int pin_button = 5, pin_led1 = 4, pin_led2 = 21, pin_led3 = 15;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(pin_button, INPUT_PULLUP);
  pinMode(pin_led1, OUTPUT);
  pinMode(pin_led2, OUTPUT);
  Serial.println("start test dubbelklik");
}

void loop() {
  static unsigned long last_pressed = 0;
  static int times_pressed = 0;

  static bool status_button_eerder = 1;
  bool status;


  status = digitalRead(pin_button);
  if (status != status_button_eerder) {
    status_button_eerder  = status;
    if (status == 0) {
      times_pressed++;
      last_pressed = millis();
    }
    delay(5);
  }

  if (times_pressed != 0) {
    if (millis() - last_pressed > 400) {
      Serial.println("you pressed " + String(times_pressed) + " times");

      // use to switch led on or off
      switch (times_pressed) {
        case 1 :
          digitalWrite(pin_led1, 1);
          break;
        case 2 :
          digitalWrite(pin_led1, 0);
          break;
        case 3 :
          digitalWrite(pin_led2, 1);
          break;
        case 4 :
          digitalWrite(pin_led2, 0);
          break;
      }

      // if (times_pressed == 1) {
      //   digitalWrite(pin_led1, 1);
      // } else if (times_pressed == 2) {
      //   digitalWrite(pin_led1, 0);
      // } else if (times_pressed == 3){
      //   digitalWrite(pin_led2, 1);
      //  } else if (times_pressed == 4) {
      //   digitalWrite(pin_led2, 0);
      //   }

      times_pressed = 0;
    }
  }
}