8-bit Microcontrollers中的主题 I2C Problems Using CW 10.3 and Processor Expert

I2C Problems Using CW 10.3 and Processor Expert

chinniwhites — Sat, 27 Jul 2013 21:04:55 GMT

Ok, so I am trying to get IIC between MC9S08AW32 and MC9RS08KB4 using processor expert working. My SCL freq match exactly at 125 kHz but my SDA is a bit different (1.8 us on Master and 1.75 us on Slave) and perhaps this is an issue. I am trying to get the 7 analog values from the kb4 to the aw32. The data is coming over but not perfect. I get one or two values that seem to be correct but then I get some zeros OR very large numbers mixing inbetween the good data. I believe errors are happening while transmitting from slave (seems to be tx_buffer_full error) after a few successful transmission. Below is the I2C code related to Master and Slave. Please, if anyone can help me out on this one it would be much appreciated.

MASTER:

//if transmit complete

if (IICTxFlag == 0){

IICTxError = I2C1_SendBlock(&IICTxData, 2, &IICTxRet);

if (IICTxError != ERR_OK){

//handle error

}

while ((!IICTxFlag) && (I2C1_CheckBus() == I2C1_BUSY));

startRx = 1;

}

//start reception of data

if (startRx == 1){

for (IICLoop; IICLoop < 7; IICLoop++){

IICRxError = I2C1_RecvBlock(&IICRxData, 2, &IICRxRet);

if (IICRxError != ERR_OK){

//handle error

}

while((!IICRxFlag) && (I2C1_CheckBus() == I2C1_BUSY));

//if receive complete

adRemChannels[IICLoop] = (IICRxData[0] << 8) | IICRxData[1];

IICRxFlag = 0;

}

if (IICLoop >= 7){

IICLoop = 0;

IICTxFlag = 0;

startRx = 0;

solarV2Counts = adRemChannels[0];

solarV1Counts = adRemChannels[1];

windV3Counts = adRemChannels[2];

windV2Counts = adRemChannels[3];

windV1Counts = adRemChannels[4];

solarAmpsCounts = adRemChannels[5];

windAmpsCounts = adRemChannels[6];

}

SLAVE:

//receive data on full buffer

while (!IICRxFlag);

if ((IICRxFlag == 1) && (startTx == 0)){

IICRxError = I2C1_RecvBlock(&IICRxData, 2, &IICRxRet);

if (IICRxError != ERR_OK){

//handle error

}

while((!IICRxFlag) && (I2C1_CheckBus() == I2C1_BUSY));

//if message command good (MM), send data to master

if ((IICRxData[0] == 0x4D) && (IICRxData[1] == 0x4D)){

IICRxData[0] = 0;

IICRxData[1] = 0;

startTx = 1;

}

if (startTx == 1){

for (loop; loop < 7; loop++){

IICTxData[0] = (unsigned char)(adChannels[loop] >> 8);

IICTxData[1] = (unsigned char)adChannels[loop];

IICTxError = I2C1_SendBlock(&IICTxData, 2, &IICTxRet);

if (IICTxError != ERR_OK){

//handle error

}

while (((IICTxFlag & TX_EMPTY) == 0) && (I2C1_CheckBus() == I2C1_BUSY));

}

if (loop >= 7){

loop = 0;

startTx = 0;

IICRxFlag = 0;

}

Re: I2C Problems Using CW 10.3 and Processor Expert

pavel_sadek — Sun, 28 Jul 2013 09:15:48 GMT

I would clear the loop variable in Slave directly after checking of startTx

for (loop=0;loop<7;loop++) {...

to be sure about data alignment

Pavel

Re: I2C Problems Using CW 10.3 and Processor Expert

chinniwhites — Wed, 31 Jul 2013 16:38:29 GMT

Ok, so I made loop = 0 before entering startTx on slave as you suggested. It helped but comm not totally ironed out. I get all the information coming back from my other micro, but something (error) is causing the info to get out of order (solarCounts will show windampCounts and the like). I am using PE on both master and slave. On slave, i have my input buffer at 2 and output buffer at 3 (per example via help component). On master, the length of buffer arrays are 2. Is this where my problem could be? Am I not making room for the empty character somewhere those causing sporadic transmission buffer full errors that then gets the comm out of order? I am pulling hairs now because code looks correct but functionality is not (very very very close though). Perhaps someone with experience can point me in the right direction.

Thanks

MASTER:

unsigned char IICTxFlag = 0;

unsigned char IICTxError = 0;

unsigned char IICTxData[2];

unsigned int IICTxRet = 0;

unsigned char IICRxFlag = 0;

unsigned char IICRxError = 0;

unsigned char IICRxData[2];

unsigned int IICRxRet = 0;

unsigned char startRx = 0;

unsigned int RxData;

//if transmit complete

if (IICTxFlag == 0){

IICTxError = I2C1_SendBlock(&IICTxData, 2, &IICTxRet);

if (IICTxError != ERR_OK){

//handle error

while (I2C1_CheckBus() == I2C1_BUSY);

IICTxFlag = 0;

}

else{

while ((!IICTxFlag) || (I2C1_CheckBus() == I2C1_BUSY));

IICLoop = 0;

startRx = 1;

}

//start reception of data

if (startRx == 1){

for (IICLoop; IICLoop < 7; IICLoop++){

IICRxError = I2C1_RecvBlock(&IICRxData, 2, &IICRxRet);

//below is needed

if (IICRxError != ERR_OK){

while (I2C1_CheckBus() == I2C1_BUSY);

IICRxFlag = 0;

break;

}

while ((!IICRxFlag) || (I2C1_CheckBus() == I2C1_BUSY));

//if receive complete

adRemChannels[IICLoop] = (IICRxData[0] << 8) | IICRxData[1];

IICRxFlag = 0;

}

if (IICLoop >= 7){

IICLoop = 0;

IICTxFlag = 0;

startRx = 0;

solarV2Counts = adRemChannels[0];

solarV1Counts = adRemChannels[1];

windV3Counts = adRemChannels[2];

windV2Counts = adRemChannels[3];

windV1Counts = adRemChannels[4];

solarAmpsCounts = adRemChannels[5];

windAmpsCounts = adRemChannels[6];

}

SLAVE:

#define	TX_CHAR		1
#define	BUFFER_FREE	2
#define	TX_EMPTY	4

unsigned int adChannels[7] = { 0, 0, 0, 0, 0, 0, 0 };

unsigned char IICTxFlag = 0;

unsigned char IICRxFlag = 0;

unsigned char IICTxError = 0;

unsigned char IICRxError = 0;

unsigned char IICErrorFlag = 0;

unsigned char IICTxData[2];

unsigned char IICRxData[2];

unsigned int IICTxRet = 0;

unsigned int IICRxRet = 0;

unsigned char IICReadFlag = 0;

unsigned char IICWriteFlag = 0;

unsigned char startTx = 0;

unsigned char loop = 0;

void main(void)

{

/* Write your local variable definition here */

/*** Processor Expert internal initialization. DON'T REMOVE THIS CODE!!! ***/

PE_low_level_init();

/*** End of Processor Expert internal initialization.

***/

IICRxData[0] = 0;

IICRxData[1] = 0;

IICTxData[0] = 0;

IICTxData[1] = 0;

/* Write your code here */

(void)AD1_Measure(1);

(void)AD1_GetValue(adChannels);

I2C1_ClearRxBuf();

I2C1_ClearTxBuf();

/* For example: for(;;) { } */

for(;;){

//receive data on full buffer

while (!IICRxFlag);

if ((IICRxFlag == 1) && (startTx == 0)){

IICRxError = I2C1_RecvBlock(&IICRxData, 2, &IICRxRet);
if (IICRxError != ERR_OK){
	//handle error
	while(I2C1_CheckBus() == I2C1_BUSY);
	IICRxFlag = 0;
	(void)I2C1_ClearRxBuf();
	(void)I2C1_ClearTxBuf();
}
else{
	while((!IICRxFlag) \|\| (I2C1_CheckBus() == I2C1_BUSY));

	//if message command good (MM), send data to master
	if ((IICRxData[0] == 0x4D) && (IICRxData[1] == 0x4D)){
		(void)I2C1_ClearRxBuf();
		IICRxData[0] = 0;
		IICRxData[1] = 0;
		startTx = 1;
		loop = 0;
	}
}

}

if (startTx == 1){

for (loop; loop < 7; loop++){
	IICTxData[0] = adChannels[loop] >> 8;
	IICTxData[1] = (unsigned char)(adChannels[loop]);

	IICTxFlag = 0;
	IICTxError = I2C1_SendBlock(&IICTxData, 2, &IICTxRet);
	if (IICTxError != ERR_OK){
		//handle error
		while (I2C1_CheckBus() == I2C1_BUSY);
		(void)I2C1_ClearTxBuf();
		break;
	}
	//while ((IICTxFlag & TX_EMPTY) == 0);
	//while (((IICTxFlag & TX_EMPTY) == 0) \|\| (I2C1_CheckBus() == I2C1_BUSY));
	while (I2C1_CheckBus() == I2C1_BUSY);
}
if (loop >= 7){
	loop = 0;
	startTx = 0;
	IICRxFlag = 0;
}

}

Re: I2C Problems Using CW 10.3 and Processor Expert

chinniwhites — Wed, 31 Jul 2013 16:44:34 GMT

Also, the slave code below never seems to set my IICTxFlag. I followed example on help component and via interrupts, IICTxFlag |= TX_EMPTY, TX_CHAR, and BUFFER_FREE. If I use the commented out code "while ((IICTxFlag & TX_EMPTY) == 0);" after send block command, i never make it past the statement in code as if that flag is never setting. I dont know how this is possible. I altered that specific statement for each state of IICTxFlag and none of them made it past that line of code.

if (startTx == 1){

for (loop; loop < 7; loop++){

IICTxData[0] = adChannels[loop] >> 8;

IICTxData[1] = (unsigned char)(adChannels[loop]);

IICTxFlag = 0;

IICTxError = I2C1_SendBlock(&IICTxData, 2, &IICTxRet);

if (IICTxError != ERR_OK){

//handle error

while (I2C1_CheckBus() == I2C1_BUSY);

(void)I2C1_ClearTxBuf();

break;

}

//while ((IICTxFlag & TX_EMPTY) == 0);

//while (((IICTxFlag & TX_EMPTY) == 0) || (I2C1_CheckBus() == I2C1_BUSY));

while (I2C1_CheckBus() == I2C1_BUSY);

}

if (loop >= 7){

loop = 0;

startTx = 0;

IICRxFlag = 0;

}