Passive Buzzer Module

// Passive Buzzer Module example for Arduino Uno
// Plays a short melody using a PWM/square wave output on D9.

const int BUZZER_PIN = 9;

// Note frequencies in Hz
const int NOTE_C4 = 262;
const int NOTE_D4 = 294;
const int NOTE_E4 = 330;
const int NOTE_G4 = 392;
const int NOTE_C5 = 523;

void playTone(int frequency, int duration) {
  tone(BUZZER_PIN, frequency);
  delay(duration);
  noTone(BUZZER_PIN);
  delay(50);
}

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
  Serial.begin(9600);
  Serial.println("Passive Buzzer Module demo starting...");
}

void loop() {
  Serial.println("Playing melody...");

  playTone(NOTE_C4, 300);
  playTone(NOTE_D4, 300);
  playTone(NOTE_E4, 300);
  playTone(NOTE_G4, 300);
  playTone(NOTE_C5, 600);

  delay(1000);
}