STM32 SPI通信--OLED

一、0.96寸OLED

二、原理图

二、GPIO模拟SPI

1. 硬件连接

通过引脚和模块电路图可以分析出SPI的电路连接

OLED                    STM32

GND      <---------->   GND

VCC      <---------->   3.3V

D0       <---------->   PA4(CLK)

D1       <---------->   PA3(MOSI)

RES      <---------->   PA2(RET复位)

DC       <---------->   PA1(命令|数据dc)

CS       <---------->   GND

2. 软件驱动

由OLED模块数据手册上SPI的操作时序图写出由GPIO口模拟的SPI驱动代码，模块只支持向模块写数据不能读数据，所以只需要写SPI发送即可

2.1 “SPI.h”

#define OLED_CMD 0   //命令声明

#define OLED_DATA 1 //数据声明

#define OLED_CLK    PAout(4)    // CLK时钟    d0

#define OLED_MOSI   PAout(3)    // MOSI     d1

#define OLED_RST    PAout(2)    // RET复位    ret

#define OLED_DC     PAout(1)    // 命令|数据    dc  （0表传输命令1表传输数据）

void OLED_SPI_Init(void); //配置MCU的SPI

void SPI_WriteByte(uint8_t addr,uint8_t data); //向寄存器地址写一个byte的数据

void WriteCmd(unsigned char cmd); //写命令

void WriteDat(unsigned char data); //写数据

2.2 “SPI.c”

void OLED_SPI_Init(void)

{

    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA ,ENABLE);//使能PA端口时钟

    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4; //端口配置

    GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;//推挽输出

    GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;//IO口速度为50MHz

    GPIO_Init(GPIOA,&GPIO_InitStructure);//根据设定参数初始化GPIOA

}

void SPI_WriteByte(unsigned char data,unsigned char cmd)

{

    unsigned char i=0;

    OLED_DC =cmd;

    OLED_CLK=0;

    for(i=0;i<8;i++)

    {

        OLED_CLK=0;

        if(data&0x80)OLED_MOSI=1; //从高位到低位

        else OLED_MOSI=0;

        OLED_CLK=1;

        data<<=1;

    }

    OLED_CLK=1;

    OLED_DC=1;

}

void WriteCmd(unsigned char cmd)

{

    SPI_WriteByte(cmd,OLED_CMD);

}

void WriteData(unsigned char data)

{

    SPI_WriteByte(data,OLED_DATA);

}

三、STM32对OLED模块的控制

3.1 指令集

3.2 “OLED.h”

void OLED_Init(void);//初始化OLED

void OLED_ON(void);//唤醒OLED

void OLED_OFF(void);//OLED休眠

void OLED_Refresh_Gram(void);//更新显存到OLED

void OLED_Clear(void);//清屏

void OLED_DrawPoint(u8 x,u8 y,u8 t);//画点

void OLED_Fill(u8 x1,u8 y1,u8 x2,u8 y2,u8 dot);//填充

void OLED_ShowChar(u8 x,u8 y,u8 chr,u8 size,u8 mode);//显示字符

void OLED_ShowNum(u8 x,u8 y,u32 num,u8 len,u8 size);//显示2个数字

void OLED_ShowString(u8 x,u8 y,const u8 *p,u8 size);//显示字符串

3.3 “OLED.c”

//OLED的显存

//存放格式如下.

//[0]0 1 2 3 ... 127    

//[1]0 1 2 3 ... 127    

//[2]0 1 2 3 ... 127    

//[3]0 1 2 3 ... 127    

//[4]0 1 2 3 ... 127    

//[5]0 1 2 3 ... 127    

//[6]0 1 2 3 ... 127    

//[7]0 1 2 3 ... 127           

u8 OLED_GRAM[128][8];   

void OLED_DLY_ms(unsigned int ms)

{                         

  unsigned int a;

  while(ms)

  {

    a=1335;

    while(a--);

    ms--;

  }

}

void OLED_Init(void)

{

    OLED_SPI_Init();

    OLED_CLK = 1;

    OLED_RST = 0;

    OLED_DLY_ms(100);

    OLED_RST = 1;

    //从上电到下面开始初始化要有足够的时间，即等待RC复位完毕

    WriteCmd(0xAE);         // Display Off (0x00)

    WriteCmd(0xD5);

    WriteCmd(0x80);         // Set Clock as 100 Frames/Sec

    WriteCmd(0xA8);

    WriteCmd(0x3F);         // 1/64 Duty (0x0F~0x3F)

    WriteCmd(0xD3);

    WriteCmd(0x00);         // Shift Mapping RAM Counter (0x00~0x3F)

    WriteCmd(0x40 | 0x00);  // Set Mapping RAM Display Start Line (0x00~0x3F)

    WriteCmd(0x8D);

    WriteCmd(0x10 | 0x04);  // Enable Embedded DC/DC Converter (0x00/0x04)

    WriteCmd(0x20);

    WriteCmd(0x02);         // Set Page Addressing Mode (0x00/0x01/0x02)

    WriteCmd(0xA0 | 0x01);  // Set SEG/Column Mapping    

    WriteCmd(0xC0);  // Set COM/x Scan Direction   

    WriteCmd(0xDA);

    WriteCmd(0x02 | 0x10);  // Set Sequential Configuration (0x00/0x10)

    WriteCmd(0x81);

    WriteCmd(0xCF);         // Set SEG Output Current

    WriteCmd(0xD9);

    WriteCmd(0xF1);         // Set Pre-Charge as 15 Clocks & Discharge as 1 Clock

    WriteCmd(0xDB);

    WriteCmd(0x40);         // Set VCOM Deselect Level

    WriteCmd(0xA4 | 0x00);  // Disable Entire Display On (0x00/0x01)

    WriteCmd(0xA6 | 0x00);  // Disable Inverse Display On (0x00/0x01)

    WriteCmd(0xAE | 0x01);  // Display On (0x01)

    OLED_Clear();  //初始清屏   

}

void OLED_ON(void)

{

    WriteCmd(0X8D);  //设置电荷泵

    WriteCmd(0X14);  //开启电荷泵

    WriteCmd(0XAF);  //OLED唤醒

}

void OLED_OFF(void)

{

    WriteCmd(0X8D);  //设置电荷泵

    WriteCmd(0X10);  //关闭电荷泵

    WriteCmd(0XAE);  //OLED休眠

}

void OLED_Refresh_Gram(void)

{

    u8 i,n;         

    for(i=0;i<8;i++)  

    {  

        WriteCmd(0xb0+i);   //设置页地址（0~7）

        WriteCmd(0x00);      //设置显示位置—列低地址

        WriteCmd(0x10);      //设置显示位置—列高地址   

        for(n=0;n<128;n++)WriteData(OLED_GRAM[n][i]); 

    }   

}

void OLED_Clear(void)  

{  

    u8 i,n;  

    for(i=0;i<8;i++)for(n=0;n<128;n++)OLED_GRAM[n][i]=0X00;  

    OLED_Refresh_Gram();//更新显示

}

void OLED_DrawPoint(u8 x,u8 y,u8 t)

{

    u8 pos,bx,temp=0;

    if(x>127||y>63)return;//超出范围了.

    pos=7-y/8;

    bx=y%8;

    temp=1<<(7-bx);

    if(t)OLED_GRAM[x][pos]|=temp;

    else OLED_GRAM[x][pos]&=~temp;     

}

void OLED_Fill(u8 x1,u8 y1,u8 x2,u8 y2,u8 dot)  

{  

    u8 x,y;  

    for(x=x1;x<=x2;x++)

    {

        for(y=y1;y<=y2;y++)OLED_DrawPoint(x,y,dot);

    }                                                       

    OLED_Refresh_Gram();//更新显示

}

void OLED_ShowChar(u8 x,u8 y,u8 chr,u8 size,u8 mode)

{                   

    u8 temp,t,t1;

    u8 y0=y;

    u8 csize=(size/8+((size%8)?1:0))*(size/2);      //得到字体一个字符对应点阵集所占的字节数

    chr=chr-' ';//得到偏移后的值        

    for(t=0;t

    {   

        if(size==12)temp=asc2_1206[chr][t];         //调用1206字体

        else if(size==16)temp=asc2_1608[chr][t];    //调用1608字体

        else if(size==24)temp=asc2_2412[chr][t];    //调用2412字体

        else return;                                //没有的字库

        for(t1=0;t1<8;t1++)

        {

            if(temp&0x80)OLED_DrawPoint(x,y,mode);

            else OLED_DrawPoint(x,y,!mode);

            temp<<=1;

            y++;

            if((y-y0)==size)

            {

                y=y0;

                x++;

                break;

            }

        }    

    }          

}

//m^n函数

u32 mypow(u8 m,u8 n)

{

    u32 result=1;    

    while(n--)result*=m;    

    return result;

}                 

void OLED_ShowNum(u8 x,u8 y,u32 num,u8 len,u8 size)

{           

    u8 t,temp;

    u8 enshow=0;                           

    for(t=0;t

    {

        temp=(num/mypow(10,len-t-1));

        if(enshow==0&&t<(len-1))

        {

            if(temp==0)

            {

                OLED_ShowChar(x+(size/2)*t,y,' ',size,1);

                continue;

            }else enshow=1; 

        }

        OLED_ShowChar(x+(size/2)*t,y,temp+'0',size,1); 

    }

} 

void OLED_ShowString(u8 x,u8 y,const u8 *p,u8 size)

{   

    while((*p<='~')&&(*p>=' '))//判断是不是非法字符!

    {       

        if(x>(128-(size/2))){x=0;y+=size;}

        if(y>(64-size)){y=x=0;OLED_Clear();}

        OLED_ShowChar(x,y,*p,size,1);    

        x+=size/2;

        p++;

    }  

四、用STM32的SPI资源

也可以不使用GPIO口模拟，使用STM32的SPI资源，驱动代码如下:

void OLED_SPI_Init(void)

{

    GPIO_InitTypeDef GPIO_InitStructure;

    SPI_InitTypeDef SPI_InitStructure;

    RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOA|

    RCC_APB2Periph_SPI1, ENABLE ); //①GPIO,SPI 时钟使能

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_7;

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_Init(GPIOA, &GPIO_InitStructure);

    GPIO_SetBits(GPIOA,GPIO_Pin_5|GPIO_Pin_7); //①初始化 GPIO

    GPIO_InitStructure.GPIO_Pin=GPIO_Pin_1|GPIO_Pin_2;//端口配置

    GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;//推挽输出

    GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;//IO口速度为50MHz

    GPIO_Init(GPIOA,&GPIO_InitStructure);//根据设定参数初始化GPIOA

    SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; //设置 SPI 全双工

    SPI_InitStructure.SPI_Mode = SPI_Mode_Master; //设置 SPI 工作模式:设置为主 SPI

    SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; // 8 位帧结构

    SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;//选择了串行时钟的稳态:时钟悬空高

    SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge; //数据捕获于第二个时钟沿

    SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; //NSS 信号由硬件管理

    SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16; //预分频 256

    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; //数据传输从 MSB 位开始

    SPI_InitStructure.SPI_CRCPolynomial = 7; //CRC 值计算的多项式

    SPI_Init(SPI1, &SPI_InitStructure); //②根据指定的参数初始化外设 SPIx 寄存器

    SPI_Cmd(SPI1, ENABLE); //③使能 SPI 外设

    //SPI1_ReadWriteByte(0xff);//④启动传输

}

void OLED_WB(uint8_t data)

{

    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);

    SPI_I2S_SendData(SPI1, data);

}

void SPI_WriteByte(unsigned char data,unsigned char cmd)

{

    unsigned char i=0;

    OLED_DC =cmd;

    OLED_WB(data);

}