SAMDTimer BuzzerTimer(TIMER_TC5);

bool attached = false;

void initBuzzer() {
  pinMode(BUZZER_PIN, OUTPUT);
}

void buzzerISR() {
  digitalWrite(BUZZER_PIN, !digitalRead(BUZZER_PIN));
}

void buzz() {
  if (attached)
    BuzzerTimer.enableTimer();
  else
    BuzzerTimer.attachInterrupt(BUZZER_FREQ *2, buzzerISR);
}

void noBuzz() {
  BuzzerTimer.disableTimer();
}