File content as of revision 7:e1dfd64eba81:

#include "mbed.h"
#include "stm32746g_discovery_audio.h"
#include "stm32746g_discovery_sdram.h"
#include "stm32746g_discovery_lcd.h"

typedef enum {
    BUFFER_OFFSET_NONE = 0,
    BUFFER_OFFSET_HALF = 1,
    BUFFER_OFFSET_FULL = 2,
} BUFFER_StateTypeDef;


// #define AUDIO_BLOCK_SIZE   ((uint32_t)512)
#define AUDIO_BLOCK_SIZE   ((uint32_t)256)

#define SDRAM_DEVICE_ADDR_AUDIO_MEM  ((uint32_t)0xC00A0000)
#define AUDIO_BUFFER_IN     SDRAM_DEVICE_ADDR_AUDIO_MEM
#define AUDIO_BUFFER_OUT   (AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE * 2))

#define OSC_START_X_POS     10
#define OSC_LINE_SIZE       256
#define L_CHANNEL_Y_POS     120
#define R_CHANNEL_Y_POS     220
#define AUDIO_DRAW_LIMIT    30

volatile uint32_t  audio_rec_buffer_state = BUFFER_OFFSET_NONE;
static void Erase_Trace(uint16_t Xpos, uint16_t L_Ypos, uint16_t R_Ypos, uint16_t Length);
static void Draw_Trace(uint16_t Xpos, uint16_t L_Ypos, uint16_t R_Ypos, uint32_t Mem_start, uint16_t Length);

int main()
{
    
    BSP_LCD_Init();
    BSP_LCD_LayerDefaultInit(LTDC_ACTIVE_LAYER, LCD_FB_START_ADDRESS);
    BSP_LCD_SelectLayer(LTDC_ACTIVE_LAYER);

    BSP_LCD_Clear(LCD_COLOR_BLACK);
    BSP_LCD_SetFont(&LCD_DEFAULT_FONT);
        

    BSP_LCD_SetBackColor(LCD_COLOR_BLACK);
    BSP_LCD_SetTextColor(LCD_COLOR_ORANGE);
    BSP_LCD_DisplayStringAt(0, 0, (uint8_t *)"487 Mic Audio Test Code", LEFT_MODE);

    printf("\n\nAUDIO LOOPBACK EXAMPLE START:\n");

    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);
    printf("AUDIO loop from digital micro (U20 & U21 components on board) to headphone (CN10 jack connector)\n");

    // BSP_LCD_DisplayStringAt(10, 20, (uint8_t *)"SDRAM Initialization", LEFT_MODE);


    /* 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);
    printf("SDRAM init done\n");

    audio_rec_buffer_state = BUFFER_OFFSET_NONE;

    /* 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");
    }


    BSP_LCD_SetTextColor(LCD_COLOR_BLUE);
    uint32_t counter;
    counter = 0;

    char buf[10];

    while (1) {
    /* First Half */

        /* Wait end of half block recording */
        while (audio_rec_buffer_state == BUFFER_OFFSET_HALF) {
        }
        audio_rec_buffer_state = BUFFER_OFFSET_NONE;

        /* Copy recorded 1st half block */
        memcpy((uint16_t *)(AUDIO_BUFFER_OUT), (uint16_t *)(AUDIO_BUFFER_IN), AUDIO_BLOCK_SIZE);

    /* Second Half */

        /* Wait end of one block recording */
        while (audio_rec_buffer_state == BUFFER_OFFSET_FULL) {
        }
        audio_rec_buffer_state = BUFFER_OFFSET_NONE;

        /* Copy recorded 2nd half block */
        memcpy((uint16_t *)(AUDIO_BUFFER_OUT + (AUDIO_BLOCK_SIZE)), (uint16_t *)(AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE)), AUDIO_BLOCK_SIZE);

        Erase_Trace(OSC_START_X_POS, L_CHANNEL_Y_POS, R_CHANNEL_Y_POS, 256);
        Draw_Trace(OSC_START_X_POS, L_CHANNEL_Y_POS, R_CHANNEL_Y_POS, AUDIO_BUFFER_OUT, 256);
        
        counter++;
        sprintf(buf, "%d", counter);
        BSP_LCD_SetTextColor(LCD_COLOR_RED);
        BSP_LCD_DisplayStringAt(0, 40, (uint8_t *) buf, LEFT_MODE);
    }
}

/**
  * @brief  Draws a trace of the data line.
  * @param  Xpos: X position
  * @param  L_Ypos: Left channel Y position
  * @param  R_Ypos: Right channel Y position
  * @param  Mem_start: Start of memory location
  * @param  Length: length of trace
  * @retval None
  */
void Erase_Trace(uint16_t Xpos, uint16_t L_Ypos, uint16_t R_Ypos, uint16_t Length)
{
    BSP_LCD_SetTextColor(LCD_COLOR_BROWN);
    BSP_LCD_FillRect(Xpos, L_Ypos - AUDIO_DRAW_LIMIT, Length, AUDIO_DRAW_LIMIT);
    BSP_LCD_FillRect(Xpos, L_Ypos+1, Length, AUDIO_DRAW_LIMIT);
    BSP_LCD_FillRect(Xpos, R_Ypos - AUDIO_DRAW_LIMIT, Length, AUDIO_DRAW_LIMIT);
    BSP_LCD_FillRect(Xpos, R_Ypos+1, Length, AUDIO_DRAW_LIMIT);
    
    BSP_LCD_SetTextColor(LCD_COLOR_BLUE);
    BSP_LCD_DrawHLine(OSC_START_X_POS, L_CHANNEL_Y_POS, Length);
    BSP_LCD_DrawHLine(OSC_START_X_POS, R_CHANNEL_Y_POS, Length);

}


/**
  * @brief  Draws a trace of the data line.
  * @param  Xpos: X position
  * @param  L_Ypos: Left channel Y position
  * @param  R_Ypos: Right channel Y position
  * @param  Mem_start: Start of memory location
  * @param  Length: length of trace
  * @retval None
  */
void Draw_Trace(uint16_t Xpos, uint16_t L_Ypos, uint16_t R_Ypos, uint32_t Mem_start, uint16_t Length)
{
    uint16_t i;
    uint32_t data_value;
    uint32_t* mem_address;
    char buf[10];
    int16_t L_audio_value;
    int16_t R_audio_value;
    
    data_value = *((uint32_t*) Mem_start);
    L_audio_value = (int16_t) ((data_value >> 16) & 0xFFFF);
    R_audio_value = (int16_t) (data_value & 0xFFFF);
    
    //sprintf(buf, "%12d", L_audio_value);
    //BSP_LCD_DisplayStringAt(0, 60, (uint8_t *) buf, LEFT_MODE);
    
    //sprintf(buf, "%12d", R_audio_value);
    //BSP_LCD_DisplayStringAt(0, 80, (uint8_t *) buf, LEFT_MODE);
      
    for (i=0; i<Length+50; i++)
   {
        mem_address = (uint32_t*) Mem_start + i;
        data_value = *((uint32_t*) mem_address);
        L_audio_value = (int16_t) ((data_value >> 16) & 0xFFFF);
        R_audio_value = (int16_t) (data_value & 0xFFFF);
        
        L_audio_value = L_audio_value / 50;
        R_audio_value = R_audio_value / 50;
        
        //sprintf(buf, "%12d", L_audio_value);
        //BSP_LCD_DisplayStringAt(0, 60, (uint8_t *) buf, LEFT_MODE);
        
        //sprintf(buf, "%12d", R_audio_value);
        //BSP_LCD_DisplayStringAt(0, 80, (uint8_t *) buf, LEFT_MODE);


        //L_audio_value = -i;
        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) L_Ypos + L_audio_value), LCD_COLOR_WHITE);
        BSP_LCD_DrawPixel(Xpos + i, (uint16_t) ((int16_t) R_Ypos + R_audio_value), LCD_COLOR_WHITE);
   }
   
}
    
/* Read data value from SDRAM memory */
//    ret = *(__IO uint32_t*) (hLtdcHandler.LayerCfg[ActiveLayer].FBStartAdress + (4*(Ypos*BSP_LCD_GetXSize() + Xpos)));


/*-------------------------------------------------------------------------------------
       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");
}