const int PIN_CONTACT = 2;
const int PIN_BUZZER  = 8;
const int PIN_LED     = 7;
const int PIN_ARRET   = 3;

void setup() {
  pinMode(PIN_CONTACT, INPUT_PULLUP);
  pinMode(PIN_BUZZER, OUTPUT);
  pinMode(PIN_LED, OUTPUT);
  pinMode(PIN_ARRET, INPUT_PULLUP);
}

void loop() {
  if (digitalRead(PIN_CONTACT) == HIGH) { // Porte ouverte
    while (digitalRead(PIN_ARRET) == HIGH) {
      digitalWrite(LED, HIGH);
      digitalWrite(BUZZER, HIGH);
      delay(150);
      digitalWrite(LED, LOW);
      digitalWrite(BUZZER, LOW);
      delay(150);
    }
  } else {
    digitalWrite(LED, LOW);
    digitalWrite(BUZZER, LOW);
  }
}