本篇介绍电路设计。底部可下载参考电路。

一、硬件样板：

该板需要外接MCU，图示接法为SPI-4线。

可接AT043TN25和AT070TN92，及兼容接口的屏。

二、RA8889芯片引脚定义

再上一张引脚简化图，概览引脚结构：

电路中没有画MCU，需外接，采用何种接口方式，可通过PS2~0来选择。最简单的话SPI-3/4线即可。

RA8889各个VCC和LDO（1.2V）引脚均需要接旁路电容进行滤波，且放置距离芯片引脚要近一些。

三、FLASH

RA8889可外接4颗FLASH，一般建议使用NOR FLASH，基本够用了：

该设计中仅接出两颗FLASH，RA8889有两路BUS总线，每路总线可扩展2个片选，故总共可外接4颗FLASH。

FLASH是用于存放UI界面的图资，可以采用JPG格式存入，支持BMP、JPG、PNG、AVI影片，用户根据需要选择。

FLASH引脚需要上拉，一是扩展比较多颗负载重，二是在烧录时会吃多一些电流。

四、液晶屏接口

输出的TTL串联22欧姆电阻，是为了降低EMC而加。

输出配置两种接口，40PIN和50PIN，常用的4.3寸采用40PIN，7寸采用50PIN。

五、FLASH烧录口的设计

FLASH外接线进行烧录，烧录器采用CH341A即可，便宜易买。该接口引出2路BUS总线，烧录时TEST1跳线至3.3V，正常工作时取下跳线。

另外将PS2~0跳线口也放置到该连接器，通过跳线帽便于改变MCU的通信方式。

六、5V转3.3V电路

采用通用的1117-3.3芯片即可，注意芯片周围的覆铜，以便散热。

七、5V转LED背光

背光是整个电路功耗最大的一块，注意电感L2和肖特基二极管D1的覆铜，便以散热。适当调整反馈电阻R11//R12，以防电流过大，零件过热。

可以接上R9，通过RA8889的PWM0输出方波调整背光亮度。

八、LCD驱动电压

这部份功耗不大，主要是提供LCD的驱动电压，不太吃电流。

4.3寸的话不需要加这部分电路；AT070TN92则需要外加驱动电压，看是繁琐，其实和LED的升压电路大同小异。

焊接时要注意齐纳二极管D3和D6的方向，一个负压，一个正压。

九、关于地线

Layout走线时，注意电源的地单独走线、覆铜，主要是升压、和降压电路，数字地单独走线、覆铜，最终在滤波电容附近收到一起。这样做可极大地预防电源杂讯对数字电路的干扰。

本章完

参考电路图下载：
*附件：RT8889CNN03_v1.0.pdf

单片机驱动彩屏最简方案：单片机_RA8889最小开发板驱动控制TFT彩屏介绍（三）软件设计

本篇介绍软件设计，相关代码请从本人相关文章获取，已上传多种参考代码，大同小异。

一、老样子，先上一张软件代码导图：

代码三步曲：

• 设定通信方式（已写好各种通信方式的参考代码了）；
• 初始化RA8889，如上图所示，看似很多，代码都是直接调用API函数；
• 调用API函数进行界面设计，对于工业上所使用的UI，这些API足够用，也十分简洁！

二、代码要点：

1. 一些宏定义请先修改，在userdef.h
（1）显存规划：

/* RA8889显存和显示配置 */
#define canvas_image_width  1600		//画布宽度，设定为屏宽的n倍
#define main_image_width  1600			//图像宽度，设定为屏宽的n倍
#define LCD_Width  800 
#define LCD_Height  480

（2）主频配置，一般只修改SCAN_FREQ即可

/* RA8889频率配置 */
#define OSC_FREQ	10			//晶振频率，外接晶振请使用10MHz
#define DRAM_FREQ	133			//SDRAM刷新频率，最高166MHz
#define CORE_FREQ	120			//RA8889核心频率，最高133MHz 
#define SCAN_FREQ	30			//PCLK液晶扫描频率，最高100MHz

（3）液晶屏型号定义，最终是在初始化中Set_LCD_Panel();执行，不同液晶屏配置不同，许多RD还不熟悉彩屏，这里先卖个关子，待后续文章另起新篇针对该项专门介绍。

下方为AT070TN92的液晶屏参数配置：

#ifdef L80480R70

	//**[10h]**//
	Select_LCD_Sync_Mode();	// Enable XVSYNC, XHSYNC, XDE.
//	Select_LCD_DE_Mode();	// XVSYNC & XHSYNC in idle state.
	
	PCLK_Falling();
//	PCLK_Rising();

	VSCAN_T_to_B();
	PDATA_Set_RGB();

	HSYNC_Low_Active();
	VSYNC_Low_Active();
	DE_High_Active();
//	DE_Low_Active();

	LCD_HorizontalWidth_VerticalHeight(800,480);
	LCD_Horizontal_Non_Display(64);
	LCD_HSYNC_Start_Position(208);
	LCD_HSYNC_Pulse_Width(24);
	LCD_Vertical_Non_Display(16);
	LCD_VSYNC_Start_Position(22);
	LCD_VSYNC_Pulse_Width(16);

#endif

下方为AT043TN25的液晶屏参数配置：

#ifdef AT043TN25

    //**[10h]**//
    //Select_LCD_Sync_Mode();	// Enable XVSYNC, XHSYNC, XDE.
    Select_LCD_DE_Mode(); // XVSYNC & XHSYNC in idle state.

    //	PCLK_Rising();
    PCLK_Falling();
    VSCAN_T_to_B();
    PDATA_Set_RGB();

    //**[13h]**//
    HSYNC_Low_Active();
    VSYNC_Low_Active();
    DE_High_Active();
    //	DE_Low_Active();
    //------------------------------------
    //**[14h][15h][1Ah][1Bh]**//
    LCD_HorizontalWidth_VerticalHeight(480, 272); // LCD Resolution 480x272。
    //**[16h][17h]**//
    LCD_Horizontal_Non_Display(38); // 480x272，HSYNC Back Porch=38。
    //**[18h]**//
    LCD_HSYNC_Start_Position(20); // 480x272 HSYNC Front Porch = 20。
    //**[19h]**//
    LCD_HSYNC_Pulse_Width(20); // 480x272，HSYNC Pulse Width=5~30,set 20。
    //**[1Ch][1Dh]**//
    LCD_Vertical_Non_Display(4); // 480x272，VSYNC Back Porch =4。
    //**[1Eh]**//
    LCD_VSYNC_Start_Position(15); // 480x272，VSYNC Front Porch =15。
    //**[1Fh]**//
    LCD_VSYNC_Pulse_Width(3); // 480x272，VSYNC Pulse Width =3。

#endif

参考演示程序已经预设各种分辨率的液晶屏参数配置，可以直接代入测试，再进行微调。使用上非常简单！

（4）MCU通信方式和显示色深定义：

/*==== MCU接口通信位数和显示色深定义 ====*/
//#define MCU_8bit_ColorDepth_8bpp
//#define MCU_8bit_ColorDepth_16bpp
#define MCU_8bit_ColorDepth_24bpp
//#define MCU_16bit_ColorDepth_16bpp
//#define MCU_16bit_ColorDepth_24bpp_Mode_1
//#define MCU_16bit_ColorDepth_24bpp_Mode_2

2. 延时函数
   使用毫秒即可，请依照自己的MCU主频调整延时长度：

void delay_ms(unsigned int n);

三、进行UI界面设计

底层封装好API函数了，存放在RA8889_API.c（51单片机请改用RA8889_API_51.c），每个函数头均有用法说明，不明白请进函数查阅详细参数说明。并且所有代码透明，感兴趣的话请进入函数查看底层寄存器的设定。

UI界面基础三要素为 绘图、显示文字、显示图片， 这些都是RA8889硬件支持的功能，显示速度很快！如下列举主要的显示函数：

/* MCU直接写点，基础函数 */
void putPixel(unsigned short x,unsigned short y,unsigned long color);

/* 数据直接写显存 */
void MPU8_8bpp_Memory_Write (unsigned short x,unsigned short y,unsigned short w ,unsigned short h ,const unsigned char *data_array);
void MPU8_16bpp_Memory_Write (unsigned short x,unsigned short y,unsigned short w ,unsigned short h ,const unsigned char *data_array);
void MPU8_24bpp_Memory_Write (unsigned short x,unsigned short y,unsigned short w ,unsigned short h ,const unsigned char *data_array);
void MPU16_16bpp_Memory_Write (unsigned short x,unsigned short y,unsigned short w ,unsigned short h ,const unsigned short *data_array);
void MPU16_24bpp_Mode1_Memory_Write (unsigned short x,unsigned short y,unsigned short w ,unsigned short h ,const unsigned short *data_array);
void MPU16_24bpp_Mode2_Memory_Write (unsigned short x,unsigned short y,unsigned short w ,unsigned short h ,const unsigned short *data_array);

/* 绘图：各种几何图形（硬件实现，高速） */
void Draw_Line(unsigned long LineColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2);
void Draw_Triangle(unsigned long ForegroundColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2,unsigned short X3,unsigned short Y3);
void Draw_Triangle_Fill(unsigned long ForegroundColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2,unsigned short X3,unsigned short Y3);
void Draw_Circle(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short R);
void Draw_Circle_Fill(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short R);
void Draw_Ellipse(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Ellipse_Fill(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Left_Up_Curve(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Left_Up_Curve_Fill(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Right_Down_Curve(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Right_Down_Curve_Fill(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Right_Up_Curve(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Right_Up_Curve_Fill(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Left_Down_Curve(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Left_Down_Curve_Fill(unsigned long ForegroundColor,unsigned short XCenter,unsigned short YCenter,unsigned short X_R,unsigned short Y_R);
void Draw_Square(unsigned long ForegroundColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2);
void Draw_Square_Fill(unsigned long ForegroundColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2);
void Draw_Circle_Square(unsigned long ForegroundColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2,unsigned short R,unsigned short Y_R);
void Draw_Circle_Square_Fill(unsigned long ForegroundColor,unsigned short X1,unsigned short Y1,unsigned short X2,unsigned short Y2,unsigned short R,unsigned short Y_R);

/* 内存操作：复制、运算、剔除底色、单色延展彩色、淡入淡出（硬件实现，快速） */
void BTE_Memory_Copy(unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long S1_Addr,unsigned short S1_W,unsigned short XS1,unsigned short YS1,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned int ROP_Code,unsigned short X_W,unsigned short Y_H);
void BTE_Memory_Copy_Chroma_key(unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned long Background_color,unsigned short X_W,unsigned short Y_H);
void BTE_MCU_Write_MCU_8bit(unsigned long S1_Addr,unsigned short S1_W,unsigned short XS1,unsigned short YS1,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned int ROP_Code,unsigned short X_W,unsigned short Y_H,const unsigned char *data_array);
void BTE_MCU_Write_MCU_16bit(unsigned long S1_Addr,unsigned short S1_W,unsigned short XS1,unsigned short YS1,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned int ROP_Code,unsigned short X_W,unsigned short Y_H,const unsigned short *data_array);
void BTE_MCU_Write_Chroma_key_MCU_8bit(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned long Background_color,unsigned short X_W,unsigned short Y_H,const unsigned char *data_array);
void BTE_MCU_Write_Chroma_key_MCU_16bit(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned long Background_color,unsigned short X_W,unsigned short Y_H,const unsigned short *data_array);
void BTE_Memory_Copy_ColorExpansion(unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned long Foreground_color,unsigned long Background_color);
void BTE_Memory_Copy_ColorExpansion_Chroma_key(unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned long Foreground_color);
void BTE_MCU_Write_ColorExpansion_MCU_8bit(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned long Foreground_color,unsigned long Background_color,const unsigned char *data_array);
void BTE_MCU_Write_ColorExpansion_MCU_16bit(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned long Foreground_color,unsigned long Background_color,const unsigned short *data_array);
void BTE_MCU_Write_ColorExpansion_Chroma_key_MCU_8bit(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned long Foreground_color,const unsigned char *data_array);
void BTE_MCU_Write_ColorExpansion_Chroma_key_MCU_16bit(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned long Foreground_color,const unsigned short *data_array);
void BTE_Pattern_Fill(unsigned char P_8x8_or_16x16, unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long S1_Addr,unsigned short S1_W,unsigned short XS1,unsigned short YS1,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned int ROP_Code,unsigned short X_W,unsigned short Y_H);
void BTE_Pattern_Fill_With_Chroma_key(unsigned char P_8x8_or_16x16 ,unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long S1_Addr,unsigned short S1_W,unsigned short XS1,unsigned short YS1,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned int ROP_Code,unsigned long Background_color,unsigned short X_W,unsigned short Y_H);
void BTE_Solid_Fill(unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned long Foreground_color,unsigned short X_W,unsigned short Y_H);
void BTE_Alpha_Blending_Picture_Mode(unsigned long S0_Addr,unsigned short S0_W,unsigned short XS0,unsigned short YS0,unsigned long S1_Addr,unsigned short S1_W,unsigned short XS1,unsigned short YS1,unsigned long Des_Addr,unsigned short Des_W, unsigned short XDes,unsigned short YDes,unsigned short X_W,unsigned short Y_H,unsigned char alpha);

/* DMA功能，快速显示图片（JPG，BMP），播放AVI影片 */
void DMA_24bit(unsigned char Clk ,unsigned short X1,unsigned short Y1,unsigned short X_W,unsigned short Y_H ,unsigned short P_W ,unsigned long Addr);
void DMA_32bit(unsigned char Clk ,unsigned short X1,unsigned short Y1,unsigned short X_W,unsigned short Y_H ,unsigned short P_W,unsigned long Addr);
void JPG_NOR (unsigned long addr,unsigned long JPGsize,unsigned long IDEC_canvas_width,unsigned short x,unsigned short y);
void AVI_NOR(unsigned long addr,unsigned long videosize,unsigned long shadow_buffer_addr,unsigned long PIP_buffer_addr,unsigned long x,unsigned long y,unsigned long height,unsigned long width,unsigned long PIP_width);

四、彩蛋

我们已经开发好一款新的RA8889开发板，简单易用，使用您的单片机，通过并口或者串口直接连接即可，外接一片AT043TN25或者AT070TN92，只要接口兼容，通通都能点！
RA8889精简版：RA6809，该芯片仅提供SPI接口与MCU通信，但
功能上和RA8889完全一样！更详细信息请关注我们的产品开发进展！

以下效果使用51单片机STC8H8K64U+RA6809开发板+1024x600/800x480彩屏进行演示：

STC8H8K64U单片机板+RA8889/RA6809开发板控制彩屏效果演示图：

有没有兴趣？来官方论坛来了解：单片机的视窗