Keith G / Mbed 2 deprecated MoppyController

An floppy drive audio generator using dsp on live audio

Dependencies:   Terminal asyncADC mbed-dsp mbed

main2.cpp@1:02553973d9cf, 2017-05-24 (annotated)

Committer:
Condo2k4
Date:
Wed May 24 11:59:27 2017 +0000
Revision:
1:02553973d9cf
Parent:
0:84c336a81482 
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Condo2k4 0:84c336a81482 1 #include "mbed.h"
Condo2k4 0:84c336a81482 2 #include <algorithm>
Condo2k4 0:84c336a81482 3 #include "asyncADC.h"
Condo2k4 0:84c336a81482 4 #include "arm_math.h"
Condo2k4 0:84c336a81482 5 #include "arm_common_tables.h"
Condo2k4 0:84c336a81482 6 #include "moppy.h"
Condo2k4 0:84c336a81482 7
Condo2k4 0:84c336a81482 8 #define AUDIO_PIN (A0)
Condo2k4 0:84c336a81482 9
Condo2k4 0:84c336a81482 10 Serial pc(USBTX, USBRX, 115200);
Condo2k4 0:84c336a81482 11 DigitalOut red(LED_RED), green(LED_GREEN), blue(LED_BLUE);
Condo2k4 0:84c336a81482 12 Timer timer;
Condo2k4 0:84c336a81482 13 InterruptIn filterBtn(SW2);
Condo2k4 0:84c336a81482 14 bool useFilter = false;
Condo2k4 0:84c336a81482 15
Condo2k4 0:84c336a81482 16 #define LED_ON (0)
Condo2k4 0:84c336a81482 17 #define LED_OFF (1)
Condo2k4 0:84c336a81482 18
Condo2k4 0:84c336a81482 19 #define FFT_SIZE 1024
Condo2k4 0:84c336a81482 20 #include "fft.h"
Condo2k4 0:84c336a81482 21
Condo2k4 0:84c336a81482 22 #define TARGET_SAMPLE_RATE_HZ 19200 // Sample rate in Hertz
Condo2k4 0:84c336a81482 23 float achievedSampleRate;
Condo2k4 0:84c336a81482 24
Condo2k4 0:84c336a81482 25 #define BIN_TO_FREQ(bin) ((bin*(long)achievedSampleRate)/FFT_SIZE)
Condo2k4 0:84c336a81482 26
Condo2k4 0:84c336a81482 27 #define PC_BUFFER_SIZE (FFT_SIZE+30)
Condo2k4 0:84c336a81482 28
Condo2k4 0:84c336a81482 29 //BUFFERS
Condo2k4 0:84c336a81482 30
Condo2k4 0:84c336a81482 31 uint16_t adcBuffer[FFT_SIZE*2];
Condo2k4 0:84c336a81482 32 int spectrumBufferIndex = 0, spectrumBufferLength = 0;
Condo2k4 0:84c336a81482 33 char spectrumBuffer[PC_BUFFER_SIZE];
Condo2k4 0:84c336a81482 34 float fftBuffer[FFT_SIZE*2];
Condo2k4 0:84c336a81482 35 float magnitudes[FFT_SIZE];
Condo2k4 0:84c336a81482 36
Condo2k4 0:84c336a81482 37 // INTERRUPTS
Condo2k4 0:84c336a81482 38
Condo2k4 0:84c336a81482 39 volatile int sectionCounter = 0;
Condo2k4 0:84c336a81482 40 volatile bool sectionFilled = false, toggleFilter;
Condo2k4 0:84c336a81482 41 volatile uint32_t sectionStart, sectionEnd;
Condo2k4 0:84c336a81482 42
Condo2k4 0:84c336a81482 43 void callback(uint32_t start, uint32_t end) {
Condo2k4 0:84c336a81482 44 sectionFilled = true;
Condo2k4 0:84c336a81482 45 sectionCounter++;
Condo2k4 0:84c336a81482 46 sectionStart = start;
Condo2k4 0:84c336a81482 47 sectionEnd = end;
Condo2k4 0:84c336a81482 48 }
Condo2k4 0:84c336a81482 49
Condo2k4 0:84c336a81482 50 void press() {
Condo2k4 0:84c336a81482 51 toggleFilter=true;
Condo2k4 0:84c336a81482 52 }
Condo2k4 0:84c336a81482 53
Condo2k4 0:84c336a81482 54 // UTILS
Condo2k4 0:84c336a81482 55
Condo2k4 0:84c336a81482 56 uint32_t ceilToPowerOf2(uint32_t i) {
Condo2k4 0:84c336a81482 57 i--;
Condo2k4 0:84c336a81482 58 i|=(i>>1);
Condo2k4 0:84c336a81482 59 i|=(i>>2);
Condo2k4 0:84c336a81482 60 i|=(i>>4);
Condo2k4 0:84c336a81482 61 i|=(i>>8);
Condo2k4 0:84c336a81482 62 i|=(i>>16);
Condo2k4 0:84c336a81482 63 return i+1;
Condo2k4 0:84c336a81482 64 }
Condo2k4 0:84c336a81482 65
Condo2k4 0:84c336a81482 66 void trySwp(int16_t *indices, float *magnitudes, int a, int b) {
Condo2k4 0:84c336a81482 67 if(magnitudes[indices[a]]>magnitudes[indices[b]]) {
Condo2k4 0:84c336a81482 68 int x = indices[a];
Condo2k4 0:84c336a81482 69 indices[a] = indices[b];
Condo2k4 0:84c336a81482 70 indices[b] = x;
Condo2k4 0:84c336a81482 71 }
Condo2k4 0:84c336a81482 72 }
Condo2k4 0:84c336a81482 73
Condo2k4 0:84c336a81482 74 void sort(int16_t *indices, float *magnitudes, int size) {
Condo2k4 0:84c336a81482 75 indices[0] = 0;
Condo2k4 0:84c336a81482 76 for(int i=1; i<size; i++) {
Condo2k4 0:84c336a81482 77 indices[i]=i;
Condo2k4 0:84c336a81482 78 for(int j=i; j-->0;) {
Condo2k4 0:84c336a81482 79 trySwp(indices, magnitudes, j, j+1);
Condo2k4 0:84c336a81482 80 }
Condo2k4 0:84c336a81482 81 }
Condo2k4 0:84c336a81482 82 }
Condo2k4 0:84c336a81482 83
Condo2k4 0:84c336a81482 84 bool magComparator(int const & a, int const & b) {
Condo2k4 0:84c336a81482 85 return magnitudes[a] > magnitudes[b];
Condo2k4 0:84c336a81482 86 }
Condo2k4 0:84c336a81482 87
Condo2k4 0:84c336a81482 88 // POST PROCESSING
Condo2k4 0:84c336a81482 89
Condo2k4 0:84c336a81482 90 float mqe(float* fft) {
Condo2k4 0:84c336a81482 91 float t0_real, t0_imag, t1_real, t1_imag; //temp values
Condo2k4 0:84c336a81482 92
Condo2k4 0:84c336a81482 93 t0_real = fft[0]-fft[4];
Condo2k4 0:84c336a81482 94 t0_imag = fft[1]-fft[5];
Condo2k4 0:84c336a81482 95
Condo2k4 0:84c336a81482 96 t1_real = fft[2]*2.0f - (fft[0] + fft[4]);
Condo2k4 0:84c336a81482 97 t1_imag = fft[3]*2.0f - (fft[1] + fft[5]);
Condo2k4 0:84c336a81482 98
Condo2k4 0:84c336a81482 99 return (t0_real*t1_real + t0_imag*t1_imag)/(t1_real*t1_real + t1_imag*t1_imag);
Condo2k4 0:84c336a81482 100 }
Condo2k4 0:84c336a81482 101
Condo2k4 0:84c336a81482 102 void modifiedQuadraticEstimator() {
Condo2k4 0:84c336a81482 103 //Post process
Condo2k4 0:84c336a81482 104 float prev = mqe(&fftBuffer[2]);
Condo2k4 0:84c336a81482 105 for(int i=4; i<FFT_SIZE/2; i+=2) {
Condo2k4 0:84c336a81482 106 //Eric Jacobsen's Modified Quadratic Estimator
Condo2k4 0:84c336a81482 107 float curr = mqe(&fftBuffer[i]);
Condo2k4 0:84c336a81482 108 fftBuffer[i-2]+=prev;
Condo2k4 0:84c336a81482 109 prev = curr;
Condo2k4 0:84c336a81482 110 }
Condo2k4 0:84c336a81482 111 fftBuffer[FFT_SIZE/2]+=prev;
Condo2k4 0:84c336a81482 112 }
Condo2k4 0:84c336a81482 113
Condo2k4 0:84c336a81482 114 float getMag(int index) {
Condo2k4 0:84c336a81482 115 return (index<1 && index>=FFT_SIZE/2) ? 0.0f : magnitudes[index];
Condo2k4 0:84c336a81482 116 }
Condo2k4 0:84c336a81482 117
Condo2k4 0:84c336a81482 118 #define FILTER_CUTOFF (10000.0f)
Condo2k4 0:84c336a81482 119 void localMaximaRad10() {
Condo2k4 0:84c336a81482 120 float p10, p9, p8, p7, p6, p5, p4, p3, p2, p1, c, n1, n2, n3, n4, n5, n6, n7, n8, n9, n10;
Condo2k4 0:84c336a81482 121 c = getMag(1);
Condo2k4 0:84c336a81482 122 n1 = getMag(2);
Condo2k4 0:84c336a81482 123 n2 = getMag(3);
Condo2k4 0:84c336a81482 124 n3 = getMag(4);
Condo2k4 0:84c336a81482 125 n4 = getMag(5);
Condo2k4 0:84c336a81482 126 n5 = getMag(6);
Condo2k4 0:84c336a81482 127 n6 = getMag(7);
Condo2k4 0:84c336a81482 128 n7 = getMag(8);
Condo2k4 0:84c336a81482 129 n8 = getMag(9);
Condo2k4 0:84c336a81482 130 n9 = getMag(10);
Condo2k4 0:84c336a81482 131 n10 = getMag(11);
Condo2k4 0:84c336a81482 132
Condo2k4 0:84c336a81482 133 magnitudes[1] = (c>=FILTER_CUTOFF && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 134 p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(12);
Condo2k4 0:84c336a81482 135 magnitudes[2] = (c>=FILTER_CUTOFF && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 136 p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(13);
Condo2k4 0:84c336a81482 137 magnitudes[3] = (c>=FILTER_CUTOFF && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 138 p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(14);
Condo2k4 0:84c336a81482 139 magnitudes[4] = (c>=FILTER_CUTOFF && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 140 p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(15);
Condo2k4 0:84c336a81482 141 magnitudes[5] = (c>=FILTER_CUTOFF && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 142 p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(16);
Condo2k4 0:84c336a81482 143 magnitudes[6] = (c>=FILTER_CUTOFF && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 144 p6=p5; p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(17);
Condo2k4 0:84c336a81482 145 magnitudes[7] = (c>=FILTER_CUTOFF && c>p6 && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 146 p7=p6; p6=p5; p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(18);
Condo2k4 0:84c336a81482 147 magnitudes[8] = (c>=FILTER_CUTOFF && c>p7 && c>p6 && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 148 p8=p7; p7=p6; p6=p5; p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(19);
Condo2k4 0:84c336a81482 149 magnitudes[9] = (c>=FILTER_CUTOFF && c>p8 && c>p7 && c>p6 && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 150 p9=p8; p8=p7; p7=p6; p6=p5; p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(20);
Condo2k4 0:84c336a81482 151 magnitudes[10]= (c>=FILTER_CUTOFF && c>p9 && c>p8 && c>p7 && c>p6 && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 152
Condo2k4 0:84c336a81482 153 for(int i=11; i<FFT_SIZE/2; i++) {
Condo2k4 0:84c336a81482 154 p10=p9; p9=p8; p8=p7; p7=p6; p6=p5; p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=n7; n7=n8; n8=n9; n9=n10; n10=getMag(i+10);
Condo2k4 0:84c336a81482 155 magnitudes[i] = (c>=FILTER_CUTOFF && c>p10 && c>p9 && c>p8 && c>p7 && c>p6 && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6 && c>=n7 && c>=n8 && c>=n9 && c>=n10) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 156 }
Condo2k4 0:84c336a81482 157 }
Condo2k4 0:84c336a81482 158 void localMaximaRad6() {
Condo2k4 0:84c336a81482 159 float p6, p5, p4, p3, p2, p1, c, n1, n2, n3, n4, n5, n6;
Condo2k4 0:84c336a81482 160 c = getMag(1);
Condo2k4 0:84c336a81482 161 n1 = getMag(2);
Condo2k4 0:84c336a81482 162 n2 = getMag(3);
Condo2k4 0:84c336a81482 163 n3 = getMag(4);
Condo2k4 0:84c336a81482 164 n4 = getMag(5);
Condo2k4 0:84c336a81482 165 n5 = getMag(6);
Condo2k4 0:84c336a81482 166 n6 = getMag(7);
Condo2k4 0:84c336a81482 167
Condo2k4 0:84c336a81482 168 magnitudes[1] = (c>=FILTER_CUTOFF && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 169 p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=getMag(5);
Condo2k4 0:84c336a81482 170 magnitudes[2] = (c>=FILTER_CUTOFF && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 171 p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=getMag(6);
Condo2k4 0:84c336a81482 172 magnitudes[3] = (c>=FILTER_CUTOFF && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 173 p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=getMag(7);
Condo2k4 0:84c336a81482 174 magnitudes[4] = (c>=FILTER_CUTOFF && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 175 p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=getMag(8);
Condo2k4 0:84c336a81482 176 magnitudes[5] = (c>=FILTER_CUTOFF && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 177 p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=n4; n4=n5; n5=n6; n6=getMag(9);
Condo2k4 0:84c336a81482 178 magnitudes[6] = (c>=FILTER_CUTOFF && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 179
Condo2k4 0:84c336a81482 180 for(int i=7; i<FFT_SIZE/2; i++) {
Condo2k4 0:84c336a81482 181 p6=p5; p5=p4; p4=p3; p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=getMag(i+6);
Condo2k4 0:84c336a81482 182 magnitudes[i] = (c>=FILTER_CUTOFF && c>p6 && c>p5 && c>p4 && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3 && c>=n4 && c>=n5 && c>=n6) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 183 }
Condo2k4 0:84c336a81482 184 }
Condo2k4 0:84c336a81482 185 void localMaximaRad3() {
Condo2k4 0:84c336a81482 186 float p3, p2, p1, c, n1, n2, n3;
Condo2k4 0:84c336a81482 187 c = getMag(1);
Condo2k4 0:84c336a81482 188 n1 = getMag(2);
Condo2k4 0:84c336a81482 189 n2 = getMag(3);
Condo2k4 0:84c336a81482 190 n3 = getMag(4);
Condo2k4 0:84c336a81482 191
Condo2k4 0:84c336a81482 192 magnitudes[1] = (c>=FILTER_CUTOFF && c>=n1 && c>=n2 && c>=n3) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 193 p1=c; c=n1; n1=n2; n2=n3; n3=getMag(5);
Condo2k4 0:84c336a81482 194 magnitudes[2] = (c>=FILTER_CUTOFF && c>p1 && c>=n1 && c>=n2 && c>=n3) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 195 p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=getMag(6);
Condo2k4 0:84c336a81482 196 magnitudes[3] = (c>=FILTER_CUTOFF && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 197
Condo2k4 0:84c336a81482 198 for(int i=4; i<FFT_SIZE/2; i++) {
Condo2k4 0:84c336a81482 199 p3=p2; p2=p1; p1=c; c=n1; n1=n2; n2=n3; n3=getMag(i+3);
Condo2k4 0:84c336a81482 200 magnitudes[i] = (c>=FILTER_CUTOFF && c>p3 && c>p2 && c>p1 && c>=n1 && c>=n2 && c>=n3) ? sqrt(c) : 0;
Condo2k4 0:84c336a81482 201 }
Condo2k4 0:84c336a81482 202 }
Condo2k4 0:84c336a81482 203
Condo2k4 0:84c336a81482 204 // MAIN
Condo2k4 0:84c336a81482 205
Condo2k4 0:84c336a81482 206 int main()
Condo2k4 0:84c336a81482 207 {
Condo2k4 0:84c336a81482 208 filterBtn.fall(press);
Condo2k4 0:84c336a81482 209 red = LED_OFF;
Condo2k4 0:84c336a81482 210 green = LED_OFF;
Condo2k4 0:84c336a81482 211 blue = LED_OFF;
Condo2k4 0:84c336a81482 212
Condo2k4 0:84c336a81482 213 Moppy moppy(D1, D0, 38400); // tx, rx, baud
Condo2k4 0:84c336a81482 214
Condo2k4 0:84c336a81482 215 achievedSampleRate = approximateFrequency((float)TARGET_SAMPLE_RATE_HZ);
Condo2k4 0:84c336a81482 216 switch(asyncAnalogToCircularBuffer(AUDIO_PIN, adcBuffer, 2*FFT_SIZE, TARGET_SAMPLE_RATE_HZ, callback)) {
Condo2k4 0:84c336a81482 217 case E_ASYNC_ADC_ACTIVE:
Condo2k4 0:84c336a81482 218 error("AsyncADC already in use");
Condo2k4 0:84c336a81482 219 case E_DMA_IN_USE:
Condo2k4 0:84c336a81482 220 error("DMA already in use");
Condo2k4 0:84c336a81482 221 case E_INVALID_BUFFER_SIZE:
Condo2k4 0:84c336a81482 222 error("Invalid destination buffer size");
Condo2k4 0:84c336a81482 223 }
Condo2k4 0:84c336a81482 224
Condo2k4 0:84c336a81482 225 //fixed header
Condo2k4 0:84c336a81482 226 spectrumBuffer[0]=255;
Condo2k4 0:84c336a81482 227 spectrumBuffer[1]=(FFT_SIZE/2-1)/255;
Condo2k4 0:84c336a81482 228 spectrumBuffer[2]=(FFT_SIZE/2-1)%255;
Condo2k4 0:84c336a81482 229
Condo2k4 0:84c336a81482 230 timer.start();
Condo2k4 0:84c336a81482 231
Condo2k4 0:84c336a81482 232 while(1) {
Condo2k4 0:84c336a81482 233 if(toggleFilter) {
Condo2k4 0:84c336a81482 234 useFilter = !useFilter;
Condo2k4 0:84c336a81482 235 toggleFilter = false;
Condo2k4 0:84c336a81482 236 }
Condo2k4 0:84c336a81482 237 if(sectionFilled) {
Condo2k4 0:84c336a81482 238 if(useFilter)
Condo2k4 0:84c336a81482 239 green = LED_ON;
Condo2k4 0:84c336a81482 240 else
Condo2k4 0:84c336a81482 241 blue = LED_ON;
Condo2k4 0:84c336a81482 242
Condo2k4 0:84c336a81482 243 bool buildSpectrumBuffer = false;
Condo2k4 0:84c336a81482 244
Condo2k4 0:84c336a81482 245 if(spectrumBufferIndex==spectrumBufferLength) {
Condo2k4 0:84c336a81482 246 buildSpectrumBuffer = true;
Condo2k4 0:84c336a81482 247 spectrumBufferIndex = 0;
Condo2k4 0:84c336a81482 248 }
Condo2k4 0:84c336a81482 249
Condo2k4 0:84c336a81482 250 timer.reset();
Condo2k4 0:84c336a81482 251
Condo2k4 0:84c336a81482 252 //convert to floating point
Condo2k4 0:84c336a81482 253 for(int i=sectionStart, j=0; i<=sectionEnd; i++, j+=2) {
Condo2k4 0:84c336a81482 254 fftBuffer[j] = (float)adcBuffer[i];
Condo2k4 0:84c336a81482 255 fftBuffer[j+1] = 0.0f;
Condo2k4 0:84c336a81482 256 }
Condo2k4 0:84c336a81482 257
Condo2k4 0:84c336a81482 258 // Calculate FFT if a full sample is available.
Condo2k4 0:84c336a81482 259 // Run FFT on sample data.
Condo2k4 0:84c336a81482 260 arm_cfft_f32(FFT_BUFFER, fftBuffer, 0, 1);
Condo2k4 0:84c336a81482 261 // Calculate magnitude of complex numbers output by the FFT.
Condo2k4 0:84c336a81482 262
Condo2k4 0:84c336a81482 263 //Convert FFT complex vectors to magnitudes
Condo2k4 0:84c336a81482 264 arm_cmplx_mag_f32(fftBuffer, magnitudes, FFT_SIZE);
Condo2k4 0:84c336a81482 265
Condo2k4 0:84c336a81482 266 //Post Process / Filtering
Condo2k4 0:84c336a81482 267 if(useFilter) {
Condo2k4 0:84c336a81482 268 localMaximaRad10();
Condo2k4 0:84c336a81482 269 } else {
Condo2k4 0:84c336a81482 270 for(int i=FFT_SIZE/2; i-->0;) {
Condo2k4 0:84c336a81482 271 magnitudes[i]=magnitudes[i]<FILTER_CUTOFF ? 0.0f : sqrt(magnitudes[i]); //trivial amplitude filtering and normalise
Condo2k4 0:84c336a81482 272 }
Condo2k4 0:84c336a81482 273 }
Condo2k4 0:84c336a81482 274
Condo2k4 0:84c336a81482 275 if(buildSpectrumBuffer) {
Condo2k4 0:84c336a81482 276 spectrumBufferLength = 3;
Condo2k4 0:84c336a81482 277 //data
Condo2k4 0:84c336a81482 278 for(int i=1; i<(FFT_SIZE/2); i++) {
Condo2k4 0:84c336a81482 279 int m = ((int)magnitudes[i]+2)>>2;
Condo2k4 0:84c336a81482 280 spectrumBuffer[spectrumBufferLength++] = m>=254?254:m;
Condo2k4 0:84c336a81482 281 }
Condo2k4 0:84c336a81482 282 }
Condo2k4 0:84c336a81482 283
Condo2k4 0:84c336a81482 284 for(int i=moppy.getFloppyDrives(); i-->0;) {
Condo2k4 0:84c336a81482 285 int peak = 1;
Condo2k4 0:84c336a81482 286 for(int j=FFT_SIZE/2; j-->2;) {
Condo2k4 0:84c336a81482 287 if(magnitudes[j]>magnitudes[peak])
Condo2k4 0:84c336a81482 288 peak=j;
Condo2k4 0:84c336a81482 289 }
Condo2k4 0:84c336a81482 290 if(magnitudes[peak]<30.0f) {
Condo2k4 0:84c336a81482 291 moppy.setFrequency(i, 0);
Condo2k4 0:84c336a81482 292 while(i-->0)
Condo2k4 0:84c336a81482 293 moppy.setFrequency(i, 0);
Condo2k4 0:84c336a81482 294 break;
Condo2k4 0:84c336a81482 295 }
Condo2k4 0:84c336a81482 296 moppy.setFrequency(i, BIN_TO_FREQ(peak));
Condo2k4 0:84c336a81482 297 magnitudes[peak]*=0.5f;
Condo2k4 0:84c336a81482 298 if(buildSpectrumBuffer) {
Condo2k4 0:84c336a81482 299 spectrumBuffer[spectrumBufferLength++] = peak;
Condo2k4 0:84c336a81482 300 }
Condo2k4 0:84c336a81482 301 }
Condo2k4 0:84c336a81482 302 moppy.flush();
Condo2k4 0:84c336a81482 303
Condo2k4 0:84c336a81482 304 if(buildSpectrumBuffer) {
Condo2k4 0:84c336a81482 305 spectrumBuffer[spectrumBufferLength++] = 0; //mark end of playing
Condo2k4 0:84c336a81482 306 //process time
Condo2k4 0:84c336a81482 307 long usedTime = timer.read_us();
Condo2k4 0:84c336a81482 308 long availTime = 1000000*FFT_SIZE/achievedSampleRate;
Condo2k4 0:84c336a81482 309 long percent = usedTime*10000/availTime; //fixed point to 0.01%
Condo2k4 0:84c336a81482 310 spectrumBuffer[spectrumBufferLength++] = percent/255;
Condo2k4 0:84c336a81482 311 spectrumBuffer[spectrumBufferLength++] = percent%255;
Condo2k4 0:84c336a81482 312 }
Condo2k4 0:84c336a81482 313
Condo2k4 0:84c336a81482 314 if(useFilter)
Condo2k4 0:84c336a81482 315 green = LED_OFF;
Condo2k4 0:84c336a81482 316 else
Condo2k4 0:84c336a81482 317 blue = LED_OFF;
Condo2k4 0:84c336a81482 318
Condo2k4 0:84c336a81482 319 sectionFilled = false;
Condo2k4 0:84c336a81482 320 }
Condo2k4 0:84c336a81482 321
Condo2k4 0:84c336a81482 322 if(spectrumBufferIndex<spectrumBufferLength) {
Condo2k4 0:84c336a81482 323 pc.putc(spectrumBuffer[spectrumBufferIndex++]);
Condo2k4 0:84c336a81482 324 } else {
Condo2k4 0:84c336a81482 325 sleep();
Condo2k4 0:84c336a81482 326 }
Condo2k4 0:84c336a81482 327 }
Condo2k4 0:84c336a81482 328 }