read_filter_emg.h

00001 /*
00002  * read_filter_emg.h
00003  *
00004  *  Created on: Oct 14, 2015
00005  *      Author: User
00006  */
00007 
00008 #ifndef READ_FILTER_EMG_H_
00009 #define READ_FILTER_EMG_H_
00010 
00011 class EMG {
00012     public:
00013         //create instance of the EMG class
00014         EMG(AnalogIn &aI_, double &v1_, double &v2_);
00015         AnalogIn aI(pinName);
00016         double v1;
00017         double v2;
00018         double input_sample;
00019         double filtered_sample;
00020 
00021         //reads emg value and saves as input_sample
00022         void sample();
00023 
00024         /*general biquad function to be used in the filtering
00025         biquad coefficients are in the filter functions */
00026         double biquad(double u, double &v1, double &v2, const double a1,
00027                 const double a2, const double b0, const double b1, const double b2);
00028 
00029         //20 hz highpass filter contains 3 biquads. Returns filtered value
00030         double highpass_filter(double hpInput);
00031 
00032         //Rectify the input (take absolute value). Input is output of highpass
00033         double rectify(double rcInput);
00034 
00035         //6 hz low pass filter, contains 3 biquads, input output of rectify
00036         double lowpass_filter(double lpInput);
00037 
00038         //function containing all three filter steps. Input raw signal value, output is filtered envelope value
00039         double filter(double input);
00040 };
00041 
00042 #endif /* READ_FILTER_EMG_H_ */
00043