Maik Overmars / Mbed 2 deprecated EMG

Working moving average filter. IIR filters (low pass, high pass) still have to be implemented via biquad.

Dependencies:   HIDScope biquadFilter mbed

Fork of EMG by Tom Tom

main.cpp@21:3ac3c2e9d9ae, 2018-10-12 (annotated)

Committer:
MaikOvermars
Date:
Fri Oct 12 13:12:31 2018 +0000
Revision:
21:3ac3c2e9d9ae
Parent:
20:97059009a491
Child:
22:d2393c670afd
working moving average filter for an emg signal. still have to look at biquadfilter coefficients

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vsluiter 0:32bb76391d89 1 #include "mbed.h"
MaikOvermars 21:3ac3c2e9d9ae 2 #include "BiQuad.h"
vsluiter 11:ce72ec658a95 3 #include "HIDScope.h"
vsluiter 0:32bb76391d89 4
vsluiter 4:8b298dfada81 5 //Define objects
MaikOvermars 21:3ac3c2e9d9ae 6 HIDScope scope(2); // We’re going to send 2 channels of data
tomlankhorst 19:2bf824669684 7 AnalogIn emg0( A0 );
tomlankhorst 19:2bf824669684 8 AnalogIn emg1( A1 );
tomlankhorst 19:2bf824669684 9
MaikOvermars 21:3ac3c2e9d9ae 10 Ticker emgSampleTicker;
MaikOvermars 21:3ac3c2e9d9ae 11
MaikOvermars 21:3ac3c2e9d9ae 12 // filter chains for high pass, low pass and notch filters
MaikOvermars 21:3ac3c2e9d9ae 13 BiQuadChain bqc;
MaikOvermars 21:3ac3c2e9d9ae 14 BiQuad bq1( 4.1660e04,8.3320e04,4.1660e04,1.4797e+00,.5582e01);
MaikOvermars 21:3ac3c2e9d9ae 15 BiQuad bq2( 1.0000e+00, 2.0000e+00, 1.0000e+00, 1.7010e+00,7.8850e01);
MaikOvermars 21:3ac3c2e9d9ae 16 volatile double y[50]= { };
MaikOvermars 21:3ac3c2e9d9ae 17 volatile int n = 0;
MaikOvermars 21:3ac3c2e9d9ae 18 volatile bool full = 0;
vsluiter 2:e314bb3b2d99 19
MaikOvermars 21:3ac3c2e9d9ae 20 void emgSample() {
MaikOvermars 21:3ac3c2e9d9ae 21 //double emgFiltered = bqc.step( emg0.read() );
MaikOvermars 21:3ac3c2e9d9ae 22 double emgFiltered = emg0.read();
MaikOvermars 21:3ac3c2e9d9ae 23 scope.set(0,emgFiltered);
MaikOvermars 21:3ac3c2e9d9ae 24
MaikOvermars 21:3ac3c2e9d9ae 25 // moving average
MaikOvermars 21:3ac3c2e9d9ae 26 y[n] = abs(emgFiltered - 0.45);
MaikOvermars 21:3ac3c2e9d9ae 27 double emgavg = 0;
MaikOvermars 21:3ac3c2e9d9ae 28 if(full == 0){
MaikOvermars 21:3ac3c2e9d9ae 29 for(int i=0;i<50;i++){
MaikOvermars 21:3ac3c2e9d9ae 30 emgavg = emgavg + y[i];
MaikOvermars 21:3ac3c2e9d9ae 31 }
MaikOvermars 21:3ac3c2e9d9ae 32 emgavg = emgavg/(n+1);
MaikOvermars 21:3ac3c2e9d9ae 33 }
MaikOvermars 21:3ac3c2e9d9ae 34 else{
MaikOvermars 21:3ac3c2e9d9ae 35 for(int i=0;i<50;i++){
MaikOvermars 21:3ac3c2e9d9ae 36 emgavg = emgavg + y[i];
MaikOvermars 21:3ac3c2e9d9ae 37 }
MaikOvermars 21:3ac3c2e9d9ae 38 emgavg = emgavg/50;
MaikOvermars 21:3ac3c2e9d9ae 39 }
MaikOvermars 21:3ac3c2e9d9ae 40 n++;
MaikOvermars 21:3ac3c2e9d9ae 41 if(n == 50){
MaikOvermars 21:3ac3c2e9d9ae 42 n = 0;
MaikOvermars 21:3ac3c2e9d9ae 43 full = 1;
MaikOvermars 21:3ac3c2e9d9ae 44 }
MaikOvermars 21:3ac3c2e9d9ae 45 scope.set(1,emgavg);
vsluiter 11:ce72ec658a95 46 scope.send();
MaikOvermars 21:3ac3c2e9d9ae 47 // do stuff with filtered point emgavg
vsluiter 2:e314bb3b2d99 48 }
vsluiter 0:32bb76391d89 49
MaikOvermars 21:3ac3c2e9d9ae 50
vsluiter 0:32bb76391d89 51 int main()
tomlankhorst 19:2bf824669684 52 {
MaikOvermars 21:3ac3c2e9d9ae 53 bqc.add( &bq1 ).add( &bq2 );
MaikOvermars 21:3ac3c2e9d9ae 54 emgSampleTicker.attach( &emgSample, 0.01 );
MaikOvermars 21:3ac3c2e9d9ae 55
tomlankhorst 14:f83354387756 56 /*empty loop, sample() is executed periodically*/
tomlankhorst 15:0da764eea774 57 while(1) {}
vsluiter 0:32bb76391d89 58 }