int val = 0;
int val1 = 0;
int val2 = 0;
//int val3 = 0;
int led = 13;
int piezo1 = 10;
int piezo2 = 11;
//int piezo3 = 6;
int pulso = 0;


void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
  // make the pushbutton's pin an input:
  pinMode(led, OUTPUT);
  pinMode(piezo1, OUTPUT);
  pinMode(piezo2, OUTPUT);
 // pinMode(piezo3, OUTPUT);
}

void loop() {
  val = Serial.available();
  if (val > 0) {
    //// read x value of abs
    val1 = Serial.read();
    if ((val1 == 'G') || (val1 == 'A') || (val1 == 'B') || (val1 == 'C')) {
      if (val1 == 'G') {
        pulso = 2551; //pulso == amount of time (microseconds) in half a Period of the waveform. 
      }
      if (val1 == 'A') {
        pulso = 2272;
      }
      if (val1 == 'B') {
        pulso = 2024;
      }
      if (val1 == 'C') {
        pulso = 1915;
      } 
     digitalWrite(piezo1, HIGH);
  delayMicroseconds(pulso);
  digitalWrite(piezo1, LOW);
  delayMicroseconds(pulso);
    }  
   else if ((val1 == 'D') || (val1 == 'E') || (val1 == 'F') || (val1 == 'G')) {
      if (val2 == 'D') {
      pulso = 1700; //pulso == amount of time (microseconds) in half a Period of the waveform. 
    }
    if (val2 == 'E') {
      pulso = 1519;
    }
    if (val2 == 'F') {
      pulso = 1351;
    }
    if (val2 == 'G') {
      pulso = 1275;
    } 
     digitalWrite(piezo2, HIGH);
  delayMicroseconds(pulso);
  digitalWrite(piezo2, LOW);
  delayMicroseconds(pulso);
}
}
}