mozzi fm synth

/* Jack's FM Synth

  based on the Knob_Lightlevel_FMSynth_x2 example from the mozzi examples
  -adding two new effects
  -a volume knob
  -a screen that reads the carrier frequency and the modulation rate
*/


#define MOZZI_ANALOG_READ_RESOLUTION 10 // code below assumes readings to be in the classic 10-bit (0-1023) range
#include <Mozzi.h>
#include <Oscil.h> // oscillator
#include <tables/cos2048_int8.h> // table for Oscils to play
#include <tables/cos512_int8.h> // for filter
#include <Smooth.h>
#include <AutoMap.h> // maps unpredictable inputs to a range
#include <ResonantFilter.h> //resonsnant filter for fx 1


// desired carrier frequency max and min, for AutoMap
const int MIN_CARRIER_FREQ = 22;
const int MAX_CARRIER_FREQ = 440;

// desired intensity max and min, for AutoMap, note they're inverted for reverse dynamics
const int MIN_INTENSITY = 700;
const int MAX_INTENSITY = 10;

// desired mod speed max and min, for AutoMap, note they're inverted for reverse dynamics
const int MIN_MOD_SPEED = 10000;
const int MAX_MOD_SPEED = 1;

// max and min filter cutoff
const int MIN_CUTOFF_FREQ = 50;
const int MAX_CUTOFF_FREQ = 6000;

AutoMap kMapCarrierFreq(0,1023,MIN_CARRIER_FREQ,MAX_CARRIER_FREQ);
AutoMap kMapIntensity(0,1023,MIN_INTENSITY,MAX_INTENSITY);
AutoMap kMapModSpeed(0,1023,MIN_MOD_SPEED,MAX_MOD_SPEED);
AutoMap kMapCutoffFreq(0,1023,MIN_CUTOFF_FREQ,MAX_CUTOFF_FREQ);

const int KNOB_PIN = 0; // set the input for the knob to analog pin 0
const int LDR1_PIN=1; // set the analog input for fm_intensity to pin 1
const int LDR2_PIN=2; // set the analog input for mod rate to pin 2
const int FILTER_PIN = 3; //pin for filter knob

Oscil<COS2048_NUM_CELLS, MOZZI_AUDIO_RATE> aCarrier(COS2048_DATA);
Oscil<COS2048_NUM_CELLS, MOZZI_AUDIO_RATE> aModulator(COS2048_DATA);
Oscil<COS2048_NUM_CELLS, MOZZI_CONTROL_RATE> kIntensityMod(COS2048_DATA);
Oscil<COS512_NUM_CELLS, MOZZI_CONTROL_RATE> kLowPass(COS512_DATA);

int mod_ratio = 5; // brightness (harmonics)
long fm_intensity; // carries control info from updateControl to updateAudio

// smoothing for intensity to remove clicks on transitions
float smoothness = 0.95f;
Smooth <long> aSmoothIntensity(smoothness);

LowPassFilter lpf; //low pass filter object

uint8_t resonance = 200; //LPF resonance value

void setup(){
  //Serial.begin(9600); // for Teensy 3.1, beware printout can cause glitches
  Serial.begin(115200); // set up the Serial output so we can look at the piezo values // set up the Serial output so we can look at the light level
  startMozzi(); // :))
}


void updateControl(){
  // read the knob
  int knob_value = mozziAnalogRead(KNOB_PIN); // value is 0-1023

  // map the knob to carrier frequency
  int carrier_freq = kMapCarrierFreq(knob_value);

  //calculate the modulation frequency to stay in ratio
  int mod_freq = carrier_freq * mod_ratio;

  //set the filter freqency
  int filter_knob_val = mozziAnalogRead(FILTER_PIN);
  int cutoff_freq = kMapCutoffFreq(filter_knob_val);

  // set the FM oscillator frequencies
  aCarrier.setFreq(carrier_freq);
  aModulator.setFreq(mod_freq);

  // read the light dependent resistor on the width Analog input pin
  int LDR1_value= mozziAnalogRead(LDR1_PIN); // value is 0-1023
  // print the value to the Serial monitor for debugging
  Serial.print("LDR1 = ");
  Serial.print(LDR1_value);
  Serial.print("\t"); // prints a tab

  int LDR1_calibrated = kMapIntensity(LDR1_value);
  Serial.print("LDR1_calibrated = ");
  Serial.print(LDR1_calibrated);
  Serial.print("\t"); // prints a tab

 // calculate the fm_intensity
  fm_intensity = ((long)LDR1_calibrated * (kIntensityMod.next()+128))>>8; // shift back to range after 8 bit multiply
  Serial.print("fm_intensity = ");
  Serial.print(fm_intensity);
  Serial.print("\t"); // prints a tab

  // read the light dependent resistor on the speed Analog input pin
  int LDR2_value= mozziAnalogRead(LDR2_PIN); // value is 0-1023
  Serial.print("LDR2 = ");
  Serial.print(LDR2_value);
  Serial.print("\t"); // prints a tab

  // use a float here for low frequencies
  float mod_speed = (float)kMapModSpeed(LDR2_value)/1000;
  Serial.print("   mod_speed = ");
  Serial.print(mod_speed);
  kIntensityMod.setFreq(mod_speed);
  Serial.print("\t"); // prints a tab

  // set the filter cutoff frequency and resonance
  lpf.setCutoffFreqAndResonance(cutoff_freq, resonance);

  Serial.print("  cutoff freq = ");
  Serial.print(cutoff_freq);

  Serial.println(); // finally, print a carraige return for the next line of debugging info
}


AudioOutput updateAudio(){
  long modulation = aSmoothIntensity.next(fm_intensity) * aModulator.next();

  //return wave;
  return MonoOutput::from8Bit(aCarrier.phMod(modulation));

}


void loop(){
  audioHook();
}