44..STM32F469I---LCD简单测试之“弹幕”

feixiang20

【STM32F469I试用】LCD简单测试之“弹幕”【转】

STM32F469有个分辨率很高的4寸屏幕，无论显示图片还是字体都很清晰细腻，下面的测试就模仿大家经常见到的“弹幕”效果进行测试。
板载的LCD是使用MIPI接口（DSI）来实现的，配合LTDC和DMA2D使用更加功能强大。LCD驱动部分总的结构框图如下：



DSI接口配置较为复杂，还好的是ST给出了参考的配置过程，分别初始化SDRAM，DSI，LTDC这些接口即可，使用时直接写SDRAM用来更新显示。除此之外也可以使用CubeMX配置更加简单方便。
主要的LCD初始化代码如下：
uint8_t BSP_LCD_InitEx(LCD_OrientationTypeDef orientation)
{
  DSI_PLLInitTypeDef dsiPllInit;
  static RCC_PeriphCLKInitTypeDef  PeriphClkInitStruct;
  uint32_t LcdClock  = 27429; /*!< LcdClk = 27429 kHz */
  uint32_t Clockratio  = 0;
  uint32_t laneByteClk_kHz = 0;
  uint32_t                   VSA; /*!< Vertical start active time in units of lines */
  uint32_t                   VBP; /*!< Vertical Back Porch time in units of lines */
  uint32_t                   VFP; /*!< Vertical Front Porch time in units of lines */
  uint32_t                   VACT; /*!< Vertical Active time in units of lines = imageSize Y in pixels to display */
  uint32_t                   HSA; /*!< Horizontal start active time in units of lcdClk */
  uint32_t                   HBP; /*!< Horizontal Back Porch time in units of lcdClk */
  uint32_t                   HFP; /*!< Horizontal Front Porch time in units of lcdClk */
  uint32_t                   HACT; /*!< Horizontal Active time in units of lcdClk = imageSize X in pixels to display */


  /* Toggle Hardware Reset of the DSI LCD using
  * its XRES signal (active low) */
  BSP_LCD_Reset();

  /* Call first MSP Initialize only in case of first initialization
  * This will set IP blocks LTDC, DSI and DMA2D
  * - out of reset
  * - clocked
  * - NVIC IRQ related to IP blocks enabled
  */
  BSP_LCD_MspInit();

/*************************DSI Initialization***********************************/  

  /* Base address of DSI Host/Wrapper registers to be set before calling De-Init */
  hdsi_eval.Instance = DSI;

  HAL_DSI_DeInit(&(hdsi_eval));

#if !defined(USE_STM32469I_DISCO_REVA)
  dsiPllInit.PLLNDIV  = 125;
  dsiPllInit.PLLIDF   = DSI_PLL_IN_DIV2;
  dsiPllInit.PLLODF   = DSI_PLL_OUT_DIV1;
#else  
  dsiPllInit.PLLNDIV  = 100;
  dsiPllInit.PLLIDF   = DSI_PLL_IN_DIV5;
  dsiPllInit.PLLODF   = DSI_PLL_OUT_DIV1;
#endif
  laneByteClk_kHz = 62500; /* 500 MHz / 8 = 62.5 MHz = 62500 kHz */

  /* Set number of Lanes */
  hdsi_eval.Init.NumberOfLanes = DSI_TWO_DATA_LANES;

  /* TXEscapeCkdiv = f(LaneByteClk)/15.62 = 4 */
  hdsi_eval.Init.TXEscapeCkdiv = laneByteClk_kHz/15620;

  HAL_DSI_Init(&(hdsi_eval), &(dsiPllInit));
  Clockratio = laneByteClk_kHz/LcdClock;
  /* Timing parameters for all Video modes
  * Set Timing parameters of LTDC depending on its chosen orientation
  */
  if(orientation == LCD_ORIENTATION_PORTRAIT)
  {
    VSA  = OTM8009A_480X800_VSYNC;        /* 12 */
    VBP  = OTM8009A_480X800_VBP;          /* 12 */
    VFP  = OTM8009A_480X800_VFP;          /* 12 */
    HSA  = OTM8009A_480X800_HSYNC;        /* 120 */
    HBP  = OTM8009A_480X800_HBP;          /* 120 */
    HFP  = OTM8009A_480X800_HFP;          /* 120 */
    lcd_x_size = OTM8009A_480X800_WIDTH;  /* 480 */
    lcd_y_size = OTM8009A_480X800_HEIGHT; /* 800 */                                
  }
  else
  {
    /* lcd_orientation == LCD_ORIENTATION_LANDSCAPE */
    VSA  = OTM8009A_800X480_VSYNC;        /* 12 */
    VBP  = OTM8009A_800X480_VBP;          /* 12 */
    VFP  = OTM8009A_800X480_VFP;          /* 12 */
    HSA  = OTM8009A_800X480_HSYNC;        /* 120 */
    HBP  = OTM8009A_800X480_HBP;          /* 120 */
    HFP  = OTM8009A_800X480_HFP;          /* 120 */
    lcd_x_size = OTM8009A_800X480_WIDTH;  /* 800 */
    lcd_y_size = OTM8009A_800X480_HEIGHT; /* 480 */                                
  }  

  HACT = lcd_x_size;
  VACT = lcd_y_size;


  hdsivideo_handle.VirtualChannelID = LCD_OTM8009A_ID;
  hdsivideo_handle.ColorCoding = LCD_DSI_PIXEL_DATA_FMT_RBG888;
  hdsivideo_handle.VSPolarity = DSI_VSYNC_ACTIVE_HIGH;
  hdsivideo_handle.HSPolarity = DSI_HSYNC_ACTIVE_HIGH;
  hdsivideo_handle.DEPolarity = DSI_DATA_ENABLE_ACTIVE_HIGH;  
  hdsivideo_handle.Mode = DSI_VID_MODE_BURST; /* Mode Video burst ie : one LgP per line */
  hdsivideo_handle.NullPacketSize = 0xFFF;
  hdsivideo_handle.NumberOfChunks = 0;
  hdsivideo_handle.PacketSize                = HACT; /* Value depending on display orientation choice portrait/landscape */
  hdsivideo_handle.HorizontalSyncActive      = HSA*Clockratio;
  hdsivideo_handle.HorizontalBackPorch       = HBP*Clockratio;
  hdsivideo_handle.HorizontalLine            = (HACT + HSA + HBP + HFP)*Clockratio; /* Value depending on display orientation choice portrait/landscape */
  hdsivideo_handle.VerticalSyncActive        = VSA;
  hdsivideo_handle.VerticalBackPorch         = VBP;
  hdsivideo_handle.VerticalFrontPorch        = VFP;
  hdsivideo_handle.VerticalActive            = VACT; /* Value depending on display orientation choice portrait/landscape */

  /* Enable or disable sending LP command while streaming is active in video mode */
  hdsivideo_handle.LPCommandEnable = DSI_LP_COMMAND_ENABLE; /* Enable sending commands in mode LP (Low Power) */

  /* Largest packet size possible to transmit in LP mode in VSA, VBP, VFP regions */
  /* Only useful when sending LP packets is allowed while streaming is active in video mode */
  hdsivideo_handle.LPLargestPacketSize = 64;

  /* Largest packet size possible to transmit in LP mode in HFP region during VACT period */
  /* Only useful when sending LP packets is allowed while streaming is active in video mode */
  hdsivideo_handle.LPVACTLargestPacketSize = 64;


  /* Specify for each region of the video frame, if the transmission of command in LP mode is allowed in this region */
  /* while streaming is active in video mode                                                                         */
  hdsivideo_handle.LPHorizontalFrontPorchEnable = DSI_LP_HFP_ENABLE;   /* Allow sending LP commands during HFP period */
  hdsivideo_handle.LPHorizontalBackPorchEnable  = DSI_LP_HBP_ENABLE;   /* Allow sending LP commands during HBP period */
  hdsivideo_handle.LPVerticalActiveEnable = DSI_LP_VACT_ENABLE;  /* Allow sending LP commands during VACT period */
  hdsivideo_handle.LPVerticalFrontPorchEnable = DSI_LP_VFP_ENABLE;   /* Allow sending LP commands during VFP period */
  hdsivideo_handle.LPVerticalBackPorchEnable = DSI_LP_VBP_ENABLE;   /* Allow sending LP commands during VBP period */
  hdsivideo_handle.LPVerticalSyncActiveEnable = DSI_LP_VSYNC_ENABLE; /* Allow sending LP commands during VSync = VSA period */

  /* Configure DSI Video mode timings with settings set above */
  HAL_DSI_ConfigVideoMode(&(hdsi_eval), &(hdsivideo_handle));
  /* Enable the DSI host and wrapper : but LTDC is not started yet at this stage */
  HAL_DSI_Start(&(hdsi_eval));
/*************************End DSI Initialization*******************************/


/************************LTDC Initialization***********************************/  

  /* Timing Configuration */   
  hltdc_eval.Init.HorizontalSync = (HSA - 1);
  hltdc_eval.Init.AccumulatedHBP = (HSA + HBP - 1);
  hltdc_eval.Init.AccumulatedActiveW = (lcd_x_size + HSA + HBP - 1);
  hltdc_eval.Init.TotalWidth = (lcd_x_size + HSA + HBP + HFP - 1);

  /* Initialize the LCD pixel width and pixel height */
  hltdc_eval.LayerCfg->ImageWidth  = lcd_x_size;
  hltdc_eval.LayerCfg->ImageHeight = lcd_y_size;   


  /* LCD clock configuration */
  /* PLLSAI_VCO Input = HSE_VALUE/PLL_M = 1 Mhz */
  /* PLLSAI_VCO Output = PLLSAI_VCO Input * PLLSAIN = 384 Mhz */
  /* PLLLCDCLK = PLLSAI_VCO Output/PLLSAIR = 384 MHz / 7 = 54.857 MHz */
  /* LTDC clock frequency = PLLLCDCLK / LTDC_PLLSAI_DIVR_2 = 54.857 MHz / 2 = 27.429 MHz */
  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LTDC;
  PeriphClkInitStruct.PLLSAI.PLLSAIN = 384;
  PeriphClkInitStruct.PLLSAI.PLLSAIR = 7;
  PeriphClkInitStruct.PLLSAIDivR = RCC_PLLSAIDIVR_2;
  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);

  /* Background value */
  hltdc_eval.Init.Backcolor.Blue = 0;
  hltdc_eval.Init.Backcolor.Green = 0;
  hltdc_eval.Init.Backcolor.Red = 0;
  hltdc_eval.Init.PCPolarity = LTDC_PCPOLARITY_IPC;
  hltdc_eval.Instance = LTDC;

  /* Get LTDC Configuration from DSI Configuration */
  HAL_LTDC_StructInitFromVideoConfig(&(hltdc_eval), &(hdsivideo_handle));

  /* Initialize the LTDC */  
  HAL_LTDC_Init(&hltdc_eval);

#if !defined(DATA_IN_ExtSDRAM)
  /* Initialize the SDRAM */
  BSP_SDRAM_Init();
#endif /* DATA_IN_ExtSDRAM */

  /* Initialize the font */
  BSP_LCD_SetFont(&LCD_DEFAULT_FONT);

/************************End LTDC Initialization*******************************/


/***********************OTM8009A Initialization********************************/  

  /* Initialize the OTM8009A LCD Display IC Driver (KoD LCD IC Driver)
  *  depending on configuration set in 'hdsivideo_handle'.
  */
  OTM8009A_Init(hdsivideo_handle.ColorCoding, orientation);

/***********************End OTM8009A Initialization****************************/


  return LCD_OK;
}

然后实现一个简单的字符串滚动函数：
unsigned int Colorbuff[] = {LCD_COLOR_BLUE,LCD_COLOR_GREEN,LCD_COLOR_RED,LCD_COLOR_CYAN,\
LCD_COLOR_MAGENTA,LCD_COLOR_YELLOW,LCD_COLOR_LIGHTBLUE,LCD_COLOR_DARKBLUE,LCD_COLOR_ORANGE,\
LCD_COLOR_ORANGE,LCD_COLOR_WHITE,LCD_COLOR_RED,LCD_COLOR_BLUE,LCD_COLOR_GREEN};

//滚动显示一个字符串
void BSP_LCD_SlideShow(uint16_t x,uint16_t y,uint16_t num)
{        
        BSP_LCD_ShowStr(x,y,LCD_COLOR_BLACK,LCD_COLOR_BLACK,TextBuff[num],0);
        BSP_LCD_ShowStr(x+1,y,Colorbuff[num],LCD_COLOR_BLACK,TextBuff[num],0);
}

最后就是在main函数中来滚动显示想要显示的字符串了：
int main(void)
{
        uint8_t LedSta = LED_ON;
        uint16_t x0,t;
        HAL_Init();
        SystemClock_Config();
        LED_Init();
        BSP_LCD_Init();
        BSP_LCD_Layer();        
        while(1)
        {
                for(x0 = 0;x0 < 800;x0++)
                {
                                for(t = 0;t < 14;t++)
                                {
                                        BSP_LCD_SlideShow(x0,10 + 30*t,t);
                                }
                                GREEN_STA(LedSta);ORANGE_STA(LedSta);RED_STA(LedSta);BLUE_STA(LedSta);
                                LedSta = !LedSta;
                }
        }
}

效果大概如下：







总体来说显示滚动还很流畅，但是可能是优化不是很好，有的字符串有轻微的闪烁。通过简单的“弹幕”测试，可以发现虽然整个LCD显示配置过程比较复杂，但是一旦配置就可以较为简单的使用，而且显示效果也较为理想。