Diff: main.cpp

Revision:

2:9ccaf6885ced

Parent:

1:9442dff3bfdc

--- a/main.cpp	Mon Mar 12 12:00:25 2012 +0000
+++ b/main.cpp	Tue Jan 08 17:00:49 2013 +0000
@@ -1,23 +1,32 @@
-#include <stdio.h>
 #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
-#define SNR_THRESHOLD_F32   140.0f
+
+/* -------------------------------------------------------------------
+ * 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]; 
 
-// The input signal and reference output
-extern float32_t          signal[TEST_LENGTH_SAMPLES]; 
-extern float32_t filtered_signal[TEST_LENGTH_SAMPLES]; 
+/* ------------------------------------------------------------------- 
+ * Declare State buffer of size (numTaps + blockSize - 1)
+ * ------------------------------------------------------------------- */
+static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1]; 
 
-// Declare FIR State buffer of size (numTaps + blockSize - 1)
-float32_t fir_state[BLOCK_SIZE + NUM_TAPS - 1]; 
-
-// FIR Coefficients
-const float32_t fir_coeff[NUM_TAPS] = { 
+/* ---------------------------------------------------------------------- 
+ * 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,
@@ -26,23 +35,31 @@
     +0.0036977508f, +0.0000000000f, -0.0015879294f, -0.0018225230f
 };
 
+/* ---------------------------------------------------------------------- 
+ * FIR LPF Example 
+ * ------------------------------------------------------------------- */
 int32_t main(void) { 
-    // Call FIR init function to initialize the instance structure.
-    arm_fir_instance_f32 fir;
-    arm_fir_init_f32(&fir, NUM_TAPS, (float32_t *)fir_coeff, fir_state, BLOCK_SIZE); 
+    /* 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 BLOCK_SIZE samples  
+    /* ---------------------------------------------------------------------- 
+     * Call the FIR process function for every blockSize samples  
+     * ------------------------------------------------------------------- */ 
     for (uint32_t i=0; i < NUM_BLOCKS; i++) {
-        float32_t* signal_buffer =  signal + (i * BLOCK_SIZE);
-        arm_fir_f32(&fir, signal_buffer, signal_buffer, BLOCK_SIZE);
+        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
-    float32_t snr = arm_snr_f32(filtered_signal, signal, TEST_LENGTH_SAMPLES);
+    /* ---------------------------------------------------------------------- 
+     * 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");
     }
-}
+}