Cubmax IIC协议 OLED

一、背景

        IIC（Inter-Integrated Circuit）其实是IICBus简称，所以中文应该叫集成电路总线，它是一种串行通信总线，使用多主从架构，由飞利浦公司在1980年代为了让主版、嵌入式系统或手机以连接低速周边设备而发展。I²C的正确读法为“I平方C”（"I-squared-C"），而“I二C”（"I-two-C"）则是另一种错误但被广泛使用的读法。自2006年10月1日起，使用I²C协议已经不需要支付专利付费，但制造商仍然需要付费以获取I²C从属设备地址。

       随着大规模集成电路技术的发展，把CPU和一个单独工作系统所必需的ROM.RAM等外围电路集成在一个单片内而制成的单片机或微孔愈来愈方便。目前，世界上许多公司生产单片机，品种很多。其中包括各种字长的CPU，各种容量的ROM、RAM以及功能各异的I/O接口电路等等，但是，单片机的品种规格仍然有限，所以只能选用某种单片机来进行扩展。扩展的方法有两种：一种是并行总线，另一种是串行总线。由于串行总线的连线少，结构简单，往往不用专门的母板和插座而直接用导线连接各个设备。因此，采用串行线可大大简化系统的硬件设计。PHILIPS公司早在十几年前就推出了I2C串行总线，利用该总线可实现多主机系统所需的裁决和高低速设备同步等功能。因此，这是一种高性能的串行总线。

二、IIC物理层

2.1

      IIC主要为低俗设备通信发明，用于CPU和被控IC之间，IC与IC之间进行双向传送，所以速率比不上SPI，IIC总线的传输速率在标准模式下可达100kbit/s;快速模式下可达400kbit/s;高速模式下可达3.4Mbit/s，

要注意SDA和SCL在初始的时候都是高电平。

   IIC只有两个总线：一条是双向的串行数据线SDA：D也就是传输数据的DATA，一条是串行时钟线SCK，C也就是时钟的Clock，控制数据发送的时钟。

地址问题：

所有接到I2C总线设备上的串行数据SDA都接到总线的SDA上，各设备的时钟线SCL接到总线的SCL上。I2C总线上的每个设备都自己一个唯一的地址，来确保不同设备之间访问的准确性。

注意IIC是半双工，不是全双工。

2.2IIC的高阻态

漏极开路（Open Drain）即高阻状态，适用于输入/输出，其可独立输入/输出低电平和高阻状态，若需要产生高电平，则需使用外部上拉电阻

高阻状态：高阻状态是三态门电路的一种状态。逻辑门的输出除有高、低电平两种状态外，还有第三种状态——高阻状态的门电路。电路分析时高阻态可做开路理解。

我们知道IIC的所有设备是接在一根总线上的，那么我们进行通信的时候往往只是几个设备进行通信，那么这时候其余的空闲设备可能会受到总线干扰，或者干扰到总线，怎么办呢？

为了避免总线信号的混乱，IIC的空闲状态只能有外部上拉， 而此时空闲设备被拉到了高阻态，也就是相当于断路， 整个IIC总线只有开启了的设备才会正常进行通信，而不会干扰到其他设备。

2.3 主机和从机概念

    主机就是负责整个系统的任务协调与分配，从机一般是通过接收主机的指令从而完成某些特定的任务，主机和从机之间通过总线连接，进行数据通讯。

主机：发布主要命令的称为

从机：接受命令的称为 

三、协议层

3.1基础知识

可以分为三类：起始信号、应答信号、结束信号

1.开始信号：

    SDA由高电平变为低电平后，延时(>4.7us)，SCL变为低电平开始传送数据。

2.应答信号：

每当主机向从机发送完一个字节的数据，主机总是需要等待从机给出一个应答信号，以确认从机是否成功接收到了数据，技术数据的IC在接收到8bit数据后，向发送数据的IC发送特定的低电平，表示接收到数据。CPU向单元发送一个信号后，等待受控的单元发出应答信号，收到应答信号之后，根据实际的情况，判断是否继续传递信号的判断，如果没有收到应答信号，就说明发送数据的单元出现故障。

应答信号：主机SCL拉高，读取从机SDA的电平，为低电平表示产生应答

应答信号为低电平时，规定为有效应答位（ACK，简称应答位），表示接收器已经成功地接收了该字节；
应答信号为高电平时，规定为非应答位（NACK），一般表示接收器接收该字节没有成功。

**每发送一个字节（8个bit）**在一个字节传输的8个时钟后的第九个时钟期间，接收器接收数据后必须回一个ACK应答信号给发送器，这样才能进行数据传输。

应答出现在每一次主机完成8个数据位传输后紧跟着的时钟周期，低电平0表示应答，1表示非应答，

3.结束信号

  SCL为高电平，SDA向低电平跳转为高电平，结束传输数据

3.2数据传输

3.2.1发送

数据传送格式：

由于时钟线在高电平的时候，会是开始或者停止的状态，所以是在SCL为低电平的时候，将会进行数据的传输。

四、软件IIC和硬件IIC

软件IIC：软件IIC通信指的是用单片机的两个I/O端口模拟出来的IIC，用软件控制管脚状态以模拟I2C通信波形，软件模拟寄存器的工作方式。

硬件IIC：一块硬件电路，硬件I2C对应芯片上的I2C外设，有相应I2C驱动电路，其所使用的I2C管脚也是专用的，硬件（固件）I2C是直接调用内部寄存器进行配置。

硬件I2C的效率要远高于软件的，而软件I2C由于不受管脚限制，接口比较灵活。
 

五、根据OLED，写入指令数据

六、OLED显示一个点

oled的内存管理模式

oled显示一个点有三种方式，

1 页地址模式

2.水平地址模式

3.垂直地址模式

七、Cubmax代码

7.1 硬件IIC

iic.c

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    i2c.c
  * @brief   This file provides code for the configuration
  *          of the I2C instances.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "i2c.h"

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

I2C_HandleTypeDef hi2c1;

/* I2C1 init function */
void MX_I2C1_Init(void)
{

  /* USER CODE BEGIN I2C1_Init 0 */

  /* USER CODE END I2C1_Init 0 */

  /* USER CODE BEGIN I2C1_Init 1 */

  /* USER CODE END I2C1_Init 1 */
  hi2c1.Instance = I2C1;
  hi2c1.Init.ClockSpeed = 100000;
  hi2c1.Init.DutyCycle = I2C_DUTYCYCLE_2;
  hi2c1.Init.OwnAddress1 = 0;
  hi2c1.Init.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
  hi2c1.Init.DualAddressMode = I2C_DUALADDRESS_DISABLE;
  hi2c1.Init.OwnAddress2 = 0;
  hi2c1.Init.GeneralCallMode = I2C_GENERALCALL_DISABLE;
  hi2c1.Init.NoStretchMode = I2C_NOSTRETCH_DISABLE;
  if (HAL_I2C_Init(&hi2c1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN I2C1_Init 2 */

  /* USER CODE END I2C1_Init 2 */

}

void HAL_I2C_MspInit(I2C_HandleTypeDef* i2cHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(i2cHandle->Instance==I2C1)
  {
  /* USER CODE BEGIN I2C1_MspInit 0 */

  /* USER CODE END I2C1_MspInit 0 */

    __HAL_RCC_GPIOB_CLK_ENABLE();
    /**I2C1 GPIO Configuration
    PB6     ------> I2C1_SCL
    PB7     ------> I2C1_SDA
    */
    GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* I2C1 clock enable */
    __HAL_RCC_I2C1_CLK_ENABLE();
  /* USER CODE BEGIN I2C1_MspInit 1 */

  /* USER CODE END I2C1_MspInit 1 */
  }
}

void HAL_I2C_MspDeInit(I2C_HandleTypeDef* i2cHandle)
{

  if(i2cHandle->Instance==I2C1)
  {
  /* USER CODE BEGIN I2C1_MspDeInit 0 */

  /* USER CODE END I2C1_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_I2C1_CLK_DISABLE();

    /**I2C1 GPIO Configuration
    PB6     ------> I2C1_SCL
    PB7     ------> I2C1_SDA
    */
    HAL_GPIO_DeInit(GPIOB, GPIO_PIN_6);

    HAL_GPIO_DeInit(GPIOB, GPIO_PIN_7);

  /* USER CODE BEGIN I2C1_MspDeInit 1 */

  /* USER CODE END I2C1_MspDeInit 1 */
  }
}

/* USER CODE BEGIN 1 */
void Oled_Write_Cmd(uint8_t dataCmd)
{
	HAL_I2C_Mem_Write(&hi2c1, 0x78, 0x00, I2C_MEMADD_SIZE_8BIT,&dataCmd, 1, 0xff);
} 

void Oled_Write_Data(uint8_t dataData)
{
	HAL_I2C_Mem_Write(&hi2c1, 0x78, 0x40, I2C_MEMADD_SIZE_8BIT,&dataData, 1, 0xff);
}
/* USER CODE END 1 */
void Oled_Init(void)
{
		Oled_Write_Cmd(0xAE);//--display off
		Oled_Write_Cmd(0x00);//---set low column address
		Oled_Write_Cmd(0x10);//---set high column address
		Oled_Write_Cmd(0x40);//--set start line address
		Oled_Write_Cmd(0xB0);//--set page address
		Oled_Write_Cmd(0x81); // contract control
		Oled_Write_Cmd(0xFF);//--128
		Oled_Write_Cmd(0xA1);//set segment remap
		Oled_Write_Cmd(0xA6);//--normal / reverse
		Oled_Write_Cmd(0xA8);//--set multiplex ratio(1 to 64)
		Oled_Write_Cmd(0x3F);//--1/32 duty
		Oled_Write_Cmd(0xC8);//Com scan direction
		Oled_Write_Cmd(0xD3);//-set display offset
		Oled_Write_Cmd(0x00);//
		Oled_Write_Cmd(0xD5);//set osc division
		Oled_Write_Cmd(0x80);//
		Oled_Write_Cmd(0xD8);//set area color mode off
		Oled_Write_Cmd(0x05);//
		Oled_Write_Cmd(0xD9);//Set Pre-Charge Period
		Oled_Write_Cmd(0xF1);//
		Oled_Write_Cmd(0xDA);//set com pin configuartion
		Oled_Write_Cmd(0x12);//
		Oled_Write_Cmd(0xDB);//set Vcomh
		Oled_Write_Cmd(0x30);//
		Oled_Write_Cmd(0x8D);//set charge pump enable
		Oled_Write_Cmd(0x14);//
		Oled_Write_Cmd(0xAF);//--turn on oled panel
}

void Oled_Screen_Clear(void)
	{
	int i,n;
	Oled_Write_Cmd (0x20); //set memory addressing mode
	Oled_Write_Cmd (0x02); //page addressing mode
	for(i=0;i<8;i++){
		Oled_Write_Cmd(0xb0+i); //éè??ò3μ??·￡¨0~7￡?
		Oled_Write_Cmd(0x00); //éè????ê??????aáDμíμ??·
		Oled_Write_Cmd(0x10); //éè????ê??????aáD??μ??·
	for(n=0;n<128;n++)
		Oled_Write_Data(0x00);
	}
}

void Oled_Show_Image(unsigned char *image)
{
	unsigned char i;
	unsigned int j;
	for(i=0;i<8;i++)
	{
		Oled_Write_Cmd(0xB0 + i);//page0--page7
		//每个page从0列
		Oled_Write_Cmd(0x00);
		Oled_Write_Cmd(0x10);
		//0到127列，依次写入0，每写入数据，列地址自动偏移
		for(j = 128 * i; j<(128 * (i+1));j++){
			Oled_Write_Data(image[j]);
			}
	}
}

iic.h

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    i2c.h
  * @brief   This file contains all the function prototypes for
  *          the i2c.c file
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __I2C_H__
#define __I2C_H__

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

extern I2C_HandleTypeDef hi2c1;

/* USER CODE BEGIN Private defines */

/* USER CODE END Private defines */

void MX_I2C1_Init(void);

/* USER CODE BEGIN Prototypes */
void Oled_Init(void);
void Oled_Screen_Clear(void);
void Oled_Write_Data(uint8_t dataData);
void Oled_Write_Cmd(uint8_t dataCmd);
void Oled_Show_Image(unsigned char *image);
/* USER CODE END Prototypes */

#ifdef __cplusplus
}
#endif

#endif /* __I2C_H__ */

main.c

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "i2c.h"
#include "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */
unsigned char bmpImager[] = {
	/*-- 调入了一幅图像：D:\无标题.bmp --*/
	/*-- 宽度x高度=128x64 --128x8x8*/
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0xF0,0x08,0x0C,0x04,0x06,0x06,0x0C,0x04,0x0C,0xFC,0x1C,0x74,0xFC,0xF8,
	0xF0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x01,0x07,0x04,0x88,0xF8,0x08,0x08,0x0C,0x06,0x01,0x00,0x00,0x01,0x1F,
	0x7F,0xFF,0xDC,0xF8,0xE0,0xC0,0x40,0xC0,0x80,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xE0,0x10,0x18,0x08,0x0C,
	0x04,0x04,0x06,0x02,0x01,0x01,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3F,0x60,0xC0,0x80,0x80,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3F,0xE0,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x03,0x06,0x1C,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x07,0xFC,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x08,0x88,0xE8,0x38,0x0E,0x09,0x08,
	0x08,0x88,0xE8,0x18,0x08,0x08,0x08,0x00,0x00,0xFF,0x89,0x89,0x89,0xFF,0x00,0xFF,
	0x89,0x89,0x89,0x89,0xFF,0x00,0x00,0x04,0x04,0x84,0x74,0x6F,0xA4,0x24,0x24,0x24,
	0x24,0xA4,0x64,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x80,0xF0,0x1F,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x7F,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x10,0x10,0x10,0x08,0x09,0x09,0x06,0x06,
	0x06,0x05,0x08,0x08,0x10,0x10,0x00,0x00,0x0C,0x03,0x10,0x10,0x10,0x1F,0x18,0x07,
	0x00,0x00,0x10,0x10,0x1F,0x00,0x10,0x08,0x06,0x11,0x10,0x08,0x09,0x0A,0x06,0x06,
	0x0B,0x08,0x10,0x10,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xF0,
	0x1E,0x03,0x00,0x00,0xC0,0x60,0x30,0x0C,0x04,0x06,0x02,0x01,0x01,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x03,
	0x1E,0x60,0x78,0x0F,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
	0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
};
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_I2C1_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */
	MX_I2C1_Init();
	/* USER CODE BEGIN 2 */
	//1. OLED初始化
	Oled_Init();
	//2. 选择一个位置
	//2.1 确认页寻址模式
	Oled_Write_Cmd(0x20);
	Oled_Write_Cmd(0x02);
	Oled_Screen_Clear();
	Oled_Show_Image(bmpImager);
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  while (1)
  {
  }
  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

面试问题：

1、IIC的应答时序描述一下

2、IIC最多可挂在多少设备

127个

3、IIC在OLED上的显示速率

4、IIC的速率

普通100kbits,高速400kbits,