mozziUSB.ino

/*  Example of a sound being triggered by MIDI input.

    Demonstrates playing notes with Mozzi in response to MIDI input,
    using  Arduino MIDI library v4.2
    (https://github.com/FortySevenEffects/arduino_midi_library/releases/tag/4.2)

    Circuit:
      MIDI input circuit as per http://arduino.cc/en/Tutorial/Midi
      Note: midi input on rx pin, not tx as in the illustration on the above page.
      Midi has to be disconnected from rx for sketch to upload.
      Audio output on digital pin 9 on a Uno or similar.

		Mozzi documentation/API
		https://sensorium.github.io/Mozzi/doc/html/index.html

		Mozzi help/discussion/announcements:
    https://groups.google.com/forum/#!forum/mozzi-users

    Tim Barrass 2013-14, CC by-nc-sa.
*/

#include "MIDIUSB.h"
#include <MozziGuts.h>
#include <Oscil.h> // oscillator template
#include <tables/sin2048_int8.h> // sine table for oscillator
#include <mozzi_midi.h>
#include <ADSR.h>
const byte NOTEON = 0x09;
const byte NOTEOFF = 0x08;

long audio_data;
long envelope_data;
long audio_final_data;

// use #define for CONTROL_RATE, not a constant
#define CONTROL_RATE 64 // Hz, powers of 2 are most reliable

// audio sinewave oscillator
Oscil <SIN2048_NUM_CELLS, AUDIO_RATE> aSin(SIN2048_DATA);

// envelope generator
ADSR <CONTROL_RATE, AUDIO_RATE> envelope;

void HandleNoteOn(byte channel, byte note, byte velocity) {
  aSin.setFreq(mtof(float(note)));
  envelope.noteOn();
}

void HandleNoteOff(byte channel, byte note, byte velocity) {
  //envelope.noteOff();
}

void setup() {
  Serial.begin(115200);

  envelope.setADLevels(255, 64);
  envelope.setTimes(50, 200, 10000, 200); // 10000 is so the note will sustain 10 seconds unless a noteOff comes

  aSin.setFreq(440); // default frequency
  startMozzi(CONTROL_RATE);
}


void updateControl() {
  midiEventPacket_t rx = MidiUSB.read();

  switch (rx.header) {
    case 0:
      break;
    case NOTEON:
      if (rx.byte3 == 0x00) {
        HandleNoteOff(rx.byte1, rx.byte2, rx.byte3);
      }
      HandleNoteOn(rx.byte1, rx.byte2, rx.byte3);
    case NOTEOFF:
      HandleNoteOff(rx.byte1, rx.byte2, rx.byte3);
  }
  if (rx.header != 0) {
    /*
      Serial.print(rx.header, HEX);
      Serial.print("-");
      Serial.print(rx.byte1, HEX);
      Serial.print("-");
      Serial.print(rx.byte2, HEX);
      Serial.print("-");
      Serial.println(rx.byte3, HEX);
    */
  }
  envelope.update();
  Serial.print(envelope_data);
  Serial.print(",");
  Serial.print(audio_data);
  Serial.print(",");
  Serial.println(audio_final_data);
  MidiUSB.flush();
}


int updateAudio() {
  envelope_data = envelope.next();
  audio_data = aSin.next();
  audio_final_data = (envelope_data * audio_data) >> 12;
  return (int) audio_final_data;
}


void loop() {
  audioHook(); // required here
}