T10General-purpose SPI2 (FSPI) IO MUX pin - chip select (FSPICS0)
- T11General-purpose SPI2 (FSPI) IO MUX pin - data in (FSPID)
- T12General-purpose SPI2 (FSPI) IO MUX pin - clock (FSPICLK)
- LED_BUILTINGeneral-purpose SPI2 (FSPI) IO MUX pin - data out (FSPIQ)
- A4General-purpose SPI2 (FSPI) IO MUX pin - write-protect/data line (FSPIWP)
A3GPIO15 32.768 kHz RTC crystal oscillator positive input (XTAL_32K_P); also functions as GPIO15 (U0RTS, ADC2_CH4). Other
If an external 32 kHz crystal is used for RTC, this pin is dedicated to the crystal and cannot be used as GPIO.
A2GPIO16 32.768 kHz RTC crystal negative input (XTAL_32K_N); also GPIO16 (U0CTS, ADC2_CH5). Other
If using an external 32 kHz crystal, this pin is connected to the crystal and should not be used as general I/O.
TXGPIO39 JTAG test clock pin (MTCK); also usable as GPIO39 or as a clock output (CLK_OUT3). JTAG
Used for JTAG debugging interface; using this pin for other purposes will disable JTAG clock input.
SSGPIO42 JTAG test mode select pin (MTMS); also GPIO42. JTAG
JTAG TMS pin; should not be repurposed if JTAG debugging or programming via JTAG is required.
Only if you know the tricks
4 pins · 1 thing to knowPIN_NEOPIXELGPIO33MOSIGPIO35SCKGPIO36MISOGPIO37 Octal (8-line) flash/PSRAM data and strobe lines; free unless the chip runs its flash/PSRAM in 8-line mode Flash
The datasheet keeps GPIO33-37 for "the higher 4 bits data line interface and DQS interface for the SPI0/1 interface in 8-line SPI mode, and can be GPIO pins if the chip is not connected to flash or PSRAM in 8-line SPI mode". Quad-SPI parts leave it free.
- PIN_NEOPIXELOctal (8-line) flash/PSRAM data line DQ4; free unless the chip runs its flash/PSRAM in 8-line mode
- MOSIOctal (8-line) flash/PSRAM data line DQ6; free unless the chip runs its flash/PSRAM in 8-line mode
- SCKOctal (8-line) flash/PSRAM data line DQ7; free unless the chip runs its flash/PSRAM in 8-line mode
- MISOOctal (8-line) flash/PSRAM data strobe DQS/DM; free unless the chip runs its flash/PSRAM in 8-line mode
All 25 pins on the Adafruit Feather ESP32-S2 are usable GPIO, spaced at the standard 2.54 mm pitch.
Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO3 and SCL on GPIO4; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO39 and GPIO38 cover serial logging and flashing.
Beyond plain digital I/O you get 6 ADC-capable pins for sensors and battery monitoring, 9 capacitive-touch inputs and 2 true DAC outputs.
10 of the exposed pins carry boot-time or system duties on the ESP32-S2 (T9, T10, T11 and 7 more) - check the guidance above before wiring anything to them. NEOPIXEL_NUM, SDA, SCL, T5 and 7 more are free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32S2 Dev Module USB CDC On Boot: Enabled Flash Size: 4MB (32Mb) Flash Mode: DIO PSRAM: QSPI PSRAM Partition Scheme: Default 4MB with spiffs (1.2MB APP/1.5MB SPIFFS) Upload Speed: 921600
// toggle GPIO1 - wire an LED and resistor to it
void setup() {
pinMode(1, OUTPUT);
}
void loop() {
digitalWrite(1, HIGH); delay(500);
digitalWrite(1, LOW); delay(500);
}[env:adafruit_feather_esp32s2]
platform = espressif32
board = esp32-s2-saola-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_qspi
build_flags = -DBOARD_HAS_PSRAMesp32-s2-saola-1 - or type it after board =.esp32:
board: esp32-s2-saola-1
variant: esp32s2
framework:
type: esp-idf
psram:
mode: quad
speed: 80MHz
# 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 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32-S2 · 52.4 × 22.8 mm · vs other ESP32 chips →Dimensions
About this board
Inside sits the ESP32-S2 - a single-core Xtensa with native USB-OTG and no Bluetooth.
The $17.50 price tag is typical for an ESP32-S2 board.
Around the module: 2MB (QSPI) PSRAM, a STEMMA QT connector, an addressable RGB LED (GPIO33), a battery fuel gauge (MAX17048), battery charging (MCP73831) via JST-PH 2.0, status LEDs (On, Charge, User (D13)) and Reset/DFU (BOOT0) buttons.
It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S2 boards.
- Also sold in a u.FL external-antenna variant
- Early units shipped with an LC709203F fuel gauge instead of the MAX17048
Where to buy
prices are typical street pricesResources
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