inoProjects/Theremin/Theremin.ino

/*
 *@author James McKenzie
 *@lang C89 Based
 *@contact lunarised@outlook.com
 */
 int mode;
void setup() {
    pinMode(0, INPUT_PULLUP);
    pinMode (13, OUTPUT);
  pinMode(8, OUTPUT);
    Serial.begin (9600);        //set up a serial connection with the computer

  pinMode(11, OUTPUT);   //the trigger pin 
  pinMode(12, INPUT);    //echo pin
  if (digitalRead(0) ==HIGH){
    mode = 0;
    mode = 1;
  }
}

void loop() {
  if (mode == 0){
    digitalWrite(13, HIGH);
    tone(8, getNote()); 
  }
}
float getNote()
{
  float echoTime;
  float calculatedDistance;
  digitalWrite(11, HIGH);
  delayMicroseconds(20); 
  digitalWrite(11, LOW);

  echoTime = pulseIn(12, HIGH);                                       
  calculatedDistance = echoTime / 8; 
  calculatedDistance += 110;
  if (calculatedDistance > 1760){ //

    calculatedDistance = 1760;
  }
   Serial.print(calculatedDistance);      //print units after the distance
    Serial.println(" hz");      //print units after the distance
  return calculatedDistance;
}