polling I2C with another intrrupt

Posted on May 17, 2011 at 13:14

I use I2C2 to comunicate between STM32 and another device that his address is 0x5E .

I take the function that do read and write (in polling) from the examples of the STM32 I2C example5 .

The problem is :

when I enabled interrupts , after few cycles (write and read)of I2C work the I2C is stuck and dont exit from the function and all the firmware is stuck .

when I disabled the interrupts it is work very good .

this is the function :

void I2C_Write(u8* pBuffer, u8 WriteAddr, u8 NumByteToWrite)

{

/* While the bus is busy */

while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY));

/* Send START condition */

I2C_GenerateSTART(I2C2, ENABLE);

/* Test on EV5 and clear it */

while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for write */

I2C_Send7bitAddress(I2C2, 0x5E, I2C_Direction_Transmitter);

/* Test on EV6 and clear it */

while(!I2C_CheckEvent(I2C2,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

/* Send the EEPROM's internal address to write to */

I2C_SendData(I2C2, WriteAddr);

/* Test on EV8 and clear it */

while(! I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

/* While there is data to be written */

while(NumByteToWrite--)

{

/* Send the current byte */

I2C_SendData(I2C2, *pBuffer);

/* Point to the next byte to be written */

pBuffer++;

/* Test on EV8 and clear it */

while (!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

}

/* Send STOP condition */

I2C_GenerateSTOP(I2C2, ENABLE);

}

void I2C_Read(u8* pBuffer, u8 ReadAddr, u16 NumByteToRead)

{

/* While the bus is busy */

while(I2C_GetFlagStatus(I2C2, I2C_FLAG_BUSY));

/* Send START condition */

I2C_GenerateSTART(I2C2, ENABLE);

/* Test on EV5 and clear it */

while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for write */

I2C_Send7bitAddress(I2C2, 0x5E, I2C_Direction_Transmitter);

/* Test on EV6 and clear it */

while(!I2C_CheckEvent(I2C2,I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

/* Clear EV6 by setting again the PE bit */

I2C_Cmd(I2C2, ENABLE);

/* Send the EEPROM's internal address to write to */

I2C_SendData(I2C2, ReadAddr);

/* Test on EV8 and clear it */

while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

/* Send STRAT condition a second time */

I2C_GenerateSTART(I2C2, ENABLE);

/* Test on EV5 and clear it */

while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_MODE_SELECT));

/* Send EEPROM address for read */

I2C_Send7bitAddress(I2C2, 0x5E, I2C_Direction_Receiver);

/* Test on EV6 and clear it */

while(!I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));

/* While there is data to be read */

while(NumByteToRead)

{

if(NumByteToRead == 1)

{

/* Disable Acknowledgement */

I2C_AcknowledgeConfig(I2C2, DISABLE);

/* Send STOP Condition */

I2C_GenerateSTOP(I2C2, ENABLE);

}

/* Test on EV7 and clear it */

if(I2C_CheckEvent(I2C2, I2C_EVENT_MASTER_BYTE_RECEIVED))

{

/* Read a byte from the EEPROM */

*pBuffer = I2C_ReceiveData(I2C2);

/* 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(I2C2, ENABLE);

}

wait to your assistant

Posted on May 17, 2011 at 13:14

There are some well known issues with the STM32 and I2C.

Check out the errata (doc # 14732), section 2.9.1.

Also check out this post:

http://www.st.com/mcu/forums-cat-7652-23.html

- Matt