STM32---------- I2C

I2C主模式接收（Receiver）过程：  （注意事件为EV7)

          

I2C主模式发送（Transmitter）过程：  （注意事件为EV8)

          

先发一个起始信号S ,再发一个地址，接着等待一个回应A ,然后发数据，再回应（在发完一个S后，要等待一个事件EVENT,比如

while（！I2C_CheckEvent（I2C2,I2C_EVENT_MASTER_MODE_SELECT)    )    I2C_EVENT_MASTER_MODE_SELECT 就是EV5

发送地址   I2C_Send7bitAddress(I2C1, DevAddr, I2C_Direction_Transmitter);//发送器件地址  DevAddr是外部如EEPROM等设备的地址，Transmitter是指STM32要从外部设备读取数据，因为外部数据要发送（Transmitter）

发完地址要等一个EV6的事件while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)

I2C在STM32中使用的步骤如下：

        1、开启时钟，APB2 的GPIOB 和APB1的I2C2

        2、设置GPIOB的10和11引脚，注意要设置为复用开漏输出GPIO_MODE_AF_OD

        3、I2C 的配置（Mode 设置为I2C_Mode_I2C   DutyCycle是一种快速模式）

            

                 使能和初始化I2C模块

           4、完整例程

/* Includes ------------------------------------------------------------------*/#include "stm32f10x_lib.h"#include "i2c_ee.h"#include"delay.h"/* Private typedef -----------------------------------------------------------*//* Private define ------------------------------------------------------------*/#define I2C_Speed              10000#define I2C1_SLAVE_ADDRESS7    0xA0#define I2C_PageSize           4/* Private macro -------------------------------------------------------------*//* Private variables ---------------------------------------------------------*/u16 EEPROM_ADDRESS;/* Private function prototypes -----------------------------------------------*/void I2C_Configuration(void);/******************************************************************************** Function Name : I2C_Configuration* Description    : I2C Configuration* Input          : None* Output         : None* Return         : None*******************************************************************************/void I2C_Configuration(void){GPIO_InitTypeDef GPIO_InitStructure; I2C_InitTypeDef I2C_InitStructure;/* Configure I2C1 pins: SCL and SDA */GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;//开漏输出GPIO_Init(GPIOB, &GPIO_InitStructure);/* I2C configuration */I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;//设置 I2C为 I2C模式I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;//I2C快速模式 Tlow / Thigh = 2    I2C_InitStructure.I2C_OwnAddress1 = I2C1_SLAVE_ADDRESS7;//设置第一个设备地址I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;//使能应答I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;//应答 7位地址I2C_InitStructure.I2C_ClockSpeed = I2C_Speed;//设置时钟频率/* I2C Peripheral Enable */I2C_Cmd(I2C1, ENABLE);//使能I2C外设/* Apply I2C configuration after enabling it */I2C_Init(I2C1, &I2C_InitStructure);}/******************************************************************************** Function Name : I2C_EE_Init* Description    : Initializes peripherals used by the I2C EEPROM driver.* Input          : None* Output         : None* Return         : None*******************************************************************************/void I2C_EE_Init(){/* I2C configuration */I2C_Configuration();/* depending on the EEPROM Address selected in the i2c_ee.h file */#ifdef EEPROM_Block0_ADDRESS/* Select the EEPROM Block0 to write on */EEPROM_ADDRESS = EEPROM_Block0_ADDRESS;#endif#ifdef EEPROM_Block1_ADDRESS/* Select the EEPROM Block1 to write on */EEPROM_ADDRESS = EEPROM_Block1_ADDRESS;#endif#ifdef EEPROM_Block2_ADDRESS/* Select the EEPROM Block2 to write on */EEPROM_ADDRESS = EEPROM_Block2_ADDRESS;#endif#ifdef EEPROM_Block3_ADDRESS/* Select the EEPROM Block3 to write on */EEPROM_ADDRESS = EEPROM_Block3_ADDRESS;#endif}/******************************************************************************** Function Name : I2C_EE_BufferWrite* Description    : Writes buffer of data to the I2C EEPROM.* Input          : - pBuffer : pointer to the buffer containing the data to be *                    written to the EEPROM.*                  - WriteAddr : EEPROM's internal address to write to.*                  - NumByteToWrite : number of bytes to write to the EEPROM.* Output         : None* Return         : NonepBuffer：指向要写入数据数组的指针WriteAddr：24c02中要写入数据的首地址NumByteToWrite：写入的字节数*******************************************************************************/void I2C_EE_BufferWrite(u8* pBuffer, u8 WriteAddr, u16 NumByteToWrite)//将缓冲器的数据写入EEPROM{u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0;Addr = WriteAddr % I2C_PageSize;//写入地址是每页的第几位count = I2C_PageSize - Addr;//在开始的一页要写入的个数NumOfPage = NumByteToWrite / I2C_PageSize;//要写入的页数NumOfSingle = NumByteToWrite % I2C_PageSize;//不足一页的个数I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态/* If WriteAddr is I2C_PageSize aligned */if(Addr == 0) //写入地址是页的开始{    /* If NumByteToWrite < I2C_PageSize */    if(NumOfPage == 0) //数据小于一页    {      I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);//写少于一页的数据      I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态    }    /* If NumByteToWrite > I2C_PageSize */    else //数据大于等于一页    {      while(NumOfPage--)//要写入的页数      {        I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize); //写一页的数据    I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态        WriteAddr += I2C_PageSize;        pBuffer += I2C_PageSize;      }      if(NumOfSingle!=0)//剩余数据小于一页      {        I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);//写少于一页的数据        I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态      }    }}/* If WriteAddr is not I2C_PageSize aligned */else //写入地址不是页的开始{    /* If NumByteToWrite < I2C_PageSize */    if(NumOfPage== 0) //数据小于一页    {      I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);//写少于一页的数据      I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态    }    /* If NumByteToWrite > I2C_PageSize */    else//数据大于等于一页    {      NumByteToWrite -= count;      NumOfPage = NumByteToWrite / I2C_PageSize; //重新计算要写入的页数      NumOfSingle = NumByteToWrite % I2C_PageSize;//重新计算不足一页的个数            if(count != 0)//在此处count一定不为0，此判断条件好象有点多余      {         I2C_EE_PageWrite(pBuffer, WriteAddr, count);//将开始的空间写满一页        I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态        WriteAddr += count;        pBuffer += count;      }             while(NumOfPage--)//要写入的页数      {        I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize);//写一页的数据        I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态        WriteAddr += I2C_PageSize;        pBuffer += I2C_PageSize;       }      if(NumOfSingle != 0)//剩余数据小于一页      {        I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle); //写少于一页的数据        I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态      }    }}}/******************************************************************************** Function Name : I2C_EE_ByteWrite* Description    : Writes one byte to the I2C EEPROM.* Input          : - pBuffer : pointer to the buffer containing the data to be *                    written to the EEPROM.*                  - WriteAddr : EEPROM's internal address to write to.* Output         : None* Return         : NonepBuffer：指向要写入数据数组的指针WriteAddr：24c02中要写入数据的首地址*******************************************************************************/void I2C_EE_ByteWrite(u8* pBuffer, u8 WriteAddr)//写一个字节到EEPROM{/* Send STRAT condition */I2C_GenerateSTART(I2C1, ENABLE);//产生 I2Cx传输 START条件/* Test on EV5 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)); //检查最近一次 I2C事件是否是输入的事件/* Send EEPROM address for write */I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//向指定的从 I2C设备传送地址字,选择发送方向/* Test on EV6 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//检查最近一次 I2C事件是否是输入的事件      /* Send the EEPROM's internal address to write to */I2C_SendData(I2C1, WriteAddr);//通过外设 I2Cx发送地址/* Test on EV8 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//检查最近一次 I2C事件是否是输入的事件/* Send the byte to be written */I2C_SendData(I2C1, *pBuffer); //通过外设 I2Cx发送数据   /* Test on EV8 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//检查最近一次 I2C事件是否是输入的事件/* Send STOP condition */I2C_GenerateSTOP(I2C1, ENABLE);//产生 I2Cx传输 STOP条件}/******************************************************************************** Function Name : I2C_EE_PageWrite* Description    : Writes more than one byte to the EEPROM with a single WRITE*                  cycle. The number of byte can't exceed the EEPROM page size.* Input          : - pBuffer : pointer to the buffer containing the data to be *                    written to the EEPROM.*                  - WriteAddr : EEPROM's internal address to write to.*                  - NumByteToWrite : number of bytes to write to the EEPROM.* Output         : None* Return         : NonepBuffer：指向要写入数据数组的指针WriteAddr：24c02中要写入数据的首地址NumByteToWrite：写入的字节数*******************************************************************************/void I2C_EE_PageWrite(u8* pBuffer, u8 WriteAddr, u8 NumByteToWrite)//写少于一页的数据{/* Send START condition */I2C_GenerateSTART(I2C1, ENABLE);//产生 I2Cx传输 START条件/* Test on EV5 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT)); //检查最近一次 I2C事件是否是输入的事件/* Send EEPROM address for write */I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//向指定的从 I2C设备传送地址字,选择发送方向/* Test on EV6 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); //检查最近一次 I2C事件是否是输入的事件/* Send the EEPROM's internal address to write to */    I2C_SendData(I2C1, WriteAddr); //通过外设 I2Cx发送地址/* Test on EV8 and clear it */while(! I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED)); //检查最近一次 I2C事件是否是输入的事件/* While there is data to be written */while(NumByteToWrite--) {    /* Send the current byte */    I2C_SendData(I2C1, *pBuffer); //通过外设 I2Cx发送数据    /* Point to the next byte to be written */    pBuffer++;     /* Test on EV8 and clear it */    while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//检查最近一次 I2C事件是否是输入的事件}/* Send STOP condition */I2C_GenerateSTOP(I2C1, ENABLE);//产生 I2Cx传输 STOP条件}/******************************************************************************** Function Name : I2C_EE_BufferRead* Description    : Reads a block of data from the EEPROM.* Input          : - pBuffer : pointer to the buffer that receives the data read *                    from the EEPROM.*                  - ReadAddr : EEPROM's internal address to read from.*                  - NumByteToRead : number of bytes to read from the EEPROM.* Output         : None* Return         : NonepBuffer：指向要保存读出数据的数组的指针ReadAddr：24c02中要读出数据的首地址NumByteToRead：读出的字节数*******************************************************************************/void I2C_EE_BufferRead(u8* pBuffer, u8 ReadAddr, u16 NumByteToRead)//将EEPROM的数据读入缓冲器{ I2C_EE_WaitEepromStandbyState();//EEPROM设为待命状态/* Send START condition */I2C_GenerateSTART(I2C1, ENABLE);//产生 I2Cx传输 START条件/* Test on EV5 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));//检查最近一次 I2C事件是否是输入的事件/* In the case of a single data transfer disable ACK before reading the data */if(NumByteToRead==1) {    I2C_AcknowledgeConfig(I2C1, DISABLE);//使能或者失能指定 I2C的应答功能}/* Send EEPROM address for write */I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//向指定的从 I2C设备传送地址字,选择发送方向/* Test on EV6 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//检查最近一次 I2C事件是否是输入的事件/* Clear EV6 by setting again the PE bit */I2C_Cmd(I2C1, ENABLE);//使能或者失能 I2C外设/* Send the EEPROM's internal address to write to */I2C_SendData(I2C1, ReadAddr); //通过外设 I2Cx发送地址/* Test on EV8 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));//检查最近一次 I2C事件是否是输入的事件/* Send STRAT condition a second time */ I2C_GenerateSTART(I2C1, ENABLE);//产生 I2Cx传输 START条件/* Test on EV5 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));//检查最近一次 I2C事件是否是输入的事件/* Send EEPROM address for read */I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Receiver);//向指定的从 I2C设备传送地址字,选择接收方向/* Test on EV6 and clear it */while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));//检查最近一次 I2C事件是否是输入的事件/* While there is data to be read */while(NumByteToRead) {    /* Test on EV7 and clear it */    if(I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED)) //检查最近一次 I2C事件是否是输入的事件    {      if(NumByteToRead == 2)      {        /* Disable Acknowledgement */        I2C_AcknowledgeConfig(I2C1, DISABLE);//使能或者失能指定 I2C的应答功能      }      if(NumByteToRead == 1)      {        /* Send STOP Condition */        I2C_GenerateSTOP(I2C1, ENABLE);//产生 I2Cx传输 STOP条件      }            /* Read a byte from the EEPROM */      *pBuffer = I2C_ReceiveData(I2C1);//返回通过 I2Cx最近接收的数据      /* Point to the next location where the byte read will be saved */      pBuffer++;             /* Decrement the read bytes counter */      NumByteToRead--;        }   }/* Enable Acknowledgement to be ready for another reception */I2C_AcknowledgeConfig(I2C1, ENABLE);//使能或者失能指定 I2C的应答功能}/******************************************************************************** Function Name : I2C_EE_WaitEepromStandbyState* Description    : Wait for EEPROM Standby state* Input          : None* Output         : None* Return         : None*******************************************************************************/void I2C_EE_WaitEepromStandbyState(void) //EEPROM设为待命状态     {vu16 SR1_Tmp = 0;do{    /* Send START condition */    I2C_GenerateSTART(I2C1, ENABLE);//产生 I2Cx传输 START条件    /* Read I2C1 SR1 register */    SR1_Tmp = I2C_ReadRegister(I2C1, I2C_Register_SR1);//读取指定的 I2C寄存器 I2C_SR1 并返回其值    /* Send EEPROM address for write */    I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);//向指定的从 I2C设备传送地址字 ,选择发送方向}while(!(I2C_ReadRegister(I2C1, I2C_Register_SR1) & 0x0002));//地址发送结束/* Clear AF flag */I2C_ClearFlag(I2C1, I2C_FLAG_AF);//清除 I2Cx的应答错误标志位}