lab 3
Dependencies: mbed BSP_DISCO_F746NG mbed-dsp
Diff: main.cpp
- Revision:
- 0:c0f52e8223fe
- Child:
- 3:02dd3dd9120a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/main.cpp Fri Jan 31 21:41:25 2020 +0000 @@ -0,0 +1,403 @@ +/** + ****************************************************************************** + * @file main.c + * @author Brian Mazzeo + * @date 2020 + * @brief This file provides a set of code for signal processing in 487. + * Parts are taken from example code from STMIcroelectronics + ****************************************************************************** + * @attention + * This code was specifically developed for BYU ECEn 487 course + * Introduction to Digital Signal Processing. + * + * + ****************************************************************************** + */ + + +#include "mbed.h" +#include "stm32746g_discovery_audio.h" +#include "stm32746g_discovery_sdram.h" +#include "stm32746g_discovery_lcd.h" +#include "arm_math.h" +#include "signal_processing.h" + +/* The following type definitions are used to control the + * buffering of the audio data using a double buffering technique. + * Most of the transactions between the WM8994 and the microcontroller + * are handled by other code - but this signals what the buffering state + * is, so the data can be appropriately processed. */ +typedef enum { + BUFFER_OFFSET_NONE = 0, + BUFFER_OFFSET_HALF = 1, + BUFFER_OFFSET_FULL = 2, +} BUFFER_StateTypeDef; + +/* These audio block samples define the size of the buffering */ +#define AUDIO_BLOCK_SAMPLES ((uint32_t)128) // Number of samples (L and R) in audio block (each samples is 16 bits) +#define AUDIO_BLOCK_SIZE ((uint32_t)512) // Number of bytes in audio block (4 * AUDIO_BLOCK_SAMPLES) + +/* These RAM addresses are important to determine where the audio data is stored. */ +#define SDRAM_DEVICE_ADDR_AUDIO_MEM ((uint32_t)0xC0400000) +#define AUDIO_BUFFER_IN SDRAM_DEVICE_ADDR_AUDIO_MEM +#define AUDIO_BUFFER_OUT (AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE * 2)) + +/* These definitions define the size of the oscilloscope that is used to display data. */ +#define OSC_START_X_POS 20 +#define OSC_LINE_SIZE 256 +#define OSC_Y_POS 130 +#define AUDIO_DRAW_LIMIT 50 + +/* This define a timer that is then used to record the timing of the different processing stages. */ +Timer timer; + +/* This variable is important because it define the audio buffer recording state. */ +volatile uint32_t audio_rec_buffer_state = BUFFER_OFFSET_NONE; + +/* Function declarations */ +static void Erase_Trace(uint16_t Xpos, uint16_t Ypos, uint16_t Length); +static void Draw_Trace(uint16_t Xpos, uint16_t Ypos, uint16_t* Mem_start, uint16_t Length); +static void Audio_to_Float(uint16_t* buffer_in, float32_t* L_out, float32_t* R_out, uint16_t Length); +static void Float_to_Audio(float32_t* L_in, float32_t* R_in, uint16_t* buffer_out, uint16_t Length); + +/* These memory blocks are important for converting to floating point representation. */ +float32_t L_channel_float_in[AUDIO_BLOCK_SAMPLES]; +float32_t R_channel_float_in[AUDIO_BLOCK_SAMPLES]; +float32_t L_channel_float_out[AUDIO_BLOCK_SAMPLES]; +float32_t R_channel_float_out[AUDIO_BLOCK_SAMPLES]; +float32_t *L_channel_float_in_p = &L_channel_float_in[0]; +float32_t *R_channel_float_in_p = &R_channel_float_in[0]; +float32_t *L_channel_float_out_p = &L_channel_float_out[0]; +float32_t *R_channel_float_out_p = &R_channel_float_out[0]; + +/* These memory blocks are where the information is stored to send back out to the WM8994 chip. */ +uint16_t Processed_audio[AUDIO_BLOCK_SAMPLES]; +uint16_t *Processed_audio_p = &Processed_audio[0]; + +/* Useful variables during looping */ +uint32_t counter = 0; // Loop counter +char buf[40]; // Character buffer for sprintf statements to the LCD +int first_half_time = 0; // Time of first processing block +int second_half_time = 0; // Time of second processing block +int total_time = 0; // Time of total loop (first and second blocks) + +/* Main Function */ +int main() +{ + /* Initialize the LCD Screen and display information */ + BSP_LCD_Init(); + BSP_LCD_LayerDefaultInit(LTDC_ACTIVE_LAYER, LCD_FB_START_ADDRESS); + BSP_LCD_SelectLayer(LTDC_ACTIVE_LAYER); + + /* Clear the LCD and set the font to be default */ + BSP_LCD_Clear(LCD_COLOR_BLACK); + BSP_LCD_SetFont(&LCD_DEFAULT_FONT); + + /* Set the backcolor to be black and the textcolor to be orange. */ + BSP_LCD_SetBackColor(LCD_COLOR_BLACK); + BSP_LCD_SetTextColor(LCD_COLOR_ORANGE); + + /* The following are static display elements that will remain on the screen. */ + BSP_LCD_DisplayStringAt(0, 0, (uint8_t *)"487 Demo Code (Mazzeo)", LEFT_MODE); + + /* Display the L and R colors for the channels */ + BSP_LCD_SetTextColor(LCD_COLOR_BLUE); + BSP_LCD_DisplayStringAt(0, OSC_Y_POS - 20, (uint8_t *)"L", LEFT_MODE); + BSP_LCD_SetTextColor(LCD_COLOR_GREEN); + BSP_LCD_DisplayStringAt(0, OSC_Y_POS, (uint8_t *)"R", LEFT_MODE); + + /* The following code should not be code that you need to worry about - it sets up the audio interfaces. */ + /* Initialize the Audio Interface */ + BSP_AUDIO_IN_OUT_Init(INPUT_DEVICE_DIGITAL_MICROPHONE_2, OUTPUT_DEVICE_HEADPHONE, DEFAULT_AUDIO_IN_FREQ, DEFAULT_AUDIO_IN_BIT_RESOLUTION, DEFAULT_AUDIO_IN_CHANNEL_NBR); + + /* Initialize SDRAM buffers */ + BSP_SDRAM_Init(); + memset((uint16_t *)AUDIO_BUFFER_IN, 0, AUDIO_BLOCK_SIZE * 2); + memset((uint16_t *)AUDIO_BUFFER_OUT, 0, AUDIO_BLOCK_SIZE * 2); + + /* Start Recording */ + if (BSP_AUDIO_IN_Record((uint16_t *)AUDIO_BUFFER_IN, AUDIO_BLOCK_SIZE) != AUDIO_OK) { printf("BSP_AUDIO_IN_Record error\n"); } + + /* Start Playback */ + BSP_AUDIO_OUT_SetAudioFrameSlot(CODEC_AUDIOFRAME_SLOT_02); + if (BSP_AUDIO_OUT_Play((uint16_t *)AUDIO_BUFFER_OUT, AUDIO_BLOCK_SIZE * 2) != AUDIO_OK) { printf("BSP_AUDIO_OUT_Play error\n"); } + + /* The audio interfaces are all now working. + * Importantly - AUDIO_BUFFER_IN is the pointer to the incoming data from the WM8994 + * AUDIO_BUFFER_OUT is the pointer to the outgoing data to the WM8994 */ + + + /* Initialize signal processing filters - usually there are variables that + * need to be set up or that there are arrays you need to precompute - this + * function call allows you to do that. */ + initalize_signal_processing(); + + /* Hardware timer starts. Set to zero */ + timer.start(); + + /* Main signal processing while loop */ + while (1) { + + /* First Half */ + /* Wait until end of half block recording before going on in the first half cycle*/ + while (audio_rec_buffer_state != BUFFER_OFFSET_HALF) {} + + /* This captures the time of an entire cycle */ + total_time = timer.read_us(); + + /* Reset the timer counter to zero */ + timer.reset(); + + /* Plot traces of first half block recording */ + Erase_Trace(OSC_START_X_POS, OSC_Y_POS, AUDIO_BLOCK_SAMPLES); + Draw_Trace(OSC_START_X_POS, OSC_Y_POS, (uint16_t *) AUDIO_BUFFER_IN, AUDIO_BLOCK_SAMPLES); + + /* Convert data to floating point representation for processing */ + Audio_to_Float((uint16_t *) AUDIO_BUFFER_IN, L_channel_float_in_p, R_channel_float_in_p, AUDIO_BLOCK_SAMPLES); + + /* ------------------------------------------------------------------------ */ + /* Here is where signal processing can be done on the floating point arrays */ + + process_audio_channel_signals(L_channel_float_in_p, R_channel_float_in_p, L_channel_float_out_p, R_channel_float_out_p, AUDIO_BLOCK_SAMPLES); + + /* Here is where signal processing can end on the floating point arrays */ + /* -------------------------------------------------------------------- */ + + /* Covert floating point data back to fixed point audio format */ + Float_to_Audio(L_channel_float_out_p, R_channel_float_out_p, (uint16_t *) Processed_audio, AUDIO_BLOCK_SAMPLES); + + /* Copy recorded 1st half block into the audio buffer that goes out */ + /* Replace the second memcpy with this first one once you have worked out the processed audio functions. */ + memcpy((uint16_t *)(AUDIO_BUFFER_OUT), (uint16_t *)(Processed_audio), AUDIO_BLOCK_SIZE); + //memcpy((uint16_t *)(AUDIO_BUFFER_OUT), (uint16_t *)(AUDIO_BUFFER_IN), AUDIO_BLOCK_SIZE); + + /* Display useful cycle information (split up information display so the processing is more balanced) */ + sprintf(buf, "Cycles: %9d", counter); + BSP_LCD_SetTextColor(LCD_COLOR_RED); + BSP_LCD_DisplayStringAt(0, 46, (uint8_t *) buf, LEFT_MODE); + + + /* Capture the timing of the first half processing */ + first_half_time = timer.read_us(); + /* End First Half */ + + /* Second Half */ + /* Wait end of one block recording */ + while (audio_rec_buffer_state != BUFFER_OFFSET_FULL) {} + + /* Plot traces of second half block recording */ + Erase_Trace(OSC_START_X_POS+AUDIO_BLOCK_SAMPLES, OSC_Y_POS, AUDIO_BLOCK_SAMPLES); + Draw_Trace( OSC_START_X_POS+AUDIO_BLOCK_SAMPLES, OSC_Y_POS, (uint16_t *) (AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE)), AUDIO_BLOCK_SAMPLES); + + /* Convert data to floating point representation for processing */ + Audio_to_Float((uint16_t *) (AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE)), L_channel_float_in_p, R_channel_float_in_p, AUDIO_BLOCK_SAMPLES); + + /* ------------------------------------------------------------------------ */ + /* Here is where signal processing can be done on the floating point arrays */ + + process_audio_channel_signals(L_channel_float_in_p, R_channel_float_in_p, L_channel_float_out_p, R_channel_float_out_p, AUDIO_BLOCK_SAMPLES); + + /* Here is where signal processing can end on the floating point arrays */ + /* -------------------------------------------------------------------- */ + + /* Covert floating point data back to fixed point audio format */ + Float_to_Audio(L_channel_float_out_p, R_channel_float_out_p, (uint16_t *) Processed_audio, AUDIO_BLOCK_SAMPLES); + + /* Copy recorded 2nd half block into the audio buffer that goes out */ + memcpy((uint16_t *)(AUDIO_BUFFER_OUT + (AUDIO_BLOCK_SIZE)), (uint16_t *) (Processed_audio), AUDIO_BLOCK_SIZE); + //memcpy((uint16_t *)(AUDIO_BUFFER_OUT + (AUDIO_BLOCK_SIZE)), (uint16_t *)(AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE)), AUDIO_BLOCK_SIZE); + + + /* Compute important cycle information and display it*/ + sprintf(buf, "1:%6d 2:%6d T:%6d", first_half_time, second_half_time, total_time); + BSP_LCD_SetTextColor(LCD_COLOR_RED); + BSP_LCD_DisplayStringAt(0, 20, (uint8_t *) buf, LEFT_MODE); + + /* Copy recorded 2nd half block into audio output buffer */ + + /* Change the recording buffer state to reflect the status of the buffer */ + audio_rec_buffer_state = BUFFER_OFFSET_NONE; + + /* Increase the counter */ + counter++; + + /* Measures the amount of time to process the second half */ + second_half_time = timer.read_us(); + + /* End Second Half */ + } +} + +/** + * @brief Draws a trace of the data line. + * @param Xpos: X position + * @param Ypos: Y position + * @param Mem_start: Start of memory location + * @param Length: length of trace + * @retval None + */ +void Erase_Trace(uint16_t Xpos, uint16_t Ypos, uint16_t Length) +{ + /* Creates a brown rectangle above and below the axis */ + BSP_LCD_SetTextColor(LCD_COLOR_BROWN); + BSP_LCD_FillRect(Xpos, Ypos - AUDIO_DRAW_LIMIT, Length, AUDIO_DRAW_LIMIT); + BSP_LCD_FillRect(Xpos, Ypos+1, Length, AUDIO_DRAW_LIMIT); + + /* Draw axis for plotting */ + BSP_LCD_SetTextColor(LCD_COLOR_WHITE); + BSP_LCD_DrawHLine(Xpos, Ypos, Length); + +} + + +/** + * @brief Draws a trace of the data line. + * @param Xpos: X position + * @param Ypos: Y position + * @param Mem_start: Start of memory location + * @param Length: length of trace + * @retval None + */ +void Draw_Trace(uint16_t Xpos, uint16_t Ypos, uint16_t* Mem_start, uint16_t Length) +{ + uint16_t i; + uint16_t* mem_address; + char buf[10]; + int16_t L_audio_value; + int16_t R_audio_value; + + mem_address = Mem_start; + + for (i=0; i<Length; i++) + { + R_audio_value = (int16_t) *mem_address; + mem_address++; + L_audio_value = (int16_t) *mem_address; + mem_address++; + + L_audio_value = L_audio_value / 100; + R_audio_value = R_audio_value / 100; + + if (L_audio_value > AUDIO_DRAW_LIMIT) {L_audio_value = AUDIO_DRAW_LIMIT;} + else if (L_audio_value < -AUDIO_DRAW_LIMIT) {L_audio_value = -AUDIO_DRAW_LIMIT;} + + if (R_audio_value > AUDIO_DRAW_LIMIT) {R_audio_value = AUDIO_DRAW_LIMIT;} + else if (R_audio_value < -AUDIO_DRAW_LIMIT) {R_audio_value = -AUDIO_DRAW_LIMIT;} + + BSP_LCD_DrawPixel(Xpos + i, (uint16_t) ((int16_t) Ypos + L_audio_value), LCD_COLOR_BLUE); + BSP_LCD_DrawPixel(Xpos + i, (uint16_t) ((int16_t) Ypos + R_audio_value), LCD_COLOR_GREEN); + } + +} + +/** + * @brief Converts audio data in buffer to floating point representation. + * @param buffer_in: Pointer to Audio buffer start location + * @param L_out: Pointer to Left channel out data (float32_t) + * @param R_out: Pointer to Right channel out data (float32_t) + * @param Length: length of data to convert + * @retval None + */ +void Audio_to_Float(uint16_t* buffer_in, float32_t* L_out, float32_t* R_out, uint16_t Length) +{ + uint16_t i; + uint16_t* audio_mem_address; + float32_t* L_chan_mem_address; + float32_t* R_chan_mem_address; + float32_t L_audio_value; + float32_t R_audio_value; + + audio_mem_address = buffer_in; + L_chan_mem_address = L_out; + R_chan_mem_address = R_out; + + for (i=0; i<Length; i++) + { + R_audio_value = (float32_t) ((int16_t) *audio_mem_address); + audio_mem_address++; + L_audio_value = (float32_t) ((int16_t) *audio_mem_address); + audio_mem_address++; + + *L_chan_mem_address = L_audio_value; + L_chan_mem_address++; + + *R_chan_mem_address = R_audio_value; + R_chan_mem_address++; + } +} + +/** + * @brief Converts audio data in buffer to floating point representation. + * @param L_out: Pointer to Left channel in data (float32_t) + * @param R_out: Pointer to Right channel in data (float32_t) + * @param buffer_out: Pointer to combined 32 bit (two 16-bit int samples) + * @param Length: length of data to convert + * @retval None + */ +void Float_to_Audio(float32_t* L_in, float32_t* R_in, uint16_t* buffer_out, uint16_t Length) +{ + uint16_t i; + uint16_t* audio_mem_address; + float32_t* L_chan_mem_address; + float32_t* R_chan_mem_address; + int16_t L_audio_value; + int16_t R_audio_value; + + audio_mem_address = buffer_out; + L_chan_mem_address = L_in; + R_chan_mem_address = R_in; + + for (i=0; i<Length; i++) + { + L_audio_value = (int16_t) ((float32_t) *L_chan_mem_address); + L_chan_mem_address++; + + R_audio_value = (int16_t) ((float32_t) *R_chan_mem_address); + R_chan_mem_address++; + + *audio_mem_address = (uint16_t) R_audio_value; + audio_mem_address++; + *audio_mem_address = (uint16_t) L_audio_value; + audio_mem_address++; + } +} + + + + + +/*------------------------------------------------------------------------------------- + Callbacks implementation: + the callbacks API are defined __weak in the stm32746g_discovery_audio.c file + and their implementation should be done in the user code if they are needed. + Below some examples of callback implementations. + -------------------------------------------------------------------------------------*/ +/** + * @brief Manages the DMA Transfer complete interrupt. + * @param None + * @retval None + */ +void BSP_AUDIO_IN_TransferComplete_CallBack(void) +{ + audio_rec_buffer_state = BUFFER_OFFSET_FULL; +} + +/** + * @brief Manages the DMA Half Transfer complete interrupt. + * @param None + * @retval None + */ +void BSP_AUDIO_IN_HalfTransfer_CallBack(void) +{ + audio_rec_buffer_state = BUFFER_OFFSET_HALF; +} + +/** + * @brief Audio IN Error callback function. + * @param None + * @retval None + */ +void BSP_AUDIO_IN_Error_CallBack(void) +{ + printf("BSP_AUDIO_IN_Error_CallBack\n"); +}