int buzzerPin = 4;

// Definisi nada (frekuensi dalam Hz)
#define NOTE_C4  262
#define NOTE_D4  294
#define NOTE_E4  330
#define NOTE_F4  349
#define NOTE_G4  392
#define NOTE_A4  440
#define NOTE_B4  494
#define NOTE_C5  523
#define NOTE_D5  587
#define NOTE_E5  659
#define NOTE_F5  698
#define NOTE_G5  784

// Melodi Happy Birthday
int melody[] = {
  NOTE_C4, NOTE_C4, NOTE_D4, NOTE_C4, NOTE_F4, NOTE_E4,
  NOTE_C4, NOTE_C4, NOTE_D4, NOTE_C4, NOTE_G4, NOTE_F4,
  NOTE_C4, NOTE_C4, NOTE_C5, NOTE_A4, NOTE_F4, NOTE_E4, NOTE_D4,
  NOTE_B4, NOTE_B4, NOTE_A4, NOTE_F4, NOTE_G4, NOTE_F4
};

// Durasi tiap nada (4 = seperempat nada, 8 = seperdelapan, dll.)
int noteDurations[] = {
  4, 8, 4, 4, 4, 2,
  4, 8, 4, 4, 4, 2,
  4, 8, 4, 4, 4, 4, 2,
  4, 8, 4, 4, 4, 2
};

void setup() {
  // Mainkan melodi
  for (int thisNote = 0; thisNote < 25; thisNote++) {
    int duration = 1000 / noteDurations[thisNote]; // lama nada
    tone(buzzerPin, melody[thisNote], duration);

    // jeda antar nada
    int pause = duration * 1.3;
    delay(pause);

    noTone(buzzerPin);
  }
}

void loop() {
  // Kosong - lagu dimainkan sekali saat start
}