首先我们看到F1系列单片机引脚的截图，可以看到PB7，PB8可以复用为I2C1接口。PB10，PB11可以复用为I2C2接口。
在后面i2c产生起始位，以及使能的时候，会填入参数：i2cX，这时候要和复用的GPIO口对应的通讯线路一致
从51单片机学习的时候可以知道，I2C接口需要配置上拉电阻。保证通讯，在这里上拉电阻配置在外面，所以说GPIO口复用的时候配置为开漏输出模式。
I2C通讯的软件架构和之前的51单片机也略微有些不同：
总体而言就是增加了官方的固件库：stm32f10x_i2c 用于配置底层的功能寄存器，寄存器进一步管理硬件电路，而实现功能。所以自然i2c总线驱动函数中调用stm32f10x_i2c的库函数是不可少的。
其中着重说一下这个I2C_CheckEvent()函数，在后面的函数中，多次嵌套在while循环中进行判断，这个相当于是51单片机里面，每次发送数据后都要等一个Ack，具体等待的是什么发来的应答就要到库函数里面去看了，基本掌握运用就行。
通过对库函数的重新封装，组合成新的驱动函数，具体可以见下面的.h文件，定义的5个基本函数
（下面的代码注释紊乱是编码的问题，复制到Keil5里选择ANSI编码就没问题了）
#define I2CPORT GPIOB //?¨ò?IO?ó?ú
#define I2C_SCL GPIO_Pin_6 //?¨ò?IO?ó?ú
#define I2C_SDA GPIO_Pin_7 //?¨ò?IO?ó?ú
#define HostAddress 0xc0 //×ü???÷?úμ??÷?tμ??·
#define BusSpeed 200000 //×ü???ù?è￡¨2???óú400000￡?
void I2C_Configuration(void);
void I2C_SAND_BUFFER(u8 SlaveAddr, u8 WriteAddr, u8* pBuffer, u16 NumByteToWrite);
void I2C_SAND_BYTE(u8 SlaveAddr,u8 writeAddr,u8 pBuffer);
void I2C_READ_BUFFER(u8 SlaveAddr,u8 readAddr,u8* pBuffer,u16 NumByteToRead);
u8 I2C_READ_BYTE(u8 SlaveAddr,u8 readAddr);
看到下面的初始化结构体函数中
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;我们定义的是7位地址模式，十位地址定义如下：
#define I2C_AcknowledgedAddress_7bit ((uint16_t)0x4000)
#define I2C_AcknowledgedAddress_10bit ((uint16_t)0xC000)
#include "i2c.h"
void I2C_GPIO_Init(void){ //I2C?ó?ú3?ê??ˉ(?????ó?ú￡??ú??óúvoid I2C_Configuration(void)￡?é?à-μ?×è?úμ￥???úía￡??ùò?ó??′ó??a??ê?3?)
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOC,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE); //???ˉI2C1|?ü
GPIO_InitStructure.GPIO_Pin = I2C_SCL | I2C_SDA; //???????úo?
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD; //????IO?ó?ú1¤×÷·?ê?
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //éè??IO?ó?ú?ù?è￡¨2/10/50MHz￡?
GPIO_Init(I2CPORT, &GPIO_InitStructure);
}
void I2C_Configuration(void){ //I2C3?ê??ˉ
I2C_InitTypeDef I2C_InitStructure;//?¨ò??á11ì?￡???DD3?ê??ˉ
I2C_GPIO_Init(); //?èéè??GPIO?ó?úμ?×′ì?
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;//éè???aI2C?￡ê?
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = HostAddress; //?÷?úμ??·￡¨′ó?ú2?μ?ó?′?μ??·￡?(ò?°??a0xc0?ú.h???tà????¨ò?μ?óD)
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;//?êDíó|′e
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; //7??μ??·?￡ê?
I2C_InitStructure.I2C_ClockSpeed = BusSpeed; //×ü???ù?èéè??
I2C_Init(I2C1,&I2C_InitStructure);
I2C_Cmd(I2C1,ENABLE);//?a??I2C1(?ù?Yòy???′ó?êóí?￡?F1?μáDμ?μ￥???úóD2×éi2c?ó?ú￡??aà?ó?μ?ê?μúò?×é)
}
void I2C_SAND_BUFFER(u8 SlaveAddr,u8 WriteAddr,u8* pBuffer,u16 NumByteToWrite){ //I2C·￠?íêy?Y′?￡¨?÷?tμ??·￡???′??÷￡??ú2?μ??·￡?êyá?￡?
I2C_GenerateSTART(I2C1,ENABLE);//2úéú?eê???
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT)); //??3yEV5
I2C_Send7bitAddress(I2C1,SlaveAddr,I2C_Direction_Transmitter);//·￠?í?÷?tμ??·
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//??3yEV6
I2C_SendData(I2C1,WriteAddr); //?ú2?1|?üμ??·
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED));//ò?????′??÷·???￡?êy?Y??′??÷ò???￡?2úéúEV8￡?·￠?íêy?Yμ?DR?è??3y??ê??t
while(NumByteToWrite--){ //?-?··￠?íêy?Y
I2C_SendData(I2C1,*pBuffer); //·￠?íêy?Y
pBuffer++; //êy?Y????ò???
while (!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED));//??3yEV8
}
I2C_GenerateSTOP(I2C1,ENABLE);//2úéúí￡?1D?o?
}
void I2C_SAND_BYTE(u8 SlaveAddr,u8 writeAddr,u8 pBuffer){ //I2C·￠?íò???×??ú￡¨′óμ??·￡??ú2?μ??·￡??úèY￡?
I2C_GenerateSTART(I2C1,ENABLE); //·￠?í?aê?D?o?
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT)); //μè′yíê3é
I2C_Send7bitAddress(I2C1,SlaveAddr, I2C_Direction_Transmitter); //·￠?í′ó?÷?tμ??·?°×′ì?￡¨D′è?￡?
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED)); //μè′yíê3é
I2C_SendData(I2C1,writeAddr); //·￠?í′ó?÷?t?ú2???′??÷μ??·
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED)); //μè′yíê3é
I2C_SendData(I2C1,pBuffer); //·￠?íòaD′è?μ??úèY
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED)); //μè′yíê3é
I2C_GenerateSTOP(I2C1,ENABLE); //·￠?í?áê?D?o?
}
void I2C_READ_BUFFER(u8 SlaveAddr,u8 readAddr,u8* pBuffer,u16 NumByteToRead){ //I2C?áè?êy?Y′?￡¨?÷?tμ??·￡???′??÷￡?′￠′??÷μ??·￡?×??ú3¤?è￡?
while(I2C_GetFlagStatus(I2C1,I2C_FLAG_BUSY));
I2C_GenerateSTART(I2C1,ENABLE);//?a??D?o?
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT)); //??3y EV5
I2C_Send7bitAddress(I2C1,SlaveAddr, I2C_Direction_Transmitter); //D′è??÷?tμ??·
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));//??3y EV6
I2C_Cmd(I2C1,ENABLE);
I2C_SendData(I2C1,readAddr); //·￠?í?áμ?μ??·
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED)); //??3y EV8
I2C_GenerateSTART(I2C1,ENABLE); //?a??D?o?
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT)); //??3y EV5
I2C_Send7bitAddress(I2C1,SlaveAddr,I2C_Direction_Receiver); //???÷?tμ??·′?3?￡??÷?ú?a?á
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED)); //??3yEV6
while(NumByteToRead){
if(NumByteToRead == 1){ //??ê￡??×?oóò???êy?Yê±??è? if ó???
I2C_AcknowledgeConfig(I2C1,DISABLE); //×?oóóDò???êy?Yê±1?±?ó|′e??
I2C_GenerateSTOP(I2C1,ENABLE); //×?oóò???êy?Yê±ê1?üí￡?1??
}
if(I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_RECEIVED)){ //?áè?êy?Y
*pBuffer = I2C_ReceiveData(I2C1);//μ÷ó??aoˉêy??êy?Yè?3?μ? pBuffer
pBuffer++; //????ò???
NumByteToRead--; //×??úêy?? 1
}
}
I2C_AcknowledgeConfig(I2C1,ENABLE);
}
u8 I2C_READ_BYTE(u8 SlaveAddr,u8 readAddr){ //I2C?áè?ò???×??ú
u8 a;
while(I2C_GetFlagStatus(I2C1,I2C_FLAG_BUSY));//è·?¨i2c×ü????óD????éè±?????
I2C_GenerateSTART(I2C1,ENABLE);//i2c?aê?ì??t
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1,SlaveAddr, I2C_Direction_Transmitter);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
I2C_Cmd(I2C1,ENABLE);//??ó?i2c
I2C_SendData(I2C1,readAddr);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_BYTE_TRANSMITTED));
I2C_GenerateSTART(I2C1,ENABLE);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_MODE_SELECT));
I2C_Send7bitAddress(I2C1,SlaveAddr, I2C_Direction_Receiver);
while(!I2C_CheckEvent(I2C1,I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
I2C_AcknowledgeConfig(I2C1,DISABLE); //×?oóóDò???êy?Yê±1?±?ó|′e??
I2C_GenerateSTOP(I2C1,ENABLE); //×?oóò???êy?Yê±ê1?üí￡?1??
a = I2C_ReceiveData(I2C1);
return a;
}
