Adding a toggle function to wiring_digital.c

[Perehama]

I suggest the code below be added to wiring_digital.c and the Arduino language. This would make the task easier for beginning programmers and eliminate the need to check the state of the pin first, making a speed improvement at the same time.

void digitalToggle(uint8_t pin) {
  uint8_t timer = digitalPinToTimer(pin);
  uint8_t bit = digitalPinToBitMask(pin);
  uint8_t port = digitalPinToPort(pin);
  volatile uint8_t *out;
  if (port == NOT_A_PIN) return;
  if (timer != NOT_ON_TIMER) turnOffPWM(timer);
  out = portOutputRegister(port);
  uint8_t oldSREG = SREG;
  cli();
  *out ^= bit;
  SREG = oldSREG;
}

[matthijskooijman]

Thanks for you suggestion. I edited your post to use triple backticks to create a more readable code block.

Also, change to the Arduino API like this should be coordinated between cores, this coordination of happens in the ArduinoCore-API repository. There is already an issue about this, see arduino/ArduinoCore-API#130, so I'm going to close this issue and direct you to that one (feel free to add more info and new arguments to it, but if you just want to voice support for it, please use a thumbsup rather than a "me too" comment).

Also, note that on AVR, toggling can be implemented even faster by writing to the input register, which makes the hardware toggle pins.