Emilio Monti / Mbed 2 deprecated dsp_fir

Example FIR filter using the draft mbed DSP API

Dependencies:   mbed mbed-dsp

main.cpp@2:697afbb006f5, 2012-03-12 (annotated)

Committer:
emilmont
Date:
Mon Mar 12 12:04:27 2012 +0000
Revision:
2:697afbb006f5
Parent:
1:0814c87942ca
Child:
3:15d0df9ab05b

        

        
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#include "mbed.h"





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#include "dsp.h"





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#define BLOCK_SIZE              (32)





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#define NUM_BLOCKS              (10)





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#define TEST_LENGTH_SAMPLES     (BLOCK_SIZE * NUM_BLOCKS)





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#define SAMPLE_RATE             (48000)





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#define SNR_THRESHOLD_F32       (50.0f)





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float32_t expected_output[TEST_LENGTH_SAMPLES];





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float32_t signal[TEST_LENGTH_SAMPLES]; 





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/* FIR Coefficients buffer generated using fir1() MATLAB function: fir1(28, 6/24) */





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#define NUM_TAPS            29





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const float32_t fir_coeff[NUM_TAPS] = { 





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    -0.0018225230f, -0.0015879294f, +0.0000000000f, +0.0036977508f, +0.0080754303f,





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    +0.0085302217f, -0.0000000000f, -0.0173976984f, -0.0341458607f, -0.0333591565f,





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    +0.0000000000f, +0.0676308395f, +0.1522061835f, +0.2229246956f, +0.2504960933f,





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    +0.2229246956f, +0.1522061835f, +0.0676308395f, +0.0000000000f, -0.0333591565f,





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    -0.0341458607f, -0.0173976984f, -0.0000000000f, +0.0085302217f, +0.0080754303f,





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    +0.0036977508f, +0.0000000000f, -0.0015879294f, -0.0018225230f





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};





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#define WARMUP    (NUM_TAPS-1)





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#define DELAY     (WARMUP/2)





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int main() {





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    Sine_f32 sine_1K(  1000, SAMPLE_RATE, 1.0);





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    Sine_f32 sine_15K(15000, SAMPLE_RATE, 0.5);





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    FIR_f32<NUM_TAPS> fir(fir_coeff);





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    for (int i=0; i<NUM_BLOCKS; i++) {





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        float32_t *signal_buffer = signal + i*BLOCK_SIZE;





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        sine_1K.process(signal_buffer);





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        sine_15K.process(signal_buffer);





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        fir.process(signal_buffer);





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    }





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    sine_1K.reset();





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    for (int i=0; i<NUM_BLOCKS; i++) {





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        float32_t *signal_buffer = expected_output + i*BLOCK_SIZE;





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        sine_1K.process(signal_buffer);





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    }





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    float snr = arm_snr_f32(&expected_output[DELAY-1], &signal[WARMUP-1], TEST_LENGTH_SAMPLES-WARMUP);





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    printf("snr: %f\n\r", snr);





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    if (snr < SNR_THRESHOLD_F32) {





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        printf("Failed\n\r");





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    } else {





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        printf("Success\n\r");





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    }





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}