Team S - EDP 2 / Mbed 2 deprecated signal_processing

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Dependencies:   mbed

main.cpp@5:651843de21ce, 2018-02-14 (annotated)

Committer:
2247469r
Date:
Wed Feb 14 15:26:02 2018 +0000
Revision:
5:651843de21ce
Parent:
4:878821708feb 
Added flashing LED function (potential bugs).

Who changed what in which revision?

UserRevisionLine numberNew contents of line
2247469r 5:651843de21ce 1 //Rango says, hey there Connnor!
2236693B 0:005922ecb765 2
2236693B 0:005922ecb765 3 #include "mbed.h"
2236693B 0:005922ecb765 4
2247469r 5:651843de21ce 5 DigitalOut led(LED1);
2236693B 0:005922ecb765 6 AnalogIn Ain(PTB1);
2236693B 0:005922ecb765 7
2236693B 2:29c3d03c9231 8 int const MAX_B = 10;
2236693B 3:c9f4c9c84e36 9 int const alpha = 0.5;
2236693B 2:29c3d03c9231 10 int const AVG_LEN = 160;
2247469r 5:651843de21ce 11 float const DISP_MAX = 7; //size of display indexed from 0
2247469r 5:651843de21ce 12 float const trigger_high = DISP_MAX/2 + 1;
2247469r 5:651843de21ce 13 float const trigger_low = DISP_MAX/2 - 1;
2236693B 2:29c3d03c9231 14
2236693B 2:29c3d03c9231 15 int sample_buffer[2*MAX_B] = {};
2236693B 2:29c3d03c9231 16 int local_buffer[2*MAX_B] = {};
2236693B 2:29c3d03c9231 17 int avg_buffer[AVG_LEN] = {};
2236693B 0:005922ecb765 18 int read = 0;
2236693B 0:005922ecb765 19 int write = 0;
2236693B 0:005922ecb765 20
2236693B 2:29c3d03c9231 21 int avg_write = 0;
2236693B 2:29c3d03c9231 22
2236693B 2:29c3d03c9231 23 int avg_sum;
2236693B 3:c9f4c9c84e36 24 bool first;
2236693B 3:c9f4c9c84e36 25 float avg;
2247469r 5:651843de21ce 26 float pre_point;
2247469r 5:651843de21ce 27
2247469r 5:651843de21ce 28 bool rising = false;
2236693B 2:29c3d03c9231 29
2236693B 2:29c3d03c9231 30 Ticker sampler;
2236693B 2:29c3d03c9231 31
2236693B 4:878821708feb 32 void sampling () { //Sample Signal
2236693B 2:29c3d03c9231 33 unsigned int sample = Ain.read_u16();
2236693B 2:29c3d03c9231 34 sample_buffer[write++] = sample;
2236693B 2:29c3d03c9231 35 write = write%(2*MAX_B);
2236693B 2:29c3d03c9231 36
2236693B 2:29c3d03c9231 37 }
2236693B 2:29c3d03c9231 38
2247469r 5:651843de21ce 39 float min_of_avg(){
2247469r 5:651843de21ce 40 int min = avg_buffer[0];
2247469r 5:651843de21ce 41 for (int i = 0; i < AVG_LEN; i++){
2247469r 5:651843de21ce 42 if (avg_buffer[i] < min){
2247469r 5:651843de21ce 43 min = avg_buffer[i];
2247469r 5:651843de21ce 44 }
2247469r 5:651843de21ce 45 }
2247469r 5:651843de21ce 46 return min;
2247469r 5:651843de21ce 47 }
2247469r 5:651843de21ce 48
2247469r 5:651843de21ce 49 float max_of_avg(){
2247469r 5:651843de21ce 50 int max = avg_buffer[0];
2247469r 5:651843de21ce 51 for (int i = 0; i < AVG_LEN; i++){
2247469r 5:651843de21ce 52 if (avg_buffer[i] > max){
2247469r 5:651843de21ce 53 max = avg_buffer[i];
2247469r 5:651843de21ce 54 }
2247469r 5:651843de21ce 55 }
2247469r 5:651843de21ce 56 return max;
2247469r 5:651843de21ce 57 }
2247469r 5:651843de21ce 58
2247469r 5:651843de21ce 59 float normalise(float point) { //Normalise the value
2247469r 5:651843de21ce 60 float avg_min = min_of_avg();
2247469r 5:651843de21ce 61 return (DISP_MAX * (point / (max_of_avg() - avg_min)) + avg_min);
2236693B 3:c9f4c9c84e36 62 }
2236693B 3:c9f4c9c84e36 63
2236693B 4:878821708feb 64 float filter (float output) { //Filter signal digtally to make more precise
2247469r 5:651843de21ce 65 float point = alpha*output + (1- alpha)*pre_point;
2247469r 5:651843de21ce 66 point = normalise(point);
2236693B 3:c9f4c9c84e36 67 return point;
2236693B 3:c9f4c9c84e36 68 }
2236693B 3:c9f4c9c84e36 69
2247469r 5:651843de21ce 70 float average(){
2236693B 3:c9f4c9c84e36 71 float point;
2236693B 3:c9f4c9c84e36 72 avg = avg_sum/AVG_LEN;
2236693B 4:878821708feb 73 int normalised = avg_buffer[avg_write-1] - avg;
2236693B 4:878821708feb 74 point = filter(normalised);
2236693B 3:c9f4c9c84e36 75
2236693B 3:c9f4c9c84e36 76 return point;
2236693B 3:c9f4c9c84e36 77
2236693B 3:c9f4c9c84e36 78
2236693B 3:c9f4c9c84e36 79 }
2236693B 3:c9f4c9c84e36 80
2247469r 5:651843de21ce 81 bool above_trig_low(float point){
2247469r 5:651843de21ce 82 if(point <= trigger_low){
2247469r 5:651843de21ce 83 rising = false;
2247469r 5:651843de21ce 84 return true;
2247469r 5:651843de21ce 85 }
2247469r 5:651843de21ce 86 return false;
2247469r 5:651843de21ce 87 }
2247469r 5:651843de21ce 88
2247469r 5:651843de21ce 89 bool above_trig_high(float point){
2247469r 5:651843de21ce 90 if(point >= trigger_high){
2247469r 5:651843de21ce 91 rising = true;
2247469r 5:651843de21ce 92 return true;
2247469r 5:651843de21ce 93 }
2247469r 5:651843de21ce 94 return false;
2247469r 5:651843de21ce 95 }
2247469r 5:651843de21ce 96
2247469r 5:651843de21ce 97 void identify_pulse(float point) {
2247469r 5:651843de21ce 98 // Implementation of hysteresis
2247469r 5:651843de21ce 99 if(rising){
2247469r 5:651843de21ce 100 if (!above_trig_low(point)){
2247469r 5:651843de21ce 101 led = 1;
2247469r 5:651843de21ce 102 } else {
2247469r 5:651843de21ce 103 led = 0;
2247469r 5:651843de21ce 104 }
2247469r 5:651843de21ce 105 } else if (!rising){
2247469r 5:651843de21ce 106 if (!above_trig_high(point)){
2247469r 5:651843de21ce 107 led = 0;
2247469r 5:651843de21ce 108 } else {
2247469r 5:651843de21ce 109 led = 1;
2247469r 5:651843de21ce 110 }
2247469r 5:651843de21ce 111 }
2247469r 5:651843de21ce 112 }
2247469r 5:651843de21ce 113
2247469r 5:651843de21ce 114 float data_process() { //Setup for data process
2236693B 3:c9f4c9c84e36 115 float point ;
2236693B 2:29c3d03c9231 116 if (first) {
2236693B 2:29c3d03c9231 117 for (int i =0; i <MAX_B; i++) {
2247469r 5:651843de21ce 118 int data = local_buffer[i];
2247469r 5:651843de21ce 119 avg_buffer[avg_write] = data;
2236693B 2:29c3d03c9231 120 avg_write = (++avg_write) % AVG_LEN;
2247469r 5:651843de21ce 121 avg_sum += data;
2247469r 5:651843de21ce 122 }
2247469r 5:651843de21ce 123 if (avg_write == 0) {
2247469r 5:651843de21ce 124 first = false;
2247469r 5:651843de21ce 125 pre_point = local_buffer[MAX_B - 1];
2236693B 2:29c3d03c9231 126 }
2236693B 2:29c3d03c9231 127 }
2236693B 2:29c3d03c9231 128 else {
2236693B 2:29c3d03c9231 129 for (int i =0; i <MAX_B; i++) {
2236693B 2:29c3d03c9231 130 int data = local_buffer[i];
2236693B 2:29c3d03c9231 131 avg_sum = avg_sum + data - avg_buffer[avg_write];
2236693B 2:29c3d03c9231 132
2236693B 2:29c3d03c9231 133 avg_buffer[avg_write] = data;
2247469r 5:651843de21ce 134 avg_write = (++avg_write) % AVG_LEN;
2247469r 5:651843de21ce 135 pre_point = point;
2247469r 5:651843de21ce 136 point = average();
2247469r 5:651843de21ce 137 identify_pulse(point);
2236693B 2:29c3d03c9231 138 }
2236693B 2:29c3d03c9231 139 }
2236693B 4:878821708feb 140 return point; //The tenth point
2236693B 2:29c3d03c9231 141
2236693B 2:29c3d03c9231 142 }
2236693B 2:29c3d03c9231 143
2247469r 5:651843de21ce 144 void write_to_display(float output) {
2236693B 0:005922ecb765 145 }
2236693B 0:005922ecb765 146
2236693B 0:005922ecb765 147 int main() {
2236693B 0:005922ecb765 148 sampler.attach(&sampling, 0.0125); //Sample at 80Hz
2236693B 0:005922ecb765 149
2236693B 0:005922ecb765 150 while(1) {
2236693B 2:29c3d03c9231 151 if (write-read > MAX_B || read-write > MAX_B) { // |write-read| > MAX_B/2
2236693B 0:005922ecb765 152 for(int i = 0; i < MAX_B/2; i++) {
2236693B 0:005922ecb765 153 local_buffer[i] = sample_buffer[read];
2236693B 0:005922ecb765 154 read = (++read) % MAX_B;
2236693B 0:005922ecb765 155 }
2236693B 0:005922ecb765 156 }
2236693B 4:878821708feb 157 float output = data_process();
2247469r 5:651843de21ce 158
2236693B 4:878821708feb 159 write_to_display(output);
2236693B 0:005922ecb765 160 }
2236693B 0:005922ecb765 161 }
2236693B 0:005922ecb765 162
2236693B 0:005922ecb765 163
2236693B 0:005922ecb765 164