CheapSynth_FM4oscZoom_v0_5_5.ino

/*  
 *  FM+LFO notes from Mozzi in response to MIDI input,
 *  using the standard Arduino MIDI library:
 *  http://playground.arduino.cc/Main/MIDILibrary
 *
 *  Mozzi help/discussion/announcements:
 *  https://groups.google.com/forum/#!forum/mozzi-users
 *
 *  Massively based on examples by Tim Barrass 2013nextenv
 *  This example code is in the public domain.
 *
 *  sgreen/dpape/dgreen - modified to bring together harmonic FM, LFO, portamento, 
 *  mono note priority, & Rock Band keytar controls - http://www.cheapsynth.com/
 *
 *  Audio output from pin 9 (pwm)
 *  Midi plug pin 2 (centre) to Arduino gnd, pin 5 to RX (0)
 *  http://www.philrees.co.uk/midiplug.htm
 *
 */

#include <MIDI.h>
#include <MozziGuts.h>
#include <Oscil.h> // oscillator template
#include <Line.h> // for envelope
#include <tables/cos2048_int8.h> // table for Oscils to play
#include <tables/saw1024_int8.h> // table for Oscils to play
#include <tables/smoothsquare8192_int8.h> // NB portamento requires table > 512 size?
#include <mozzi_midi.h>
#include <ADSR.h>384
#include <mozzi_fixmath.h>
#include <LowPassFilter.h>
#include <Portamento.h>

// use #define for CONTROL_RATE, not a constant
#define CONTROL_RATE 128 // powers of 2 please

//  Mozzi example uses COS waves for carrier and modulator
//  DP: "gets brutal very fast" (esp in higher octaves) if you use a saw/square carrier
//  gets subtly more brutal if you use smaller wavetables (fewer samples per cycle)
Oscil<SMOOTHSQUARE8192_NUM_CELLS, AUDIO_RATE> oscCarrier(SMOOTHSQUARE8192_DATA); // huge file :(
Oscil<SMOOTHSQUARE8192_NUM_CELLS, AUDIO_RATE> oscSquare2(SMOOTHSQUARE8192_DATA); // huge file :(
Oscil<COS2048_NUM_CELLS, AUDIO_RATE> oscModulator(COS2048_DATA);
Oscil<COS2048_NUM_CELLS, AUDIO_RATE> oscLFO(COS2048_DATA);
Oscil<SAW1024_NUM_CELLS, AUDIO_RATE> oscTri1(SAW1024_DATA); 
Oscil<SAW1024_NUM_CELLS, AUDIO_RATE> oscTri2(SAW1024_DATA); 

// envelope generator
ADSR <CONTROL_RATE> envelope;
ADSR <CONTROL_RATE> envelope2;

Portamento <CONTROL_RATE>aPortamento;
//LowPassFilter lpf; // LPF left over from earlier versions of code, may reinstate!
//int crushCtrl = 0; // ditto bitcrush

#define LED 13 // to see if MIDI is being recieved

unsigned long vibrato=0;

// initialise globals (some eg amplitude no longer used) 
int maxmode=4;
float carrierFreq = 10.f;
float carrier2 = 10.f;
float modFreq = 10.f;
float modDepth = 0;
float amplitude = 0.f;
float modOffset =1;
byte lastnote1=0;
byte lastnote2=0;
int nextenv=1;
int portSpeed=0;
float shifted=0.1f;
int mode=0;
unsigned long harmonic;
int squaredsin1;
int squaredsin2;
int bitmask=64;
int multiplier;

float modOffsets[] = {
4,3.5,3,2.5,2,1.5,1,0.6666666,0.5,0.4,0.3333333,0.2857,0.25,0,0,0,0,0,0,
}; // harmonic ratios corresponding to DP's preferred intervals of 7, 12, 7, 19, 24, 0, 12, -12, etc

void setup() {
  pinMode(LED, OUTPUT);

  // Initiate MIDI communications, listen to all channels
  MIDI.begin(MIDI_CHANNEL_OMNI);

  // Connect the HandleNoteOn function to the library, so it is called upon reception of a NoteOn.
  MIDI.setHandleNoteOn(HandleNoteOn);  // Put only the name of the function
  MIDI.setHandleNoteOff(HandleNoteOff);  // Put only the name of the function
  MIDI.setHandleControlChange(HandleControlChange);
  MIDI.setHandlePitchBend(HandlePitchBend);  // Put only the name of the function
  MIDI.setHandleProgramChange(HandleProgramChange); 
  MIDI.setHandleContinue(HandleContinue); 
  MIDI.setHandleStop(HandleStop); 

  envelope.setADLevels(127,100);
  envelope.setTimes(20,20,20000,850); // 20000 is so the note will sustain 20 seconds unless a noteOff comes
  envelope2.setADLevels(127,100);
  envelope2.setTimes(20,20,20000,850); // 20000 is so the note will sustain 20 seconds unless a noteOff comes

  aPortamento.setTime(0u);
//  lpf.setResonance(200);
//  lpf.setCutoffFreq(255);
  oscLFO.setFreq(10); // default LFO frequency

  startMozzi(CONTROL_RATE); 
}


void HandleProgramChange (byte channel, byte number)
{
  modOffset = modOffsets[number%15];
  modFreq=(carrierFreq * modOffset / (64/bitmask) );

//dreadful hack as ProgramChange returns absolute prog number 0-127, "gets stuck" at upper/lower ends 
}

void HandleNoteOn(byte channel, byte note, byte velocity) { 
  aPortamento.start(note); 
//  carrierFreq=(mtof(note)); // simple but less accurate frequency
//  osc.setFreq_Q16n16(Q16n16_mtof(Q8n0_to_Q16n16(note))); // accurate frequency

if ( (mode==0) || portSpeed) 
 {nextenv=1;   lastnote2=999;}

  if (nextenv==1) 
  { 
  lastnote1=note;
  envelope.noteOn();
  digitalWrite(LED,HIGH);
  nextenv=2; // send next note to other envelope, unless overridden in the meantime
  
  carrierFreq = Q16n16_to_float (Q16n16_mtof(Q8n0_to_Q16n16(lastnote1)));
  oscCarrier.setFreq(carrierFreq);
  oscTri1.setFreq(carrierFreq);
  modFreq=(carrierFreq * modOffset / (64/bitmask) );
  }
  else
  {
  lastnote2=note;
  envelope2.noteOn();
  digitalWrite(LED,HIGH); 
  nextenv=1; // send next note to other envelope, unless overridden in the meantime

  carrier2 = Q16n16_to_float (Q16n16_mtof(Q8n0_to_Q16n16(lastnote2)));
  oscSquare2.setFreq(carrier2);
  oscTri2.setFreq(carrier2 * (1.0f + ((shifted -0.1f) / 384)) );
  }

}

void HandleStop () { //this is the Back button on the Xbox keyboard
 portSpeed++; 
 {if (portSpeed>2) portSpeed = 0;}
  aPortamento.setTime( (portSpeed*portSpeed*100) ); // values of 0,100,400 milliseconds? (next 900)
}

void HandleContinue () { // the big round button on all keytars
 mode++; 
 {if (mode>maxmode) mode = 0;} //currently has a silent mode at the end so you know where you are : )
}

void HandleNoteOff(byte channel, byte note, byte velocity) { 
  digitalWrite(LED,LOW); // may as well switch LED off

  if ( (note == lastnote1) )
  {
  envelope.noteOff(); nextenv=1;} //kill envelope if prev note released 

  if ( (note == lastnote2) ) 
  {envelope2.noteOff(); nextenv=2;} //kill envelope if prev note released 
  
}


void HandlePitchBend (byte channel, int bend)
{
//bend value from +/-8192, translate to 0.1-8 Hz?
shifted= float ((bend+8500) /2048.f ) +0.1f;  
if (mode==0) {oscLFO.setFreq(shifted); }
if (mode==1) 
  {
   bitmask= 1 << (int (shifted)); multiplier=7-(int (shifted)); 
  }
  else {bitmask=64;}

if (mode==2) {   oscTri2.setFreq(carrier2 * (1.0f + ((shifted -0.1f) / 384)) ); }

}

void HandleControlChange (byte channel, byte number, byte value)
{
// http://www.indiana.edu/~emusic/cntrlnumb.html

/*
Serial.end(); // sample debug code to check values through (noisy) terminal interface 
Serial.begin(38400);
Serial.print("  number:");   
Serial.print(number);
Serial.print(" value:");   
Serial.println( value );
Serial.println();
Serial.end();
Serial.begin(31250);
*/

  switch(number) {
//  case 3: // could trap different controller IDs here

  case 1: // modulation wheel
  //lpf.setResonance(value*2);

  //WORKING MODDEPTH CONTROLLER
  float divided= float (value /46.f ); // values=0-127, map to 0-2.75
  modDepth = (divided * divided);      // square to 0-8
  if (modDepth>7.5) {modDepth=7.5;}        // sanity check (prob unnecessary) 
  if (modDepth<0.2) {modDepth=0;}      // easier to get pure tone 
  break;
  }
}

void updateControl(){
  MIDI.read();
  envelope.update();
  envelope2.update();

if ( portSpeed ) 
  {
  carrierFreq = Q16n16_to_float ( aPortamento.next() ); //NB presumably returns frequency as Q16n16
  oscCarrier.setFreq(carrierFreq);
  oscTri1.setFreq(carrierFreq);
  modFreq=(carrierFreq * modOffset / (64/bitmask) );
  }

if (mode)
  {
  float modFreq2=(carrier2 * modOffset / (64/bitmask) ); //NB no longer LFO
  
  if (mode>1)
    {
    modFreq *= 1.0f + ((shifted -0.1f) / 384); // generates fake LFO via detuning mod osc
    modFreq2 *= 1.0f + ((shifted -0.1f) / 384); // generates fake LFO via detuning mod osc
    }
  oscLFO.setFreq (modFreq2);
  }
oscModulator.setFreq( modFreq ); 
   
}

// strip the low bits off! - not used in current implementation
int bitCrush(int x, int a)
{
  return (x>>a)<<a;
}

int updateAudio(){
  
    switch(mode) 
    {
  case 0: // FM with LFO 
//NB this multiplication split into 2 chunks to preserve small precise values?  
vibrato = (unsigned long) ( oscLFO.next() * oscModulator.next() ) >>7 ;
vibrato*= (unsigned long) (carrierFreq * modDepth)>>3;
return (int) ((oscCarrier.phMod( vibrato ) ) * (envelope.next() ) ) >> 8;
// >> 7 = 7 fast binary divisions by 2 = divide by 128
  break;

  case 1: // ADDING square + "converted" sine
//squaredsin1= ( (oscModulator.next() & 0b0000000001000000)-1 ) <<1;
squaredsin1= ( (oscModulator.next() & bitmask) ) <<multiplier;
squaredsin2= ( (oscLFO.next() & bitmask) ) <<multiplier;
return (int) 
( 
  ( ( (oscCarrier.next() + squaredsin1 )>>1 )*envelope.next() )
+ ( ( (oscSquare2.next() + squaredsin2 )>>1 )*envelope2.next() )
) >> 8;
  break;

  case 2: // 2 tri poly
return (int)( 
             ( oscTri1.next() *envelope.next() )
           + ( oscTri2.next() *envelope2.next() ) 
            ) >> 8;
  break;

  case 3: // STARTED AS 2 sq poly ORd with matching sines, now big whoop
return (int)(
             ( (oscCarrier.next()|oscModulator.next()) * envelope.next() )  
           + ( (oscSquare2.next()|oscLFO.next()) * envelope2.next() ) 
            ) >> 8;
//return (int) ( (oscCarrier.next() | ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
  break;

  case 13: // 2 sq poly XORd with matching sines
return (int) ( ( (oscCarrier.next()^oscModulator.next() ) * envelope.next()) + ( (oscSquare2.next()^oscLFO.next() ) * envelope2.next()) ) >> 8;
//return (int) ( (oscCarrier.next() | ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
  break;


  case 6: // 2 sq poly
return (int) ( (oscCarrier.next() * envelope.next()) + (oscSquare2.next() * envelope2.next()) ) >> 8;
//return (int) ( (oscCarrier.next() | ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
  break;

//case 5 intentionally left blank

/*
  case 6: // ADDING squares
return (int) ( (oscCarrier.next() + oscSquare2.next() )  * (envelope.next() ) ) >> 8;
//return (int) ( (oscCarrier.next() | ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
  break;
*/
// case 1: // AND with fake LFO
//all this 'harmonic' stuff a failed attempt to use the same LFO as FM, causes massive beat f/x?
//harmonic = ( oscLFO.next() * oscModulator.next() ) >> 7; 
//harmonic = ( harmonic * int (modDepth+1) ) >>3 ;
//return (int) ( (oscCarrier.next() ^ ( harmonic ))  * (envelope.next() ) ) >> 7;
//return (int) ( (oscCarrier.next() & ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
//  break;

/*  case 3: // OR with fake LFO
//int harmonic = ( oscLFO.next() * oscModulator.next() ) >>7;
//return (int) ( (oscCarrier.next() | ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
//  break;
  case 4: // XOR with fake LFO
//int harmonic = ( oscLFO.next() * oscModulator.next() ) >>7;
return (int) ( (oscCarrier.next() ^ ( (oscModulator.next() * int (modDepth+1))>>3 ) )  * (envelope.next() ) ) >> 7;
  break;
  */
    }
    
// OLD CODE FROM BITCRUNCHED SINEWAVE, DIFF WAYS OF DOING THAT 
// int x = (envelope.next() * lpf.next(osc.next()))>>8; 
//  x = bitCrush(x, crushCtrl>>4);
// x = (x * crushCtrl)>>4;  // simple gain
// x = bitCrush(x, 6);
//  x = lpf.next(x);
//  return x;
}


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