单片机与RA8875接法及软件初始化之二（通过串口连接）
作者：david 发表日期：2020-10-22 来源： 浏览：
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3SPI_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 datado{SDA = 1; //SET SDA=1 is let this singal keeping in input mode before read dataSCK = 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 displayLCD_DataWrite(0x0F); // if 16bit MCU interface and 65k color displaydelay_us(1);LCD_CmdWrite(0x04); //PCLK inverseLCD_DataWrite(0x81);
delay_ms(1);
液晶屏相关配置 （以AT070TN92为例）
//Horizontal setLCD_CmdWrite(0x14); //HDWR//Horizontal Display Width Setting Bit[6:0]LCD_DataWrite(0x63);//Horizontal display width(pixels) = (HDWR + 1)*8LCD_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)*8LCD_CmdWrite(0x17); //HSTR//HSYNC Start Position[4:0]LCD_DataWrite(0x02);//HSYNC Start Position(PCLK) = (HSTR + 1)*8LCD_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 setLCD_CmdWrite(0x19); //VDHR0 //Vertical Display Height Bit [7:0]LCD_DataWrite(0xdf);//Vertical pixels = VDHR + 1LCD_CmdWrite(0x1a); //VDHR1 //Vertical Display Height Bit [8]LCD_DataWrite(0x01);//Vertical pixels = VDHR + 1LCD_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 XLCD_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 YLCD_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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