? ? ? ? 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stm32,所以每學習一個模塊都會把程序放進去,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));
下面進行簡單的分析:
? ? ? ?1,很多時候,如果在線調試中發(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,是否重復使用IO口導致異常,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,于是把多的程序全部刪掉就好了。
? ? ? 3,這位樓主STM32 庫I2c 調試成功?。?!也是遇到功能用重復了,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)本人反復折騰發(fā)現(xiàn),引腳在你認為的“空閑”時間表現(xiàn)為低電平的的另一種可能,就是程序寫的有問題,AT24c0x把總線拉低表現(xiàn)為等待主機響應,要想知道是什么原因導致總線電平被拉低,可以重新插從器件供電,并使主器件復位(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)應用函數(shù)庫????????? ?*?實驗平臺: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 ?*?調用??:內部調用 ?*/ static?void?I2C_GPIO_Config(void) { ??GPIO_InitTypeDef??GPIO_InitStructure;? //?使能與?I2C1?有關的時鐘?/ ??//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 ?*?調用??:內部調用 ?*/ 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(EEPROM)初始化 ?*?輸入??:無 ?*?輸出??:無 ?*?調用??:外部調用 ?*/ 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 ?*?調用??:外部調用 ?*/ 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 ?*?調用??:外部調用 ?*/ 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 ?*?調用??:外部調用 ?*/ 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 ?*?調用??:外部調用 ?*/ 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*************************************/