单片机与RA8875接法及软件初始化之二（通过串口连接）
2020-10-22
本篇文章主要介绍使用硬件SPI/IIC以及IO口模拟SPI/IIC方式驱动RA8875
一、硬件设计
单片机引脚
RA8875引脚
二、软件设计
1、硬件SPI //硬件IIC与SPI都属于STM32资源，初始化原理相同这里不做一 一阐述，以SPI为例
初始化
**
static void SPI_Mode_Config(void)
{
SPI_InitTypeDef SPI_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 ,ENABLE);
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16 ; //时钟分频因子
//SPI 使用模式3
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge ;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_High ;
SPI_InitStructure.SPI_CRCPolynomial = 7;//不使用CRC功能，数值随便写 //设置CRC校验的表达方式
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex ;//双线全双工
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB ;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master ;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft ;
SPI_Init(FLASH_SPIx,&SPI_InitStructure); //写入配置到寄存器
SPI_Cmd(FLASH_SPIx,ENABLE);//使能SPI
}写和读函数
**
void LCD_CmdWrite(uint8_t cmd)
{
Flash_cs_low();
SPI_Peripheral_SendByte(0x80);
SPI_Peripheral_SendByte(cmd);
Flash_cs_high();
}
void LCD_DataWrite(uint8_t Data)
{
Flash_cs_low();
SPI_Peripheral_SendByte(0x00);
SPI_Peripheral_SendByte(Data);
Flash_cs_high();
}
uint8_t LCD_DataRead(void)
{
uint8_t Data;
Flash_cs_low();
SPI_Peripheral_SendByte(0x40);
Data=SPI_Peripheral_ReadByte();
Flash_cs_high();
return Data;
}
uint8_t LCD_StatusRead(void)
{
uint8_t Data;
Flash_cs_low();
SPI_Peripheral_SendByte(0xc0);
Data=SPI_Peripheral_ReadByte();
Flash_cs_high();
return Data;**
}
2、普通IO口模拟SPI //3线SPI与4线SPI皆可驱动，3线模式时芯片引脚SDI不适用接至VDD，SDO作为数据传输脚
SPI时序
**
void SPI_Delay(void)
{
unsigned char t;
t=100; //Adjusted by different
while(--t!=0);
}
void SPI_Init(void)
{
SCK = 1;
SDA = 1;
ZCS = 1;
}**
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;
}**
unsigned char SPI_Read() //当以4线方式驱动时SDA应改为SDO
{
unsigned char dat;
unsigned char t = 8;
SDA = 1; //SET SDA=1 is let this singal keeping in input mode before read data
do
{
SDA = 1; //SET SDA=1 is let this singal keeping in input mode before read data
SCK = 0;
SPI_Delay();
dat <<= 1;
if ( SDA ) dat++;
SCK = 1;
SPI_Delay();
} while ( --t != 0 );
return dat;
}**
void LCD_CmdWrite(uchar cmd)
{
SCK = 1;
SDA = 1;
ZCS = 0;
SPI_Delay();
SPI_Write(0x80);
SPI_Write(cmd);
ZCS = 1;
SPI_Delay();
}
//----------------------//
**
void LCD_DataWrite(uchar Data)
{
SCK = 1;
SDA = 1;
ZCS = 0;
SPI_Delay();
SPI_Write(0x00);
SPI_Write(Data);
SPI_Delay();
ZCS = 1;
SPI_Delay();
}
**
uchar LCD_DataRead(void)
{
uchar Data;
SCK = 1;
SDA = 1;
ZCS = 0;
SPI_Write(0x40);
Data = SPI_Read();
SPI_Delay();
ZCS = 1;
return Data;
} //-----------------------//
**
uchar LCD_StatusRead(void)
{
uchar Data;
SCK = 1;
SDA = 1;
ZCS = 0;
SPI_Delay();
SPI_Write(0xc0);
Data = SPI_Read();
SPI_Delay();
ZCS = 1;
return Data;
}
初始化芯片及配置相关时钟频率
**
GPIO_ResetBits(GPIOB, GPIO_Pin_7);
delay_ms(1);
GPIO_SetBits(GPIOB, GPIO_Pin_7);
delay_ms(1);
//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);液晶屏相关配置 （以AT070TN92为例）
**
//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);至此RA8875初始化完成。
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