Current FM patch is based on Knob_LightLevel_x2_FMsynth example from Mozzi library

FM/FM.ino

@@ -0,0 +1,129 @@
+#include <MozziGuts.h>
+#include <Oscil.h> // oscillator 
+#include <tables/cos2048_int8.h> // table for Oscils to play
+#include <Smooth.h>
+#include <AutoMap.h> // maps unpredictable inputs to a range
+#include <MIDIUSB.h>
+
+#define CONTROL_RATE 64
+
+bool gate = 0;
+
+ 
+// desired carrier frequency max and min, for AutoMap
+const int MIN_CARRIER_FREQ = 22;
+const int MAX_CARRIER_FREQ = 440;
+
+const int MIN = 1;
+const int MAX = 10;
+
+const int MIN_2 = 1;
+const int MAX_2 = 15;
+
+// 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;
+
+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 mapThis(0,1023,MIN,MAX);
+AutoMap mapThisToo(0,1023,MIN_2,MAX_2);
+
+//Mapping the knob pins
+const int CONTROLL1 = 0;
+const int CONTROLL2 = 1;
+const int CONTROLL3 = 2;
+const int CONTROLL4 = 3;
+
+Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aCarrier(COS2048_DATA);
+Oscil<COS2048_NUM_CELLS, AUDIO_RATE> aModulator(COS2048_DATA);
+Oscil<COS2048_NUM_CELLS, CONTROL_RATE> kIntensityMod(COS2048_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);
+
+const float notefreqs[128] = {8.176, 8.662, 9.177, 9.723, 10.301, 10.913, 11.562, 12.25, 12.978, 13.75, 14.568, 15.434, 16.352, 17.324, 18.354, 19.445, 20.602, 21.827, 23.125, 24.5, 25.957, 27.5, 29.135, 30.868, 32.703, 34.648, 36.708, 38.891, 41.203, 43.654, 46.249, 48.999, 51.913, 55, 58.27, 61.735, 65.406, 69.296, 73.416, 77.782, 82.407, 87.307, 92.499, 97.999, 103.826, 110, 116.541, 123.471, 130.813, 138.591, 146.832, 155.563, 164.814, 174.614, 184.997, 195.998, 207.652, 220, 233.082, 246.942, 261.626, 277.183, 293.665, 311.127, 329.628, 349.228, 369.994, 391.995, 415.305, 440, 466.164, 493.883, 523.251, 554.365, 587.33, 622.254, 659.255, 698.456, 739.989, 783.991, 830.609, 880, 932.328, 987.767, 1046.502, 1108.731, 1174.659, 1244.508, 1318.51, 1396.913, 1479.978, 1567.982, 1661.219, 1760, 1864.655, 1975.533, 2093.005, 2217.461, 2349.318, 2489.016, 2637.02, 2793.826, 2959.955, 3135.963, 3322.438, 3520, 3729.31, 3951.066, 4186.009, 4434.922, 4698.636, 4978.032, 5274.041, 5587.652, 5919.911, 6271.927, 6644.875, 7040, 7458.62, 7902.133, 8372.018, 8869.844, 9397.273, 9956.063, 10548.08, 11175.3, 11839.82, 12543.85};
+int carrier_freq = 440;
+
+void noteOn(byte channel, byte note, byte velocity) {
+  carrier_freq = notefreqs[(int) note];
+  gate = 1;
+}
+
+void noteOff(byte channel, byte note, byte velocity) {
+  gate = 0;
+}
+
+void setup(){
+  startMozzi();
+
+  pinMode(LED_BUILTIN_TX,INPUT); //switch rx and tx leds of, so they don't blink on midi
+  pinMode(LED_BUILTIN_RX,INPUT);
+}
+
+
+void updateControl(){
+  midiEventPacket_t rx;
+  do {
+    rx = MidiUSB.read();
+    if (rx.header == 0x09) {
+      noteOn(rx.byte1, rx.byte2, rx.byte3);
+    } else if (rx.header == 0x08) {
+      noteOff(rx.byte1, rx.byte2, rx.byte3);
+    }
+  } while (rx.header != 0);
+    
+   int freqVal = mozziAnalogRead(CONTROLL3); // value is 0-1023
+   int FRQ = mapThis(freqVal);
+   
+   int knob2 = mozziAnalogRead(CONTROLL4); // value is 0-1023
+   int knob2Val = mapThis(knob2);
+  
+  //calculate the modulation frequency to stay in ratio
+  int mod_freq = carrier_freq * mod_ratio * FRQ;
+  
+  // 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(CONTROLL1); // value is 0-1023
+
+
+  int LDR1_calibrated = kMapIntensity(LDR1_value);
+
+  
+ // calculate the fm_intensity
+  fm_intensity = ((long)LDR1_calibrated * knob2Val * (kIntensityMod.next()+128))>>8; // shift back to range after 8 bit multiply
+
+  
+  // read the light dependent resistor on the speed Analog input pin
+  int LDR2_value= mozziAnalogRead(CONTROLL2); // value is 0-1023
+
+  
+  // use a float here for low frequencies
+  float mod_speed = (float)kMapModSpeed(LDR2_value)/1000;
+
+  kIntensityMod.setFreq(mod_speed);
+}
+
+
+int updateAudio(){
+  long modulation = aSmoothIntensity.next(fm_intensity) * aModulator.next();
+  if (gate == 1) {
+    return aCarrier.phMod(modulation);//(int)(envelope.next() * aCarrier.phMod(modulation))>>8;
+  }
+}
+
+void loop(){
+  audioHook();
+}