Documentation

Code dump, if you want/need it:

//I/O
const int FADER1 = A0;
const int FADER2 = A1;
const int FADER3 = A2;
const int FADER4 = A3;
const int FEEDBACK = A4;
const int PITCH_SLIDER = A5;
const int AUDIO_OUT = 11;

//global variables
int pitchAfterSlider = 0;
int feedbackAmount = 0;
float outputVoltage = 0;

void setup() {
  // Serial Initialisation
  Serial.begin(9600);

  //Don't know, don't care, don't touch
  TCCR2A = _BV(COM2A0) | _BV(COM2B1) | _BV(WGM20);

  TCCR2B = _BV(WGM22) | _BV(CS22);

  OCR2A = 1;
}

void loop() {
  // Call my functions.
  pitchStuff();
  faderOscillator();
  feedbackStuff();

  //Serial printLine
  Serial.println(analogRead(FEEDBACK));


  //pitchAfterSlider = 255;
}

//Does some things. Maps feedback to 8-bit int, adds some of the output back in, then slaps it on pitch
void feedbackStuff() {
  feedbackAmount = map(FEEDBACK, 0, 1023, 0, 255);

  //feedbackAmount += (outputVoltage);
  OCR2A += (1/feedbackAmount) * outputVoltage;
}

//Don't even know if the Slider works, but this should do pitch things.
void pitchStuff() {
  pitchAfterSlider = map(analogRead(PITCH_SLIDER), 300, 800, 1, 255);
  pitchAfterSlider += 10;
  if (pitchAfterSlider > 0) {
    OCR2A = pitchAfterSlider;
  }

  //UNNEEDED
  //Serial.println(analogRead(PITCH_SLIDER));
  //delay(pitchAfterSlider/100);
}

//4 step Sequencer
void faderOscillator() {
  outputVoltage = map(analogRead(FADER1), 0, 1023, 255, 0);
  analogWrite(AUDIO_OUT, outputVoltage);
  delay(1);
  outputVoltage = map(analogRead(FADER2), 0, 1023, 255, 0);
  analogWrite(AUDIO_OUT, outputVoltage);
  delay(1);
  outputVoltage = map(analogRead(FADER3), 0, 1023, 255, 0);
  analogWrite(AUDIO_OUT, outputVoltage);
  delay(1);
  outputVoltage = map(analogRead(FADER4), 0, 1023, 255, 0);
  analogWrite(AUDIO_OUT, outputVoltage);
  delay(1);
}