qmk-firmware/docs/internals_gpio_control.md

1.6 KiB

GPIO Control

QMK has a GPIO control abstraction layer which is microcontroller agnostic. This is done to allow easy access to pin control across different platforms.

Functions

The following functions can provide basic control of GPIOs and are found in quantum/quantum.h.

Function Description
setPinInput(pin) Set pin as input with high impedance (High-Z)
setPinInputHigh(pin) Set pin as input with build in pull-up
setPinInputLow(pin) Set pin as input with build in pull-down (Supported only on STM32)
setPinOutput(pin) Set pin as output
writePinHigh(pin) Set pin level as high, assuming it is an output
writePinLow(pin) Set pin level as low, assuming it is an output
writePin(pin, level) Set pin level, assuming it is an output
readPin(pin) Returns the level of the pin

Advanced Settings

Each microcontroller can have multiple advanced settings regarding its GPIO. This abstraction layer does not limit the use of architecture-specific functions. Advanced users should consult the datasheet of their desired device and include any needed libraries. For AVR, the standard avr/io.h library is used; for STM32, the ChibiOS PAL library is used.