main.cpp

00001 //libraries
00002 #include "mbed.h"
00003 #include "HIDScope.h"
00004 #include "BiQuad.h"  
00005 
00006 //Define objects
00007 AnalogIn    emg_biceps_right_in( A0 );              //analog in to get EMG in to c++
00008 Ticker      sample_timer;                           //ticker
00009 HIDScope    scope( 3);                              //open 3 channels in hidscope
00010 DigitalOut richting_motor1(D4);     //motor1 direction output    
00011 PwmOut pwm_motor1(D5);              //motor1 velocity  output
00012 DigitalOut  led(LED_GREEN);
00013 DigitalIn   button (D9);
00014 
00015 //define variables
00016 double emg_biceps_right;
00017 double emg_filtered_high_biceps_right;
00018 double emg_abs_biceps_right;
00019 double emg_filtered_biceps_right;
00020 int    onoffsignal=0;
00021 double cut_off_value=0.20;
00022 double max_right_biceps; 
00023 
00024 BiQuad filterhigh(9.5654e-01,-1.9131e+00,9.5654e-01,-1.9112e+00,9.1498e-01);
00025 BiQuad filterlow (6.2942e-06, 1.2588e-05,6.2942e-06,-1.9929e+00,9.9292e-01);
00026 
00027 //functions which are called in ticker
00028 void filter(){
00029         emg_biceps_right=emg_biceps_right_in.read();                            //read the emg value from the elektrodes
00030         emg_filtered_high_biceps_right= filterhigh.step(emg_biceps_right);
00031         emg_abs_biceps_right=fabs(emg_filtered_high_biceps_right); //fabs because float
00032         emg_filtered_biceps_right=filterlow.step(emg_abs_biceps_right);
00033         led=!led;
00034         
00035         if (emg_filtered_biceps_right>cut_off_value)
00036         {onoffsignal=1;}
00037           
00038         else 
00039         {onoffsignal=0;}
00040                       
00041         //send signals  to scope
00042         scope.set(0, emg_biceps_right );           //set emg signal to scope in channel 1
00043         scope.set(1, emg_filtered_biceps_right);    
00044         scope.set(2, onoffsignal);
00045         scope.send();                       //send all the signals to the scope
00046                 }
00047                 
00048 void calibration(){
00049             for(int n =0; n<5000;n++){                                                  //read for 5000 samples as calibration
00050             emg_biceps_right=emg_biceps_right_in.read();                            //read the emg value from the elektrodes
00051             emg_filtered_high_biceps_right= filterhigh.step(emg_biceps_right);      //highpass
00052             emg_abs_biceps_right=fabs(emg_filtered_high_biceps_right);              //fabs because float
00053             emg_filtered_biceps_right=filterlow.step(emg_abs_biceps_right);         //lowpass to envelope
00054             if (emg_filtered_biceps_right > max_right_biceps){                      //determine what the highest reachable emg signal is
00055                 max_right_biceps = emg_filtered_biceps_right;
00056                 }
00057             
00058             cut_off_value=0.2*max_right_biceps;    
00059             }
00060 //program
00061 
00062 int main()
00063 {
00064 sample_timer.attach(&filter, 0.001);        //continously execute the EMG reader and filter, it ensures that filter and sampling is executed every 1/frequency seconds
00065 
00066 //endless loop
00067     while(1) {
00068          if(button==0){
00069          &calibri(); } //if button pressed calibration starts again!
00070          
00071         if (onoffsignal==1)
00072         {
00073         richting_motor1 = 0;    //motordirection (ccw)
00074         pwm_motor1 = 1;         //motorspeed 1  
00075         
00076         }
00077         else if(onoffsignal==0)
00078         {
00079         richting_motor1 = 0;    //motordirection (ccw)
00080         pwm_motor1 = 0;         //motorspeed 0
00081         }
00082         
00083     }        
00084 }