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51单片机+RA8875控制液晶显示

2021-01-11

本篇文章分别以AT89C51控制RA8875及RA8876为例，详细讲解8位单片机如何通过瑞佑的液晶控制芯片来进行显示控制。

一、硬件

由于8位单片机IO口有限，所以在这里选择SPI通讯方式（还可选择IIC模式）

二、软件

1、软件SPI时序

**
/SPI时序/

void SPI_Init(void)

{

 SCK = 1; 

 SDA = 1; 

    ZCS = 1;

}

 

/******************************************************************************

SPI_Write()

******************************************************************************/

void SPI_Write(unsigned char dat)

{

    unsigned char t = 8;

  do

  {

  SDA = (bit)(dat & 0x80);

  dat <<= 1;

  SCK = 0; 

                SPI_Delay();

  SCK = 1;

                SPI_Delay();

 

  } while ( --t != 0 );

    SCK = 1;

    SDA = 1;

}

 

/******************************************************************************

SPI_Read() If 4-wire SPI be used, and then the SDA singal in this subroutine should be rename to SDO 

******************************************************************************/

unsigned char SPI_Read()

{

   unsigned char dat;

   unsigned char t = 8;

 SDO = 1; //SET SDA=1 is let this singal keeping in input mode before read data

 do

 {

  SDO = 1; //SET SDA=1 is let this singal keeping in input mode before read data

  SCK = 0; 

  SPI_Delay();

  dat <<= 1;

  if ( SDO ) dat++;

  SCK = 1; 

                SPI_Delay();

 } while ( --t != 0 );

 return dat;

} 

 

//*********4_wire_SPI****************************

 

void LCD_CmdWrite(uchar cmd)

{ uchar j; 

   SCK = 1; 

   SDA = 1; 

   ZCS = 0;   

   SPI_Delay();

   SPI_Write(0x80); 

   SPI_Write(cmd);

   SPI_Delay();

   ZCS = 1;

}

 

//----------------------//

void LCD_DataWrite(uchar Data)

{ 

    SCK = 1; 

   SDA = 1;   //

   ZCS = 0;

   SPI_Delay();

   SPI_Write(0x00); 

   SPI_Write(Data);

   SPI_Delay();

   ZCS = 1;

}

 

 

//----------------------//

uchar LCD_DataRead(void)

{

 uchar Data;

   SCK = 1; 

   SDO = 1;   //

   ZCS = 0;

   SPI_Delay();

   SPI_Write(0x40);  

   Data = SPI_Read();

   SPI_Delay();

   ZCS = 1;

 

 return Data;

}  

//-----------------------//

uchar LCD_StatusRead(void)

{

 uchar Data;

 

   SCK = 1; 

   SDO = 1;   //

   ZCS = 0;

   SPI_Delay();

   SPI_Write(0xc0); 

   Data = SPI_Read();

   SPI_Delay();

   ZCS = 1;

 return Data;

}

2、RA8875芯片时钟频率以及液晶屏参数设置（AT070TN92为例）

**

void INIT(void)

{

RST=0;

  delay_us(100);

  RST=1;

  delay_us(100);

 

//RA8875_PLL_ini();

LCD_CmdWrite(0x88);       

    LCD_DataWrite(0x0b);

    delay_ms(1);    

    LCD_CmdWrite(0x89);       

    LCD_DataWrite(0x02);  

    delay_ms(1);

 

  LCD_CmdWrite(0x10);  //SYSR   bit[4:3]=00 256 color  bit[2:1]=  00 8bit MPU interface

    //LCD_DataWrite(0x000c);   // if 8bit MCU interface   and 65k color display       

   LCD_DataWrite(0x0F); // if 16bit MCU interface   and 65k color display  

delay_us(1); 

 

LCD_CmdWrite(0x04);     //PCLK inverse 

   LCD_DataWrite(0x81);

   delay_ms(1);

  

   //Horizontal set

   LCD_CmdWrite(0x14); //HDWR//Horizontal Display Width Setting Bit[6:0]                   

   LCD_DataWrite(0x63);//Horizontal display width(pixels) = (HDWR + 1)*8 

                   

   LCD_CmdWrite(0x15); //Horizontal Non-Display Period Fine Tuning Option Register (HNDFTR)

   LCD_DataWrite(0x03);//Horizontal Non-Display Period Fine Tuning(HNDFT) [3:0]   

          

   LCD_CmdWrite(0x16); //HNDR//Horizontal Non-Display Period Bit[4:0]                      

   LCD_DataWrite(0x03);//Horizontal Non-Display Period (pixels) = (HNDR + 1)*8 

             

   LCD_CmdWrite(0x17); //HSTR//HSYNC Start Position[4:0]                                   

   LCD_DataWrite(0x02);//HSYNC Start Position(PCLK) = (HSTR + 1)*8    

                     

   LCD_CmdWrite(0x18); //HPWR//HSYNC Polarity ,The period width of HSYNC.                  

   LCD_DataWrite(0x00);//HSYNC Width [4:0]   HSYNC Pulse width(PCLK) = (HPWR + 1)*8   

 

   //Vertical set    

   LCD_CmdWrite(0x19); //VDHR0 //Vertical Display Height Bit [7:0]                         

   LCD_DataWrite(0xdf);//Vertical pixels = VDHR + 1       

                                 

   LCD_CmdWrite(0x1a); //VDHR1 //Vertical Display Height Bit [8]                           

   LCD_DataWrite(0x01);//Vertical pixels = VDHR + 1  

                                      

   LCD_CmdWrite(0x1b); //VNDR0 //Vertical Non-Display Period Bit [7:0]                     

   LCD_DataWrite(0x14);//Vertical Non-Display area = (VNDR + 1) 

                           

   LCD_CmdWrite(0x1c); //VNDR1 //Vertical Non-Display Period Bit [8]                       

   LCD_DataWrite(0x00);//Vertical Non-Display area = (VNDR + 1)  

                          

   LCD_CmdWrite(0x1d); //VSTR0 //VSYNC Start Position[7:0]                                 

   LCD_DataWrite(0x06);//VSYNC Start Position(PCLK) = (VSTR + 1)  

                          

   LCD_CmdWrite(0x1e); //VSTR1 //VSYNC Start Position[8]                                   

   LCD_DataWrite(0x00);//VSYNC Start Position(PCLK) = (VSTR + 1)   

                        

   LCD_CmdWrite(0x1f); //VPWR //VSYNC Polarity ,VSYNC Pulse Width[6:0]                     

   LCD_DataWrite(0x01);//VSYNC Pulse Width(PCLK) = (VPWR + 1)                              

 

   LCD_CmdWrite(0xf2);  

   LCD_DataWrite(0x01);

//Active window  set 

   //setting active window X

    LCD_CmdWrite(0x30); //Horizontal Start Point 0 of Active Window (HSAW0)

    LCD_DataWrite(0x00); //Horizontal Start Point of Active Window [7:0]

//delay_us(1); 

    LCD_CmdWrite(0x31); //Horizontal Start Point 1 of Active Window (HSAW1)    

    LCD_DataWrite(0x00); //Horizontal Start Point of Active Window [9:8]

//delay_us(1); 

    LCD_CmdWrite(0x34); //Horizontal End Point 0 of Active Window (HEAW0)

    LCD_DataWrite(0x1F); //Horizontal End Point of Active Window [7:0]

//delay_us(1); 

    LCD_CmdWrite(0x35); //Horizontal End Point 1 of Active Window (HEAW1)    

    LCD_DataWrite(0x03); //Horizontal End Point of Active Window [9:8]

//delay_us(1); 

 

   //setting active window Y

    LCD_CmdWrite(0x32); //Vertical Start Point 0 of Active Window (VSAW0)

    LCD_DataWrite(0x00); //Vertical Start Point of Active Window [7:0]

//delay_us(1); 

    LCD_CmdWrite(0x33); //Vertical Start Point 1 of Active Window (VSAW1)    

    LCD_DataWrite(0x00); //Vertical Start Point of Active Window [8]

//delay_us(1); 

    LCD_CmdWrite(0x36); //Vertical End Point of Active Window 0 (VEAW0)

    LCD_DataWrite(0xdf); //Vertical End Point of Active Window [7:0]

//delay_us(1); 

    LCD_CmdWrite(0x37); //Vertical End Point of Active Window 1 (VEAW1)    

    LCD_DataWrite(0x01); //Vertical End Point of Active Window [8]

 

// /*setting RA8875 display on*/

    LCD_CmdWrite(0x01); //  

    LCD_DataWrite(0x80); // 

    delay_ms(20); 

/*setting RA8875 memory clear with active window*/

    Clear_Active_Window();

 

// /*setting backlight on RA8875 PWM1 control*/

// PWM1_enable();

//    PWM1_fnuction_sel();

//    PWM1_clock_ratio(0x02); //bit0~3  58KHZ   

//    PWM1_duty_cycle(0xff); // 獹

//    Brightness_level=10;

 

 

//LCD_Clear(0xffff);//

Text_color(0xFFFF);

Geometric_Coordinate(0,800,0,480);

    Draw_square_fill();

    Chk_Busy()；

}

3、RA8876芯片及液晶屏初始化函数调用（RA8876_Initial(); ）

**
**RA8876_Initial

{**

RA8876_HW_Reset();
Check_IC_ready();

// System_Check_Temp();

 

RA8876_SW_Reset();

Check_IC_ready();

 

//------------------------------------

RA8876_PLL();// Set RA8876/77 PLL and Start PLL.

//------------------------------------

RA8876_SDRAM_initial();// set the SDRAM parameter.  

//------------------------------------

 

//**[01h]**//

TFT_24bit();//RA8876 only

 

//**[01h]**//

#if defined (MCU_8bit_ColorDepth_8bpp) || defined (MCU_8bit_ColorDepth_16bpp) || defined (MCU_8bit_ColorDepth_24bpp)

Host_Bus_8bit();

#endif

 

#if defined (MCU_16bit_ColorDepth_16bpp) || defined (MCU_16bit_ColorDepth_24bpp_Mode_1) || defined (MCU_16bit_ColorDepth_24bpp_Mode_2)

Host_Bus_16bit();

#endif

//**[02h]**//

Data_Format_8b_16bpp();

MemWrite_Left_Right_Top_Down();//(Default) Memory Write: Left to Right, Top to Down.

//------------------------------------

//**[03h]**//

 

Graphic_Mode();

// Text_Mode();

 

Memory_Select_SDRAM();

 

//------------------------------------

//** Set color depth, define in [UserDef.h] **//

Select_Main_Window_16bpp(); //[10h]Set main window color depth

Memory_16bpp_Mode(); //[5Eh]Set active memory color depth

 

Select_PIP1_Window_16bpp(); //[11h] PIP 1 Window Color Depth

Select_PIP2_Window_16bpp(); //[11h] PIP 2 Window Color Depth

 

BTE_S0_Color_16bpp(); //[92h] Source_0 Color Depth

BTE_S1_Color_16bpp(); //[92h] Source_1 Color Depth

BTE_Destination_Color_16bpp(); //[92h] Destination Color Depth

//**[12h]~[1Fh]]**//

Set_LCD_Panel(); // define in [UserDef.h]

 

//------------------------------------

//**[20h][21h][22h][23h]**//

Main_Image_Start_Address(0);

//**[24h][25h]**//

Main_Image_Width(2048);

//**[26h][27h][28h][29h]**//

Main_Window_Start_XY(0,0);

//**[50h][51h][52h][53h]**//

Canvas_Image_Start_address(0);

//**[54h][55h]**//

Canvas_image_width(2048);

//**[56h][57h][58h][59h]**//

Active_Window_XY(0,0);

//**[5Ah][5Bh][5Ch][5Dh]**//

Active_Window_WH(1024,600);

BTE_Solid_Fill(0,2048,0,0,0x0000,1024,600); //Memory Clear

}

三、相关API函数的调用

RA8875函数库：“RA8875_subroutine.c”，“lcd.c”

RA8876函数库：“RA8876.c”，“RA8876_API.c”，“RA8876_MCU_IF.c”

瑞佑芯片有非常完善方便调用的函数库，由于C51存储空间较小，建议将需要用到的函数从函数库中复制出来调用。

DEMO展示：

**
Text_color(Red);     //RA8875

Geometric_Coordinate(10,200,10,10);

Draw_line();

Chk_Busy();

RA8875_Draw_Circle_Square(50,50,200,200,Red);

Draw_Triangle_3point_Coordinate(10,20,80,90,80,20);

Draw_Triangle();

 

Draw_Triangle_3point_Coordinate(400,20,600,200,600,20);

Draw_Triangle_fill();

 

Circle_Coordinate_Radius(100,250,50);

Draw_circle_fill();

  Chk_Busy();

 

Text_color(Red);

Circle_Square_Coordinate_setting(300,400,0,100,10,10);

Draw_Circle_Square_fill();

Chk_Busy();

 

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