03 OLED显示屏实现

发表于 更新于 分类于
实现OLED屏幕的显示

前言

这一章主要是上一节没有讲完的项目的一个编写，上一章我们说道单片机的输入和输出，包括四种单片机与外设之间的数据交换使用到的方式，这一章就利用前面说到的这几种方式来编写一个OLED显示屏的驱动。

一、软件模拟IIC协议

这使用的OLED屏幕是用的4引脚IIC协议的，在编写相关代码之前我们需要先了解一下什么是IIC协议，在单片机中，IIC通常指的是Inter-Integrated Circuit，也称为I2C（Inter-Integrated Circuit）总线，它是一种用于在集成电路之间进行通信的串行通信协议。

I2C总线由飞利浦公司（现在的恩智浦半导体公司）开发，用于在数字集成电路之间进行通信。它通常用于连接微控制器和外部设备，如传感器、存储器、扩展模块等。

I2C总线使用两根线进行通信：串行数据线（SDA）和串行时钟线（SCL）。通过这两根线，多个设备可以在同一总线上进行通信。每个设备都有一个唯一的地址，因此可以通过地址来选择要通信的特定设备。

I2C总线采用主从结构，主设备负责发起通信并控制总线，而从设备则响应主设备的命令。这种通信协议简单而灵活，适用于连接多种类型的设备。

简单来说IIC协议就是一种串行通讯协议，我们只需要对两根数据线进行操作就可以了，在32中有对应的IIC的函数库，我们可以直接调用来实现，但是那个内容我安排在后面了，我们实现先学习上一节用输入和输出来进行模拟的方式，学习完后我们才可以用一些传感器来观察效果并实现更高级的内容。

1.开启IIC协议

我们在使用IIC协议之前需要发送一个开始信号的，这个开始信号的时序图如下：

3.png

可以看到左边是起始条件，我们要开启IIC协议必须得先发送其实条件，这里的代码很容易就可以编写，这里我用了一下宏定义和位操作：

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void IIC_Start(void){
    GPIO_SetBits(GPIO, SDA);
    GPIO_SetBits(GPIO, SCL);
    GPIO_ResetBits(GPIO, SDA);
    GPIO_ResetBits(GPIO, SCL);
}

这个函数就可以让IIC协议开始，当开始后我们就可以参数数据和一些命令了。

2.结束IIC协议

当一条IIC协议传输完成后需要发送一条协议结束信号，这个信号的写法也很简单，代码如下：

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void IIC_Stop(void){
    GPIO_ResetBits(GPIO, SDA);
    GPIO_SetBits(GPIO, SCL);
    GPIO_SetBits(GPIO, SDA);
}

这样就可以结束上一次的IIC数据传输。

3.传输数据

这个的时序图也可以参考上面的时序图

3.png

看中间的位置，这个位置就是传输一位数据时的时序图，那么我们就可以根据这个图写出传输一个字节的数据了，这里需要注意一下，我们传输一条字节数据时是需要先传递高位数据，在SCL从高电平到低电平的时候才会将数据传递过去，代码如下：

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void IIC_WriteBit(u8 byte){
    u8 i;
    for (i = 0; i < 8; i++){
        if (byte & 0x80){
            GPIO_SetBits(GPIO, SDA);
        }
        else{
            GPIO_ResetBits(GPIO, SDA);
        }
        byte <<= 1;
        GPIO_SetBits(GPIO, SCL);
        GPIO_ResetBits(GPIO, SCL);
    }
    // 跳过一个ACK信号
    GPIO_SetBits(GPIO, SCL);
    GPIO_ResetBits(GPIO, SCL);
}

这里就是向IIC传递一个字节数据的函数，最后这里写了一个跳过ACK响应，这个ACK响应是什么呢？

我们可以看这个时序图：

3.jpg

可以看到WORD数据后有一个ACK信号，这个ACK信号是响应信号，就是当我们数据传递到IIC设备后，它如果接受到数据后就会发送一个接受信号，这个就是接受信号，我们不需要这个信号，所以直接忽略即可。

好了，模拟IIC的操作就是这些了，下面我们就介绍一下OLED的操作了。

二、OLED的操作

1.传输数据的准备

在用IIC协议向OLED传输数据前需要做的操作有下面这几步，我们只有操作好了才能正确的传输命令或者数据：

1.开启IIC协议

2.向OLED传入从地址

3.传输是写入的是命令还是数据

4.开始传输数据

5.结束IIC协议

在传输数据或者命令之前要先向OLED传入它的地址，相当于一个片选，当选中了才可以进行操作，每个OLED的地址都是固定的，都是为0x78，如果要更改需要联系厂家

4.png

这个就是时序图，在右边的SSD1306 Slave Address就是它的地址，我们就将这个先传入即可，在下面的写入命令会有这个代码。

然后就是传入是数据还是命令，在words这个数据块中可以告诉你该如何传入，第一个Co不用管，默认0皆可，然后第二个是选择命令还是数据，1是数据，0是命令，所以就可以得到下面的内容，当我们要写命令的时候，传入完地址后再传入0x00。如果要写数据得到的时候，要传入0x40。

2.写入命令

知道了上面的过程后我们就可以写写入命令的函数了：

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void write_command(u8 cmd){
    IIC_Start();        // 开启IIC协议
    IIC_Write(0x78);    // 传入地址
    IIC_Write(0x00);    // 传入0x00代表要传入命令
    IIC_Write(cmd);     // 传入命令
    IIC_Stop();         // 结束IIC协议
}

这样就完成了一次写入命令。

3.写入数据

写入数据的函数和上面的函数一样，只不过就是传入地址后传入的内容不同：

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void write_data(u8 data){
    IIC_Start();
    IIC_Write(0x78);
    IIC_Write(0x40);
    IIC_Write(data);
    IIC_Stop();
}

这样就可以完成一次数据的传送。

这些基础功能讲完了，后面的操作是需要结合命令列表来进行操作了。

4.初始化函数

首先我们要操作需要先进行初始化，这里初始化的功能不会全部说明，大家如果有问题可以查一下OLED的数据手册即可。

初始化传入的命令步骤如下：

  1. 关闭显示屏

  2. 设置显示时钟分频比/振荡器频率

  3. 设置多路复用率

  4. 显示开始行

  5. 设置左右方向

  6. 设置上下方向

  7. 设置COM引脚硬件配置

  8. 设置对比度

  9. 设置预充电周期

  10. 设置VCOMH取消选择级别

  11. 设置整个显示打开/关闭

  12. 设置正常/倒转显示

  13. 设置充电泵

  14. 开启显示

这个内容需要查看手册来慢慢写，我这里就不一个一个介绍了，我这写好了，你们可以直接复制和粘贴

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#define CMD 0x00
#define DATA 0x40
#define CLOSESHOW 0xAE
#define SETCLS 0xD5
#define RATE    0xA8
#define OFFSET  0xD3
#define START   0x40
#define LEFTRIG 0xA1
#define UPDOWN  0xC8
#define HARD    0xDA
#define RATION  0x81
#define  CYCLE  0xD9
#define VCOM    0xDB
#define SHOWUP  0xA4
#define BEN     0x8D
#define SHOWOK  0xAF
void OLED_Init(){
    write_command(CLOSESHOW);
    write_command(SETCLS);
    write_command(0x80);
    write_command(RATE);
    write_command(0x3F);
    write_command(OFFSET);
    write_command(0x00);
    write_command(START);
    write_command(LEFTRIG);
    write_command(UPDOWN);
    write_command(HARD);
    write_command(0x12);
    write_command(RATION);
    write_command(0xCF);
    write_command(CYCLE);
    write_command(0xF1);
    write_command(VCOM);
    write_command(0x30);
    write_command(SHOWUP);
    write_command(0xA6);
    write_command(BEN);
    write_command(0x14);
    write_command(SHOWOK);
}

5.设置光标

在屏幕中有一个光标，只不过我们在初始化的时候就把这个光标给隐藏了，但是你要有这个概念，设置光标也是需要使用命令来进行操作，这里也需要参考一下命令手册，但是，我这已经写好了，直接用就可以了：

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void set_currsor(u8 row, u8 col){
    write_command(0xB0 |row);
    write_command(0x10 | ((col & 0xF0) >> 4));
    write_command(0x00 | (col & 0x0F));
}

row就是光标所在的行，col是光标所在的列。

6.显示字符

要让OLED显示字符需要使用到取摸3工具取出来，因为我们显示其实就是让那些液晶块亮，哪些不亮，所以需要取摸，这里我没找到Linux下的取摸工具，等后面我有时间后我写一个，然后下面是我之前取好的ASCII后32个字符对应的字摸，大家可以直接拿来用：

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static unsigned char ASCII1[][16] = {
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},

{0x00,0x00,0x00,0xF8,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x33,0x00,0x00,0x00,0x00},/*"!",0*/

{0x00,0x10,0x0C,0x02,0x10,0x0C,0x02,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*""",1*/

{0x00,0x40,0xC0,0x78,0x40,0xC0,0x78,0x00,0x00,0x04,0x3F,0x04,0x04,0x3F,0x04,0x00},/*"#",2*/

{0x00,0x70,0x88,0x88,0xFC,0x08,0x30,0x00,0x00,0x18,0x20,0x20,0xFF,0x21,0x1E,0x00},/*"$",3*/

{0xF0,0x08,0xF0,0x80,0x60,0x18,0x00,0x00,0x00,0x31,0x0C,0x03,0x1E,0x21,0x1E,0x00},/*"%",4*/

{0x00,0xF0,0x08,0x88,0x70,0x00,0x00,0x00,0x1E,0x21,0x23,0x2C,0x19,0x27,0x21,0x10},/*"&",5*/

{0x00,0x12,0x0E,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"'",6*/

{0x00,0x00,0x00,0xE0,0x18,0x04,0x02,0x00,0x00,0x00,0x00,0x07,0x18,0x20,0x40,0x00},/*"(",7*/

{0x00,0x02,0x04,0x18,0xE0,0x00,0x00,0x00,0x00,0x40,0x20,0x18,0x07,0x00,0x00,0x00},/*")",8*/

{0x40,0x40,0x80,0xF0,0x80,0x40,0x40,0x00,0x02,0x02,0x01,0x0F,0x01,0x02,0x02,0x00},/*"*",9*/

{0x00,0x00,0x00,0x00,0xE0,0x00,0x00,0x00,0x00,0x01,0x01,0x01,0x0F,0x01,0x01,0x01},/*"+",10*/

{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x90,0x70,0x00,0x00,0x00,0x00,0x00},/*",",11*/

{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x01,0x01,0x01,0x01,0x00},/*"-",12*/

{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00,0x00,0x00},/*".",13*/

{0x00,0x00,0x00,0x00,0xC0,0x38,0x04,0x00,0x00,0x60,0x18,0x07,0x00,0x00,0x00,0x00},/*"/",14*/

{0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x0F,0x10,0x20,0x20,0x10,0x0F,0x00},/*"0",0*/

{0x00,0x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00},/*"1",1*/

{0x00,0x70,0x08,0x08,0x08,0x08,0xF0,0x00,0x00,0x30,0x28,0x24,0x22,0x21,0x30,0x00},/*"2",2*/

{0x00,0x30,0x08,0x08,0x08,0x88,0x70,0x00,0x00,0x18,0x20,0x21,0x21,0x22,0x1C,0x00},/*"3",3*/

{0x00,0x00,0x80,0x40,0x30,0xF8,0x00,0x00,0x00,0x06,0x05,0x24,0x24,0x3F,0x24,0x24},/*"4",4*/

{0x00,0xF8,0x88,0x88,0x88,0x08,0x08,0x00,0x00,0x19,0x20,0x20,0x20,0x11,0x0E,0x00},/*"5",5*/

{0x00,0xE0,0x10,0x88,0x88,0x90,0x00,0x00,0x00,0x0F,0x11,0x20,0x20,0x20,0x1F,0x00},/*"6",6*/

{0x00,0x18,0x08,0x08,0x88,0x68,0x18,0x00,0x00,0x00,0x00,0x3E,0x01,0x00,0x00,0x00},/*"7",7*/

{0x00,0x70,0x88,0x08,0x08,0x88,0x70,0x00,0x00,0x1C,0x22,0x21,0x21,0x22,0x1C,0x00},/*"8",8*/

{0x00,0xF0,0x08,0x08,0x08,0x10,0xE0,0x00,0x00,0x01,0x12,0x22,0x22,0x11,0x0F,0x00},/*"9",9*/

{0x00,0x00,0x00,0xC0,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x30,0x30,0x00,0x00,0x00},/*":",0*/

{0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xE0,0x00,0x00,0x00,0x00},/*";",1*/

{0x00,0x00,0x80,0x40,0x20,0x10,0x08,0x00,0x00,0x01,0x02,0x04,0x08,0x10,0x20,0x00},/*"<",2*/

{0x00,0x40,0x40,0x40,0x40,0x40,0x40,0x00,0x00,0x02,0x02,0x02,0x02,0x02,0x02,0x00},/*"=",3*/

{0x00,0x08,0x10,0x20,0x40,0x80,0x00,0x00,0x00,0x20,0x10,0x08,0x04,0x02,0x01,0x00},/*">",4*/

{0x00,0x70,0x48,0x08,0x08,0x88,0x70,0x00,0x00,0x00,0x00,0x30,0x37,0x00,0x00,0x00},/*"?",5*/

{0xC0,0x30,0xC8,0x28,0xE8,0x10,0xE0,0x00,0x07,0x18,0x27,0x28,0x2F,0x28,0x17,0x00},/*"@",6*/

{0x00,0x00,0xC0,0x38,0xE0,0x00,0x00,0x00,0x20,0x3C,0x23,0x02,0x02,0x27,0x38,0x20},/*"A",0*/

{0x08,0xF8,0x88,0x88,0x88,0x70,0x00,0x00,0x20,0x3F,0x20,0x20,0x20,0x11,0x0E,0x00},/*"B",1*/

{0xC0,0x30,0x08,0x08,0x08,0x08,0x38,0x00,0x07,0x18,0x20,0x20,0x20,0x10,0x08,0x00},/*"C",2*/

{0x08,0xF8,0x08,0x08,0x08,0x10,0xE0,0x00,0x20,0x3F,0x20,0x20,0x20,0x10,0x0F,0x00},/*"D",3*/

{0x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,0x20,0x3F,0x20,0x20,0x23,0x20,0x18,0x00},/*"E",4*/

{0x08,0xF8,0x88,0x88,0xE8,0x08,0x10,0x00,0x20,0x3F,0x20,0x00,0x03,0x00,0x00,0x00},/*"F",5*/

{0xC0,0x30,0x08,0x08,0x08,0x38,0x00,0x00,0x07,0x18,0x20,0x20,0x22,0x1E,0x02,0x00},/*"G",6*/

{0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x20,0x3F,0x21,0x01,0x01,0x21,0x3F,0x20},/*"H",7*/

{0x00,0x08,0x08,0xF8,0x08,0x08,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00},/*"I",8*/

{0x00,0x00,0x08,0x08,0xF8,0x08,0x08,0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00,0x00},/*"J",9*/

{0x08,0xF8,0x88,0xC0,0x28,0x18,0x08,0x00,0x20,0x3F,0x20,0x01,0x26,0x38,0x20,0x00},/*"K",10*/

{0x08,0xF8,0x08,0x00,0x00,0x00,0x00,0x00,0x20,0x3F,0x20,0x20,0x20,0x20,0x30,0x00},/*"L",11*/

{0x08,0xF8,0xF8,0x00,0xF8,0xF8,0x08,0x00,0x20,0x3F,0x01,0x3E,0x01,0x3F,0x20,0x00},/*"M",12*/

{0x08,0xF8,0x30,0xC0,0x00,0x08,0xF8,0x08,0x20,0x3F,0x20,0x00,0x07,0x18,0x3F,0x00},/*"N",13*/

{0xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,0x0F,0x10,0x20,0x20,0x20,0x10,0x0F,0x00},/*"O",14*/

{0x08,0xF8,0x08,0x08,0x08,0x08,0xF0,0x00,0x20,0x3F,0x21,0x01,0x01,0x01,0x00,0x00},/*"P",15*/

{0xE0,0x10,0x08,0x08,0x08,0x10,0xE0,0x00,0x0F,0x10,0x28,0x28,0x30,0x50,0x4F,0x00},/*"Q",16*/

{0x08,0xF8,0x88,0x88,0x88,0x88,0x70,0x00,0x20,0x3F,0x20,0x00,0x03,0x0C,0x30,0x20},/*"R",17*/

{0x00,0x70,0x88,0x08,0x08,0x08,0x38,0x00,0x00,0x38,0x20,0x21,0x21,0x22,0x1C,0x00},/*"S",18*/

{0x18,0x08,0x08,0xF8,0x08,0x08,0x18,0x00,0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00},/*"T",19*/

{0x08,0xF8,0x08,0x00,0x00,0x08,0xF8,0x08,0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00},/*"U",20*/

{0x08,0x78,0x88,0x00,0x00,0xC8,0x38,0x08,0x00,0x00,0x07,0x38,0x0E,0x01,0x00,0x00},/*"V",21*/

{0x08,0xF8,0x00,0xF8,0x00,0xF8,0x08,0x00,0x00,0x03,0x3E,0x01,0x3E,0x03,0x00,0x00},/*"W",22*/

{0x08,0x18,0x68,0x80,0x80,0x68,0x18,0x08,0x20,0x30,0x2C,0x03,0x03,0x2C,0x30,0x20},/*"X",23*/

{0x08,0x38,0xC8,0x00,0xC8,0x38,0x08,0x00,0x00,0x00,0x20,0x3F,0x20,0x00,0x00,0x00},/*"Y",24*/

{0x10,0x08,0x08,0x08,0xC8,0x38,0x08,0x00,0x20,0x38,0x26,0x21,0x20,0x20,0x18,0x00},/*"Z",25*/

{0x00,0x00,0x00,0xFE,0x02,0x02,0x02,0x00,0x00,0x00,0x00,0x7F,0x40,0x40,0x40,0x00},/*"[",0*/

{0x00,0x04,0x38,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x06,0x38,0xC0,0x00},/*"\",1*/

{0x00,0x02,0x02,0x02,0xFE,0x00,0x00,0x00,0x00,0x40,0x40,0x40,0x7F,0x00,0x00,0x00},/*"]",2*/

{0x00,0x00,0x04,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"^",3*/

{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80},/*"_",4*/

{0x00,0x02,0x02,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"`",5*/

{0x00,0x00,0x80,0x80,0x80,0x00,0x00,0x00,0x00,0x19,0x24,0x24,0x12,0x3F,0x20,0x00},/*"a",0*/

{0x10,0xF0,0x00,0x80,0x80,0x00,0x00,0x00,0x00,0x3F,0x11,0x20,0x20,0x11,0x0E,0x00},/*"b",1*/

{0x00,0x00,0x00,0x80,0x80,0x80,0x00,0x00,0x00,0x0E,0x11,0x20,0x20,0x20,0x11,0x00},/*"c",2*/

{0x00,0x00,0x80,0x80,0x80,0x90,0xF0,0x00,0x00,0x1F,0x20,0x20,0x20,0x10,0x3F,0x20},/*"d",3*/

{0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x1F,0x24,0x24,0x24,0x24,0x17,0x00},/*"e",4*/

{0x00,0x80,0x80,0xE0,0x90,0x90,0x20,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00},/*"f",5*/

{0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x6B,0x94,0x94,0x94,0x93,0x60,0x00},/*"g",6*/

{0x10,0xF0,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20},/*"h",7*/

{0x00,0x80,0x98,0x98,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00},/*"i",8*/

{0x00,0x00,0x00,0x80,0x98,0x98,0x00,0x00,0x00,0xC0,0x80,0x80,0x80,0x7F,0x00,0x00},/*"j",9*/

{0x10,0xF0,0x00,0x00,0x80,0x80,0x80,0x00,0x20,0x3F,0x24,0x06,0x29,0x30,0x20,0x00},/*"k",10*/

{0x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00,0x00},/*"l",11*/

{0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x20,0x3F,0x20,0x00,0x3F,0x20,0x00,0x3F},/*"m",12*/

{0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x20,0x3F,0x21,0x00,0x00,0x20,0x3F,0x20},/*"n",13*/

{0x00,0x00,0x80,0x80,0x80,0x80,0x00,0x00,0x00,0x1F,0x20,0x20,0x20,0x20,0x1F,0x00},/*"o",14*/

{0x80,0x80,0x00,0x80,0x80,0x00,0x00,0x00,0x80,0xFF,0x91,0x20,0x20,0x11,0x0E,0x00},/*"p",15*/

{0x00,0x00,0x00,0x80,0x80,0x00,0x80,0x00,0x00,0x0E,0x11,0x20,0x20,0x91,0xFF,0x80},/*"q",16*/

{0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x20,0x20,0x3F,0x21,0x20,0x00,0x01,0x00},/*"r",17*/

{0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x33,0x24,0x24,0x24,0x24,0x19,0x00},/*"s",18*/

{0x00,0x80,0x80,0xE0,0x80,0x80,0x00,0x00,0x00,0x00,0x00,0x1F,0x20,0x20,0x10,0x00},/*"t",19*/

{0x80,0x80,0x00,0x00,0x00,0x80,0x80,0x00,0x00,0x1F,0x20,0x20,0x20,0x10,0x3F,0x20},/*"u",20*/

{0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x03,0x0C,0x30,0x0C,0x03,0x00,0x00},/*"v",21*/

{0x80,0x80,0x00,0x80,0x80,0x00,0x80,0x80,0x01,0x0E,0x30,0x0C,0x07,0x38,0x06,0x01},/*"w",22*/

{0x00,0x80,0x80,0x80,0x00,0x80,0x80,0x00,0x00,0x20,0x31,0x0E,0x2E,0x31,0x20,0x00},/*"x",23*/

{0x80,0x80,0x80,0x00,0x00,0x80,0x80,0x80,0x00,0x81,0x86,0x78,0x18,0x06,0x01,0x00},/*"y",24*/

{0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x00,0x21,0x30,0x2C,0x22,0x21,0x30,0x00},/*"z",25*/
};

static unsigned char number1[][16] = {
{0x00,0xE0,0x10,0x08,0x08,0x10,0xE0,0x00,0x00,0x0F,0x10,0x20,0x20,0x10,0x0F,0x00},/*"0",0*/

{0x00,0x00,0x10,0x10,0xF8,0x00,0x00,0x00,0x00,0x00,0x20,0x20,0x3F,0x20,0x20,0x00},/*"1",1*/

{0x00,0x70,0x08,0x08,0x08,0x08,0xF0,0x00,0x00,0x30,0x28,0x24,0x22,0x21,0x30,0x00},/*"2",2*/

{0x00,0x30,0x08,0x08,0x08,0x88,0x70,0x00,0x00,0x18,0x20,0x21,0x21,0x22,0x1C,0x00},/*"3",3*/

{0x00,0x00,0x80,0x40,0x30,0xF8,0x00,0x00,0x00,0x06,0x05,0x24,0x24,0x3F,0x24,0x24},/*"4",4*/

{0x00,0xF8,0x88,0x88,0x88,0x08,0x08,0x00,0x00,0x19,0x20,0x20,0x20,0x11,0x0E,0x00},/*"5",5*/

{0x00,0xE0,0x10,0x88,0x88,0x90,0x00,0x00,0x00,0x0F,0x11,0x20,0x20,0x20,0x1F,0x00},/*"6",6*/

{0x00,0x18,0x08,0x08,0x88,0x68,0x18,0x00,0x00,0x00,0x00,0x3E,0x01,0x00,0x00,0x00},/*"7",7*/

{0x00,0x70,0x88,0x08,0x08,0x88,0x70,0x00,0x00,0x1C,0x22,0x21,0x21,0x22,0x1C,0x00},/*"8",8*/

{0x00,0xF0,0x08,0x08,0x08,0x10,0xE0,0x00,0x00,0x01,0x12,0x22,0x22,0x11,0x0F,0x00},/*"9",9*/
};

然后根据这个字摸，我们可以显示字符了，这里写一个显示字符的函数：

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void show_char(u8 row, u8 col, u8 charr){
    u8 i;     // 遍历变量
    set_currsor(row, col + 8);    // 设置显示位置
    for (i = 0; i < 8; i++){
        IIC_Write(ASCII1[charr - 32][i]);
    }
    set_currsor(row + 1, col + 8);  // 设置下一行显示的位置
    for (i = 0; i < 8; i++){
        IIC_Write(ASCII1[charr - 32][i + 8]);
    }
}

字摸的长度是16位，而我们显示的这个ASCII是8*8大小的，我们在第一次设置光标的时候要加上8是为了错过前面的一个字符，然后在显示字符的时候选择的是逐列式。

也就是先将第一个字节的字摸先显示，然后转到下一列再显示第二个字摸，依次下去，这样如果只有一半，也就是只有4*8,还需要转到下一行补上那4行才可以变成8*8。

在写这个函数的时候，我发现了一个好玩的，我这如果让列不跳过一个字符，而是跳过一位，那这个字符就会扭动，虽然没有什么用，但是感觉很有趣，代码如下，大家可以来试试：

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// 扭动字符显示
// 只能显示一个，显示多个就不流畅了
void show_Twistchar(u8 row, u8 col, u8 word){
    u8 i;
    set_currsor(row, col * 8);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i]);
    }
    set_currsor(row + 1, col * 8);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i + 8]);
    }
    // 下面这些可以删掉，然后在主函数调用的时候调用两遍，要一样的字符
    delay_us(5); 
    set_currsor(row, col * 8 + 1);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i]);
    }
    set_currsor(row + 1, col * 8 + 1);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i + 8]);
    }
}

7.显示字符串

这个就得看大家对于串操作的熟练程度了，就是用到对字符串的操作，但是呢，这个需要考虑到换行，代码如下：

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void show_string(u8 row, u8 col, u8* str){
    u8 i, j = 0;
    for (i = 0; str[i] != '\0'; i++, j++){
        if (j >= 16){
            row += 1;
            col = 0;
            j = 0;
        }
        show_char(row, col + j, str[i]);
    }
}

这里我用一个变量作为判断条件，因为一行有128个像素点，我们显示8*8的字符，那一行只能显示16个8*8的字符，所以当j变量到了16个字符，我们就让行换一行，列清零，这样就可以实现换行操作了。

8.清屏

这个操作很简单，就是将每一行和每一列的所有像素点全部变为0x00就可以了，代码如下：

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void clear(){
    u8 i, j;
    for (i = 0; i < 8; i++){
        set_currsor(i, 0);
        for (j = 0; j < 128; j++){
            write_data(0x00);
        }
    }
}

9.显示汉字

这个也是需要使用取摸得到，然后每个汉字是16*16的点阵，我们只需要显示即可：

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// 现实汉字
void show_hz(u8 row, u8 col, u8 len){
    u8 i, j, x, y;
    y = row;
    x = col;
    for (j = 0; j < len * 2; j += 2, y+= 2){
        if ((x + y) * 8 >= 128){
            y = 0;
            row = 2;
        }
        set_currsor(row, (x + y) * 8);
        for (i = 0; i < 16; i++){
            write_data(hz[j][i]);
        }
        set_currsor(row + 1, (x + y) * 8);
        for (i = 0; i < 16; i++){
            write_data(hz[j + 1][i]);
        }
    }
}

这个也是可以自动换行的，但在使用前需要将字摸放入到hz这个数组中，这个数组的格式如下：

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static unsigned char hz[][16] = {
	{0x20,0x24,0x24,0x24,0xFE,0x23,0x22,0x20,0x20,0xFF,0x20,0x22,0x2C,0xA0,0x20,0x00},
	{0x00,0x08,0x48,0x84,0x7F,0x02,0x41,0x40,0x20,0x13,0x0C,0x14,0x22,0x41,0xF8,0x00},/*"我",0*/

	{0x00,0x80,0x60,0xF8,0x07,0x00,0xF8,0x01,0x06,0x00,0x04,0x04,0x04,0xFC,0x00,0x00},
	{0x01,0x00,0x00,0xFF,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x40,0x80,0x7F,0x00,0x00},/*"们",1*/

	{0x20,0x24,0x24,0xA4,0x7F,0x24,0x34,0x28,0x26,0x20,0xFE,0x02,0x22,0xDA,0x06,0x00},
	{0x04,0x02,0xFF,0x49,0x49,0x49,0x49,0xFF,0x00,0x00,0xFF,0x08,0x10,0x08,0x07,0x00},/*"都",2*/

	{0x04,0x04,0x04,0x84,0xE4,0x3C,0x27,0x24,0x24,0x24,0x24,0xE4,0x04,0x04,0x04,0x00},
	{0x04,0x02,0x01,0x00,0xFF,0x09,0x09,0x09,0x09,0x49,0x89,0x7F,0x00,0x00,0x00,0x00},/*"有",3*/

	{0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x00},
	{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"一",4*/

	{0x80,0x80,0x40,0x20,0x10,0x08,0x04,0xC3,0x04,0x08,0x10,0x20,0x40,0x80,0x80,0x00},
	{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"个",5*/

	{0x40,0x44,0x24,0x14,0x7F,0x94,0x24,0x00,0x24,0x14,0x7F,0x14,0x24,0x44,0x40,0x00},
	{0x00,0x80,0x88,0x84,0x42,0x45,0x29,0x11,0x11,0x09,0x05,0x03,0x00,0x00,0x00,0x00},/*"梦",6*/

	{0x00,0x08,0x88,0x68,0xFF,0x48,0x88,0x00,0xFE,0x52,0x52,0x52,0xFE,0x00,0x00,0x00},
	{0x40,0x31,0x00,0x00,0x3B,0x40,0x40,0x44,0x5B,0x42,0x42,0x72,0x03,0x08,0x30,0x00},/*"想",7*/

	{0x00,0x08,0x88,0x68,0xFF,0x48,0x88,0x00,0xFE,0x52,0x52,0x52,0xFE,0x00,0x00,0x00},
	{0x40,0x31,0x00,0x00,0x3B,0x40,0x40,0x44,0x5B,0x42,0x42,0x72,0x03,0x08,0x30,0x00},/*"想",7*/

};

这里面有一些测试的汉字，大家可以测试一下。

10.显示图片

显示图片的代码我没有写，其实和显示字符和汉字一样，然后用取摸工具取出，然后看一下行有多少，列有多少，然后显示即可，这里我后面写完后会放入gitee上的，github的话因为我最近资金不足，所以没工具，懂得都懂。

11.显示动图

这个其实和GIF的原理一样，图片上覆盖图片，这样就会让图片动起来。

三、完整代码

我这个项目是分文件编写的，分为oled.c函数原型，oled.h函数声明和头文件引入，oledfont.h这个是字符库，sys.c是延时函数和系统操作,gpio.h是gpio口的初始化函数的声明

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// gpio.c
#include "gpio.h"

void MX_GPIOInit(){
    GPIO_InitTypeDef GPIO_InitStruct = {0};

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_OD;
    GPIO_InitStruct.GPIO_Pin = CLK;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIO, &GPIO_InitStruct);

    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_Out_OD;
    GPIO_InitStruct.GPIO_Pin = SDA;
    GPIO_Init(GPIO, &GPIO_InitStruct);
}
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// gpio.h
#ifndef __GPIO_H
#define __GPIO_H

#include "stm32f10x.h"

#define CLK GPIO_Pin_8
#define SDA GPIO_Pin_9
#define GPIO GPIOB

void MX_GPIOInit();

#endif

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// oled.c
#include "oled.h"

// I2C协议开始
void IIC_Start(){
    GPIO_SetBits(GPIO, SDA);
    GPIO_SetBits(GPIO, CLK);
    GPIO_ResetBits(GPIO, SDA);
    GPIO_ResetBits(GPIO, CLK);
}

// IIC协议结束
void IIC_Stop(){
    GPIO_ResetBits(GPIO, SDA);
    GPIO_SetBits(GPIO, CLK);
    GPIO_SetBits(GPIO, SDA);
}

// 通过IIC写入数据
void IIC_Write(u8 data){
    u8 i;
    for (i = 0; i < 8; i++){
        
        if (data & 0x80){
            GPIO_SetBits(GPIO, SDA);
        }
        else{
            GPIO_ResetBits(GPIO, SDA);
        }
        GPIO_SetBits(GPIO, CLK);
        GPIO_ResetBits(GPIOB, CLK);
        data <<= 1;
        // GPIO_ResetBits(GPIO, CLK);
        // GPIO_SetBits(GPIO, CLK);
    }
    GPIO_SetBits(GPIO, CLK);
    GPIO_ResetBits(GPIO, CLK);
}

// 写入命令
void write_command(u8 cmd){
    IIC_Start();
    IIC_Write(ADDR);
    IIC_Write(0x00);
    IIC_Write(cmd);
    IIC_Stop();
}

// 写入数据
void write_data(u8 data){
    IIC_Start();
    IIC_Write(ADDR);
    IIC_Write(0x40);
    IIC_Write(data);
    IIC_Stop();
}

// 设置光标
void set_currsor(u8 row, u8 col){
    write_command(0xB0 |row);
    write_command(0x10 | ((col & 0xF0) >> 4));
    write_command(0x00 | (col & 0x0F));
}

// 扭动字符显示
// 只能显示一个，显示多个就不流畅了
void show_Twistchar(u8 row, u8 col, u8 word){
    u8 i;
    set_currsor(row, col * 8);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i]);
    }
    set_currsor(row + 1, col * 8);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i + 8]);
    }
    delay_us(5);
    set_currsor(row, col * 8 + 1);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i]);
    }
    set_currsor(row + 1, col * 8 + 1);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i + 8]);
    }
}

// 显示一个字符
void show_char(u8 row, u8 col, u8 word){
    u8 i;
    set_currsor(row * 2, col * 8);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i]);
    }
    set_currsor(row * 2 + 1, col * 8);
    for (i = 0; i < 8; i++){
        write_data(ASCII1[word - 32][i + 8]);
    }
}

// 显示字符串
void show_string(u8 row, u8 col, u8* str){
    u8 i, j = 0;
    for (i = 0; str[i] != '\0'; i++, j++){
        if (j >= 16){
            row += 1;
            col = 0;
            j = 0;
        }
        show_char(row, col + j, str[i]);
    }
}

// 现实汉字
void show_hz(u8 row, u8 col, u8 len){
    u8 i, j, x, y;
    y = row;
    x = col;
    for (j = 0; j < len * 2; j += 2, y+= 2){
        // x = (x + j) * 8;
        if ((x + y) * 8 >= 128){
            y = 0;
            row = 2;
        }
        set_currsor(row, (x + y) * 8);
        for (i = 0; i < 16; i++){
            write_data(hz[j][i]);
        }
        set_currsor(row + 1, (x + y) * 8);
        for (i = 0; i < 16; i++){
            write_data(hz[j + 1][i]);
        }
    }
}

// 清屏
void clear(){
    u8 i, j;
    for (i = 0; i < 8; i++){
        set_currsor(i, 0);
        for (j = 0; j < 128; j++){
            write_data(0x00);
        }
    }
}

// 初始化函数
void OLED_Init(){
    u32 i, j;
    for (i = 0; i < 1000; i++){
        for (j = 0; j < 1000; j++);
    }
    write_command(CLOSESHOW);
    write_command(SETCLS);
    write_command(0x80);
    write_command(RATE);
    write_command(0x3F);
    write_command(OFFSET);
    write_command(0x00);
    write_command(START);
    write_command(LEFTRIG);
    write_command(UPDOWN);
    write_command(HARD);
    write_command(0x12);
    write_command(RATION);
    write_command(0xCF);
    write_command(CYCLE);
    write_command(0xF1);
    write_command(VCOM);
    write_command(0x30);
    write_command(SHOWUP);
    write_command(0xA6);
    write_command(BEN);
    write_command(0x14);
    write_command(SHOWOK);
    clear();
}
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// oled.h
#ifndef __OLED_H
#define __OLED_H

#include "stm32f10x.h"
#include "gpio.h"
#include "oledfont.h"
#include "sys.h"

#define ADDR 0x78

#define CMD 0x00
#define DATA 0x40
#define CLOSESHOW 0xAE
#define SETCLS 0xD5
#define RATE    0xA8
#define OFFSET  0xD3
#define START   0x40
#define LEFTRIG 0xA1
#define UPDOWN  0xC8
#define HARD    0xDA
#define RATION  0x81
#define  CYCLE  0xD9
#define VCOM    0xDB
#define SHOWUP  0xA4
#define BEN     0x8D
#define SHOWOK  0xAF

void OLED_Init();
void clear();
void show_char(u8 row, u8 col, u8 word);
void set_currsor(u8 row, u8 col);
void show_Twistchar(u8 row, u8 col, u8 word);
void show_string(u8 row, u8 col, u8* str);
void show_hz(u8 row, u8 col, u8 len);

#endif

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// sys.c
#include "sys.h"

void delay_us(u32 time){
    u32 temp;
    SysTick -> LOAD = 9 * time;
    SysTick -> CTRL = 0x01;
    SysTick -> VAL = 0;
    do{
        temp = SysTick -> CTRL;
    }while((temp & 0x01) && (!(temp & (1 << 16))));
    SysTick -> CTRL = 0;
    SysTick -> VAL = 0;
}
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// sys.h
#ifndef __SYS_H
#define __SYS_H

#include "stm32f10x.h"

void delay_us(u32 time);

#endif

总结

学会了这个显示屏如何显示后后面我们可以对传感器进行操作了，到时候传感器接收到的数据就可以直接显示在OLED上，这样就能很好的观察其中的变化了。

下一章准备介绍一下显示屏的一些操作，比如显示进度条，显示动图或者其他内容。