其实头文件，库函数要这么看。。。

1万 · 2015-11-10 12:53

/**
  ******************************************************************************
  * @file stm32f429i_discovery_lcd.c
  * @author  MCD Application Team
  * @version V2.1.2
  * @date 02-March-2015
  * @brief This file includes the LCD driver for ILI9341 Liquid Crystal
  *       Display Modules of STM32F429I-Discovery kit (MB1075).
  ******************************************************************************
  * @attention
  *
  * <h2><center>© COPYRIGHT(c) 2015 STMicroelectronics</center></h2>
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  * 1. Redistributions of source code must retain the above copyright notice,
  *    this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  * 3. Neither the name of STMicroelectronics nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */

/* File Info : -----------------------------------------------------------------
                                 User NOTES
1. How To use this driver:
--------------------------
- This driver is used to drive directly an LCD TFT using LTDC controller.
- This driver select dynamically the mounted LCD, ILI9341 240x320 LCD mounted
   on MB1075B discovery board, and use the adequate timing and setting for
   the specified LCD using device ID of the ILI9341 mounted on MB1075B discovery board

2. Driver description:
---------------------
  + Initialization steps :
   o Initialize the LCD using the LCD_Init() function.
   o Apply the Layer configuration using LCD_LayerDefaultInit() function
   o Select the LCD layer to be used using LCD_SelectLayer() function.
   o Enable the LCD display using LCD_DisplayOn() function.

  + Options
   o Configure and enable the color keying functionality using LCD_SetColorKeying()
   function.
   o Modify in the fly the transparency and/or the frame buffer address
   using the following functions :
   - LCD_SetTransparency()
   - LCD_SetLayerAddress()

  + Display on LCD
   o Clear the hole LCD using LCD_Clear() function or only one specified string
      line using LCD_ClearStringLine() function.
   o Display a character on the specified line and column using LCD_DisplayChar()
      function or a complete string line using LCD_DisplayStringAtLine() function.
   o Display a string line on the specified position (x,y in pixel) and align mode
      using LCD_DisplayStringAtLine() function.
   o Draw and fill a basic shapes (dot, line, rectangle, circle, ellipse, .. bitmap)
      on LCD using the available set of functions

------------------------------------------------------------------------------*/

/* Includes ------------------------------------------------------------------*/
#include "stm32f429i_discovery_lcd.h"
#include "../../../Utilities/Fonts/fonts.h"
#include "../../../Utilities/Fonts/font24.c"
#include "../../../Utilities/Fonts/font20.c"
#include "../../../Utilities/Fonts/font16.c"
#include "../../../Utilities/Fonts/font12.c"
#include "../../../Utilities/Fonts/font8.c"
--------------------------------------------------------------------------------------------------------------------
且看这一段，我们要看哪里呢，请看沙发。

1万 · 2015-11-10 12:54

      这里，用户注意了，，，，                      User NOTES
1. How To use this driver:             怎样使用这个驱动程序
--------------------------
- This driver is used to drive directly an LCD TFT using LTDC controller.
- This driver select dynamically the mounted LCD, ILI9341 240x320 LCD mounted
   on MB1075B discovery board, and use the adequate timing and setting for
      the specified LCD using device ID of the ILI9341 mounted on MB1075B discovery board

2. Driver description:                      驱动程序的描述
---------------------
  + Initialization steps :
   o Initialize the LCD using the LCD_Init() function.
   o Apply the Layer configuration using LCD_LayerDefaultInit() function
   o Select the LCD layer to be used using LCD_SelectLayer() function.
   o Enable the LCD display using LCD_DisplayOn() function.

  + Options
   o Configure and enable the color keying functionality using LCD_SetColorKeying()
   function.
   o Modify in the fly the transparency and/or the frame buffer address
   using the following functions :
   - LCD_SetTransparency()
   - LCD_SetLayerAddress()

  + Display on LCD
   o Clear the hole LCD using LCD_Clear() function or only one specified string
      line using LCD_ClearStringLine() function.
   o Display a character on the specified line and column using LCD_DisplayChar()
      function or a complete string line using LCD_DisplayStringAtLine() function.
   o Display a string line on the specified position (x,y in pixel) and align mode
      using LCD_DisplayStringAtLine() function.
   o Draw and fill a basic shapes (dot, line, rectangle, circle, ellipse, .. bitmap)
      on LCD using the available set of functions

1万 · 2015-11-10 12:55

+ Initialization steps :                         初始化步骤很重要
   o Initialize the LCD using the LCD_Init() function.
   o Apply the Layer configuration using LCD_LayerDefaultInit() function
   o Select the LCD layer to be used using LCD_SelectLayer() function.
   o Enable the LCD display using LCD_DisplayOn() function.

  + Options                      初始化后要干啥
   o Configure and enable the color keying functionality using LCD_SetColorKeying()
   function.
   o Modify in the fly the transparency and/or the frame buffer address
   using the following functions :
   - LCD_SetTransparency()
   - LCD_SetLayerAddress()

  + Display on LCD                   如何工作，
   o Clear the hole LCD using LCD_Clear() function or only one specified string
      line using LCD_ClearStringLine() function.
   o Display a character on the specified line and column using LCD_DisplayChar()
      function or a complete string line using LCD_DisplayStringAtLine() function.
   o Display a string line on the specified position (x,y in pixel) and align mode
      using LCD_DisplayStringAtLine() function.
   o Draw and fill a basic shapes (dot, line, rectangle, circle, ellipse, .. bitmap)
      on LCD using the available set of functions

上面就是三大步流程。。。

只看该作者 · 2015-11-10 13:48

震惊不已

1万 · 2015-11-11 08:35

zhangbolily 发表于 2015-11-10 13:48
震惊不已

谢谢鼓励，马上我来个实例。。

1万 · 2015-11-11 10:34

经过跟实际函数的对比，发现，说明里面漏掉了一个关键词的：BSP_
我们看前面的初始化函数原型：
/** @defgroup STM32F429I_DISCOVERY_LCD_Private_Functions
  * @{
  */

/**
  * @brief  Initializes the LCD.
  * @param  None
  * @retval LCD state
  */
uint8_t BSP_LCD_Init(void)
{

……
}
其中的内容太复杂了，就不写了，主要是调用该显示控制芯片的头文件的参数配置
我们看到该函数是个无传递参数的。也就是个void参数，返回值是有的，无符号字节类型
全部执行完后返回的是LCD_OK.
LCD_OK是什么呢，按照通常的理解应该是返回0的时候为OK是吧。
看定义
typedef enum
{
  LCD_OK = 0,
  LCD_ERROR = 1,
  LCD_TIMEOUT = 2
}LCD_StatusTypeDef;

LCD状态枚举类型，里面定义了，OK就是0，错误返回的是1，超时是2，好了，我们懂了。

1万 · 2015-11-11 10:47

接下来初始化图层
LCD_LayerDefaultInit()
这个函数对应什么呢？
void BSP_LCD_LayerDefaultInit(uint16_t LayerIndex, uint32_t FB_Address)；
对应这个函数，
/**
  * @brief  Initializes the LCD layers.
  * @param  LayerIndex: the layer foreground or background.
  * @param  FB_Address: the layer frame buffer.
  * @retval None
  */

这是介绍，初始化LCD层默认初始化。
一共两个参数，一共是层索引，一共是FB地址，这两个是什么鬼？？？
这说明里面还没有罗列出来，真是坑爹啊。ST这点做的没有别的公司做的好，恶心死了。我去查查资料回来跟大家说到底是什么鬼。

1万 · 2015-11-11 10:59

/* Configure the Background Layer*/
  if(HAL_LTDC_ConfigLayer(&LtdcHandle, &pLayerCfg, 0) != HAL_OK)
  {
/* Initialization Error */
Error_Handler();
  }

  /* Configure the Foreground Layer*/
  if(HAL_LTDC_ConfigLayer(&LtdcHandle, &pLayerCfg1, 1) != HAL_OK)
-------------------------
  HAL_LTDC_ConfigLayer(&LtdcHandler, &Layercfg, LayerIndex);
上面是例程的内容，实际上刚才楼上的那个就是最终传递到这个子函数的，但是我们看到，他竟然是采用了数字0和1表示底层，顶层，也是就
地下往上增加数量的坐标定义。。。坑爹啊，我去找找，有没有定义了类似的宏。。

1万 · 2015-11-11 11:03

#define LCD_BACKGROUND_LAYER 0x0000
#define LCD_FOREGROUND_LAYER 0x0001
找到了，在那个探索板LCD头文件里，这个本应该在函数介绍里说明的，竟然没有，可见ST多么的不上心，难怪大家学起来费劲。接下来研究另外一个参数都是什么。FB_Address

1万 · 2015-11-11 11:39

Layercfg.FBStartAdress = FB_Address;
以上对结构体变量赋值是该变量的使用方法。
void    BSP_LCD_LayerDefaultInit(uint16_t LayerIndex, uint32_t FrameBuffer);
这个是头文件的定义，真恶心
void BSP_LCD_LayerDefaultInit(uint16_t LayerIndex, uint32_t FB_Address)
头文件跟实现里面起个名字还不一样，有木有这么不要脸的做法？？？
原来FB就是[size=14.1176462173462px] [size=14.1176462173462px]FrameBuffer，我们去头文件找这个东东。
#define MAX_LAYER_NUMBER    2
#define LCD_FRAME_BUFFER    ((uint32_t)0xD0000000)
#define BUFFER_OFFSET       ((uint32_t)0x50000)
[size=14.1176462173462px]会不会就是第二个？那么传递时候写什么鬼，就写[size=14.1176462173462px] [size=14.1176462173462px]LCD_FRAME_BUFFER？？我们去找个例程看看

[size=14.1176462173462px]/* Start Address configuration : frame buffer is located at FLASH memory */
[size=14.1176462173462px]  pLayerCfg1.FBStartAdress = (uint32_t)&ST_**_2;
[size=14.1176462173462px]这个疑似的，竟然是把一个图片的地址复制给了这个变量。。
[size=14.1176462173462px]参考了另外一个469的例程是这样的
#define LCD_FB_START_ADDRESS    ((uint32_t)0xC0000000)

传递的是这个内容，也许这就是个特定的入口地址，到底是什么地址后面我们再慢慢研究，也请懂的高手来解释一下。

1万 · 2015-11-11 11:43

LCD_SelectLayer()
下一步就是选择层了，就是你要使用哪个层呢？
对应下面函数实现
/**
  * @brief  Selects the LCD Layer.
  * @param  LayerIndex: the Layer foreground or background.
  * @retval None
  */
void BSP_LCD_SelectLayer(uint32_t LayerIndex)
{
  ActiveLayer = LayerIndex;
}

-----------------------
这个解释给了参数，但是我们看看到底对不对啊
头文件写的是

#define LCD_BACKGROUND_LAYER 0x0000
#define LCD_FOREGROUND_LAYER 0x0001

我们看注释里都是小写，也没有按照规范的写法，鬼知道变量是哪个啊，再次唾弃一下ST的编写人员。。不负责

1万 · 2015-11-11 11:46

LCD_DisplayOn()
初始化马上就要完成了，这个就是LCD显示开关打开了。OK？
void    BSP_LCD_DisplayOn(void);
void BSP_LCD_DisplayOn(void)
{
  if(LcdDrv->DisplayOn != NULL)
  {
LcdDrv->DisplayOn();
  }
}

上面函数实现就是这个内容，所以我们不用考虑了。
我们完成了使用LCD的第一步初始化了，哈哈哈。

1万 · 2015-11-11 11:51

本帖最后由天灵灵地灵灵于 2015-11-11 11:55 编辑

第二步设置：
   - LCD_SetTransparency()
   - LCD_SetLayerAddress()

一共两个函数，都是什么意思呢？
分别是设置透明度
      设置图层地址
----------------------------------------------------
这样来看肯定要参数了。
void    BSP_LCD_SetTransparency(uint32_t LayerIndex, uint8_t Transparency);
void    BSP_LCD_SetLayerAddress(uint32_t LayerIndex, uint32_t Address);

/**
  * @brief  Configures the Transparency.
  * @param  LayerIndex: the Layer foreground or background.
  * @param  Transparency: the Transparency,
  * This parameter must range from 0x00 to 0xFF.
  * @retval None
  */
void BSP_LCD_SetTransparency(uint32_t LayerIndex, uint8_t Transparency)
{
  HAL_LTDC_SetAlpha(&LtdcHandler, Transparency, LayerIndex);
}

这是设置透明度的函数实现，我们看到调用了LTDC设置阿尔法的函数体，其中一共两个参数，分别是图层的索引号，还有就是透明度，也就是指定图层，设置它的透明度。
图层我们已经学会了

#define LCD_BACKGROUND_LAYER 0x0000
#define LCD_FOREGROUND_LAYER 0x0001

透明度可以是0x00到0xFF的。
越大越透明。。
-----------------------------------------------------
[size=14.1176462173462px] - LCD_SetLayerAddress()

复制

/**

  * @brief  Sets a LCD layer frame buffer address.

  * @param  LayerIndex: specifies the Layer foreground or background

  * @param  Address: new LCD frame buffer value      

  * @retval None

  */

void BSP_LCD_SetLayerAddress(uint32_t LayerIndex, uint32_t Address)

{     

  HAL_LTDC_SetAddress(&LtdcHandler, Address, LayerIndex);

}

这一部分是设置图层地址的，肯定也要指定图层号，然后指定地址，新的LCD帧缓冲区的值。
回头我们研究一下这个帧到底是什么鬼。

1万 · 2015-11-11 12:00

最后就是使用LCD显示了
第一个LCD_Clear() 用于清除洞洞，搞不懂怎么用了洞洞这个词，直译的，莫非意思就是清除一个点。一个像素？？
void    BSP_LCD_Clear(uint32_t Color);
/**
  * @brief  Clears the hole LCD.
  * @param  Color: the color of the background
  * @retval None
  */
void BSP_LCD_Clear(uint32_t Color)
{
  /* Clear the LCD */
  FillBuffer(ActiveLayer, (uint32_t *)(LtdcHandler.LayerCfg[ActiveLayer].FBStartAdress), BSP_LCD_GetXSize(), BSP_LCD_GetYSize(), 0, Color);
}

根据解释就是就是清理LCD，参数就是底色，用底色清理，根据调用的函数，就是用什么色填充屏幕吧。

1万 · 2015-11-11 12:01

/**
  * @brief  Clears the selected line.
  * @param  Line: the line to be cleared
  * @retval None
  */
void BSP_LCD_ClearStringLine(uint32_t Line)
{
  uint32_t colorbackup = DrawProp[ActiveLayer].TextColor;
  DrawProp[ActiveLayer].TextColor = DrawProp[ActiveLayer].BackColor;

  /* Draw rectangle with background color */
  BSP_LCD_FillRect(0, (Line * DrawProp[ActiveLayer].pFont->Height), BSP_LCD_GetXSize(), DrawProp[ActiveLayer].pFont->Height);

  DrawProp[ActiveLayer].TextColor = colorbackup;
  BSP_LCD_SetTextColor(DrawProp[ActiveLayer].TextColor);
}
------------------------
这个就是清理行的函数，传递参数为行号，比如1,2,3等。

1万 · 2015-11-11 12:04

Display a character on the specified line and column using LCD_DisplayChar()
      function or a complete string line using LCD_DisplayStringAtLine() function.

显示一个字符可以使用
void    BSP_LCD_DisplayChar(uint16_t Xpos, uint16_t Ypos, uint8_t Ascii);
显示一个字符串可以使用
void    BSP_LCD_DisplayStringAtLine(uint16_t Line, uint8_t *ptr);
挺不错的吧。这终于可以显示字和字符串了。只不过显示一个字符需要指定坐标。。。

1万 · 2015-11-11 14:14

void    BSP_LCD_DisplayStringAtLine(uint16_t Line, uint8_t *ptr);
void    BSP_LCD_DisplayStringAt(uint16_t X, uint16_t Y, uint8_t *pText, Text_AlignModeTypdef mode);
void    BSP_LCD_DisplayChar(uint16_t Xpos, uint16_t Ypos, uint8_t Ascii);
写字符的函数一共有上面3个，分别是写写字符串在哪一行，写字符串在什么坐标位置开始，写字符在什么坐标。。
之余呢，肯定还要画图形的
void    BSP_LCD_DrawHLine(uint16_t Xpos, uint16_t Ypos, uint16_t Length);
void    BSP_LCD_DrawVLine(uint16_t Xpos, uint16_t Ypos, uint16_t Length);
void    BSP_LCD_DrawLine(uint16_t X1, uint16_t Y1, uint16_t X2, uint16_t Y2);
void    BSP_LCD_DrawRect(uint16_t Xpos, uint16_t Ypos, uint16_t Width, uint16_t Height);
void    BSP_LCD_DrawCircle(uint16_t Xpos, uint16_t Ypos, uint16_t Radius);
void    BSP_LCD_DrawPolygon(pPoint Points, uint16_t PointCount);
void    BSP_LCD_DrawEllipse(int Xpos, int Ypos, int XRadius, int YRadius);
void    BSP_LCD_DrawBitmap(uint32_t X, uint32_t Y, uint8_t *pBmp);

void    BSP_LCD_FillRect(uint16_t Xpos, uint16_t Ypos, uint16_t Width, uint16_t Height);
void    BSP_LCD_FillCircle(uint16_t Xpos, uint16_t Ypos, uint16_t Radius);
void    BSP_LCD_FillTriangle(uint16_t X1, uint16_t X2, uint16_t X3, uint16_t Y1, uint16_t Y2, uint16_t Y3);
void    BSP_LCD_FillPolygon(pPoint Points, uint16_t PointCount);
void    BSP_LCD_FillEllipse(int Xpos, int Ypos, int XRadius, int YRadius);

划横线就是HLine 纵线就是VLine，根据上面自己看吧，不懂的单词查字典。

1万 · 2015-11-11 15:34

对比下面的也可以看出来，先初始化，然后用什么色清屏，其实就是纯色填充为底色。

复制

/**

  ******************************************************************************

  * @file    main.c

  * @author  quyifei

  * @version V1.0.0

  * @date    19-Jan-2013

  * @brief   LCD demo for STM32F4 Discovery, this program initialze LCD and fill the screen with RED

*/



/*Includes ------------------------------------------------------------*/

#include "main.h"



/* declare static viariables-------------------------------------------*/

static __IO uint32_t nDelay;





/**

  * @brief  Main function

  * @param  None

  * @retval None

  */

void main(void)

{  

   

 //Init SysTick

  RCC_ClocksTypeDef clk;

  RCC_GetClocksFreq(&clk);

  if(SysTick_Config(clk.SYSCLK_Frequency/1000))

  {

    while(1);

  };



//Init LCD  

  LCD_Init();

  

  //Clear LCD with RED

  LCD_Clear(0xf800);

  

  while(1)

  {

  }

}



/**

  * @brief  Systick call function.

  * @param  None

  * @retval None

  */

void TimingDelay_Decrement(void)

{

  if(nDelay>0) nDelay--;

}





/**

  * @brief  Delay in ms

  * @param  nTime in ms

  * @retval None

  */

void Delay(__IO uint32_t nTime)

{ 

  nDelay = nTime;

  while(nDelay != 0);

}





#ifdef  USE_FULL_ASSERT



/**

  * @brief  Reports the name of the source file and the source line number

  *         where the assert_param error has occurred.

  * @param  file: pointer to the source file name

  * @param  line: assert_param error line source number

  * @retval None

  */

void assert_failed(uint8_t* file, uint32_t line)

{ 

  /* User can add his own implementation to report the file name and line number,

     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */



  /* Infinite loop */

  while (1)

  {

  }

}

#endif