Buzzer module passief Arduino

// Passive buzzer module example for Arduino Uno
// Plays a simple melody using the module's PWM input.

const int buzzerPin = 9; // Connected to x1:PWM

void setup() {
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Passive buzzer module demo starting...");
}

void playTone(int frequency, int durationMs) {
  if (frequency > 0) {
    tone(buzzerPin, frequency, durationMs);
  }
  delay(durationMs * 1.30);
  noTone(buzzerPin);
}

void loop() {
  Serial.println("Playing C major scale...");

  int melody[] = {262, 294, 330, 349, 392, 440, 494, 523};
  int noteDuration = 180;

  for (int i = 0; i < 8; i++) {
    Serial.print("Note frequency: ");
    Serial.println(melody[i]);
    playTone(melody[i], noteDuration);
  }

  Serial.println("Pausing...");
  delay(1000);
}