//------------------- piezo tone function ------------
//---  Plays a pitch thru a piezo speaker
//  setup:  Wire a piezo disk from pin 6 to gnd
//----------------------------------------------------
void setup(){
  pinMode(6, OUTPUT);  // Set the digital pin as an output
  }   
          
void loop(){
    tone(6, 440, 200);   // syntax: tone(pin, freq, duration)
    delay(700);          // silence for 500 millisec.
}