CSUSM FM Synth 2017 / Mbed 2 deprecated FMSynthCSUSM

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Dependencies:   mbed

Fork of STM32FMSynth by Steven Clark

main.cpp@6:9f8c8c3c111d, 2017-12-01 (annotated)

Committer:
davolfman
Date:
Fri Dec 01 22:48:48 2017 +0000
Revision:
6:9f8c8c3c111d
Parent:
5:ac5c4bd3ef4b
Child:
7:b0cd74923bc6
Range correction on fastSin

Who changed what in which revision?

UserRevisionLine numberNew contents of line
davolfman 0:b2f7400596ce 1 #include "mbed.h"
davolfman 3:83ac767f3a63 2 #include "sintable.h"
davolfman 0:b2f7400596ce 3
davolfman 0:b2f7400596ce 4 AnalogOut DAC0(PA_4);//Not labeled in the docs for the f401, but seems to be for all
davolfman 0:b2f7400596ce 5 AnalogOut DAC1(PA_5);
davolfman 0:b2f7400596ce 6
davolfman 0:b2f7400596ce 7 AnalogIn ADC0(PA_0);
davolfman 0:b2f7400596ce 8 AnalogIn ADC1(PA_1);
davolfman 6:9f8c8c3c111d 9 //AnalogIn ADC2(PA_2);//these are the uart pins!!
davolfman 6:9f8c8c3c111d 10 //AnalogIn ADC3(PA_3);//these are the uart pins!!
davolfman 0:b2f7400596ce 11 //AnalogIn ADC4(PA_4);//we're using these for output
davolfman 0:b2f7400596ce 12 //AnalogIn ADC5(PA_5);//we're using these for output
davolfman 0:b2f7400596ce 13 AnalogIn ADC6(PA_6);
davolfman 0:b2f7400596ce 14 AnalogIn ADC7(PA_7);
davolfman 0:b2f7400596ce 15 //AnalogIn ADC8(PB_0);//lets leave the 2 we aren't using in a single port
davolfman 0:b2f7400596ce 16 //AnalogIn ADC9(PB_1);//that way we know there's not ADCs on one of them
davolfman 0:b2f7400596ce 17 AnalogIn ADC10(PC_0);
davolfman 0:b2f7400596ce 18 AnalogIn ADC11(PC_1);
davolfman 0:b2f7400596ce 19 AnalogIn ADC12(PC_2);
davolfman 0:b2f7400596ce 20 AnalogIn ADC13(PC_3);
davolfman 0:b2f7400596ce 21 AnalogIn ADC14(PC_4);
davolfman 0:b2f7400596ce 22 AnalogIn ADC15(PC_5);
davolfman 0:b2f7400596ce 23
davolfman 2:5454dee210ed 24 BusIn keyBank(PC_10, PC_11, PC_12, PC_13, PC_14, PC_15);
davolfman 2:5454dee210ed 25 BusOut keySelect(PB_0, PB_1, PB_2, PB_3, PB_4, PB_5, PB_6, PB_7, PB_8);
davolfman 2:5454dee210ed 26 BusIn numerator(PA_8, PA_9, PA_10, PA_11);
davolfman 2:5454dee210ed 27 BusIn denominator(PA_12, PA_13, PA_14, PA_15);
davolfman 2:5454dee210ed 28
davolfman 0:b2f7400596ce 29 //Renaming ports
davolfman 0:b2f7400596ce 30 #define inVol ADC0
davolfman 0:b2f7400596ce 31 #define inModAmt ADC1
davolfman 0:b2f7400596ce 32 #define inCarA ADC6
davolfman 0:b2f7400596ce 33 #define inCarD ADC7
davolfman 0:b2f7400596ce 34 #define inCarS ADC10
davolfman 0:b2f7400596ce 35 #define inCarR ADC11
davolfman 0:b2f7400596ce 36 #define inModA ADC12
davolfman 0:b2f7400596ce 37 #define inModD ADC13
davolfman 0:b2f7400596ce 38 #define inModS ADC14
davolfman 0:b2f7400596ce 39 #define inModR ADC15
davolfman 0:b2f7400596ce 40 #define outMono DAC0
davolfman 0:b2f7400596ce 41
davolfman 2:5454dee210ed 42 #define numKeys 49
davolfman 1:f3350a372732 43 #define PI M_PI
davolfman 0:b2f7400596ce 44
davolfman 4:1d2a699c95c7 45 //constants
davolfman 4:1d2a699c95c7 46 const int carrierIncrements[] = {107, 113, 120, 127, 135, 143, 151, 160, 170,
davolfman 4:1d2a699c95c7 47 180, 190, 202, 214, 227, 240, 254, 270, 286, 303, 321, 340, 360, 381, 404,
davolfman 4:1d2a699c95c7 48 428, 454, 481, 509, 540, 572, 606, 642, 680, 720, 763, 809, 857, 908, 962,
davolfman 4:1d2a699c95c7 49 1019, 1080, 1144, 1212, 1284, 1360, 1441, 1527, 1618, 1714};
davolfman 1:f3350a372732 50 const int attackLimit = (0x1 << 16) - 1;
davolfman 1:f3350a372732 51 const int fixed2Pi = (int) ((2.0 * PI) * (0x1 << 16));
davolfman 1:f3350a372732 52
davolfman 0:b2f7400596ce 53 //non-constants
davolfman 1:f3350a372732 54 //Most of these will be recalculated or reset on every input cycle of the main
davolfman 1:f3350a372732 55 // loop, as appropriate
davolfman 0:b2f7400596ce 56 int FMmult;
davolfman 0:b2f7400596ce 57 int Volume;
davolfman 1:f3350a372732 58 int modVol;
davolfman 1:f3350a372732 59 int modAmpI;
davolfman 1:f3350a372732 60 int carAmpS;
davolfman 2:5454dee210ed 61 //bool keysPressed[numKeys];
davolfman 2:5454dee210ed 62 int64_t keyboard;
davolfman 0:b2f7400596ce 63 int carrierPhases[numKeys];
davolfman 0:b2f7400596ce 64 int modulatorPhases[numKeys];
davolfman 0:b2f7400596ce 65 short envelopeStatesC[numKeys];
davolfman 0:b2f7400596ce 66 short envelopeStatesM[numKeys];
davolfman 0:b2f7400596ce 67 int envelopeAmpsC[numKeys];
davolfman 1:f3350a372732 68 int envelopeAmpsM[numKeys];
davolfman 1:f3350a372732 69
davolfman 1:f3350a372732 70 int modA;
davolfman 1:f3350a372732 71 int modD;
davolfman 1:f3350a372732 72 int modS;
davolfman 1:f3350a372732 73 int modR;
davolfman 1:f3350a372732 74 int carA;
davolfman 1:f3350a372732 75 int carD;
davolfman 1:f3350a372732 76 int carS;
davolfman 1:f3350a372732 77 int carR;
davolfman 1:f3350a372732 78
davolfman 1:f3350a372732 79 int fastSin(const int phase){
davolfman 5:ac5c4bd3ef4b 80 int index = (phase & 0x3ffc) >> 2;
davolfman 5:ac5c4bd3ef4b 81 int subindex = phase & 0x3;
davolfman 5:ac5c4bd3ef4b 82 int quadrant = (phase & 0xc000) >> 14;
davolfman 3:83ac767f3a63 83 int sum = 0;
davolfman 5:ac5c4bd3ef4b 84 switch (quadrant) {
davolfman 5:ac5c4bd3ef4b 85 case 0:
davolfman 5:ac5c4bd3ef4b 86 sum += (4 - subindex) * sintable[index];
davolfman 5:ac5c4bd3ef4b 87 sum += subindex * sintable[index+1];
davolfman 5:ac5c4bd3ef4b 88 break;
davolfman 5:ac5c4bd3ef4b 89 case 1:
davolfman 6:9f8c8c3c111d 90 sum += (4 - subindex) * sintable[1+4095-index];
davolfman 6:9f8c8c3c111d 91 sum += subindex * sintable[4095-index];
davolfman 5:ac5c4bd3ef4b 92 break;
davolfman 5:ac5c4bd3ef4b 93 case 2:
davolfman 5:ac5c4bd3ef4b 94 sum -= (4 - subindex) * sintable[index];
davolfman 5:ac5c4bd3ef4b 95 sum -= subindex * sintable[index+1];
davolfman 5:ac5c4bd3ef4b 96 break;
davolfman 5:ac5c4bd3ef4b 97 case 3:
davolfman 6:9f8c8c3c111d 98 sum -= (4 - subindex) * sintable[1+4095-index];
davolfman 6:9f8c8c3c111d 99 sum -= subindex * sintable[4095-index];
davolfman 5:ac5c4bd3ef4b 100 break;
davolfman 5:ac5c4bd3ef4b 101 }
davolfman 3:83ac767f3a63 102 sum = sum >> 2;
davolfman 3:83ac767f3a63 103
davolfman 3:83ac767f3a63 104 return sum;
davolfman 1:f3350a372732 105 }
davolfman 0:b2f7400596ce 106
davolfman 1:f3350a372732 107 void synthesize(){
davolfman 1:f3350a372732 108 carAmpS = 0;
davolfman 1:f3350a372732 109 for(int i = 0; i < numKeys; ++i){
davolfman 2:5454dee210ed 110 if(keyboard & (0x1 << i)){
davolfman 1:f3350a372732 111 if(envelopeStatesC[i] < 2)
davolfman 1:f3350a372732 112 envelopeStatesC[i] = 4;
davolfman 1:f3350a372732 113 if(envelopeStatesM[i] < 2)
davolfman 1:f3350a372732 114 envelopeStatesM[i] = 4;
davolfman 1:f3350a372732 115
davolfman 1:f3350a372732 116 if(envelopeStatesC[i] == 4){
davolfman 1:f3350a372732 117 envelopeAmpsC[i] += carA;
davolfman 1:f3350a372732 118 if(envelopeAmpsC[i] >= attackLimit){
davolfman 1:f3350a372732 119 envelopeAmpsC[i] = attackLimit;
davolfman 1:f3350a372732 120 envelopeStatesC[i] = 3;
davolfman 1:f3350a372732 121 }
davolfman 1:f3350a372732 122 }
davolfman 1:f3350a372732 123
davolfman 1:f3350a372732 124 if(envelopeStatesM[i] == 4){
davolfman 1:f3350a372732 125 envelopeAmpsM[i] += modA;
davolfman 1:f3350a372732 126 if(envelopeAmpsM[i] >= attackLimit){
davolfman 1:f3350a372732 127 envelopeAmpsM[i] = attackLimit;
davolfman 1:f3350a372732 128 envelopeStatesM[i] = 3;
davolfman 1:f3350a372732 129 }
davolfman 1:f3350a372732 130 }
davolfman 1:f3350a372732 131
davolfman 1:f3350a372732 132 if(envelopeStatesC[i] == 3){
davolfman 1:f3350a372732 133 envelopeAmpsC[i] += carD;
davolfman 1:f3350a372732 134 if(envelopeAmpsC[i] <= carS){
davolfman 1:f3350a372732 135 envelopeAmpsC[i] = carS;
davolfman 1:f3350a372732 136 envelopeStatesC[i] = 2;
davolfman 1:f3350a372732 137 }
davolfman 1:f3350a372732 138 }
davolfman 1:f3350a372732 139
davolfman 1:f3350a372732 140 if(envelopeStatesM[i] == 3){
davolfman 1:f3350a372732 141 envelopeAmpsM[i] += modD;
davolfman 1:f3350a372732 142 if(envelopeAmpsM[i] <= modS){
davolfman 1:f3350a372732 143 envelopeAmpsM[i] = modS;
davolfman 1:f3350a372732 144 envelopeStatesM[i] = 2;
davolfman 1:f3350a372732 145 }
davolfman 1:f3350a372732 146 }
davolfman 1:f3350a372732 147 }else{
davolfman 1:f3350a372732 148 if(envelopeStatesC[i] > 1)
davolfman 1:f3350a372732 149 envelopeStatesC[i] = 1;
davolfman 1:f3350a372732 150 if(envelopeStatesM[i] > 1)
davolfman 1:f3350a372732 151 envelopeStatesM[i] = 1;
davolfman 1:f3350a372732 152
davolfman 1:f3350a372732 153 if(envelopeStatesC[i] == 1){
davolfman 1:f3350a372732 154 if(envelopeAmpsC[i] <= 0){
davolfman 1:f3350a372732 155 envelopeStatesC[i] = 0;
davolfman 1:f3350a372732 156 envelopeAmpsC[i] = 0;
davolfman 1:f3350a372732 157 }else{
davolfman 1:f3350a372732 158 envelopeAmpsC[i] -= carR;
davolfman 1:f3350a372732 159 }
davolfman 1:f3350a372732 160 }
davolfman 1:f3350a372732 161 if(envelopeStatesM[i] == 1){
davolfman 1:f3350a372732 162 if(envelopeAmpsM[i] <= 0){
davolfman 1:f3350a372732 163 envelopeStatesM[i] = 0;
davolfman 1:f3350a372732 164 envelopeAmpsM[i] = 0;
davolfman 1:f3350a372732 165 }else{
davolfman 1:f3350a372732 166 envelopeAmpsM[i] -= modR;
davolfman 1:f3350a372732 167 }
davolfman 1:f3350a372732 168 }
davolfman 1:f3350a372732 169 }
davolfman 1:f3350a372732 170
davolfman 1:f3350a372732 171 if(envelopeAmpsC[i] > 0){
davolfman 1:f3350a372732 172 modulatorPhases[i] += (Fmult * carrierIncrements[i]) >> 16;
davolfman 1:f3350a372732 173 modAmpI = fastSin((((modulatorPhases[i] * envelopeAmpsM[i]) >> 16)
davolfman 1:f3350a372732 174 * modVol) >> 16);
davolfman 1:f3350a372732 175 carrierPhases[i] += ((carrierIncrements[i] + modAmpI) * fixed2pi) >> 16;
davolfman 1:f3350a372732 176 carAmps += (fastSin(carrierPhases[i]) * envelopeAmpsC[i]) >> 16;
davolfman 1:f3350a372732 177 }
davolfman 1:f3350a372732 178 }
davolfman 1:f3350a372732 179 outMono.write_u16(((carAmps / numKeys) * Volume) >> 16);
davolfman 1:f3350a372732 180 }
davolfman 0:b2f7400596ce 181
davolfman 0:b2f7400596ce 182
davolfman 0:b2f7400596ce 183 int main() {
davolfman 2:5454dee210ed 184 int ratNumer;
davolfman 2:5454dee210ed 185 int ratDenom;
davolfman 2:5454dee210ed 186
davolfman 2:5454dee210ed 187 while(true){
davolfman 2:5454dee210ed 188 ratNumer = 0xf & ~ numerator;
davolfman 2:5454dee210ed 189 ratDenom = 0xf & ~ denom;
davolfman 2:5454dee210ed 190 FMult = (ratNumer << 16) / ratDenom;
davolfman 2:5454dee210ed 191
davolfman 2:5454dee210ed 192 Volume = (int)inVol.read_u16();
davolfman 2:5454dee210ed 193 modVol = (int)inModAmt.read_u16();
davolfman 2:5454dee210ed 194
davolfman 2:5454dee210ed 195 carA = 0xffff / ((int)inCarA.read_u16());
davolfman 2:5454dee210ed 196 carD = 0xffff / ((int)inCarD.read_u16());
davolfman 2:5454dee210ed 197 carS = (int)inCarS.read_u16();
davolfman 2:5454dee210ed 198 carR = 0xffff / ((int)inCarR.read_u16());
davolfman 2:5454dee210ed 199
davolfman 2:5454dee210ed 200 modA = 0xffff / ((int)inModA.read_u16());
davolfman 2:5454dee210ed 201 modD = 0xffff / ((int)inModD.read_u16());
davolfman 2:5454dee210ed 202 modS = (int)inModS.read_u16();
davolfman 2:5454dee210ed 203 modR = 0xffff / ((int)inModR.read_u16());
davolfman 2:5454dee210ed 204
davolfman 2:5454dee210ed 205
davolfman 2:5454dee210ed 206 }
davolfman 0:b2f7400596ce 207 }