// Define GPIO pins for LEDs and buzzer
int LED1 = 12;
int LED2 = 13;
int LED3 = 13;
int LED4 = 15;
void setup() {
  // Set pin modes
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(LED4, OUTPUT);
  
}

void loop() {
  // Turn on LEDs one by one
  digitalWrite(LED1, HIGH);
  delay(500);
  digitalWrite(LED2, HIGH);
  delay(500);
  digitalWrite(LED3, HIGH);
  delay(500);
  digitalWrite(LED4, HIGH);
  delay(500);

  // // Turn on the buzzer
  // digitalWrite(BUZZER, HIGH);
  // delay(1000);
  // digitalWrite(BUZZER, LOW);

  // Turn off LEDs one by one
  digitalWrite(LED1, LOW);
  delay(500);
  digitalWrite(LED2, LOW);
  delay(500);
  digitalWrite(LED3, LOW);
  delay(500);
  digitalWrite(LED4, LOW);
  delay(500);
}