//------------------- piezo_random_freq ---------------------
//---  Plays a pitch thru a piezo speaker
//- Set up:  > Attach a piezo speaker between ground and Digital 6 (pin 12)
//  
int piezoPin = 6;      // variable for which pin is attached to piezo
int rand_freq;         // variable for storing random frequency
int short_note = 200;
int long_note = 500;

   
void setup(){
  pinMode(piezoPin, OUTPUT);       // Set the digital LED pin as an output
  srand((int)15);                  //Set "seed" for random number generator
  }   
          
void loop(){
  for(int i = 0; i < 3; i++){               // 3 short tones
    rand_freq = random(60, 900);            // Random pitch between 60 and 900
    tone(piezoPin, rand_freq, short_note);  // syntax: tone(pin, freq, duration)
    delay(100);
  }
    for(int i = 0; i < 3; i++){           // 3 long tones
    rand_freq = random(300, 1200);        // Random pitch between 300 and 1200
    tone(piezoPin, rand_freq, long_note); 
    delay(300);
  }
}