R&J / Mbed 2 deprecated 487_Laboratory_2

initial

Dependencies:   mbed BSP_DISCO_F746NG mbed-dsp

signal_processing.cpp@1:103e3e426b55, 2020-02-12 (annotated)

Committer:
justenmg
Date:
Wed Feb 12 01:03:05 2020 +0000
Revision:
1:103e3e426b55
Parent:
0:c0f52e8223fe
Child:
2:89234085faae
feb 11

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bmazzeo 0:c0f52e8223fe 1 /**
bmazzeo 0:c0f52e8223fe 2 ******************************************************************************
bmazzeo 0:c0f52e8223fe 3 * @file signal_processing.c
bmazzeo 0:c0f52e8223fe 4 * @author Brian Mazzeo
bmazzeo 0:c0f52e8223fe 5 * @date 2020
bmazzeo 0:c0f52e8223fe 6 * @brief This file provides a set of code for signal processing in 487.
bmazzeo 0:c0f52e8223fe 7 * Parts are taken from example code from STMIcroelectronics
bmazzeo 0:c0f52e8223fe 8 ******************************************************************************
bmazzeo 0:c0f52e8223fe 9 * @attention
bmazzeo 0:c0f52e8223fe 10 * This code was specifically developed for BYU ECEn 487 course
bmazzeo 0:c0f52e8223fe 11 * Introduction to Digital Signal Processing.
bmazzeo 0:c0f52e8223fe 12 *
bmazzeo 0:c0f52e8223fe 13 *
bmazzeo 0:c0f52e8223fe 14 ******************************************************************************
bmazzeo 0:c0f52e8223fe 15 */
bmazzeo 0:c0f52e8223fe 16
bmazzeo 0:c0f52e8223fe 17 #include "mbed.h"
bmazzeo 0:c0f52e8223fe 18 #include "stm32746g_discovery_lcd.h"
bmazzeo 0:c0f52e8223fe 19 #include "arm_math.h"
bmazzeo 0:c0f52e8223fe 20 #include "arm_const_structs.h"
bmazzeo 0:c0f52e8223fe 21 #include "filter_coefficients.h"
justenmg 1:103e3e426b55 22 #include "our_filter.h"
bmazzeo 0:c0f52e8223fe 23
bmazzeo 0:c0f52e8223fe 24
bmazzeo 0:c0f52e8223fe 25 /* ----------------------------------------------------------------------
bmazzeo 0:c0f52e8223fe 26 ** Defines for signal processing
bmazzeo 0:c0f52e8223fe 27 ** ------------------------------------------------------------------- */
bmazzeo 0:c0f52e8223fe 28
bmazzeo 0:c0f52e8223fe 29 #define AUDIO_BLOCK_SAMPLES ((uint32_t)128) // Number of samples (L and R) in audio block (each samples is 16 bits)
justenmg 1:103e3e426b55 30 #define BUFFER_LENGTH (WIN_NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1)
bmazzeo 0:c0f52e8223fe 31
bmazzeo 0:c0f52e8223fe 32 /* For Lab Exercise */
justenmg 1:103e3e426b55 33 #define Lab_Execution_Type 2
justenmg 1:103e3e426b55 34
justenmg 1:103e3e426b55 35 float32_t lState[NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1];
justenmg 1:103e3e426b55 36 float32_t rState[NUM_TAPS + AUDIO_BLOCK_SAMPLES - 1];
bmazzeo 0:c0f52e8223fe 37
justenmg 1:103e3e426b55 38 float32_t l_buf[BUFFER_LENGTH];
justenmg 1:103e3e426b55 39 float32_t r_buf[BUFFER_LENGTH];
bmazzeo 0:c0f52e8223fe 40
justenmg 1:103e3e426b55 41 float32_t* l_buf_head = &l_buf;
justenmg 1:103e3e426b55 42 float32_t* r_buf_head = &r_buf;
justenmg 1:103e3e426b55 43
justenmg 1:103e3e426b55 44 arm_fir_instance_f32 filter_left;
justenmg 1:103e3e426b55 45 arm_fir_instance_f32 filter_right;
bmazzeo 0:c0f52e8223fe 46
bmazzeo 0:c0f52e8223fe 47 /* FUNCTION DEFINITIONS BELOW */
bmazzeo 0:c0f52e8223fe 48
bmazzeo 0:c0f52e8223fe 49 /**
bmazzeo 0:c0f52e8223fe 50 * @brief Initialize filter structures to be used in loops later
bmazzeo 0:c0f52e8223fe 51 * @retval None
bmazzeo 0:c0f52e8223fe 52 */
bmazzeo 0:c0f52e8223fe 53 void initalize_signal_processing(void) {
bmazzeo 0:c0f52e8223fe 54
bmazzeo 0:c0f52e8223fe 55 switch (Lab_Execution_Type)
bmazzeo 0:c0f52e8223fe 56 {
bmazzeo 0:c0f52e8223fe 57 case 0: // Passthrough case
bmazzeo 0:c0f52e8223fe 58 break;
bmazzeo 0:c0f52e8223fe 59
bmazzeo 0:c0f52e8223fe 60 case 1: // FIR case (ARM)
justenmg 1:103e3e426b55 61 arm_fir_init_f32(&filter_left, NUM_TAPS, (float32_t *)&Filter_coeffs, (float32_t *)&lState, AUDIO_BLOCK_SAMPLES);
justenmg 1:103e3e426b55 62 arm_fir_init_f32(&filter_right, NUM_TAPS, (float32_t *)&Filter_coeffs, (float32_t *)&rState, AUDIO_BLOCK_SAMPLES);
bmazzeo 0:c0f52e8223fe 63 break;
bmazzeo 0:c0f52e8223fe 64
bmazzeo 0:c0f52e8223fe 65 case 2: // FIR case (student)
justenmg 1:103e3e426b55 66 arm_fir_init_f32(&filter_left, OUR_NUM_TAPS, (float32_t *)&our_Filter_coeffs, (float32_t *)&lState, AUDIO_BLOCK_SAMPLES);
justenmg 1:103e3e426b55 67 arm_fir_init_f32(&filter_right, OUR_NUM_TAPS, (float32_t *)&our_Filter_coeffs, (float32_t *)&rState, AUDIO_BLOCK_SAMPLES);
bmazzeo 0:c0f52e8223fe 68 break;
bmazzeo 0:c0f52e8223fe 69
bmazzeo 0:c0f52e8223fe 70 case 3: // FFT Overlap-add
bmazzeo 0:c0f52e8223fe 71 break;
bmazzeo 0:c0f52e8223fe 72
bmazzeo 0:c0f52e8223fe 73 case 4: // FFT Overlap-add with real-imag efficiency
bmazzeo 0:c0f52e8223fe 74 break;
bmazzeo 0:c0f52e8223fe 75
bmazzeo 0:c0f52e8223fe 76
bmazzeo 0:c0f52e8223fe 77 }
bmazzeo 0:c0f52e8223fe 78 }
bmazzeo 0:c0f52e8223fe 79
bmazzeo 0:c0f52e8223fe 80 /**
bmazzeo 0:c0f52e8223fe 81 * @brief Process audio channel signals
bmazzeo 0:c0f52e8223fe 82 * @param L_channel_in: Pointer to Left channel data input (float32_t)
bmazzeo 0:c0f52e8223fe 83 * @param R_channel_in: Pointer to Right channel data input (float32_t)
bmazzeo 0:c0f52e8223fe 84 * @param L_channel_out: Pointer to Left channel data output (float32_t)
bmazzeo 0:c0f52e8223fe 85 * @param R_channel_out: Pointer to Right channel data output (float32_t)
bmazzeo 0:c0f52e8223fe 86 * @param Signal_Length: length of data to process
bmazzeo 0:c0f52e8223fe 87 * @retval None
bmazzeo 0:c0f52e8223fe 88 */
bmazzeo 0:c0f52e8223fe 89 void process_audio_channel_signals(float32_t* L_channel_in, float32_t* R_channel_in, float32_t* L_channel_out, float32_t* R_channel_out, uint16_t Signal_Length)
bmazzeo 0:c0f52e8223fe 90 {
bmazzeo 0:c0f52e8223fe 91 char buf[70];
bmazzeo 0:c0f52e8223fe 92 BSP_LCD_SetFont(&Font8);
bmazzeo 0:c0f52e8223fe 93 BSP_LCD_SetTextColor(LCD_COLOR_CYAN);
bmazzeo 0:c0f52e8223fe 94 sprintf(buf, "Processing Signals" );
bmazzeo 0:c0f52e8223fe 95 BSP_LCD_DisplayStringAt(0, 200, (uint8_t *) buf, LEFT_MODE);
bmazzeo 0:c0f52e8223fe 96
bmazzeo 0:c0f52e8223fe 97 switch(Lab_Execution_Type)
bmazzeo 0:c0f52e8223fe 98 {
bmazzeo 0:c0f52e8223fe 99 case 0: // Passthrough case
bmazzeo 0:c0f52e8223fe 100 arm_copy_f32(L_channel_in, L_channel_out, AUDIO_BLOCK_SAMPLES);
bmazzeo 0:c0f52e8223fe 101 arm_copy_f32(R_channel_in, R_channel_out, AUDIO_BLOCK_SAMPLES);
bmazzeo 0:c0f52e8223fe 102 break;
bmazzeo 0:c0f52e8223fe 103
bmazzeo 0:c0f52e8223fe 104 case 1: // FIR case (ARM)
justenmg 1:103e3e426b55 105 arm_fir_f32(&filter_left, L_channel_in, L_channel_out, AUDIO_BLOCK_SAMPLES);
justenmg 1:103e3e426b55 106 arm_fir_f32(&filter_right, R_channel_in, R_channel_out, AUDIO_BLOCK_SAMPLES);
bmazzeo 0:c0f52e8223fe 107 break;
bmazzeo 0:c0f52e8223fe 108
bmazzeo 0:c0f52e8223fe 109 case 2: // FIR case (student)
justenmg 1:103e3e426b55 110 arm_fir_f32(&filter_left, L_channel_in, L_channel_out, AUDIO_BLOCK_SAMPLES);
justenmg 1:103e3e426b55 111 arm_fir_f32(&filter_right, R_channel_in, R_channel_out, AUDIO_BLOCK_SAMPLES);
bmazzeo 0:c0f52e8223fe 112 break;
bmazzeo 0:c0f52e8223fe 113
bmazzeo 0:c0f52e8223fe 114 case 3: // FFT Overlap-add
bmazzeo 0:c0f52e8223fe 115 break;
bmazzeo 0:c0f52e8223fe 116
bmazzeo 0:c0f52e8223fe 117 case 4: // FFT Overlap-add with real-imag efficiency
bmazzeo 0:c0f52e8223fe 118 break;
bmazzeo 0:c0f52e8223fe 119
bmazzeo 0:c0f52e8223fe 120
bmazzeo 0:c0f52e8223fe 121 }
bmazzeo 0:c0f52e8223fe 122 /* Change font back */
bmazzeo 0:c0f52e8223fe 123 BSP_LCD_SetFont(&Font16);
bmazzeo 0:c0f52e8223fe 124 }
justenmg 1:103e3e426b55 125
justenmg 1:103e3e426b55 126
justenmg 1:103e3e426b55 127 void filter(float32_t* buffer, float32_t* d_in, float32_t* d_out, uint16_t buf_length)
justenmg 1:103e3e426b55 128 {
justenmg 1:103e3e426b55 129 float32_t result = 0;
justenmg 1:103e3e426b55 130 float32_t* data_sample = d_out;
justenmg 1:103e3e426b55 131 for(i=0; i<buf_length; i++)
justenmg 1:103e3e426b55 132 {
justenmg 1:103e3e426b55 133 *data_sample = convolve(d_in, win_filter_coeffs, AUDIO_BLOCK_SAMPLES, BUFFER_LENGTH);
justenmg 1:103e3e426b55 134 data_sample++; //*******************************************************
justenmg 1:103e3e426b55 135 }
justenmg 1:103e3e426b55 136 }
justenmg 1:103e3e426b55 137
justenmg 1:103e3e426b55 138 float32_t convolve(float32_t* data, float32_t* filter, uint16_t sig_length, uint16_t buf_length)
justenmg 1:103e3e426b55 139 {
justenmg 1:103e3e426b55 140 float32_t* data_sample = data+buf_length-1;
justenmg 1:103e3e426b55 141 float32_t* filter_sample = filter;
justenmg 1:103e3e426b55 142 float32_t result = 0;
justenmg 1:103e3e426b55 143 for(i=0; i<buf_length; i++)
justenmg 1:103e3e426b55 144 {
justenmg 1:103e3e426b55 145 result += (*filter_sample) * (*data_sample);
justenmg 1:103e3e426b55 146 }
justenmg 1:103e3e426b55 147 return result;
justenmg 1:103e3e426b55 148 }