Numero Uno / EMG

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Dependents:   PID_VelocityExample TheProgram Passief_stuurprogramma Actief_stuurprogramma

EMG.h@1:b73e3dc74d7c, 2015-10-12 (annotated)

Committer:
mganseij
Date:
Mon Oct 12 09:04:24 2015 +0000
Revision:
1:b73e3dc74d7c
Parent:
0:b5f7b64b0fe4
Child:
2:84ff5b0f5406
added second calibration factor + LED during calibration

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ewoud 0:b5f7b64b0fe4 1 #include "biquadFilter.h"
ewoud 0:b5f7b64b0fe4 2 #include <cmath>
ewoud 0:b5f7b64b0fe4 3
ewoud 0:b5f7b64b0fe4 4
ewoud 0:b5f7b64b0fe4 5 int Fs = 512; // sampling frequency
ewoud 0:b5f7b64b0fe4 6 const double low_b1 = 1.480219865318266e-04; //filter coefficients - second order butterworth filters at 2 hz low and 25 hz high, coefficents based on Fs of 512.
ewoud 0:b5f7b64b0fe4 7 const double low_b2 = 2.960439730636533e-04;
ewoud 0:b5f7b64b0fe4 8 const double low_b3 = 1.480219865318266e-04;
ewoud 0:b5f7b64b0fe4 9 const double low_a2 = -1.965293372622690e+00; // a1 is normalized to 1
ewoud 0:b5f7b64b0fe4 10 const double low_a3 = 9.658854605688177e-01;
ewoud 0:b5f7b64b0fe4 11 const double high_b1 = 8.047897937631126e-01;
ewoud 0:b5f7b64b0fe4 12 const double high_b2 = -1.609579587526225e+00;
ewoud 0:b5f7b64b0fe4 13 const double high_b3 = 8.047897937631126e-01;
ewoud 0:b5f7b64b0fe4 14 const double high_a2 = -1.571102440190402e+00; // a1 is normalized to 1
ewoud 0:b5f7b64b0fe4 15 const double high_a3 = 6.480567348620491e-01;
ewoud 0:b5f7b64b0fe4 16 biquadFilter highpass1(high_a2, high_a3, high_b1, high_b2, high_b3); // different objects for different inputs, otherwise the v1 and v2 variables get fucked up
ewoud 0:b5f7b64b0fe4 17 biquadFilter highpass2(high_a2, high_a3, high_b1, high_b2, high_b3);
ewoud 0:b5f7b64b0fe4 18 biquadFilter highpass3(high_a2, high_a3, high_b1, high_b2, high_b3);
ewoud 0:b5f7b64b0fe4 19 biquadFilter highpass4(high_a2, high_a3, high_b1, high_b2, high_b3);
ewoud 0:b5f7b64b0fe4 20 biquadFilter lowpass1(low_a2, low_a3, low_b1, low_b2, low_b3);
ewoud 0:b5f7b64b0fe4 21 biquadFilter lowpass2(low_a2, low_a3, low_b1, low_b2, low_b3);
ewoud 0:b5f7b64b0fe4 22 biquadFilter lowpass3(low_a2, low_a3, low_b1, low_b2, low_b3);
ewoud 0:b5f7b64b0fe4 23 biquadFilter lowpass4(low_a2, low_a3, low_b1, low_b2, low_b3);
ewoud 0:b5f7b64b0fe4 24
ewoud 0:b5f7b64b0fe4 25 AnalogIn input1(A0); // declaring the 4 inputs
ewoud 0:b5f7b64b0fe4 26 AnalogIn input2(A1);
ewoud 0:b5f7b64b0fe4 27 AnalogIn input3(A2);
ewoud 0:b5f7b64b0fe4 28 AnalogIn input4(A3);
ewoud 0:b5f7b64b0fe4 29 double u1; double y1; // declaring the input variables
ewoud 0:b5f7b64b0fe4 30 double u2; double y2;
ewoud 0:b5f7b64b0fe4 31 double u3; double y3;
ewoud 0:b5f7b64b0fe4 32 double u4; double y4;
ewoud 0:b5f7b64b0fe4 33
ewoud 0:b5f7b64b0fe4 34 Ticker T1;
ewoud 0:b5f7b64b0fe4 35 volatile bool sample_go;
ewoud 0:b5f7b64b0fe4 36
mganseij 1:b73e3dc74d7c 37 DigitalOut led(LED_RED);
ewoud 0:b5f7b64b0fe4 38 InterruptIn cali_button(PTA4); // initialize interrupt button for calibration stuff
mganseij 1:b73e3dc74d7c 39 double cali_fact1 = 8;
mganseij 1:b73e3dc74d7c 40 double cali_fact2 = 8; // calibration factor to normalize filter output to a scale of 0 - 1
mganseij 1:b73e3dc74d7c 41 double cali_array1[2560] = {}; // array to store values in for channel 1
mganseij 1:b73e3dc74d7c 42 double cali_array2[2560] = {}; // array to store values in for channel 2
ewoud 0:b5f7b64b0fe4 43
ewoud 0:b5f7b64b0fe4 44 void sample_filter()
ewoud 0:b5f7b64b0fe4 45 {
ewoud 0:b5f7b64b0fe4 46 u1 = input1; u2 = input2; u3 = input3; u4 = input4; // sample
ewoud 0:b5f7b64b0fe4 47 y1 = highpass1.step(u1); y2 = highpass2.step(u2); y3 = highpass3.step(u3); y4 = highpass4.step(u4); // filter order is: high-pass --> rectify --> low-pass
ewoud 0:b5f7b64b0fe4 48 y1 = fabs(y1); y2 = fabs(y2); y3 = fabs(y3); y4 = fabs(y4);
ewoud 0:b5f7b64b0fe4 49 y1 = lowpass1.step(y1)*cali_fact; y2 = lowpass2.step(y2)*cali_fact; y3 = lowpass3.step(y3)*cali_fact; y4 = lowpass4.step(y4)*cali_fact; // roughly normalize to a scale of 0 - 1, where 0 is minimum and 1 is roughly the maximum output of dennis.
ewoud 0:b5f7b64b0fe4 50 }
ewoud 0:b5f7b64b0fe4 51
ewoud 0:b5f7b64b0fe4 52 void samplego() // ticker function, set flag to true every sample interval
ewoud 0:b5f7b64b0fe4 53 {
ewoud 0:b5f7b64b0fe4 54 sample_go = 1;
ewoud 0:b5f7b64b0fe4 55 }
ewoud 0:b5f7b64b0fe4 56
ewoud 0:b5f7b64b0fe4 57 void calibrate() // function to calibrate the emg signals from the user. It takes 5 seconds of measurements of maximum output, then takes the max and normalizes to that.
ewoud 0:b5f7b64b0fe4 58 {
mganseij 1:b73e3dc74d7c 59 double cali_max1 = 0; // declare max
mganseij 1:b73e3dc74d7c 60 double cali_max2 = 0;
mganseij 1:b73e3dc74d7c 61 cali_fact1 = 1; cali_fact2 = 1;
mganseij 1:b73e3dc74d7c 62 led = 1;
ewoud 0:b5f7b64b0fe4 63 for(int cali_index = 0; cali_index < 2560; cali_index++)
ewoud 0:b5f7b64b0fe4 64 {
ewoud 0:b5f7b64b0fe4 65 sample_filter();
mganseij 1:b73e3dc74d7c 66 cali_array1[cali_index] = y1;
mganseij 1:b73e3dc74d7c 67 cali_array2[cali_index] = y2;
ewoud 0:b5f7b64b0fe4 68 wait((float)1/Fs);
ewoud 0:b5f7b64b0fe4 69 }
ewoud 0:b5f7b64b0fe4 70 for(int cali_index2 = 0; cali_index2<2560; cali_index2++)
ewoud 0:b5f7b64b0fe4 71 {
mganseij 1:b73e3dc74d7c 72 if(cali_array1[cali_index2] > cali_max1)
mganseij 1:b73e3dc74d7c 73 {
mganseij 1:b73e3dc74d7c 74 cali_max1 = cali_array1[cali_index2];
mganseij 1:b73e3dc74d7c 75 }
mganseij 1:b73e3dc74d7c 76 if(cali_array2[cali_index2] > cali_max2)
mganseij 1:b73e3dc74d7c 77 {
mganseij 1:b73e3dc74d7c 78 cali_max2 = cali_array2[cali_index2];
mganseij 1:b73e3dc74d7c 79 }
ewoud 0:b5f7b64b0fe4 80 }
mganseij 1:b73e3dc74d7c 81 cali_fact1 = (double)1/cali_max1;
mganseij 1:b73e3dc74d7c 82 cali_fact2 = (double)1/cali_max2;
mganseij 1:b73e3dc74d7c 83 led = 0;
mganseij 1:b73e3dc74d7c 84 pc.printf("Calibration factor 1: %f\nCalibration factor 2: %f\n", cali_fact1, cali_fact2);
ewoud 0:b5f7b64b0fe4 85 }
ewoud 0:b5f7b64b0fe4 86
ewoud 0:b5f7b64b0fe4 87 /*
ewoud 0:b5f7b64b0fe4 88 int main()
ewoud 0:b5f7b64b0fe4 89 {
ewoud 0:b5f7b64b0fe4 90 T1.attach(&samplego, (float)1/Fs);
ewoud 0:b5f7b64b0fe4 91 cali_button.rise(&calibrate);
ewoud 0:b5f7b64b0fe4 92 while(1)
ewoud 0:b5f7b64b0fe4 93 {
ewoud 0:b5f7b64b0fe4 94 if(sample_go)
ewoud 0:b5f7b64b0fe4 95 {
ewoud 0:b5f7b64b0fe4 96 sample_filter();
ewoud 0:b5f7b64b0fe4 97 sample_go = 0;
ewoud 0:b5f7b64b0fe4 98 }
ewoud 0:b5f7b64b0fe4 99 } // while end
ewoud 0:b5f7b64b0fe4 100 } // main end
ewoud 0:b5f7b64b0fe4 101 */