STM32-SPI之OLED

   OLED作为一种新型的显示设备，由于其优秀的性能，并且随着产量的提高价格也在不断的下降。受到了现在很多显示设备产品的青睐。高清晰，高对比的都使人们对它的使用越来越多了。对于OLED它的驱动方式有很多种，SPI、IIC、8080并口等方式，不同的方式有不同的优点。本篇文章采用的STM32自身的SPI总线的控制方式，还可以通过软件的方式来模拟SPI，难度都不大。
首先来看一下关于STM32的SPI的寄存器和函数，至于什么是SPI就没有必要解释了。

由于STM32的固件库手册版本的原因 我用的手册可能没有全部包括SPI的函数，详细的可以看英文原版的手册。

SPI的引脚映射关系

SPI的GPIO模式的设置

至于OLED大家可以参考SSD1306的相关手册，是它的驱动芯片手册。OLED在显示方面的重点是，由于OLED屏幕分辨率为128*64，
在使用的时候是将高度分为8个单位，每个单位8个像素点。称为8页，当我们在写显示数据的时候，就需要将取模得到的数据分为页和X轴的显示方式。详细的资料参考技术手册。下面附上源码，仅供参考。

#ifndef _OLED_SPI_H
#define _OLED_SPI_H
#include "stm32f10x.h"
#define     OLED_DC_H                       GPIO_SetBits(GPIOA, GPIO_Pin_11)
#define     OLED_DC_L                       GPIO_ResetBits(GPIOA, GPIO_Pin_11)
#define     OLED_RST_L                      GPIO_ResetBits(GPIOA, GPIO_Pin_12)
#define     OLED_RST_H                      GPIO_SetBits(GPIOA, GPIO_Pin_12)
#define     X_WIDTH         128
#define     Y_WIDTH         64
#define         Page                        8
#define     RCC_APB2Periph_OLED_PORT        RCC_APB2Periph_GPIOA
#define     OLED_PORT                       GPIOA
#define     OLED_RST_PIN                    GPIO_Pin_12
#define         OLED_SCK_PIN                                        GPIO_Pin_5
#define         OLED_SDA_PIN                                        GPIO_Pin_7
#define     OLED_DC_PIN                     GPIO_Pin_11

void LCD_Init(void);
void LCD_CLS(void);
void LCD_Fill(unsigned char bmp_dat);
void LCD_Set_Pos(unsigned char x, unsigned char y);
void LCD_WrCmd(unsigned char cmd);
void LCD_WrDat(unsigned char dat);
void OLED_ShowChar(int x, int y, const unsigned char *p);

void OLED_ShowChinese(int x, int y, const unsigned char *p);

#endif

#include "OLED_SPI.h"

void SPI_Configuration(void)
{
      SPI_InitTypeDef  SPI_InitStructure;
      GPIO_InitTypeDef GPIO_InitStructure;
        RCC_APB2PeriphClockCmd( RCC_APB2Periph_SPI1 | RCC_APB2Periph_OLED_PORT, ENABLE);

      SPI_SSOutputCmd(SPI1, ENABLE);

      GPIO_InitStructure.GPIO_Pin = OLED_SCK_PIN | OLED_SDA_PIN ;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_Init(OLED_PORT, &GPIO_InitStructure);


      GPIO_InitStructure.GPIO_Pin = OLED_RST_PIN | OLED_DC_PIN | GPIO_Pin_4 ;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_Init(OLED_PORT, &GPIO_InitStructure);


      SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
      SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
      SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
      SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
      SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
      SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
      SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16;
      SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
      SPI_InitStructure.SPI_CRCPolynomial = 7;
      SPI_Init(SPI1, &SPI_InitStructure);
      /* Enable SPI1 */
      SPI_Cmd(SPI1, ENABLE);
}
void OLED_WB(uint8_t data)
{

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

    SPI_I2S_SendData(SPI1, data);
}
void LCD_WrDat(unsigned char dat)
{
    OLED_DC_H;
    OLED_WB(dat);
}

void LCD_WrCmd(unsigned char cmd)
{
    OLED_DC_L;
    OLED_WB(cmd);
}

void LCD_Set_Pos(unsigned char x, unsigned char y)
{

        LCD_WrCmd((0xb0+(y&0x0f)));  
      LCD_WrCmd((((x & 0xf0)>>4)|0x10));            //设置OLED水平坐标的高4位
      LCD_WrCmd((x & 0x00));                                //设置OLED水平坐标的低4位
}
void OLED_ShowChar(int x, int y, const unsigned char *p)            //显示字符
 {
   int i = 0;
    LCD_Set_Pos(x, y);                                                  //首先确定开始的坐标
  for(i = 0; i < 16; i+=2)                                      //
   {
      LCD_WrDat(p[i]);                                              //每次显示一个字节      每个char占用16个x像素
    }
   LCD_Set_Pos(x, y+1);                                             //转到下一页显示剩下字节
    for(i = 1; i < 16; i+=2)
    {
        LCD_WrDat(p[i]);
     }
}

void OLED_ShowChinese(int x, int y, const unsigned char *p)
 {
    int i = 0;
    LCD_Set_Pos(x, y);
    for(i = 0; i < 32; i+=2)
    {
         LCD_WrDat(p[i]);
     }
         LCD_Set_Pos(x, y+1);
     for(i = 1; i < 32; i+=2)
    {
         LCD_WrDat(p[i]);
     }

 }
void LCD_DLY_ms(unsigned int ms)
{
    unsigned int a;
    while(ms)
    {
        a=1335;
        while(a--);
        ms--;
    }
    return;
}
void LCD_Fill(unsigned char bmp_dat)
{
    unsigned char y,x;

    LCD_WrCmd(0x20);//-Set Page Addressing Mode (0x00/0x01/0x02)
    LCD_WrCmd(0x00);//

    LCD_WrCmd(0x21);//-Set Column Address
    LCD_WrCmd(0x00);
    LCD_WrCmd(0x7f);

    LCD_WrCmd(0x22);//-Set Page Address
    LCD_WrCmd(0x00);
    LCD_WrCmd(0x07);

    LCD_DLY_ms(1);
    for(y=0;yfor(x=0;x/*********************清屏函数***********************/
void LCD_CLS(void)
{
    unsigned char y,x;
    for(y=0;y<8;y++)
    {
        LCD_WrCmd(0xb0+y);
        LCD_WrCmd(0x01);
        LCD_WrCmd(0x10);
        for(x=0;x0);
        LCD_DLY_ms(200);
    }
}

void LCD_Init(void)
{
        SPI_Configuration();
        OLED_RST_L;
        LCD_DLY_ms(50);
        OLED_RST_H;
    //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

    LCD_WrCmd(0xae);//--turn off oled panel

    LCD_WrCmd(0xa8);//--set multiplex ratio(1 to 64)
    LCD_WrCmd(0x3f);//--1/64 duty
    LCD_WrCmd(0xd3);//-set display offset   Shift Mapping RAM Counter (0x00~0x3F)
    LCD_WrCmd(0x00);//-not offset
    LCD_WrCmd(0x40);//--set start line address  Set Mapping RAM Display Start Line (0x00~0x3F)
    LCD_WrCmd(0xa0);//--Set SEG/Column Mapping     0xa0左右反置 0xa1正常
    LCD_WrCmd(0xc0);//Set COM/Row Scan Direction   0xc0上下反置 0xc8正常
    LCD_WrCmd(0xda);//--set com pins hardware configuration
    LCD_WrCmd(0x12);
    LCD_WrCmd(0x81);//--set contrast control register
    LCD_WrCmd(0xcf); // Set SEG Output Current Brightness
    LCD_WrCmd(0xa4);// Disable Entire Display On (0xa4/0xa5)
    LCD_WrCmd(0xa6);// Disable Inverse Display On (0xa6/a7)
    LCD_WrCmd(0xd5);//--set display clock divide ratio/oscillator frequency
    LCD_WrCmd(0x80);//--set divide ratio, Set Clock as 100 Frames/Sec
    LCD_WrCmd(0x8d);//--set Charge Pump enable/disable
    LCD_WrCmd(0x14);//--set(0x10) disable
    LCD_WrCmd(0xaf);//--turn on oled panel

    LCD_WrCmd(0xd9);//--set pre-charge period
    LCD_WrCmd(0xf8);//Set Pre-Charge as 15 Clocks & Discharge as 1 Clock

    LCD_WrCmd(0xdb);//--set vcomh
    LCD_WrCmd(0x40);//Set VCOM Deselect Level

    LCD_Fill(0x00);  //初始清屏
}