hw_timer_t *timer1 = NULL;
hw_timer_t *timer2 = NULL;
hw_timer_t *timer4 = NULL;

 
void ARDUINO_ISR_ATTR LED1(){
  static bool ledstate =false;
  digitalWrite(2, ledstate);
  ledstate=!ledstate;
}

void ARDUINO_ISR_ATTR LED2(){
  static bool ledstate =false;
  digitalWrite(16, ledstate);
  ledstate=!ledstate;
}

void ARDUINO_ISR_ATTR LED4(){
  static bool ledstate =false;
  digitalWrite(18, ledstate);
  ledstate=!ledstate;
}



void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  
  pinMode(2,OUTPUT);
  pinMode(16,OUTPUT);
  pinMode(17,OUTPUT);
  pinMode(18,OUTPUT);
  pinMode(19,OUTPUT);


  timer1 = timerBegin(1000000);
  timerAttachInterrupt(timer1, &LED1);
  timerAlarm(timer1, 1000000, true, 0);
  

  timer2 = timerBegin(1000000);
  timerAttachInterrupt(timer2, &LED2);
  timerAlarm(timer2, 100000, true, 0);

  timer4 = timerBegin(1000000);
  timerAttachInterrupt(timer4, &LED4);
  timerAlarm(timer4, 150000, true, 0);

}

unsigned long LED3Millis = millis();
uint8_t LED3 = LOW;
unsigned long LED5Millis = millis();
uint8_t LED5 = LOW;

void loop() {
  unsigned long now = millis();

  if (now > LED3Millis + 500) {
    LED3Millis = now;
    LED3 = LED3 ? LOW : HIGH;
    digitalWrite(17, LED3);
  }

  if (now > LED5Millis + 3000) {
    LED5Millis = now;
    LED5 = LED5 ? LOW : HIGH;
    digitalWrite(19, LED5);
  }
}