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Dependencies:   biquadFilter mbed

emg-utils.cpp@0:44d3f99b08c1, 2016-11-02 (annotated)

Committer:
ofosakar
Date:
Wed Nov 02 11:08:53 2016 +0000
Revision:
0:44d3f99b08c1
Child:
1:984b6b6812c7
EMG processing for two EMG signals.;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ofosakar 0:44d3f99b08c1 1 #include "mbed.h"
ofosakar 0:44d3f99b08c1 2 #include "HIDScope.h"
ofosakar 0:44d3f99b08c1 3 #include "BiQuad.h"
ofosakar 0:44d3f99b08c1 4 #include "math.h"
ofosakar 0:44d3f99b08c1 5 #include "emg-utils.h"
ofosakar 0:44d3f99b08c1 6
ofosakar 0:44d3f99b08c1 7
ofosakar 0:44d3f99b08c1 8 AnalogIn emg1(A0);
ofosakar 0:44d3f99b08c1 9 AnalogIn emg2(A1);
ofosakar 0:44d3f99b08c1 10
ofosakar 0:44d3f99b08c1 11 HIDScope scope(6);
ofosakar 0:44d3f99b08c1 12 Ticker ticker;
ofosakar 0:44d3f99b08c1 13
ofosakar 0:44d3f99b08c1 14 BiQuadChain bqc1;
ofosakar 0:44d3f99b08c1 15 BiQuadChain bqc2;
ofosakar 0:44d3f99b08c1 16
ofosakar 0:44d3f99b08c1 17 // EMG BIQUAD 1
ofosakar 0:44d3f99b08c1 18 //Bandpass butterworth filter + Notch butterworth filter.
ofosakar 0:44d3f99b08c1 19 //Bandpass: 10 --- 500 Hz
ofosakar 0:44d3f99b08c1 20 //No Bandpass filters
ofosakar 0:44d3f99b08c1 21 //Nothc: 50 +- 2 Hz
ofosakar 0:44d3f99b08c1 22 BiQuad bq11( 9.93756e-01, -1.89024e+00, 9.93756e-01, -1.89024e+00, 9.87512e-01 );
ofosakar 0:44d3f99b08c1 23
ofosakar 0:44d3f99b08c1 24 // EMG BIQUAD 2
ofosakar 0:44d3f99b08c1 25 //Bandpass butterworth filter + Notch butterworth filter.
ofosakar 0:44d3f99b08c1 26 //Bandpass: 10 --- 500 Hz
ofosakar 0:44d3f99b08c1 27 //No Bandpass filters
ofosakar 0:44d3f99b08c1 28 //Nothc: 50 +- 2 Hz
ofosakar 0:44d3f99b08c1 29 BiQuad bq12( 9.93756e-01, -1.89024e+00, 9.93756e-01, -1.89024e+00, 9.87512e-01 );
ofosakar 0:44d3f99b08c1 30
ofosakar 0:44d3f99b08c1 31
ofosakar 0:44d3f99b08c1 32 volatile float TOTAL_SAMPLE_SUM = 0;
ofosakar 0:44d3f99b08c1 33 volatile long NUMBER_SAMPLES = 0;
ofosakar 0:44d3f99b08c1 34
ofosakar 0:44d3f99b08c1 35 const int numEmgCache = 50;
ofosakar 0:44d3f99b08c1 36 float emgCache1[numEmgCache]; //sorted from new to old;
ofosakar 0:44d3f99b08c1 37 float emgCache2[numEmgCache]; //sorted from new to old;
ofosakar 0:44d3f99b08c1 38
ofosakar 0:44d3f99b08c1 39 void addFirst(float newValue, float array[], int size) {
ofosakar 0:44d3f99b08c1 40 for (int i = size - 2; i >= 0; i--) {
ofosakar 0:44d3f99b08c1 41 array[i+1] = array[i];
ofosakar 0:44d3f99b08c1 42 }
ofosakar 0:44d3f99b08c1 43 array[0] = newValue;
ofosakar 0:44d3f99b08c1 44 }
ofosakar 0:44d3f99b08c1 45
ofosakar 0:44d3f99b08c1 46 float average(float newValue, float array[], int size) {
ofosakar 0:44d3f99b08c1 47 float sum = 0;
ofosakar 0:44d3f99b08c1 48 for (int i = size - 2; i >= 0; i--) {
ofosakar 0:44d3f99b08c1 49 sum += array[i];
ofosakar 0:44d3f99b08c1 50 }
ofosakar 0:44d3f99b08c1 51 // array[0] = newValue;
ofosakar 0:44d3f99b08c1 52 sum += newValue;
ofosakar 0:44d3f99b08c1 53 return sum / size;
ofosakar 0:44d3f99b08c1 54 }
ofosakar 0:44d3f99b08c1 55
ofosakar 0:44d3f99b08c1 56 //shifts the array by adding the new emg value up front.
ofosakar 0:44d3f99b08c1 57 //returns the new calculated average
ofosakar 0:44d3f99b08c1 58 float movingAverage(float newValue, float array[], int size) {
ofosakar 0:44d3f99b08c1 59 float sum = 0;
ofosakar 0:44d3f99b08c1 60 for (int i = size - 2; i >= 0; i--) {
ofosakar 0:44d3f99b08c1 61 array[i+1] = array[i];
ofosakar 0:44d3f99b08c1 62 sum += array[i];
ofosakar 0:44d3f99b08c1 63 }
ofosakar 0:44d3f99b08c1 64 array[0] = newValue;
ofosakar 0:44d3f99b08c1 65 sum += newValue;
ofosakar 0:44d3f99b08c1 66 return sum / size;
ofosakar 0:44d3f99b08c1 67 }
ofosakar 0:44d3f99b08c1 68
ofosakar 0:44d3f99b08c1 69 float sum(float array[], int size) {
ofosakar 0:44d3f99b08c1 70 float sum = 0;
ofosakar 0:44d3f99b08c1 71 for (int i = 0; i < size; i++) {
ofosakar 0:44d3f99b08c1 72 sum += array[i];
ofosakar 0:44d3f99b08c1 73 }
ofosakar 0:44d3f99b08c1 74 return sum;
ofosakar 0:44d3f99b08c1 75 }
ofosakar 0:44d3f99b08c1 76
ofosakar 0:44d3f99b08c1 77 float mean(float array[], int size) {
ofosakar 0:44d3f99b08c1 78 return sum(array, size) / size;
ofosakar 0:44d3f99b08c1 79 }
ofosakar 0:44d3f99b08c1 80
ofosakar 0:44d3f99b08c1 81 float meanSquare(float array[], int size) {
ofosakar 0:44d3f99b08c1 82 float naam[size];
ofosakar 0:44d3f99b08c1 83 for(int i = 0; i < size; i++) {
ofosakar 0:44d3f99b08c1 84 naam[i] = pow(array[i], 2);
ofosakar 0:44d3f99b08c1 85 }
ofosakar 0:44d3f99b08c1 86 return sum(naam, size) / size;
ofosakar 0:44d3f99b08c1 87 }
ofosakar 0:44d3f99b08c1 88
ofosakar 0:44d3f99b08c1 89 float variance(float array[], int size, float avg) {
ofosakar 0:44d3f99b08c1 90 float squaredDifferences[size];
ofosakar 0:44d3f99b08c1 91 for (int i = 0; i < size; i++) {
ofosakar 0:44d3f99b08c1 92 float difference = array[i] - avg;
ofosakar 0:44d3f99b08c1 93 squaredDifferences[i] = difference*difference;
ofosakar 0:44d3f99b08c1 94 }
ofosakar 0:44d3f99b08c1 95 return mean(squaredDifferences, size);
ofosakar 0:44d3f99b08c1 96 }
ofosakar 0:44d3f99b08c1 97
ofosakar 0:44d3f99b08c1 98 float standardDeviation(float array[], int size, float avg) {
ofosakar 0:44d3f99b08c1 99 return sqrt(variance(array, size, avg));
ofosakar 0:44d3f99b08c1 100 }
ofosakar 0:44d3f99b08c1 101
ofosakar 0:44d3f99b08c1 102 int decide(float value, float threshold) {
ofosakar 0:44d3f99b08c1 103 return value < threshold ? 0 : 1;
ofosakar 0:44d3f99b08c1 104 }
ofosakar 0:44d3f99b08c1 105
ofosakar 0:44d3f99b08c1 106 float rectifier(float value) {
ofosakar 0:44d3f99b08c1 107 return fabs(value - 0.5f)*2.0f;
ofosakar 0:44d3f99b08c1 108 }
ofosakar 0:44d3f99b08c1 109
ofosakar 0:44d3f99b08c1 110 void processEMG() {
ofosakar 0:44d3f99b08c1 111 float emgOne = emg1.read();
ofosakar 0:44d3f99b08c1 112 scope.set(0, emgOne);
ofosakar 0:44d3f99b08c1 113 float notch1 = bqc1.step( emgOne );
ofosakar 0:44d3f99b08c1 114
ofosakar 0:44d3f99b08c1 115 float emgTwo = emg2.read();
ofosakar 0:44d3f99b08c1 116 scope.set(1, emgTwo);
ofosakar 0:44d3f99b08c1 117 float notch2 = bqc2.step( emgTwo );
ofosakar 0:44d3f99b08c1 118
ofosakar 0:44d3f99b08c1 119
ofosakar 0:44d3f99b08c1 120
ofosakar 0:44d3f99b08c1 121 float rect1 = rectifier(notch1);
ofosakar 0:44d3f99b08c1 122 // scope.set(2, rect1);
ofosakar 0:44d3f99b08c1 123
ofosakar 0:44d3f99b08c1 124 float rect2 = rectifier(notch2);
ofosakar 0:44d3f99b08c1 125 // scope.set(3, rect2);
ofosakar 0:44d3f99b08c1 126
ofosakar 0:44d3f99b08c1 127
ofosakar 0:44d3f99b08c1 128 float filtered1 = movingAverage( rect1, emgCache1, numEmgCache);
ofosakar 0:44d3f99b08c1 129 scope.set(2, filtered1);
ofosakar 0:44d3f99b08c1 130
ofosakar 0:44d3f99b08c1 131 float filtered2 = movingAverage( rect2, emgCache2, numEmgCache);
ofosakar 0:44d3f99b08c1 132 scope.set(3, filtered2);
ofosakar 0:44d3f99b08c1 133
ofosakar 0:44d3f99b08c1 134 float threshold1 = 0.114318;
ofosakar 0:44d3f99b08c1 135 float threshold2 = 0.118785;
ofosakar 0:44d3f99b08c1 136 int decide1 = decide(filtered1 , threshold1);
ofosakar 0:44d3f99b08c1 137 scope.set(4, decide1);
ofosakar 0:44d3f99b08c1 138
ofosakar 0:44d3f99b08c1 139 int decide2 = decide(filtered2 , threshold2);
ofosakar 0:44d3f99b08c1 140 scope.set(5, decide2);
ofosakar 0:44d3f99b08c1 141
ofosakar 0:44d3f99b08c1 142
ofosakar 0:44d3f99b08c1 143 scope.send();
ofosakar 0:44d3f99b08c1 144 }
ofosakar 0:44d3f99b08c1 145
ofosakar 0:44d3f99b08c1 146 int main()
ofosakar 0:44d3f99b08c1 147 {
ofosakar 0:44d3f99b08c1 148 bqc1.add( &bq11 );
ofosakar 0:44d3f99b08c1 149 bqc2.add( &bq12 );
ofosakar 0:44d3f99b08c1 150
ofosakar 0:44d3f99b08c1 151
ofosakar 0:44d3f99b08c1 152 // bqc1.add( &bq11 );
ofosakar 0:44d3f99b08c1 153 // bqc2.add( &bq12 );
ofosakar 0:44d3f99b08c1 154 // 500 HZ Ticker
ofosakar 0:44d3f99b08c1 155 ticker.attach(&processEMG, 0.002);
ofosakar 0:44d3f99b08c1 156 while (true);
ofosakar 0:44d3f99b08c1 157 }