Revision 22:d2393c670afd, committed 2018-10-13

Comitter:

MaikOvermars

Date:

Sat Oct 13 15:48:22 2018 +0000

Parent:

21:3ac3c2e9d9ae

Commit message:

Implemented biquad cascade of notch, low pass and high pass filter, all second order. This is in addition to the moving average and rectifier. Not tested yet on live emg-signal.

Changed in this revision

diff -r 3ac3c2e9d9ae -r d2393c670afd main.cpp
--- a/main.cpp	Fri Oct 12 13:12:31 2018 +0000
+++ b/main.cpp	Sat Oct 13 15:48:22 2018 +0000
@@ -11,18 +11,21 @@
 
 // filter chains for high pass, low pass and notch filters
 BiQuadChain bqc;
-BiQuad bq1( 4.1660e04,8.3320e04,4.1660e04,1.4797e+00,.5582e01);
-BiQuad bq2( 1.0000e+00, 2.0000e+00, 1.0000e+00, 1.7010e+00,7.8850e01);
+BiQuad bqlow( 0.0128, 0.0256, 0.0128, -1.6556, 0.7068);
+BiQuad bqhigh( 0.6458, -1.2917, 0.6458, -1.1620, 0.4213);
+BiQuad bqnotch( 0.5, 0, 0.5, 0, 0);
 volatile double y[50]= { };
 volatile int n = 0;
 volatile bool full = 0;
 
 void emgSample() {
-    //double emgFiltered = bqc.step( emg0.read() );
-    double emgFiltered = emg0.read();
-    scope.set(0,emgFiltered);
+    double emgRaw = emg0.read();
+    scope.set(0,emgRaw);
     
-    // moving average
+    double emgFiltered = bqc.step( emgRaw );
+    scope.set(1,emgFiltered);
+    
+    // moving average and rectifier
     y[n] = abs(emgFiltered - 0.45);
     double emgavg = 0;
     if(full == 0){
@@ -42,7 +45,7 @@
         n = 0;
         full = 1;
     }
-    scope.set(1,emgavg);
+    scope.set(2,emgavg);
     scope.send();
     // do stuff with filtered point emgavg
 }
@@ -50,7 +53,7 @@
 
 int main()
 {   
-    bqc.add( &bq1 ).add( &bq2 );
+    bqc.add( &bqlow ).add( &bqhigh ).add( &bqnotch );
     emgSampleTicker.attach( &emgSample, 0.01 );
     
     /*empty loop, sample() is executed periodically*/