const int led1 = 6;
const int led2 = 7;
const int led3 = 8;
const int buzzerPin = 5;

String command = "";

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

  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  digitalWrite(buzzerPin, LOW);
}

void loop() {
  if (Serial.available() > 0) {
    command = Serial.readStringUntil('\n');
    command.trim();

    Serial.print("Received: ");
    Serial.println(command);

    if (command == "REGISTER") {
      Serial.println("REGISTER received");

      digitalWrite(led1, HIGH);
      digitalWrite(led2, HIGH);
      digitalWrite(led3, HIGH);
      digitalWrite(buzzerPin, HIGH);

      delay(3000);

      digitalWrite(led1, LOW);
      digitalWrite(led2, LOW);
      digitalWrite(led3, LOW);
      digitalWrite(buzzerPin, LOW);
    }
  }
}