const int buzzer = 9; //buzzer to arduino pin 9
void setup()
{
pinMode(buzzer, OUTPUT); // Set buzzer - pin 9 as an output
}
void loop()
{
 tone(buzzer, 1000); // Send 1KHz sound signal
 delay(2000); // ...for 1 sec
 noTone(buzzer); // Stop sound
 delay(3000); // ...for 1sec
}