//PROGRAM: TIMER INTERRUPT (WAKTU PENJUMLAHAN 400ms, PENGURANGAN 200ms)

volatile int interruptCtr = 0;
int totalInterruptCtr = 0;

hw_timer_t * timer1 = NULL;   //timer untuk penjumlahan tiap 400ms
hw_timer_t * timer2 = NULL;   //timer untuk pengurangan tiap 200ms
portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;

void IRAM_ATTR onTimer1() {
  portENTER_CRITICAL_ISR(&timerMux);
  interruptCtr++;
  portEXIT_CRITICAL_ISR(&timerMux);
}

void IRAM_ATTR onTimer2() {
  portENTER_CRITICAL_ISR(&timerMux);
  interruptCtr--;
  portEXIT_CRITICAL_ISR(&timerMux);
}

void setup() {
  Serial.begin(115200);

  //timer1
  timer1 = timerBegin(0, 80, true);
  timerAttachInterrupt(timer1, &onTimer1, true);
  timerAlarmWrite(timer1, 400000, true);
  timerAlarmEnable(timer1);

  //timer2
  timer2 = timerBegin(1, 80, true);
  timerAttachInterrupt(timer2, &onTimer2, true);
  timerAlarmWrite(timer2, 200000, true);
  timerAlarmEnable(timer2);
}

void loop() {
  if (interruptCtr > 0) {
    totalInterruptCtr++;

    Serial.print("An interrupt has ocourred. Total number: ");
    Serial.println(totalInterruptCtr);

    interruptCtr = 0;
  }
}