? ? ? ? stm32是自帶硬件I2C，相比于軟件模擬I2c，硬件I2c效率更高。但是據(jù)說不穩(wěn)定，這個我倒暫時還沒有體會到。

? ? ? ? 在最開始使用硬件I2c的時候，程序總是卡死，要不從一開始就卡死，要不從某一步開始卡死。我初學(xué)stm32，所以每學(xué)習(xí)一個模塊都會把程序放進(jìn)去，程序相互疊加。但是今天移植別人的硬件I2C卻總是不能成功。一直是卡死在while等待；

? ? ? ?while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));??

? ? ? while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

? ? ? while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

? ? ? while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

下面進(jìn)行簡單的分析：

? ? ? ?1，很多時候，如果在線調(diào)試中發(fā)現(xiàn)從程序的第一個while就卡死，那很可能是配置有問題；比如SDA/SCL是否為開漏，I2C1時鐘，GPIOB時鐘是否開啟，是否重復(fù)使用IO口導(dǎo)致異常，這里有個好方法就是把程序精簡，就是把程序最簡化，然后查錯，糾正錯誤后再加；

? ? ? 2，可以用萬用表看看你的IO口空閑時是不是上拉到高電平，我的程序就是用萬用表測量SDA/SCL空閑不為高，這就有問題了，我查了很長時間沒有引腳用重復(fù)，于是把多的程序全部刪掉就好了。

? ? ? 3，這位樓主STM32 庫I2c 調(diào)試成功?。?！也是遇到功能用重復(fù)了，這里直接把帖子貼出來。

? ? ? 4，有位博主說他的硬件I2C 10K速率時穩(wěn)定，但是我覺得不至于，我用200K讀寫都很正常，如果上訴不能解決，可以調(diào)整下速率看看效果。

之前寫了一個寫單字節(jié)的讀寫程序不能用，沒辦法我移植的是野火的《stm32庫開發(fā)實(shí)戰(zhàn)指南》的硬件I2C讀寫24C02的例程，下面貼上代碼：（加上了少部分注釋）

? ? ? 5, 經(jīng)本人反復(fù)折騰發(fā)現(xiàn)，引腳在你認(rèn)為的“空閑”時間表現(xiàn)為低電平的的另一種可能，就是程序?qū)懙挠袉栴}，AT24c0x把總線拉低表現(xiàn)為等待主機(jī)響應(yīng)，要想知道是什么原因?qū)е驴偩€電平被拉低，可以重新插從器件供電，并使主器件復(fù)位（因為此時的主器件一般處于卡死循環(huán)狀態(tài)），在不觸發(fā)AT24c0x的情況下，測SDA，SCL的電平狀態(tài)，查看是否為高電平，再觸發(fā)讀寫從器件，結(jié)束后測SDA.SCL電平變化！

? ? ? 這個是頭文件：

#ifndef?__I2C_EE_H
#define	__I2C_EE_H

#include/*?EEPROM?Addresses?defines?*/
#define?EEPROM_Block0_ADDRESS?0xA0???/*?E2?=?0?*///AT24C0x的I2C硬件地址
//#define?EEPROM_Block1_ADDRESS?0xA2?/*?E2?=?0?*/
//#define?EEPROM_Block2_ADDRESS?0xA4?/*?E2?=?0?*/
//#define?EEPROM_Block3_ADDRESS?0xA6?/*?E2?=?0?*/

void?I2C_EE_Init(void);
void?I2C_EE_BufferWrite(u8*?pBuffer,?u8?WriteAddr,?u16?NumByteToWrite);
void?I2C_EE_ByteWrite(u8*?pBuffer,?u8?WriteAddr);
void?I2C_EE_PageWrite(u8*?pBuffer,?u8?WriteAddr,?u8?NumByteToWrite);
void?I2C_EE_BufferRead(u8*?pBuffer,?u8?ReadAddr,?u16?NumByteToRead);
void?I2C_EE_WaitEepromStandbyState(void);

#endif?/*?__I2C_EE_H?*/

? ? ?下面是C文件：

/********************************************************************************
?*?文件名??：i2c_ee.c
?*?描述????：i2c?EEPROM(AT24C02)應(yīng)用函數(shù)庫?????????
?*?實(shí)驗平臺：野火STM32開發(fā)板
?*?硬件連接：-----------------
?*??????????|?????????????????|
?*??????????|??PB6-I2C1_SCL	??|
?*??????????|??PB7-I2C1_SDA???|
?*??????????|?????????????????|
?*???????????-----------------
?*?庫版本??：ST3.5.0
?*?作者????：保留?
?*?論壇????：http://www.amobbs.com/forum-1008-1.html
?*?淘寶????：http://firestm32.taobao.com
**********************************************************************************/
#include?"i2c_ee.h"

#define?I2C_Speed??????????????200000
#define?I2C1_OWN_ADDRESS7????0x0A???????????//stm32z自身I2C地址，自己定義的
#define?I2C_PageSize???????????8			/*?AT24C02每頁有8個字節(jié)?*/

u16?EEPROM_ADDRESS;

/*
?*?函數(shù)名：I2C_GPIO_Config
?*?描述??：I2C1?I/O配置
?*?輸入??：無
?*?輸出??：無
?*?調(diào)用??：內(nèi)部調(diào)用
?*/
static?void?I2C_GPIO_Config(void)
{
??GPIO_InitTypeDef??GPIO_InitStructure;?

	//?使能與?I2C1?有關(guān)的時鐘?/
??//RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
??//RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1,ENABLE);??
????
??//?PB6-I2C1_SCL、PB7-I2C1_SDA/
??GPIO_InitStructure.GPIO_Pin?=??GPIO_Pin_6?|?GPIO_Pin_7;
??GPIO_InitStructure.GPIO_Speed?=?GPIO_Speed_50MHz;
??GPIO_InitStructure.GPIO_Mode?=?GPIO_Mode_AF_OD;	???????//?開漏輸出
??GPIO_Init(GPIOB,?&GPIO_InitStructure);
}

/*
?*?函數(shù)名：I2C_Configuration
?*?描述??：I2C?工作模式配置
?*?輸入??：無
?*?輸出??：無
?*?調(diào)用??：內(nèi)部調(diào)用
?*/
static?void?I2C_Mode_Configu(void)
{
??I2C_InitTypeDef??I2C_InitStructure;?

??/*?I2C?配置?*/
??I2C_InitStructure.I2C_Mode?=?I2C_Mode_I2C;
??I2C_InitStructure.I2C_DutyCycle?=?I2C_DutyCycle_2;
??I2C_InitStructure.I2C_OwnAddress1?=I2C1_OWN_ADDRESS7;?
??I2C_InitStructure.I2C_Ack?=?I2C_Ack_Enable?;
??I2C_InitStructure.I2C_AcknowledgedAddress?=?I2C_AcknowledgedAddress_7bit;
??I2C_InitStructure.I2C_ClockSpeed?=?I2C_Speed;
??
??/*?使能?I2C1?*/
??I2C_Cmd(I2C1,?ENABLE);

??/*?I2C1?初始化?*/
??I2C_Init(I2C1,?&I2C_InitStructure);

???
}

/*
?*?函數(shù)名：I2C_EE_Init
?*?描述??：I2C?外設(shè)(EEPROM)初始化
?*?輸入??：無
?*?輸出??：無
?*?調(diào)用??：外部調(diào)用
?*/
void?I2C_EE_Init(void)
{

??I2C_GPIO_Config();?
?
??I2C_Mode_Configu();

/*?根據(jù)頭文件i2c_ee.h中的定義來選擇EEPROM要寫入的地址?*/
#ifdef?EEPROM_Block0_ADDRESS
??/*?選擇?EEPROM?Block0?來寫入?*/
??EEPROM_ADDRESS?=?EEPROM_Block0_ADDRESS;
#endif

#ifdef?EEPROM_Block1_ADDRESS??
	/*?選擇?EEPROM?Block1?來寫入?*/
??EEPROM_ADDRESS?=?EEPROM_Block1_ADDRESS;
#endif

#ifdef?EEPROM_Block2_ADDRESS??
	/*?選擇?EEPROM?Block2?來寫入?*/
??EEPROM_ADDRESS?=?EEPROM_Block2_ADDRESS;
#endif

#ifdef?EEPROM_Block3_ADDRESS??
	/*?選擇?EEPROM?Block3?來寫入?*/
??EEPROM_ADDRESS?=?EEPROM_Block3_ADDRESS;
#endif
}

/*
?*?函數(shù)名：I2C_EE_BufferWrite
?*?描述??：將緩沖區(qū)中的數(shù)據(jù)寫到I2C?EEPROM中
?*?輸入??：-pBuffer?緩沖區(qū)指針
?*?????????-WriteAddr?接收數(shù)據(jù)的EEPROM的地址
?*?????????-NumByteToWrite?要寫入EEPROM的字節(jié)數(shù)
?*?輸出??：無
?*?返回??：無
?*?調(diào)用??：外部調(diào)用
?*/
void?I2C_EE_BufferWrite(u8*?pBuffer,?u8?WriteAddr,?u16?NumByteToWrite)
{
??u8?NumOfPage?=?0,?NumOfSingle?=?0,?Addr?=?0,?count?=?0;

??Addr?=?WriteAddr?%?I2C_PageSize;//通過計算寫入的初始地址是否從頁的開始寫
??count?=?I2C_PageSize?-?Addr;?????//計算寫的第一頁需要寫幾個字節(jié)（寫的首地址不在頁的開始）
??NumOfPage?=??NumByteToWrite?/?I2C_PageSize;//計算需要寫幾個整頁
??NumOfSingle?=?NumByteToWrite?%?I2C_PageSize;//計算寫完整頁后還剩幾個字節(jié)沒有寫
?
??/*?If?WriteAddr?is?I2C_PageSize?aligned??*/
??if(Addr?==?0)?//通寫入的初始地址是從頁的開始寫
??{
????/*?If?NumByteToWrite?<?I2C_PageSize?*/
????if(NumOfPage?==?0)?//如果寫的小于一頁，也就是只寫NumOfSingle個數(shù)據(jù)
????{
??????I2C_EE_PageWrite(pBuffer,?WriteAddr,?NumOfSingle);
??????I2C_EE_WaitEepromStandbyState();
????}
????/*?If?NumByteToWrite?>?I2C_PageSize?*/
????else??//如果寫的大于等于一頁，也就是寫NumOfPage個整頁?????
????{
??????while(NumOfPage--)
??????{
????????I2C_EE_PageWrite(pBuffer,?WriteAddr,?I2C_PageSize);?
????	I2C_EE_WaitEepromStandbyState();
????????WriteAddr?+=??I2C_PageSize;
????????pBuffer?+=?I2C_PageSize;
??????}

??????if(NumOfSingle!=0)?//寫完整頁后剩下的不夠一頁的
??????{
????????I2C_EE_PageWrite(pBuffer,?WriteAddr,?NumOfSingle);
????????I2C_EE_WaitEepromStandbyState();
??????}
????}
??}
??/*?If?WriteAddr?is?not?I2C_PageSize?aligned??*/
??else?//通寫入的初始地址不是從頁的開始寫，這個要比前面的要復(fù)雜很多
??{
????/*?If?NumByteToWrite?<?I2C_PageSize?*/
????if(NumOfPage==?0)?
????{
??????I2C_EE_PageWrite(pBuffer,?WriteAddr,?NumOfSingle);
??????I2C_EE_WaitEepromStandbyState();
????}
????/*?If?NumByteToWrite?>?I2C_PageSize?*/
????else
????{
??????NumByteToWrite?-=?count;
??????NumOfPage?=??NumByteToWrite?/?I2C_PageSize;
??????NumOfSingle?=?NumByteToWrite?%?I2C_PageSize;	
??????
??????if(count?!=?0)?//先把第一頁的幾個數(shù)據(jù)寫進(jìn)去例如我寫的首地址為5，則count=3,則從5寫到7
??????{??
????????I2C_EE_PageWrite(pBuffer,?WriteAddr,?count);
????????I2C_EE_WaitEepromStandbyState();
????????WriteAddr?+=?count;???//寫地址加上count，前面沒有對齊的數(shù)據(jù)寫完，該寫中間對齊的部分
????????pBuffer?+=?count;
??????}?
??????
??????while(NumOfPage--)
??????{
????????I2C_EE_PageWrite(pBuffer,?WriteAddr,?I2C_PageSize);
????????I2C_EE_WaitEepromStandbyState();
????????WriteAddr?+=??I2C_PageSize;
????????pBuffer?+=?I2C_PageSize;??
??????}
??????if(NumOfSingle?!=?0)//最后寫最后幾個沒有對齊的數(shù)據(jù)，不夠一整頁
??????{
????????I2C_EE_PageWrite(pBuffer,?WriteAddr,?NumOfSingle);?
????????I2C_EE_WaitEepromStandbyState();
??????}
????}
??}??
}

/*
?*?函數(shù)名：I2C_EE_ByteWrite
?*?描述??：寫一個字節(jié)到I2C?EEPROM中
?*?輸入??：-pBuffer?緩沖區(qū)指針
?*?????????-WriteAddr?接收數(shù)據(jù)的EEPROM的地址?
?*?輸出??：無
?*?返回??：無
?*?調(diào)用??：外部調(diào)用
?*/
void?I2C_EE_ByteWrite(u8*?pBuffer,?u8?WriteAddr)
{
??/*?Send?STRAT?condition?*/
??I2C_GenerateSTART(I2C1,?ENABLE);

??/*?Test?on?EV5?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_MODE_SELECT));??

??/*?Send?EEPROM?address?for?write?*/
??I2C_Send7bitAddress(I2C1,?EEPROM_ADDRESS,?I2C_Direction_Transmitter);
??
??/*?Test?on?EV6?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
??????
??/*?Send?the?EEPROM's?internal?address?to?write?to?*/
??I2C_SendData(I2C1,?WriteAddr);
??
??/*?Test?on?EV8?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_BYTE_TRANSMITTED));

??/*?Send?the?byte?to?be?written?*/
??I2C_SendData(I2C1,?*pBuffer);?
???
??/*?Test?on?EV8?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_BYTE_TRANSMITTED));
??
??/*?Send?STOP?condition?*/
??I2C_GenerateSTOP(I2C1,?ENABLE);
}

/*
?*?函數(shù)名：I2C_EE_PageWrite
?*?描述??：在EEPROM的一個寫循環(huán)中可以寫多個字節(jié)，但一次寫入的字節(jié)數(shù)
?*?????????不能超過EEPROM頁的大小。AT24C02每頁有8個字節(jié)。
?*?輸入??：-pBuffer?緩沖區(qū)指針
?*?????????-WriteAddr?接收數(shù)據(jù)的EEPROM的地址?
?*?????????-NumByteToWrite?要寫入EEPROM的字節(jié)數(shù)
?*?輸出??：無
?*?返回??：無
?*?調(diào)用??：外部調(diào)用
?*/
void?I2C_EE_PageWrite(u8*?pBuffer,?u8?WriteAddr,?u8?NumByteToWrite)
{
????while(I2C_GetFlagStatus(I2C1,?I2C_FLAG_BUSY));?//?Added?by?Najoua?27/08/2008
????
??/*?Send?START?condition?*/
??I2C_GenerateSTART(I2C1,?ENABLE);
??
??/*?Test?on?EV5?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_MODE_SELECT));?
??
??/*?Send?EEPROM?address?for?write?*/
??I2C_Send7bitAddress(I2C1,?EEPROM_ADDRESS,?I2C_Direction_Transmitter);
??
??/*?Test?on?EV6?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));??

??/*?Send?the?EEPROM's?internal?address?to?write?to?*/????
??I2C_SendData(I2C1,?WriteAddr);??

??/*?Test?on?EV8?and?clear?it?*/
??while(!?I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_BYTE_TRANSMITTED));

??/*?While?there?is?data?to?be?written?*/
??while(NumByteToWrite--)??
??{
????/*?Send?the?current?byte?*/
????I2C_SendData(I2C1,?*pBuffer);?

????/*?Point?to?the?next?byte?to?be?written?*/
????pBuffer++;?
??
????/*?Test?on?EV8?and?clear?it?*/
????while?(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_BYTE_TRANSMITTED));
??}

??/*?Send?STOP?condition?*/
??I2C_GenerateSTOP(I2C1,?ENABLE);
}


/*
?*?函數(shù)名：I2C_EE_BufferRead
?*?描述??：從EEPROM里面讀取一塊數(shù)據(jù)。?
?*?輸入??：-pBuffer?存放從EEPROM讀取的數(shù)據(jù)的緩沖區(qū)指針。
?*?????????-WriteAddr?接收數(shù)據(jù)的EEPROM的地址。?
?*?????????-NumByteToWrite?要從EEPROM讀取的字節(jié)數(shù)。
?*?輸出??：無
?*?返回??：無
?*?調(diào)用??：外部調(diào)用
?*/
void?I2C_EE_BufferRead(u8*?pBuffer,?u8?ReadAddr,?u16?NumByteToRead)
{??
??//*((u8?*)0x4001080c)?|=0x80;?
????while(I2C_GetFlagStatus(I2C1,?I2C_FLAG_BUSY));?//?Added?by?Najoua?27/08/2008
????
????
??/*?Send?START?condition?*/
??I2C_GenerateSTART(I2C1,?ENABLE);
??//*((u8?*)0x4001080c)?&=~0x80;
??
??/*?Test?on?EV5?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_MODE_SELECT));

??/*?Send?EEPROM?address?for?write?*/
??I2C_Send7bitAddress(I2C1,?EEPROM_ADDRESS,?I2C_Direction_Transmitter);

??/*?Test?on?EV6?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
??
??/*?Clear?EV6?by?setting?again?the?PE?bit?*/
??I2C_Cmd(I2C1,?ENABLE);

??/*?Send?the?EEPROM's?internal?address?to?write?to?*/
??I2C_SendData(I2C1,?ReadAddr);??

??/*?Test?on?EV8?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_BYTE_TRANSMITTED));
??
??/*?Send?STRAT?condition?a?second?time?*/??
??I2C_GenerateSTART(I2C1,?ENABLE);
??
??/*?Test?on?EV5?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_MODE_SELECT));
??
??/*?Send?EEPROM?address?for?read?*/
??I2C_Send7bitAddress(I2C1,?EEPROM_ADDRESS,?I2C_Direction_Receiver);
??
??/*?Test?on?EV6?and?clear?it?*/
??while(!I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
??
??/*?While?there?is?data?to?be?read?*/
??while(NumByteToRead)??
??{
????if(NumByteToRead?==?1)
????{
??????/*?Disable?Acknowledgement?*/
??????I2C_AcknowledgeConfig(I2C1,?DISABLE);
??????
??????/*?Send?STOP?Condition?*/
??????I2C_GenerateSTOP(I2C1,?ENABLE);
????}

????/*?Test?on?EV7?and?clear?it?*/
????if(I2C_CheckEvent(I2C1,?I2C_EVENT_MASTER_BYTE_RECEIVED))??
????{??????
??????/*?Read?a?byte?from?the?EEPROM?*/
??????*pBuffer?=?I2C_ReceiveData(I2C1);

??????/*?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);
}


/*
?*?函數(shù)名：I2C_EE_WaitEepromStandbyState
?*?描述??：Wait?for?EEPROM?Standby?state?
?*?輸入??：無
?*?輸出??：無
?*?返回??：無
?*?調(diào)用??：?
?*/
void?I2C_EE_WaitEepromStandbyState(void)??????
{
??vu16?SR1_Tmp?=?0;

??do
??{
????/*?Send?START?condition?*/
????I2C_GenerateSTART(I2C1,?ENABLE);
????/*?Read?I2C1?SR1?register?*/
????SR1_Tmp?=?I2C_ReadRegister(I2C1,?I2C_Register_SR1);
????/*?Send?EEPROM?address?for?write?*/
????I2C_Send7bitAddress(I2C1,?EEPROM_ADDRESS,?I2C_Direction_Transmitter);
??}while(!(I2C_ReadRegister(I2C1,?I2C_Register_SR1)?&?0x0002));
??
??/*?Clear?AF?flag?*/
??I2C_ClearFlag(I2C1,?I2C_FLAG_AF);
????/*?STOP?condition?*/????
????I2C_GenerateSTOP(I2C1,?ENABLE);?
}

/*************************END?OF?FILE*************************************/