const int pirSensorPin = 2; // Pin sensor PIR  
const int buzzerPin = 8;    // Pin buzzer  

// Nada (frekuensi dalam Hertz) untuk "Mary Had a Little Lamb"  
#define NOTE_B4  494  
#define NOTE_A4  440  
#define NOTE_G4  392  
#define NOTE_F4  349  
#define NOTE_E4  330  
#define NOTE_D4  294  
#define NOTE_C4  262  

void setup() {  
  pinMode(pirSensorPin, INPUT);  
  pinMode(buzzerPin, OUTPUT);  
  digitalWrite(buzzerPin, LOW); // Matikan buzzer saat booting  
  Serial.begin(9600);  
}  

void loop() {  
  int motionDetected = digitalRead(pirSensorPin);  
  
  if (motionDetected == HIGH) {  
    playMelody(); // Panggil fungsi untuk memainkan nada saat gerakan terdeteksi  
  } else {  
    noTone(buzzerPin); // Pastikan untuk mematikan nada jika tidak ada gerakan  
  }  
  delay(100); // Delay untuk menghindari overloading Serial Monitor  
}  

void playMelody() {  
  // Menggunakan nada "Mary Had a Little Lamb"  
  tone(buzzerPin, NOTE_E4); // E  
  delay(500); // Lama nada  
  noTone(buzzerPin);  
  delay(100); // jeda antar nada  

  tone(buzzerPin, NOTE_D4); // D  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  

  tone(buzzerPin, NOTE_C4); // C  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_D4); // D  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_E4); // E  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_E4); // E  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_E4); // E  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_D4); // D  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  

  tone(buzzerPin, NOTE_C4); // C  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_D4); // D  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
  
  tone(buzzerPin, NOTE_E4); // E  
  delay(500);  
  noTone(buzzerPin);  
  delay(100);  
}