int buzzer = 2;// pin buzzer

void setup() {
  // put your setup code here, to run once:
pinMode(buzzer,OUTPUT);//setup pin buzzer output
}

void loop() {
  // put your main code here, to run repeatedly:
tone(buzzer,200);//CHANGING FREQUENCY
delay(2000);
tone(buzzer,250);//50HZ CHANGED
delay(2000);
}