inoProjects/Theremin/Theremin.ino

/*
 *@author James McKenzie
 *@lang C89 Based
 *@contact lunarised@outlook.com
 */
 int mode;
void setup() {
    pinMode(6, INPUT_PULLUP);
    pinMode (13, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode (7, INPUT_PULLUP);

    pinMode(5, INPUT_PULLUP);
    Serial.begin (9600);        //set up a serial connection with the computer

  pinMode(11, OUTPUT);   //the trigger pin 
  pinMode(12, INPUT);    //echo pin

}

void loop() {
    if (digitalRead(6) ==HIGH){
    mode = 0;
    }else{
    mode = 1;
  }
  float note = 0;
  if (digitalRead(7) == LOW || digitalRead(5) == LOW){
  if (mode == 0){
    note = tune(getNote());
  }
  else{
    note = getNote();
  }
  if (digitalRead(5)==LOW){ //if the octave button is pressed
    note *= 2;
  }
    digitalWrite(13, HIGH);
       Serial.print(note);      //print frequency
    Serial.println(" hz");      //print units after frequency
    tone(8, note); 
  
  }
  else{
    noTone(8);
  }
}


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){ //git 

    calculatedDistance = 1760;
  }

  return calculatedDistance;
}
float tune(float toTune){
  if (toTune> 523.75){ //C5
    return 523.75;
  }
  if (toTune> 493.88){ //B4
    return 493.88;
  }
  if (toTune> 440){ //A4
    return 440;
  }
    if (toTune> 392){ //G4
    return 392;
  }
    if (toTune> 349.23){ //F4
    return 349.23;
  }
    if (toTune> 329.63){ //E5
    return 329.63;
  }
    if (toTune> 293.66){ //D4
    return 293.66;
  }
    if (toTune> 261.63){ //C4
    return 261.63;
  }
    if (toTune> 246.94){ //B3
    return 246.94;
  }
    if (toTune> 220){ //A3
    return 220;
  }
    if (toTune> 196){ //G3
    return 196;
  }
    if (toTune> 174.61){ //F3
    return 174.61;
  }
}