int buzzerPin = 3;        // the piezo buzzer is on pin D3 of the ThinkerShield

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

void loop() {
  tone(buzzerPin, 600, 30);     // play a 600 Hz tone for 30 ms...
  delay(150);                   // ...then wait 150 ms before repeating
}