Kevin Hetterscheid / EMG

emg

Fork of EMG by Tom Tom

main.cpp@18:e753220c7ba6, 2015-10-19 (annotated)

Committer:
AeroKev
Date:
Mon Oct 19 11:44:19 2015 +0000
Revision:
18:e753220c7ba6
Parent:
16:9f7797ffd0fb 
a; ;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vsluiter 0:32bb76391d89 1 #include "mbed.h"
vsluiter 11:ce72ec658a95 2 #include "HIDScope.h"
vsluiter 0:32bb76391d89 3
AeroKev 18:e753220c7ba6 4 #define MOV_AVG_NUM 100
AeroKev 18:e753220c7ba6 5
vsluiter 4:8b298dfada81 6 //Define objects
tomlankhorst 14:f83354387756 7 AnalogIn emg(A0); //Analog input
tomlankhorst 14:f83354387756 8 Ticker sample_timer;
AeroKev 18:e753220c7ba6 9 HIDScope scope(2);
AeroKev 18:e753220c7ba6 10
AeroKev 18:e753220c7ba6 11 double highV[4];
AeroKev 18:e753220c7ba6 12 double lowV[4];
AeroKev 18:e753220c7ba6 13 double lastOutputs[MOV_AVG_NUM-1];
AeroKev 18:e753220c7ba6 14
AeroKev 18:e753220c7ba6 15 double filter(double input, double coeff_input[], double coeff_output[], double prev_outputs[])
AeroKev 18:e753220c7ba6 16 {
AeroKev 18:e753220c7ba6 17 double new_input = input;
AeroKev 18:e753220c7ba6 18 for(int i=1; i<5; i++)
AeroKev 18:e753220c7ba6 19 new_input -= coeff_input[i] * prev_outputs[i-1];
AeroKev 18:e753220c7ba6 20
AeroKev 18:e753220c7ba6 21 double new_output = coeff_output[0] * new_input;
AeroKev 18:e753220c7ba6 22 for(int i=1; i<5; i++)
AeroKev 18:e753220c7ba6 23 new_output += coeff_output[i] * prev_outputs[i-1];
AeroKev 18:e753220c7ba6 24
AeroKev 18:e753220c7ba6 25 // Set the new output as the first value of the 'recent outputs'
AeroKev 18:e753220c7ba6 26 for(int i = 3; i > 0; i--)
AeroKev 18:e753220c7ba6 27 prev_outputs[i] = prev_outputs[i-1];
AeroKev 18:e753220c7ba6 28 prev_outputs[0] = new_input;
AeroKev 18:e753220c7ba6 29 return new_output;
AeroKev 18:e753220c7ba6 30 }
AeroKev 18:e753220c7ba6 31
AeroKev 18:e753220c7ba6 32 double fh_b[]= {0.7602, -3.0406, 4.5609, -3.0406, 0.7602};
AeroKev 18:e753220c7ba6 33 double fh_a[]= {1, -3.4532, 4.5041, -2.6273, 0.5778};
AeroKev 18:e753220c7ba6 34 double highpass_filter(double u)
AeroKev 18:e753220c7ba6 35 {
AeroKev 18:e753220c7ba6 36 return filter(u, fh_a, fh_b, highV);
AeroKev 18:e753220c7ba6 37 }
AeroKev 18:e753220c7ba6 38
AeroKev 18:e753220c7ba6 39 double fl_b[]= {0.00000658, 0.00002631, 0.00003947, 0.00002631, 0.00000658};
AeroKev 18:e753220c7ba6 40 double fl_a[]= {1.0000, -3.7264, 5.2160, -3.2500, 0.7605};
AeroKev 18:e753220c7ba6 41 double lowpass_filter(double u)
AeroKev 18:e753220c7ba6 42 {
AeroKev 18:e753220c7ba6 43 return filter(u, fl_a, fl_b, lowV);
AeroKev 18:e753220c7ba6 44 }
vsluiter 2:e314bb3b2d99 45
tomlankhorst 14:f83354387756 46 /** Sample function
tomlankhorst 14:f83354387756 47 * this function samples the emg and sends it to HIDScope
tomlankhorst 14:f83354387756 48 **/
tomlankhorst 14:f83354387756 49 void sample()
vsluiter 2:e314bb3b2d99 50 {
AeroKev 18:e753220c7ba6 51 double input = emg.read();
AeroKev 18:e753220c7ba6 52 double output1 = highpass_filter(input);
AeroKev 18:e753220c7ba6 53 double output2 = fabs(output1);
AeroKev 18:e753220c7ba6 54 double output3 = lowpass_filter(output2);
AeroKev 18:e753220c7ba6 55
AeroKev 18:e753220c7ba6 56 double tot = output3;
AeroKev 18:e753220c7ba6 57 for(int i=0; i<MOV_AVG_NUM-1; i++) {
AeroKev 18:e753220c7ba6 58 tot += lastOutputs[i];
AeroKev 18:e753220c7ba6 59 if(i != 0) lastOutputs[i] = lastOutputs[i-1];
AeroKev 18:e753220c7ba6 60 }
AeroKev 18:e753220c7ba6 61 lastOutputs[0] = output3;
AeroKev 18:e753220c7ba6 62 output3 = tot/MOV_AVG_NUM;
AeroKev 18:e753220c7ba6 63
tomlankhorst 14:f83354387756 64 /* Second, set the sampled emg value in channel zero (the first channel) in the 'HIDScope' variable named 'scope' */
AeroKev 18:e753220c7ba6 65 scope.set(0,input);
AeroKev 18:e753220c7ba6 66 scope.set(1,output3);
tomlankhorst 16:9f7797ffd0fb 67 /* Repeat the step above if required for more channels (channel 0 up to 5 = 6 channels) */
tomlankhorst 14:f83354387756 68 /* Finally, send all channels to the PC at once */
vsluiter 11:ce72ec658a95 69 scope.send();
vsluiter 2:e314bb3b2d99 70 }
vsluiter 0:32bb76391d89 71
vsluiter 0:32bb76391d89 72 int main()
vsluiter 0:32bb76391d89 73 {
tomlankhorst 14:f83354387756 74 /**Attach the 'sample' function to the timer 'sample_timer'.
tomlankhorst 14:f83354387756 75 * this ensures that 'sample' is executed every... 0.002 seconds
vsluiter 4:8b298dfada81 76 */
tomlankhorst 14:f83354387756 77 sample_timer.attach(&sample, 0.002);
tomlankhorst 15:0da764eea774 78
tomlankhorst 14:f83354387756 79 /*empty loop, sample() is executed periodically*/
tomlankhorst 15:0da764eea774 80 while(1) {}
vsluiter 0:32bb76391d89 81 }