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#include "arm_math.h"
#include "math_helper.h"
#include <stdio.h>
#define BLOCK_SIZE 32
#define NUM_BLOCKS 10
#define TEST_LENGTH_SAMPLES (BLOCK_SIZE * NUM_BLOCKS)
#define SNR_THRESHOLD_F32 140.0f
#define NUM_TAPS 29
/* -------------------------------------------------------------------
* The input signal and reference output (computed with MATLAB)
* are defined externally in arm_fir_lpf_data.c.
* ------------------------------------------------------------------- */
extern float32_t testInput_f32_1kHz_15kHz[TEST_LENGTH_SAMPLES];
extern float32_t refOutput[TEST_LENGTH_SAMPLES];
/* -------------------------------------------------------------------
* Declare State buffer of size (numTaps + blockSize - 1)
* ------------------------------------------------------------------- */
static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1];
/* ----------------------------------------------------------------------
* FIR Coefficients buffer generated using fir1() MATLAB function.
* fir1(28, 6/24)
* ------------------------------------------------------------------- */
const float32_t firCoeffs32[NUM_TAPS] = {
-0.0018225230f, -0.0015879294f, +0.0000000000f, +0.0036977508f, +0.0080754303f,
+0.0085302217f, -0.0000000000f, -0.0173976984f, -0.0341458607f, -0.0333591565f,
+0.0000000000f, +0.0676308395f, +0.1522061835f, +0.2229246956f, +0.2504960933f,
+0.2229246956f, +0.1522061835f, +0.0676308395f, +0.0000000000f, -0.0333591565f,
-0.0341458607f, -0.0173976984f, -0.0000000000f, +0.0085302217f, +0.0080754303f,
+0.0036977508f, +0.0000000000f, -0.0015879294f, -0.0018225230f
};
/* ----------------------------------------------------------------------
* FIR LPF Example
* ------------------------------------------------------------------- */
int main(void) {
/* Call FIR init function to initialize the instance structure. */
arm_fir_instance_f32 S;
arm_fir_init_f32(&S, NUM_TAPS, (float32_t *)&firCoeffs32[0], &firStateF32[0], BLOCK_SIZE);
/* ----------------------------------------------------------------------
* Call the FIR process function for every blockSize samples
* ------------------------------------------------------------------- */
for (uint32_t i=0; i < NUM_BLOCKS; i++) {
float32_t* signal = testInput_f32_1kHz_15kHz + (i * BLOCK_SIZE);
arm_fir_f32(&S, signal, signal, BLOCK_SIZE);
}
/* ----------------------------------------------------------------------
* Compare the generated output against the reference output computed
* in MATLAB.
* ------------------------------------------------------------------- */
float32_t snr = arm_snr_f32(refOutput, testInput_f32_1kHz_15kHz, TEST_LENGTH_SAMPLES);
printf("snr: %f\n\r", snr);
if (snr < SNR_THRESHOLD_F32) {
printf("Failed\n\r");
} else {
printf("Success\n\r");
}
}
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