const int buzzerPin = 9;  // Define the buzzer pin

void setup() {
  pinMode(buzzerPin, OUTPUT);  // Set the buzzer pin as an OUTPUT
}

void loop() {
  playTone(buzzerPin, 1000, 500);  // Play a tone at 1000 Hz for 500 ms
  delay(500);  // Pause for 500 ms
  playTone(buzzerPin, 1500, 500);  // Play a tone at 1500 Hz for 500 ms
  delay(500);  // Pause for 500 ms
  playTone(buzzerPin, 2000, 500);  // Play a tone at 2000 Hz for 500 ms
  delay(1000);  // Pause for 1 second
}

void playTone(int pin, int frequency, int duration) {
  tone(pin, frequency);      // Start the tone
  delay(duration);          // Delay for the specified duration
  noTone(pin);              // Stop the tone
}