2.7 KiB
2.7 KiB
GPIO Control :id=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 :id=functions
The following functions can provide basic control of GPIOs and are found in quantum/quantum.h.
| Function | Description | Old AVR Examples | Old ChibiOS/ARM Examples |
|---|---|---|---|
setPinInput(pin) |
Set pin as input with high impedance (High-Z) | DDRB &= ~(1<<2) |
palSetLineMode(pin, PAL_MODE_INPUT) |
setPinInputHigh(pin) |
Set pin as input with builtin pull-up resistor | DDRB &= ~(1<<2); PORTB |= (1<<2) |
palSetLineMode(pin, PAL_MODE_INPUT_PULLUP) |
setPinInputLow(pin) |
Set pin as input with builtin pull-down resistor | N/A (Not supported on AVR) | palSetLineMode(pin, PAL_MODE_INPUT_PULLDOWN) |
setPinOutput(pin) |
Set pin as output | DDRB |= (1<<2) |
palSetLineMode(pin, PAL_MODE_OUTPUT_PUSHPULL) |
writePinHigh(pin) |
Set pin level as high, assuming it is an output | PORTB |= (1<<2) |
palSetLine(pin) |
writePinLow(pin) |
Set pin level as low, assuming it is an output | PORTB &= ~(1<<2) |
palClearLine(pin) |
writePin(pin, level) |
Set pin level, assuming it is an output | (level) ? PORTB |= (1<<2) : PORTB &= ~(1<<2) |
(level) ? palSetLine(pin) : palClearLine(pin) |
readPin(pin) |
Returns the level of the pin | _SFR_IO8(pin >> 4) & _BV(pin & 0xF) |
palReadLine(pin) |
togglePin(pin) |
Invert pin level, assuming it is an output | PORTB ^= (1<<2) |
palToggleLine(pin) |
Advanced Settings :id=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.