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GPIO usage instructions

Note

This has changed since v1.0.0. Refer to the migration guide for more info.

GPIO pins can be accessed in a few ways:

  • using the raw GPIO number of the chip
  • using the "function macro" of the pin
  • using Arduino digital pin numbers (D#, deprecated)

This applies both to Arduino code and ESPHome YAML configs.

GPIO numbers - Arduino only

The simplest form of GPIO access is by using raw pin numbers of the CPU (just like on ESP8266/ESP32). For example, to access GPIO6, write digitalRead(6).

Function macros - Arduino & ESPHome

If you go to a board documentation page (like this one - CB2S) you'll see a pinout drawing, containing various labels in small blocks. There's also a table below to make the pinout a bit more clear.

You can use any of these labels to access a particular pin. For example, to access GPIO6, which is also the PWM0 pin on CB2S, one can use:

  • digitalRead(PIN_P6) (Arduino) or pin: P6 (ESPHome)
  • digitalRead(PIN_PWM0) (Arduino) or pin: PWM0 (ESPHome)

Arduino D# numbers (deprecated)

This method of accessing pins is deprecated since v1.0.0, and will (probably) be removed in the future. It's kept for legacy compatibility.

To access the previously mentioned GPIO6, use digitalRead(D2) or digitalRead(PIN_D2) or pin: D2. Note that the D# pin numbers are not consistent between boards (for example, on WB3S, GPIO6 is already D4).