EMG signalen uitlezen met filters
Dependencies: HIDScope biquadFilter mbed
main.cpp@1:0d62559f43af, 2016-10-27 (annotated)
- Committer:
- laurette
- Date:
- Thu Oct 27 14:43:21 2016 +0000
- Revision:
- 1:0d62559f43af
- Parent:
- 0:5759df060d75
- Child:
- 2:5df98e0832d6
Uitlezen emg signalen plus filtering (nog niet getest)
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
laurette | 0:5759df060d75 | 1 | #include "mbed.h" |
laurette | 0:5759df060d75 | 2 | #include "HIDScope.h" |
laurette | 1:0d62559f43af | 3 | #include "BiQuad.h" |
laurette | 0:5759df060d75 | 4 | |
laurette | 1:0d62559f43af | 5 | //Define EMG input |
laurette | 0:5759df060d75 | 6 | AnalogIn emg0( A0 ); |
laurette | 0:5759df060d75 | 7 | AnalogIn emg1( A1 ); |
laurette | 0:5759df060d75 | 8 | AnalogIn emg2( A2 ); |
laurette | 0:5759df060d75 | 9 | |
laurette | 0:5759df060d75 | 10 | Ticker sample_timer; |
laurette | 1:0d62559f43af | 11 | HIDScope scope( 3 ); // 3-channel HIDScope object |
laurette | 1:0d62559f43af | 12 | |
laurette | 1:0d62559f43af | 13 | // Filter coordinates of lowpass/highpass filter before rectifier and lowpassfilter for the envelope |
laurette | 1:0d62559f43af | 14 | const double b0_low = 0.2929, b1_low = 0.5858, b2_low = 0.2929, a1_low = 0, a2_low = 0.1716; |
laurette | 1:0d62559f43af | 15 | const double b0_high = 0.9912, b1_high = -1.9823, b2_high = 0.9912, a1_high = -1.9822, a2_high = 0.9824; |
laurette | 1:0d62559f43af | 16 | const double b0_envelope = 6.1006E-5, b1_envelope = 1.2201E-4, b2_envelope = 6.1006E-5, a1_envelope = -1.9776, a2_envelope = 0.9780; |
laurette | 1:0d62559f43af | 17 | |
laurette | 1:0d62559f43af | 18 | double y1, y2, y3; // Gefilterde output |
laurette | 0:5759df060d75 | 19 | |
laurette | 1:0d62559f43af | 20 | // Biquad filters (lowpass and highpass become a chain in the int main) |
laurette | 1:0d62559f43af | 21 | BiQuad lowpass(b0_low, b1_low , b2_low, a1_low, a2_low); |
laurette | 1:0d62559f43af | 22 | BiQuad highpass(b0_high, b1_high , b2_high, a1_high, a2_high); |
laurette | 1:0d62559f43af | 23 | BiQuad envelope(b0_envelope, b1_envelope , b2_envelope, a1_envelope, a2_envelope); |
laurette | 1:0d62559f43af | 24 | BiQuadChain bandpass; |
laurette | 1:0d62559f43af | 25 | |
laurette | 1:0d62559f43af | 26 | // Sample function, this function samples the emg and sends it to HIDScope |
laurette | 1:0d62559f43af | 27 | |
laurette | 1:0d62559f43af | 28 | void filtering() |
laurette | 0:5759df060d75 | 29 | { |
laurette | 1:0d62559f43af | 30 | y1 = bandpass.step(emg0); |
laurette | 1:0d62559f43af | 31 | y2 = bandpass.step(emg1); |
laurette | 1:0d62559f43af | 32 | y3 = bandpass.step(emg2); |
laurette | 1:0d62559f43af | 33 | y1 = fabs(y1); |
laurette | 1:0d62559f43af | 34 | y2 = fabs(y2); |
laurette | 1:0d62559f43af | 35 | y3 = fabs(y3); |
laurette | 1:0d62559f43af | 36 | y1 = envelope.step(y1); |
laurette | 1:0d62559f43af | 37 | y2 = envelope.step(y2); |
laurette | 1:0d62559f43af | 38 | y3 = envelope.step(y3); |
laurette | 0:5759df060d75 | 39 | |
laurette | 1:0d62559f43af | 40 | // Set the sampled and filtered emg values in channel 0/1/2 in the 'HIDScope' instance named 'scope' |
laurette | 1:0d62559f43af | 41 | scope.set(0, y1 ); |
laurette | 1:0d62559f43af | 42 | scope.set(1, y2 ); |
laurette | 1:0d62559f43af | 43 | scope.set(2, y3 ); |
laurette | 0:5759df060d75 | 44 | |
laurette | 1:0d62559f43af | 45 | scope.send(); // Sends all channels to the PC at once |
laurette | 0:5759df060d75 | 46 | } |
laurette | 0:5759df060d75 | 47 | |
laurette | 0:5759df060d75 | 48 | int main() |
laurette | 0:5759df060d75 | 49 | { |
laurette | 1:0d62559f43af | 50 | bandpass.add(&lowpass).add(&highpass); |
laurette | 1:0d62559f43af | 51 | sample_timer.attach(&filtering, 0.001); // Attach the 'sample' function to the timer 'sample_timer'. This ensures that 'sample' is executed every 0.001 seconds = 1000 Hz |
laurette | 1:0d62559f43af | 52 | |
laurette | 1:0d62559f43af | 53 | while(1) {} // Empty loop, sample() is executed periodically |
laurette | 0:5759df060d75 | 54 | } |