main.cpp

00001 #include "arm_math.h" 
00002 #include "math_helper.h" 
00003 #include <stdio.h>
00004 
00005 #define BLOCK_SIZE          32
00006 #define NUM_BLOCKS          10
00007 
00008 #define TEST_LENGTH_SAMPLES (BLOCK_SIZE * NUM_BLOCKS)
00009 
00010 #define SNR_THRESHOLD_F32   140.0f
00011 #define NUM_TAPS            29
00012 
00013 /* -------------------------------------------------------------------
00014  * The input signal and reference output (computed with MATLAB)
00015  * are defined externally in arm_fir_lpf_data.c.
00016  * ------------------------------------------------------------------- */
00017 extern float32_t testInput_f32_1kHz_15kHz[TEST_LENGTH_SAMPLES]; 
00018 extern float32_t refOutput[TEST_LENGTH_SAMPLES]; 
00019 
00020 /* ------------------------------------------------------------------- 
00021  * Declare State buffer of size (numTaps + blockSize - 1)
00022  * ------------------------------------------------------------------- */
00023 static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1]; 
00024 
00025 /* ---------------------------------------------------------------------- 
00026  * FIR Coefficients buffer generated using fir1() MATLAB function. 
00027  * fir1(28, 6/24)
00028  * ------------------------------------------------------------------- */ 
00029 const float32_t firCoeffs32[NUM_TAPS] = { 
00030     -0.0018225230f, -0.0015879294f, +0.0000000000f, +0.0036977508f, +0.0080754303f,
00031     +0.0085302217f, -0.0000000000f, -0.0173976984f, -0.0341458607f, -0.0333591565f,
00032     +0.0000000000f, +0.0676308395f, +0.1522061835f, +0.2229246956f, +0.2504960933f,
00033     +0.2229246956f, +0.1522061835f, +0.0676308395f, +0.0000000000f, -0.0333591565f,
00034     -0.0341458607f, -0.0173976984f, -0.0000000000f, +0.0085302217f, +0.0080754303f,
00035     +0.0036977508f, +0.0000000000f, -0.0015879294f, -0.0018225230f
00036 };
00037 
00038 /* ---------------------------------------------------------------------- 
00039  * FIR LPF Example 
00040  * ------------------------------------------------------------------- */
00041 int32_t main(void) { 
00042     /* Call FIR init function to initialize the instance structure. */
00043     arm_fir_instance_f32 S;
00044     arm_fir_init_f32(&S, NUM_TAPS, (float32_t *)&firCoeffs32[0], &firStateF32[0], BLOCK_SIZE); 
00045     
00046     /* ---------------------------------------------------------------------- 
00047      * Call the FIR process function for every blockSize samples  
00048      * ------------------------------------------------------------------- */ 
00049     for (uint32_t i=0; i < NUM_BLOCKS; i++) {
00050         float32_t* signal =  testInput_f32_1kHz_15kHz + (i * BLOCK_SIZE);
00051         arm_fir_f32(&S, signal, signal, BLOCK_SIZE);
00052     } 
00053     
00054     /* ---------------------------------------------------------------------- 
00055      * Compare the generated output against the reference output computed
00056      * in MATLAB.
00057      * ------------------------------------------------------------------- */
00058     float32_t snr = arm_snr_f32(refOutput, testInput_f32_1kHz_15kHz, TEST_LENGTH_SAMPLES);
00059     printf("snr: %f\n\r", snr);
00060     if (snr < SNR_THRESHOLD_F32) {
00061         printf("Failed\n\r");
00062     } else {
00063         printf("Success\n\r");
00064     }
00065 }