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Adafruit Feather ESP32 V2
Updated Feather ESP32 with improved power handling and USB-C - great for portable IoT and CircuitPython use.
52.3 × 22.8 mm
ESP32
MCU
240MHz
clock
8MB
flash
520KB
SRAM
24· 14 ADC
GPIO
BLE 4.2+ WiFi
radio
Pinout
24 pins · 2.54 mm pitch
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | PIN_NEOPIXELT1 | strapping | touch | |
| 2 | 2 | NEOPIXEL_I2C_POWERT2PWM | strapping | touch | |
| 3 | 4 | A5T0PWM | strapping | adc · touch | |
| 4 | 5 | SCKPWM | strapping | spi | |
| 5 | 7 | RXPWM | strapping | uart | |
| 6 | 8 | TXPWM | strapping | uart | |
| 7 | 12 | A11T5PWM | strapping | adc · touch | |
| 8 | 13 | LED_BUILTINA12T4PWM | strapping | adc · touch | |
| 9 | 14 | A6T6PWM | strapping | adc · touch | |
| 10 | 15 | A8T3PWM | strapping | adc · touch | |
| 11 | 19 | MOSIPWM | safe | spi | |
| 12 | 20 | SCLPWM | safe | i2c | |
| 13 | 21 | MISOPWM | safe | spi | |
| 14 | 22 | SDAPWM | safe | i2c | |
| 15 | 25 | A1DAC1PWM | safe | adc · dac | |
| 16 | 26 | A0DAC2PWM | safe | adc · dac | |
| 17 | 27 | A10T7PWM | safe | adc · touch | |
| 18 | 32 | A7T9PWM | safe | adc · touch | |
| 19 | 33 | SSA9T8PWM | safe | adc · touch · spi | |
| 20 | 34 | A2 | strapping | adc | |
| 21 | 35 | A13BATT_MONITOR | strapping | adc | |
| 22 | 36 | A4 | strapping | adc | |
| 23 | 38 | BUTTON | strapping | - | |
| 24 | 39 | A3 | strapping | adc |
Start with these
9 pins with no boot or system involvementMOSIPWMSCLPWMMISOPWMSDAPWMA1DAC1A0DAC2A10T7A7T9SSA9
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 |
|---|---|---|---|
| PIN_NEOPIXEL | GPIO0 | Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode. | Strapping |
| NEOPIXEL_I2C_POWER | GPIO2 | If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure. | Strapping |
| A5 | GPIO4 | Sampled at reset for boot config; should not be driven at boot (affects boot mode timing). | Strapping |
| SCK | GPIO5 | Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot. | Strapping |
| A11 | MTDI (GPIO12) | Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used. | Strapping |
| LED_BUILTIN | MTCK (GPIO13) | Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed. | Other |
| A6 | MTMS (GPIO14) | Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot. | Other |
| A8 | MTDO (GPIO15) | Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change. | Strapping |
| A2 | GPIO34 | Cannot be used as output (no drive capability); only suitable for analog/digital input. | Other |
| A13 | GPIO35 | Cannot be used as output; only suitable for input. | Other |
| A4 | GPIO36 (SENSOR_VP) | Cannot be used as output; only suitable for input (e.g., analog read). | Other |
| BUTTON | GPIO38 (SENSOR_CAPN) | Cannot be used as output; only suitable for input. | Other |
| A3 | GPIO39 (SENSOR_VN) | Cannot be used as output; only suitable for input. | Other |
Only if you know the tricks
wired to flash or USB - expect a fight| Pin | Label | What to know | Role |
|---|---|---|---|
| RX | GPIO7 (Flash SD0) | Used for internal flash/PSRAM data; not available for general GPIO. | Flash |
| TX | GPIO8 (Flash SD1) | Used for internal flash/PSRAM data; not available for general GPIO. | 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 All 24 pins on the Adafruit Feather ESP32 V2 are usable GPIO, spaced at the standard 2.54 mm pitch. Peripheral wiring is straightforward: I²C is mapped to SDA…
All 24 pins on the Adafruit Feather ESP32 V2 are usable GPIO, spaced at the standard 2.54 mm pitch.
Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO22 and SCL on GPIO20; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO8 and GPIO7 cover serial logging and flashing.
Beyond plain digital I/O you get 14 ADC-capable pins for sensors and battery monitoring, 10 capacitive-touch inputs and 2 true DAC outputs.
13 of the exposed pins carry boot-time or system duties on the ESP32 (PIN_NEOPIXEL, NEOPIXEL_I2C_POWER, A5 and 10 more) - check the guidance above before wiring anything to them. MOSI, SCL, MISO, SDA and 5 more are free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutes1
Connect over USB
Serial chip: CH9102F. Not detected? Hold BOOT while plugging in.
2
Flash with your tool
Arduino IDE, PlatformIO, ESPHome or esptool - copy the settings on the right.
3
Verify it runs
The blink example uses GPIO19 - swap for your board's LED pin if different.
Board: Adafruit Feather Esp32 V2
Flash Size: 8MB · DIO
Upload Speed: 921600
// blink
pinMode(19, OUTPUT);
digitalWrite(19, LOW); // on (often inverted)[env:adafruit_feather_esp32_v2]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32:
board: esp32dev
variant: adafruit_feather_esp32_v2
framework:
type: esp-idf
# blink - GPIO19
output:
- platform: gpio
pin: 19
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesptool.py --chip esp32 --port /dev/ttyACM0 \
write_flash 0x0 firmware.binBuild details: sketch space 1310720 B · data 327680 B · DIO
Specifications
ESP32 · 52.3 × 22.8 mmCompute
MCU
ESP32
Clock
240 MHz
SRAM · Flash
520 KB · 8MB · 2MB (QSPI) PSRAM
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
4.2 LE
Antenna
PCB
I/O
GPIO · ADC
24 · 14
UART · I²C · SPI
3 · 2 · 4
PWM
16 channels
Power
USB
USB-C
Serial
CH9102F
Boot address
0x1000
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
1.25 MB · 320 KB
52.3 × 22.8 mm · pin pitch 2.54 mm
The Adafruit Feather ESP32 V2 uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with DIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.
About this board
Inside sits the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
The $19.95 price tag is typical for an ESP32 board.
Around the module: 2MB (QSPI) PSRAM, a STEMMA QT connector, battery charging via JST-PH 2.0, status LEDs (Charge, User (D13)) and Reset/User (D38) buttons.
- Battery voltage read via a resistor divider on GPIO35 (no dedicated fuel-gauge IC)
- Boards made before 19 May 2022 shipped with a CP2102N USB-serial chip instead of the CH9102F
- A separate variant (#5438) adds a u.FL connector for an external antenna
Where to buy
prices are typical street pricesAdafruit Feather ESP32 V2
$19.95per unit, typical
Resources
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