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ESP32-C3 (DevKitM-1, SuperMini) pinout

ESP32-C3 (DevKitM-1, SuperMini) pin table: which GPIOs are free for sensors and relays, which affect booting (strapping), are taken by flash, USB or are input only, and where the ADC and I²C are. With an ESPHome example.

8 safe 5 with care 9 avoid

GPIOBoard labelUse?FunctionsNotes
GPIO0safeADC1_0, XTAL_32K_PFree; ADC1.
GPIO1safeADC1_1, XTAL_32K_NFree; ADC1.
GPIO2with careADC1_2Strapping pin: keep it HIGH or floating at boot.
GPIO3safeADC1_3Free; ADC1.
GPIO4safeADC1_4Free; ADC1.
GPIO5safeADC2_0Free; ADC2 is unreliable with Wi-Fi on.
GPIO6safe—Free.
GPIO7safe—Free.
GPIO8with care—Strapping pin (must be HIGH to flash over UART). Built-in LED on SuperMini, RGB LED on DevKitM.
GPIO9with care—Strapping pin: the BOOT button, LOW at boot = flash mode. OK as a button input.
GPIO10safe—Free.
GPIO11avoidVDD_SPIFlash power on most modules.
GPIO12avoidSPI flashConnected to the flash.
GPIO13avoidSPI flashConnected to the flash.
GPIO14avoidSPI flashConnected to the flash.
GPIO15avoidSPI flashConnected to the flash.
GPIO16avoidSPI flashConnected to the flash.
GPIO17avoidSPI flashConnected to the flash.
GPIO18USB D−avoidUSBBuilt-in USB (flashing and logs).
GPIO19USB D+avoidUSBBuilt-in USB (flashing and logs).
GPIO20RXwith careUART0 RXUART0; free if you log over USB.
GPIO21TXwith careUART0 TXUART0; free if you log over USB.

Boards route pins differently: check your board’s schematic. Strapping pins are read at power-on; if a sensor or button pulls one the wrong way, the board will not boot or will enter flash mode.

ESPHome example

esp32:
  board: esp32-c3-devkitm-1

i2c:
  sda: GPIO6
  scl: GPIO7

binary_sensor:
  - platform: gpio
    pin:
      number: GPIO3
      mode: INPUT_PULLUP
      inverted: true
    name: "Button"

A full config with sensors, keys and a pin clash check: ESPHome generator. Other boards: ESP32, ESP32-S3, ESP8266.

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