Microbit-gpio-example.cpp

#include "MicroBit.h"
MicroBit uBit;

bool started = false;
bool isSender = false;

int whatToSend = 0;

void onButtonA(MicroBitEvent event) {
  if (started){
    if (!isSender) return;
    whatToSend = !whatToSend;
    uBit.io.P0.setDigitalValue(whatToSend);
    return;
  }
  isSender = true;
  started = true;
}

void onButtonB(MicroBitEvent event) {
  isSender = false;
  started = true;
}

int main() {

  // Initialise the micro:bit runtime.
  uBit.init();


    // Sleep if we haven't started.
  while (!started){
      uBit.sleep(100);
  }

  uBit.messageBus.listen(MICROBIT_ID_BUTTON_A, MICROBIT_BUTTON_EVT_CLICK, onButtonA);
  uBit.messageBus.listen(MICROBIT_ID_BUTTON_B, MICROBIT_BUTTON_EVT_CLICK, onButtonB);

  while (1) {
    if (!isSender) {
      if (uBit.io.P0.getDigitalValue()){
        uBit.display.print("1");
      } else {
        uBit.display.print("0");
      }
      uBit.sleep(20);
    }
  }
  release_fiber();
}