• 基于stm32f103系列的简单软件I2C和硬件I2C通讯

           这篇文章主要分为三个部分来阐述，分别是I2C的基本知识，软件I2C通讯，硬件I2C通讯。I2C的基本知识这一块，部分讲解以及图表来自b站江科大的up，很感谢这位up，大家可以关注一波。操作实现的时候，up使用的是标准库讲解，我是用是HAL库，但都可以实现。

    一、I2C的基本知识

    1.基本的三种通讯方式

    学过通讯的同学都知道，基本的通讯方式有单工，半双工，全双工。那么这三种工作方式有啥区别吗？我给大家举个例子：

          单工通讯就好比象棋里面的“卒”，卒有啥特性？没错，一条路走到黑，不走回头路，说白了，这种通讯方式就是“有去无回”。我只知道我可以通过这条线发过去，但是我没法通过这条线反馈信息。

          半双工通讯就好比你在狭窄的山路上开车，你可以开入山里面，也可以开出山里面，但是山路狭窄，在同一时刻同一路段只能允许一辆车通过。所以你你要想开入山里面，就必须等到出山的车先开出来；要想开出山里面，就必须让开入山里面的车先开进去。说白了，就是说，你可以出入山里，但是一定要确保你在开车的过程中，山路上没有相反方向的车堵住你。所以半双工在同一时刻，只能有一个方向的通讯。等到这个方向通讯完成，你才可以选择下一次通讯的方向。

          全双工通讯就好比我们现在的公路，随时随地，有来有回，去的车道完全不对回来的车道有影响，大家各走各的。

          这三种通道各自有各自的优劣与使用场景，感兴趣的同学可以自己百度百度。我们今天要说的就是I2C就是半双工通讯。

    2.I2C通讯规则

    ①

    起始条件:在SCL高电平的时候，SDA由高电平变为低电平

    ②

    终止条件:在SCL高电平的时候，SDA由高电平变为低电平

    ③

    发送一个字节:SCL低电平期间，主机将数据位依次放到SDA线上（高位先行），然后释放SCL，从机将在SCL高电平期间读取数据位，所以SCL高电平期间SDA不允许有数据变化，依次循环上述过程8次，即可发送一个字节

    ④

    接收一个字节:SCL低电平期间，从机将数据位依次放到SDA线上（高位先行），然后释放SCL，主机将在SCL高电平期间读取数据位，所以SCL高电平期间SDA不允许有数据变化，依次循环上述过程8次，即可接收一个字节（主机在接收之前，需要释放SDA，就是要让SDA=1）

    ⑤

    发送应答:主机在接收完一个字节之后，在下一个时钟发送一位数据，数据0表示应答，数据1表示非应答。

    ⑥

    接收应答:主机在发送完一个字节之后，在下一个时钟接收一位数据，判断从机是否应答，数据0表示应答，数据1表示非应答（主机在接收之前，需要释放SDA）。

    请大家看清楚接受和发送的对象是谁，不要混淆了。

    3.硬件电路

    第一张图告诉我们，所有的从机设备都和主机的时序一样，因此属于同步时序。主机的SDA连接着从机的SDA，这是一张典型的一主多从模型图。主机想要和谁通讯就，只需要输入对应的从机地址就行了。图中的两个R是为了保护电路的，具体咋保护的呢？

    按道理说，只要我们按照正常的时序，就可以实现主机的SDA输出，从机的SDA输入；从机的SDA输出，主机的SDA输入，这没问题。但是如果时序没有协调好，有可能会出现一方的SDA输出1，一方的SDA输出0，这样就相当于高低电平直接接在一起，不就短路了吗？

    因此I2C的设计规定，禁止所有的设备（无论是主机还是从此，内部的SDA,SCL电路都如第二张图所示）输出强上拉的高电平，采用外置弱上拉的电阻加开路输出的电路结构，这样就不用担心短路的问题了，如上图所示，在输入时，无论是SCL还是SDA的电路，输入高低电平都无影响。但是在输出是，因为SDA和SCL都是开漏模式，因此当输出低电平时，直接导通；输出高电平时，被截断处于浮空状态。但是浮空状态不稳定容易受到干扰，因此有外接一个电阻R，相当于让浮空的引脚与电阻相连，完成弱上拉，变相的输出高电平。

    下面我以主机SDA为例，给大家画一下等效图

    无论是主机还是从机，SDA和SCL都可以这样简化。如果你想了解为什么可以这样的简化，，你可以去b站上自己学一下场效应管的知识，再结合第一第二张图片的电路，你就懂了，这里我就不细说效应管的知识了。

    4.三种基本的I2C时序通讯

    ①指定地址写：指定地址写入一个字节

    如果想要写入多个字节，在终止条件前面的应答位应答，并且再次重复主机发送字节写内容及应答即可，直到不想发送，然后在写入终止条件。

    ②当前地址读

    如果想要读入多个字节，在终止条件前面的应答位应答，并且再次重复从机发送字节写内容及应答即可，直到不想发送，然后在写入终止条件。

    当前地址指针：就是说这个指针目前指向那个寄存器。当我们写的时候，会在该指针的位置写入，写完后自动加1，向下移动；当我们读的时候，会在该指针的位置读出，读完后自动加1，向下移动。

    ③指定地址读：相当于把指定地址写的终止条件去掉，然后和当前地址读结合起来。比如说我在指定地址写的时候，选好了从机的8位储存器地址，那么当前地址指针就要指向这里，我们就在这里写，接着应答，然后开始执行当前地址读的序列，那么就可以再当前的位置（也就是我们指定的写入地址的位置）读取出来数据。

    二、软件I2C通讯

    1.前提准备

       这里还是依据51单片机的I2C模拟通讯来进行改编，不熟悉的话，可以回看一下51模拟I2C通讯实现OLED显示图片

    2.代码部分（运行出来是一条蛇）

    这里我们想要用PB7端口模拟SDA,PB6端口模拟SCL,同时根据第一部分介绍，我们应该知道SDA,SCL都应该是开漏模式，所以我们的PB7端口和PB6端口都会配置成开漏模式。

    1. #include "main.h"
    2. #include "gpio.h"
    3.  
    4. /* Private includes ----------------------------------------------------------*/
    5. /* USER CODE BEGIN Includes */
    6. #define OLED_I2C_SCL_CLK()		__HAL_RCC_GPIOB_CLK_ENABLE()
    7. #define OLED_I2C_SCL_GPIO  		GPIOB
    8. #define OLED_I2C_SCL_PIN   		GPIO_PIN_6
    9.  
    10. #define OLED_I2C_SDA_CLK()   	__HAL_RCC_GPIOB_CLK_ENABLE()
    11. #define OLED_I2C_SDA_GPIO  		GPIOB
    12. #define OLED_I2C_SDA_PIN   		GPIO_PIN_7
    13.  
    14. #define OLED_SCL_RESET() 			HAL_GPIO_WritePin(OLED_I2C_SCL_GPIO,OLED_I2C_SCL_PIN,GPIO_PIN_RESET)  //SCL
    15. #define OLED_SCL_SET() 				HAL_GPIO_WritePin(OLED_I2C_SCL_GPIO,OLED_I2C_SCL_PIN,GPIO_PIN_SET)
    16.  
    17. #define OLED_SDA_RESET() 			HAL_GPIO_WritePin(OLED_I2C_SDA_GPIO,OLED_I2C_SDA_PIN,GPIO_PIN_RESET)  //SDA
    18. #define OLED_SDA_SET() 				HAL_GPIO_WritePin(OLED_I2C_SDA_GPIO,OLED_I2C_SDA_PIN,GPIO_PIN_SET)
    19.  
    20. /* USER CODE END Includes */
    21.  
    22. /* Private typedef -----------------------------------------------------------*/
    23. /* USER CODE BEGIN PTD */
    24. void MyI2C_Start(void)//起始条件
    25. {
    26. 	OLED_SCL_SET();
    27. 	OLED_SDA_SET();
    28. 	OLED_SDA_RESET();
    29. 	OLED_SCL_RESET();
    30. 	
    31. }
    32.  
    33. void MyI2C_Stop(void)//终止条件
    34. {
    35. 	OLED_SCL_SET() ;
    36. 	OLED_SDA_RESET();
    37. 	OLED_SDA_SET();
    38. }
    39.  
    40. void MyI2C_SendByte(uint8_t Byte)//发送一个字节
    41. {
    42. 	uint8_t i;
    43. 	uint8_t m,da;
    44. 	da = Byte;
    45. 	OLED_SCL_RESET();
    46. 	for(i = 0; i < 8; i++)		
    47. 	{
    48. 		m = da;
    49. 		m = m&0x80;
    50. 		if(m == 0x80)
    51. 		  OLED_SDA_SET();
    52. 		else 
    53. 			OLED_SDA_RESET();
    54. 			da = da << 1;
    55. 		  OLED_SCL_SET();
    56. 		  OLED_SCL_RESET();
    57. 	}
    58. }
    59.  
    60.  
    61.  
    62. char MyI2C_SendAck()//发送应答
    63. {
    64. 	char flag;
    65. 	OLED_SDA_SET();//释放SDA
    66. 	OLED_SCL_SET();
    67. 	 flag=	HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_7);
    68. 	OLED_SCL_RESET();
    69. 	return flag;
    70. }
    71.  
    72.  
    73. /* USER CODE END PTD */
    74.  
    75. /* Private define ------------------------------------------------------------*/
    76. /* USER CODE BEGIN PD */
    77. void Oled_Write_Cmd(char dataCmd)//发送一个写命令字节
    78. {
    79.    MyI2C_Start();
    80.    MyI2C_SendByte(0x78);
    81. 	 MyI2C_SendAck();	
    82.    MyI2C_SendByte(0x00);
    83. 	 MyI2C_SendAck();	
    84.    MyI2C_SendByte(dataCmd); 
    85. 	 MyI2C_SendAck();	
    86.     MyI2C_Stop();
    87. }
    88.  
    89. void Oled_Write_Data(char dataData)//发送一个写数据字节
    90. {
    91.  MyI2C_Start();//起始条件
    92.     MyI2C_SendByte(0x78);//发送从机地址
    93.     MyI2C_SendAck();//应答
    94.    MyI2C_SendByte(0x40);//开启写入命令0x00或写入数据0x40
    95.     MyI2C_SendAck();	//应答
    96.    MyI2C_SendByte(dataData);//写入具体的命令或者数据
    97.      MyI2C_SendAck();
    98.     MyI2C_Stop();//IIC结束
    99. }
    100.  
    101. 	void OLED_Init(void)
    102. {
    103. 	Oled_Write_Cmd(0xAE);//--display off
    104. 	Oled_Write_Cmd(0x00);//---set low column address
    105. 	Oled_Write_Cmd(0x10);//---set high column address
    106. 	Oled_Write_Cmd(0x40);//--set start line address  
    107. 	Oled_Write_Cmd(0xB0);//--set page address
    108. 	Oled_Write_Cmd(0x81); // contract control
    109. 	Oled_Write_Cmd(0xFF);//--128   
    110. 	Oled_Write_Cmd(0xA1);//set segment remap 
    111. 	Oled_Write_Cmd(0xA6);//--normal / reverse
    112. 	Oled_Write_Cmd(0xA8);//--set multiplex ratio(1 to 64)
    113. 	Oled_Write_Cmd(0x3F);//--1/32 duty
    114. 	Oled_Write_Cmd(0xC8);//Com scan direction
    115. 	Oled_Write_Cmd(0xD3);//-set display offset
    116. 	Oled_Write_Cmd(0x00);//
    117. 	
    118. 	Oled_Write_Cmd(0xD5);//set osc division
    119. 	Oled_Write_Cmd(0x80);//
    120. 	
    121. 	Oled_Write_Cmd(0xD8);//set area color mode off
    122. 	Oled_Write_Cmd(0x05);//
    123. 	
    124. 	Oled_Write_Cmd(0xD9);//Set Pre-Charge Period
    125. 	Oled_Write_Cmd(0xF1);//
    126. 	
    127. 	Oled_Write_Cmd(0xDA);//set com pin configuartion
    128. 	Oled_Write_Cmd(0x12);//
    129. 	
    130. 	Oled_Write_Cmd(0xDB);//set Vcomh
    131. 	Oled_Write_Cmd(0x30);//
    132. 	
    133. 	Oled_Write_Cmd(0x8D);//set charge pump enable
    134. 	Oled_Write_Cmd(0x14);//
    135. 	
    136. 	Oled_Write_Cmd(0xAF);//--turn on oled panel	
    137. }
    138.  
    139. /* USER CODE END PD */
    140.  
    141. /* Private macro -------------------------------------------------------------*/
    142. /* USER CODE BEGIN PM */
    143. void Oled_Screen_Clear(void){
    144. 	unsigned char i,n;
    145. 	                   
    146.  
    147. 	for(i=0;i<8;i++){
    148. 		Oled_Write_Cmd(0xb0+i);              
    149. 		Oled_Write_Cmd(0x00);                 
    150. 		Oled_Write_Cmd(0x10);                 
    151. 		for(n=0;n<128;n++)
    152. 		Oled_Write_Data(0x00); 			
    153. 	}	
    154. }
    155.  
    156. unsigned char bmpImager[] = {
    157.  
    158. /*--  调入了一幅图像：D:\无标题.bmp  --*/
    159. /*--  宽度x高度=128x64  --128x8x8*/
    160. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    161. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    162. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    163. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    164. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    165. 0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x80,0x80,0x80,0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,
    166. 0xC0,0xC0,0xC0,0x40,0x40,0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,0x80,0x80,0x80,0x80,
    167. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    168. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    169. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    170. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    171. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    172. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xC0,0xE0,0xF0,0xB8,
    173. 0x8C,0x8E,0x86,0x03,0x03,0x01,0x01,0x01,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    174. 0x00,0x00,0x00,0x00,0x80,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x61,0xE1,0xF1,
    175. 0xE1,0x63,0x03,0x06,0x0E,0x0C,0x18,0x70,0xE0,0xC0,0x00,0x00,0x00,0x00,0x00,0x00,
    176. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    177. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    178. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    179. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    180. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xFF,0x81,0x81,
    181. 0x81,0x81,0x81,0xC1,0xC3,0x67,0x7E,0x3C,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    182. 0x00,0x00,0x00,0x03,0x07,0x07,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    183. 0x00,0x00,0x80,0x00,0x00,0x00,0x00,0xC0,0xF1,0x7F,0x1F,0x00,0x00,0x00,0x00,0x00,
    184. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    185. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    186. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    187. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    188. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x07,0x0F,0x3D,
    189. 0x71,0xE1,0xC1,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x10,0xF0,0xF0,
    190. 0xB0,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0xF0,0xF0,0xB3,0x33,0x36,0x36,0x16,0x1E,
    191. 0x1E,0x1B,0x0F,0x0C,0x06,0x07,0x03,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    192. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    193. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    194. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    195. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    196. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    197. 0x00,0x01,0x03,0x9F,0xFC,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0xFF,
    198. 0xFF,0x66,0x66,0x46,0x46,0x46,0x46,0x46,0x62,0x63,0x67,0x7F,0xFC,0xF0,0x80,0x00,
    199. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    200. 0x00,0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,
    201. 0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0xC0,0xC0,0xC0,
    202. 0xC0,0xC0,0xC0,0x60,0x60,0x60,0xE0,0xA0,0x30,0x30,0x30,0x10,0x18,0x98,0xF8,0xFC,
    203. 0x6C,0x0C,0x04,0x06,0x06,0x06,0x62,0xF3,0xF3,0xDB,0xDB,0xDB,0xDB,0xF3,0x73,0x03,
    204. 0x03,0x0F,0x1F,0x3F,0x33,0x63,0x62,0x66,0x66,0x36,0x3E,0x1E,0x06,0x06,0x06,0x06,
    205. 0x06,0x3B,0x7B,0x6F,0xCD,0xCC,0xC4,0xCC,0xCC,0x6C,0x78,0x38,0x80,0xE0,0x7C,0x3F,
    206. 0x0F,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x08,0xEC,0xFF,0x7F,0x00,
    207. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    208. 0x00,0x00,0x00,0x00,0x01,0x01,0x03,0x03,0x03,0x07,0x07,0x05,0x0D,0x0D,0x09,0x19,
    209. 0x19,0x19,0x31,0x31,0x31,0x61,0x61,0x61,0x61,0x41,0xC1,0xC0,0xC0,0xC0,0xC0,0xC0,
    210. 0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,0xC0,0xC1,0xC1,0x43,0x63,0x63,0x63,0x31,0x31,0x30,
    211. 0x10,0x18,0x18,0x18,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,0x0C,
    212. 0x0C,0x0C,0x18,0x18,0x18,0x30,0x30,0x30,0x60,0x60,0x60,0x60,0x60,0xE0,0xF0,0xF0,
    213. 0xF0,0xF0,0xF0,0xF0,0xD8,0xD8,0xD8,0xDC,0xFC,0xF6,0xF6,0xE3,0xE3,0xE3,0x63,0x63,
    214. 0x63,0x62,0x66,0x36,0x36,0x36,0x1E,0x1E,0x0E,0x0E,0x06,0x07,0x03,0x00,0x00,0x00,
    215. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    216. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    217. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    218. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    219. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    220. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    221. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    222. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    223. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    224. };
    225.  
    226. void Oled_Show_Image(unsigned char *image)
    227. {
    228. 	unsigned char i; 
    229. 	unsigned int j;
    230. 	
    231. 	for(i=0;i<8;i++){
    232. 		Oled_Write_Cmd(0xB0 + i);//page0--page7
    233. 		//每个page从0列
    234. 		Oled_Write_Cmd(0x00);
    235. 		Oled_Write_Cmd(0x10);
    236. 		//0到127列，依次写入0，每写入数据，列地址自动偏移
    237. 		for(j = 128 * i; j<(128 * (i+1));j++){
    238. 			Oled_Write_Data(image[j]);
    239. 		}
    240. 	}
    241. }
    242. /* USER CODE END PM */
    243.  
    244. /* Private variables ---------------------------------------------------------*/
    245.  
    246. /* USER CODE BEGIN PV */
    247.  
    248. /* USER CODE END PV */
    249.  
    250. /* Private function prototypes -----------------------------------------------*/
    251. void SystemClock_Config(void);
    252. /* USER CODE BEGIN PFP */
    253.  
    254. /* USER CODE END PFP */
    255.  
    256. /* Private user code ---------------------------------------------------------*/
    257. /* USER CODE BEGIN 0 */
    258.  
    259. /* USER CODE END 0 */
    260.  
    261. /**
    262.   * @brief  The application entry point.
    263.   * @retval int
    264.   */
    265. int main(void)
    266. {
    267.   /* USER CODE BEGIN 1 */
    268.  
    269.   /* USER CODE END 1 */
    270.  
    271.   /* MCU Configuration--------------------------------------------------------*/
    272.  
    273.   /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    274.   HAL_Init();
    275.  
    276.   /* USER CODE BEGIN Init */
    277.  
    278.   /* USER CODE END Init */
    279.  
    280.   /* Configure the system clock */
    281.   SystemClock_Config();
    282.  
    283.   /* USER CODE BEGIN SysInit */
    284.  
    285.   /* USER CODE END SysInit */
    286.  
    287.   /* Initialize all configured peripherals */
    288.   MX_GPIO_Init();
    289.   /* USER CODE BEGIN 2 */
    290. 	
    291.    OLED_Init();
    292. 		 
    293. 	//2. 选择一个位置
    294. 	//2.1 确认页寻址模式
    295. 	Oled_Write_Cmd(0x20);
    296. 	Oled_Write_Cmd(0x02);
    297. 	Oled_Screen_Clear();
    298. 	Oled_Show_Image(bmpImager);
    299. 	
    300.   /* USER CODE END 2 */
    301.  
    302.   /* Infinite loop */
    303.   /* USER CODE BEGIN WHILE */
    304.   while (1)
    305.   {
    306.     /* USER CODE END WHILE */
    307.  
    308.     /* USER CODE BEGIN 3 */
    309.   }
    310.   /* USER CODE END 3 */
    311. }

    3.stm32cube配置

    SYS,RCC照旧

    GPIO的配置如下图，PB6,7配置一样

    三、硬件I2C通讯

    1.前提准备

           我们的32单片机是有I2C外设的，而51里面没有I2C外设，因此，我们的32单片机既可以用硬件I2C通讯，也可以模拟I2C通讯。这里我们要实现的是利用32单片机和HAL库重新做一下OLED显示图片，oled的操作说明和图片的操作细节可以再http://t.csdnimg.cn/Bk61c和http://t.csdnimg.cn/A8htshttp://t.csdnimg.cn/Bk61c和 里面看一下。

            我们使用硬件I2C后，可以直接调用直接调用库函数来控制寄存器，让寄存器控制硬件电路的状态从而来控制SDA和SCL的时序。诸如起始终止条件，接受发送字节，应答之类的，我们不用软件I2C那样，自己手动控制SDA和SCL的时序，只需要用库函数即可控制硬件，调制出我们需要的时序。那么既然硬件那么好，为啥还要软件I2C?我玩个梗，加个外设，可以，得加钱。

    2.代码部分（运行出来是女孩头像）

    先说一下我们要用的函数

    HAL_I2C_Mem_Write(I2C_HandleTypeDef *hi2c, uint16_t DevAddress, uint16_t MemAddress, uint16_t MemAddSize, uint8_t *pData, uint16_t Size, uint32_t Timeout)

    它的作用是以阻塞方式将一定数量的数据写入特定的内存地址，下面看看参数

    参数一：I2C_HandleTypeDef *hi2c，选择哪一个I2C通道的地址

    参数二：uint16_t DevAddress，目标器件的地址，七位地址必须左对齐，外加最后一位读写位

    参数三：uint16_t MemAddress，目标器件的目标寄存器地址或者指令控制字

    参数四：uint16_t MemAddSize，目标器件内部寄存器地址数据长度及一个数据有多大，这里可以选择8位或者16位

    参数五：uint8_t *pData，待写的数据首地址

    参数六：uint16_t Size，待写的数据长度

    参数七：uint32_t Timeout，超时时间 返回值：HAL_StatusTypeDef，HAL状态（OK，busy，ERROR，TIMEOUT）

    沿着51单片机显示图片的程序，我们继续修改

    1. #include "main.h"
    2. #include "i2c.h"
    3. #include "gpio.h"
    4.  
    5. /* Private includes ----------------------------------------------------------*/
    6. /* USER CODE BEGIN Includes */
    7.  
    8. /* USER CODE END Includes */
    9.  
    10. /* Private typedef -----------------------------------------------------------*/
    11. /* USER CODE BEGIN PTD */
    12.  
    13. /* USER CODE END PTD */
    14.  
    15. /* Private define ------------------------------------------------------------*/
    16. /* USER CODE BEGIN PD */
    17. /* USER CODE END PD */
    18.  
    19. /* Private macro -------------------------------------------------------------*/
    20. /* USER CODE BEGIN PM */
    21.  
    22. /* USER CODE END PM */
    23.  
    24. /* Private variables ---------------------------------------------------------*/
    25.  
    26. /* USER CODE BEGIN PV */
    27. void Oled_Write_Cmd(uint8_t dataCmd)
    28. {
    29. 	
    30. 	HAL_I2C_Mem_Write(&hi2c1, 0x78, 0x00, I2C_MEMADD_SIZE_8BIT,
    31. 										&dataCmd, 1, 0xff);
    32. }
    33.  
    34. void Oled_Write_Data(uint8_t dataData)
    35. {
    36. 	HAL_I2C_Mem_Write(&hi2c1, 0x78, 0x40, I2C_MEMADD_SIZE_8BIT,
    37. 										&dataData, 1, 0xff);
    38. }
    39.  
    40. void Oled_Init(void){
    41. 	Oled_Write_Cmd(0xAE);//--display off
    42. 	Oled_Write_Cmd(0x00);//---set low column address
    43. 	Oled_Write_Cmd(0x10);//---set high column address
    44. 	Oled_Write_Cmd(0x40);//--set start line address  
    45. 	Oled_Write_Cmd(0xB0);//--set page address
    46. 	Oled_Write_Cmd(0x81); // contract control
    47. 	Oled_Write_Cmd(0xFF);//--128   
    48. 	Oled_Write_Cmd(0xA1);//set segment remap 
    49. 	Oled_Write_Cmd(0xA6);//--normal / reverse
    50. 	Oled_Write_Cmd(0xA8);//--set multiplex ratio(1 to 64)
    51. 	Oled_Write_Cmd(0x3F);//--1/32 duty
    52. 	Oled_Write_Cmd(0xC8);//Com scan direction
    53. 	Oled_Write_Cmd(0xD3);//-set display offset
    54. 	Oled_Write_Cmd(0x00);//
    55. 	
    56. 	Oled_Write_Cmd(0xD5);//set osc division
    57. 	Oled_Write_Cmd(0x80);//
    58. 	
    59. 	Oled_Write_Cmd(0xD8);//set area color mode off
    60. 	Oled_Write_Cmd(0x05);//
    61. 	
    62. 	Oled_Write_Cmd(0xD9);//Set Pre-Charge Period
    63. 	Oled_Write_Cmd(0xF1);//
    64. 	
    65. 	Oled_Write_Cmd(0xDA);//set com pin configuartion
    66. 	Oled_Write_Cmd(0x12);//
    67. 	
    68. 	Oled_Write_Cmd(0xDB);//set Vcomh
    69. 	Oled_Write_Cmd(0x30);//
    70. 	
    71. 	Oled_Write_Cmd(0x8D);//set charge pump enable
    72. 	Oled_Write_Cmd(0x14);//
    73. 	
    74. 	Oled_Write_Cmd(0xAF);//--turn on oled panel		
    75. }
    76.  
    77. void Oled_Screen_Clear(void){
    78. 	char i,n;
    79. 	Oled_Write_Cmd (0x20);                    //set memory addressing mode
    80. 	Oled_Write_Cmd (0x02);                    //page addressing mode
    81.  
    82. 	for(i=0;i<8;i++){
    83. 		Oled_Write_Cmd(0xb0+i);               //éè??ò3μ??·￡¨0~7￡?
    84. 		Oled_Write_Cmd(0x00);                 //éè????ê??????aáDμíμ??·
    85. 		Oled_Write_Cmd(0x10);                 //éè????ê??????aáD??μ??·   
    86. 		for(n=0;n<128;n++)
    87. 		Oled_Write_Data(0x00); 			
    88. 	}	
    89. }
    90.  
    91. unsigned char bmpImager[] = {
    92.  
    93. /*--  调入了一幅图像：D:\无标题.bmp  --*/
    94. /*--  宽度x高度=128x64  --128x8x8*/
    95. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    96. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    97. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    98. 0x00,0x00,0xF0,0x08,0x0C,0x04,0x06,0x06,0x0C,0x04,0x0C,0xFC,0x1C,0x74,0xFC,0xF8,
    99. 0xF0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    100. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    101. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    102. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    103. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    104. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    105. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    106. 0x00,0x00,0x01,0x07,0x04,0x88,0xF8,0x08,0x08,0x0C,0x06,0x01,0x00,0x00,0x01,0x1F,
    107. 0x7F,0xFF,0xDC,0xF8,0xE0,0xC0,0x40,0xC0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    108. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    109. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    110. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    111. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    112. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    113. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xE0,0x10,0x18,0x08,0x0C,
    114. 0x04,0x04,0x06,0x02,0x01,0x01,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x00,
    115. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    116. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    117. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    118. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    119. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    120. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    121. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3F,0x60,0xC0,0x80,0x80,
    122. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3F,0xE0,0x00,0x00,0x00,0x00,
    123. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    124. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    125. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    126. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    127. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    128. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    129. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,
    130. 0x03,0x06,0x1C,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x07,0xFC,0x00,0x00,
    131. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x08,0x88,0xE8,0x38,0x0E,0x09,0x08,
    132. 0x08,0x88,0xE8,0x18,0x08,0x08,0x08,0x00,0x00,0xFF,0x89,0x89,0x89,0xFF,0x00,0xFF,
    133. 0x89,0x89,0x89,0x89,0xFF,0x00,0x00,0x04,0x04,0x84,0x74,0x6F,0xA4,0x24,0x24,0x24,
    134. 0x24,0xA4,0x64,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    135. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    136. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    137. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    138. 0x00,0x80,0xF0,0x1F,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x7F,0x00,0x00,
    139. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10,0x10,0x10,0x08,0x09,0x09,0x06,0x06,
    140. 0x06,0x05,0x08,0x08,0x10,0x10,0x00,0x00,0x0C,0x03,0x10,0x10,0x10,0x1F,0x18,0x07,
    141. 0x00,0x00,0x10,0x10,0x1F,0x00,0x10,0x08,0x06,0x11,0x10,0x08,0x09,0x0A,0x06,0x06,
    142. 0x0B,0x08,0x10,0x10,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    143. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    144. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    145. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xF0,
    146. 0x1E,0x03,0x00,0x00,0xC0,0x60,0x30,0x0C,0x04,0x06,0x02,0x01,0x01,0x00,0x00,0x00,
    147. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    148. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    149. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    150. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    151. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    152. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    153. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x03,
    154. 0x1E,0x60,0x78,0x0F,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    155. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    156. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    157. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    158. 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
    159.  
    160.  
    161. };
    162.  
    163. void Oled_Show_Image(unsigned char *image)
    164. {
    165. 	unsigned char i; 
    166. 	unsigned int j;
    167. 	
    168. 	for(i=0;i<8;i++){
    169. 		Oled_Write_Cmd(0xB0 + i);//page0--page7
    170. 		//每个page从0列
    171. 		Oled_Write_Cmd(0x00);
    172. 		Oled_Write_Cmd(0x10);
    173. 		//0到127列，依次写入0，每写入数据，列地址自动偏移
    174. 		for(j = 128 * i; j<(128 * (i+1));j++){
    175. 			Oled_Write_Data(image[j]);
    176. 		}
    177. 	}
    178. }
    179.  
    180. /* USER CODE END PV */
    181.  
    182. /* Private function prototypes -----------------------------------------------*/
    183. void SystemClock_Config(void);
    184. /* USER CODE BEGIN PFP */
    185.  
    186. /* USER CODE END PFP */
    187.  
    188. /* Private user code ---------------------------------------------------------*/
    189. /* USER CODE BEGIN 0 */
    190.  
    191. /* USER CODE END 0 */
    192.  
    193. /**
    194.   * @brief  The application entry point.
    195.   * @retval int
    196.   */
    197. int main(void)
    198. {
    199.   /* USER CODE BEGIN 1 */
    200.  
    201.   /* USER CODE END 1 */
    202.  
    203.   /* MCU Configuration--------------------------------------------------------*/
    204.  
    205.   /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
    206.   HAL_Init();
    207.  
    208.   /* USER CODE BEGIN Init */
    209.  
    210.   /* USER CODE END Init */
    211.  
    212.   /* Configure the system clock */
    213.   SystemClock_Config();
    214.  
    215.   /* USER CODE BEGIN SysInit */
    216.  
    217.   /* USER CODE END SysInit */
    218.  
    219.   /* Initialize all configured peripherals */
    220.   MX_GPIO_Init();
    221.   MX_I2C1_Init();
    222.   /* USER CODE BEGIN 2 */
    223. 	//1. OLED初始化
    224. 	Oled_Init();
    225. 	//2. 选择一个位置
    226. 	//2.1 确认页寻址模式
    227. 	Oled_Write_Cmd(0x20);
    228. 	Oled_Write_Cmd(0x02);
    229. 	Oled_Screen_Clear();
    230. 	Oled_Show_Image(bmpImager);
    231.   /* USER CODE END 2 */
    232.  
    233.   /* Infinite loop */
    234.   /* USER CODE BEGIN WHILE */
    235.   while (1)
    236.   {
    237.     /* USER CODE END WHILE */
    238.  
    239.     /* USER CODE BEGIN 3 */
    240.   }
    241.   /* USER CODE END 3 */
    242. }

    3.stm32cube的配置

    SYS,RCC照旧不变。I2C1里面如下图选择

    这里要说一点，就是stm32可以作为主机或者从机是用。实验里面，只要stm32产生起始条件，我们把stm32当做主机使用，因此从机模式里面我们压根就没有管，保持他的默认形式就行。

    最后我想说的是，无论是HAL还是标准库，都可以实现我们的需求。标准库写的麻烦，但是可以染你在写程序的时候更多关注于手册的细节，HAL库看似比较简单方便，但是他是高度集成的，里面很多细节不是那么容易看出来的，因为HAL库封装的程度太高了，各取所需吧。

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  • 原文地址：https://blog.csdn.net/weixin_51374594/article/details/134247232