#define SPEAKER_PIN   (8)

void setup()
{ 
  pinMode(SPEAKER_PIN, OUTPUT);
  
  // delay(1000); // needed for simulation only because the first call to tone takes time to start
  
  for (uint8_t i = 0; i < 3; i++) {
    tone(SPEAKER_PIN, 440);
    delay(500);
    noTone(SPEAKER_PIN);
    delay(500);
  }
}

void loop()
{

}