18..STM32F469I---标准外设库DSI刷屏

feixiang20 · 发表于 2018-1-12 14:56:54

【STM32F469I试用】标准外设库DSI刷屏【转】

虽然意法现在主推HAL库，低功耗L系列的单片机甚至已不再提供标准外设库，HAL的资料越来越丰富，是接下来设计产品的主流，但现在也还有很大一部分工程师继续使用着标准外设库，或是之前项目工程是基于标准库，移植起来也相对方便。STM32F469这块板子ST在HAL库以及提供了DSI LCD部分的相关例程，使用起来真是方便。不过为了适配接下来RTT的移植（RTT是基于标准外设库），只能把HAL库的这部分的程序移植到标准外设库上。先上两张图看看效果

首先，是SDRAM的初始化，整体的程序参考标准外设库stm324x9i_eval_fmc_sdram.c文件里的初始化函数，不过由于我们采用RGB565的格式来储存像素点的数据，所以对初始化函数的内容也做相应的改动:SDRAM_MEMORY_WIDTH改为16b的宽度，以对应RGB565的两个字节数据。
FMC_SDRAMInitStructure.FMC_SDMemoryDataWidth = SDRAM_MEMORY_WIDTH;
 FMC_SDRAMInitStructure.FMC_InternalBankNumber = FMC_InternalBank_Number_4;

接下来是按照HAL库的初始化顺序，先后对DSI、LTDC初始化

LCD_Reset();
 DSI_Config();
 LCD_Config();
 DSI_Start(DSI);
 OTM8009Setup(DSI, IMAGEFORMAT_RGB565);

在LCD_Config中，值得注意的是LTDC_CFBStartAdress的设置，这个地址指向了LCD显存的地址，这里用SDRAM来作为显存，RGB565格式下，0xC0000000开始的连续两个地址代表一个像素点的颜色信息，所以打点函数也就是计算位置，往SDRAM中填入相应的颜色信息。

LTDC_Layer_InitStruct.LTDC_CFBStartAdress = ((uint32_t)0xC0000000);
/* the length of one line of pixels in bytes + 3 then :
Line Length = Active high width x number of bytes per pixel + 3
Active high width = 480
number of bytes per pixel = 2 (pixel_format : RGB565) */
LTDC_Layer_InitStruct.LTDC_CFBLineLength = ((480 * 2) + 3);
/* the pitch is the increment from the start of one line of pixels to the
start of the next line in bytes, then :
Pitch = Active high width x number of bytes per pixel */
LTDC_Layer_InitStruct.LTDC_CFBPitch = (480 * 2);
/* Configure the number of lines */
LTDC_Layer_InitStruct.LTDC_CFBLineNumber = 800;
/* Initializes the Layer */
LTDC_LayerInit(LTDC_Layer1, <DC_Layer_InitStruct);
/* Enable Layer 1 */
LTDC_LayerCmd(LTDC_Layer1, ENABLE);
/* Reload configuration of Layer 1 */
LTDC_ReloadConfig(LTDC_IMReload);
/* Enable The LCD */
LTDC_Cmd(ENABLE);

SDRAM显存与LCD显示的关系如下图：画得不是很好、呵呵、不过应该能大致了解。

整个屏幕实现横屏和竖屏的效果，由宏定义控制，其中0为横屏，1为竖屏。

#define OTM_8009_sta 1 //横屏 0 竖屏 1

横屏和竖屏的效果在最底层的打点函数上实现

#if OTM_8009_sta==0
*(__IO uint16_t*) (LCD_FB_START_ADDRESS + (2*(Xpos*480 + 480-Ypos))) = RGB_Code;
#else
 /* Write data value to all SDRAM memory */
 *(__IO uint16_t*) (LCD_FB_START_ADDRESS + (2*(Ypos*480 + Xpos))) = RGB_Code;
#endif

其他的字符函数、画圆、画矩形函数都是基于上述打点函数，基本是从HAL库直接复制过来，基本不用修改。

void BSP_LCD_DrawCircle(uint16_t Xpos, uint16_t Ypos, uint16_t Radius)
{
 int32_t D; /* Decision Variable */
 uint32_t CurX; /* Current X Value */
 uint32_t CurY; /* Current Y Value */
 D = 3 - (Radius << 1);
 CurX = 0;
 CurY = Radius;
 while (CurX <= CurY)
 {
BSP_LCD_DrawPixel((Xpos + CurX), (Ypos - CurY), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos - CurX), (Ypos - CurY), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos + CurY), (Ypos - CurX), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos - CurY), (Ypos - CurX), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos + CurX), (Ypos + CurY), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos - CurX), (Ypos + CurY), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos + CurY), (Ypos + CurX), DrawProp[ActiveLayer].TextColor);
BSP_LCD_DrawPixel((Xpos - CurY), (Ypos + CurX), DrawProp[ActiveLayer].TextColor);
if (D < 0)
{
 D += (CurX << 2) + 6;
}
else
{
 D += ((CurX - CurY) << 2) + 10;
 CurY--;
}
CurX++;
 }
}

void BSP_LCD_DisplayStringAt(uint16_t Xpos, uint16_t Ypos, uint8_t *Text, Text_AlignModeTypdef Mode)
{
 uint16_t refcolumn = 1, i = 0;
 uint32_t size = 0, xsize = 0;
 uint8_t *ptr = Text;
 /* Get the text size */
 while (*ptr++) size ++ ;
 /* Characters number per line */
 xsize = (OTM8009A_800X480_WIDTH/DrawProp[ActiveLayer].pFont->Width);
 switch (Mode)
 {
 case CENTER_MODE:
{
 refcolumn = Xpos + ((xsize - size)* DrawProp[ActiveLayer].pFont->Width) / 2;
 break;
}
 case LEFT_MODE:
{
 refcolumn = Xpos;
 break;
}
 case RIGHT_MODE:
{
 refcolumn = - Xpos + ((xsize - size)*DrawProp[ActiveLayer].pFont->Width);
 break;
}
 default:
{
 refcolumn = Xpos;
 break;
}
 }
 /* Check that the Start column is located in the screen */
 if ((refcolumn < 1) || (refcolumn >= 480))//0x8000
 {
refcolumn = 1;
 }
 /* Send the string character by character on LCD */
 while ((*Text != 0) & (((OTM8009A_800X480_WIDTH - (i*DrawProp[ActiveLayer].pFont->Width)) & 0xFFFF) >= DrawProp[ActiveLayer].pFont->Width))
 {
/* Display one character on LCD */
BSP_LCD_DisplayChar(refcolumn, Ypos, *Text);
/* Decrement the column position by 16 */
refcolumn += DrawProp[ActiveLayer].pFont->Width;
/* Point on the next character */
Text++;
i++;
 }
}

STM32F4xx_DSP_StdPeriph_Lib_V1.6.1.zip (1.32 MB, 下载次数: 9, 售价: 2 与非币)

18..STM32F469I---标准外设库DSI刷屏

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