I2C communication problems TMS320F28035

Someone can help me please !

Hello Nicolas,

I am not sure this is your case, but I think you may concern too.

In my case when I tried to write I2C EEPROM, I needed to put delay 5ms after writing, if not the EEPROM will not be written (but when I debugged it step by step, it was written properly).

So I looked again the datasheet of the EEPROM and found out that it needed 5ms write cycle time.

I looked the datasheet of your digital pot and i saw that it had many minimum/maximum times that you should be concerned about (for example: Tbuf)

Maybe you can play a little bit about the time and see whether this is the case.

Even if it isn't, I wish you to be able to solve it soon.

Best regards,

Maria

Am trying to read MPU9150 sensors values through I2c by using TMS320F28035piccolo [GPIO28 and GPIO29],my problem is  I don't see the activity on SCL line however. As the pin was initially high, as soon as the code is run, the SCL goes low and stays low. It's not pulsing at all. I'm not seeing SDATA doing any activity either. It stays as it is, high.

So this code is what I come with

//**************I2c initialization

void I2CA_Init(void)
{
I2caRegs.I2CMDR.all = 0x0000;

I2caRegs.I2CSAR = 0x68;

I2caRegs.I2CPSC.all = 6;

I2caRegs.I2CCLKL = 10; 

I2caRegs.I2CCLKH = 5; 

I2caRegs.I2CIER.all = 0x3E; 

I2caRegs.I2CMDR.all = 0x0020; 

I2caRegs.I2CFFTX.all = 0x6000; 

I2caRegs.I2CFFRX.all = 0x2040; 

return;
}

//************WRITE FUNCTION

void writeRegisterWithPiccolo(char reg,char write_data,char stop_bit)
{

while(I2caRegs.I2CMDR.bit.STP == 1) { //// wait until the STP bit is cleared from any previous master communication
}

while (I2caRegs.I2CSTR.bit.BB == 1) { // wait until bus not busy
}

// Setup slave address
I2caRegs.I2CSAR = MPU9150_I2C_ADDR;

// Setup number of bytes to send
I2caRegs.I2CCNT = 2;

// Setup data to send
I2caRegs.I2CDXR = reg; 

I2caRegs.I2CDXR = write_data; 

if(stop_bit == 'y') // if there should be a stop bit at the end of transmission, then

{
while(I2caRegs.I2CMDR.all != 0x6E20){
I2caRegs.I2CMDR.all = 0x6E20; // send start as master transmitter, w/ stop condition once all bytes have been sent
}

while(I2caRegs.I2CSTR.bit.SCD != 1) {} // wait until stop condition is detected

I2caRegs.I2CSTR.bit.SCD = 1; // clear stop condition detected bit in I2C status register

}

else // if there should not be a stop condition at end of transmission (master retains control of bus), then

{
while(I2caRegs.I2CMDR.all != 0x2620){
I2caRegs.I2CMDR.all = 0x2620; // start condition, master mode, TX mode
}

while(I2caRegs.I2CSTR.bit.ARDY != 1) {} // wait for I2C registers to finish working

I2caRegs.I2CSTR.bit.ARDY = 1; // clear ARDY bit in I2C status register
}

}

//***************READ FUNCTION

 unsigned short readRegisterWithPiccolo(unsigned char reg)

{

while(I2caRegs.I2CMDR.bit.STP == 1) { //// wait until the STP bit is cleared from any previous master communication
}

I2caRegs.I2CSAR = MPU9150_I2C_ADDR;

// Check if bus busy
while (I2caRegs.I2CSTR.bit.BB == 1){ // wait until bus not busy
}

I2caRegs.I2CCNT = 1;
I2caRegs.I2CDXR = reg;

while(I2caRegs.I2CMDR.all != 0x2620)
{
I2caRegs.I2CMDR.all = 0x2620; // Send data to setup MEMS address
}
I2caRegs.I2CCNT = 2; // Setup how many bytes to expect

while(I2caRegs.I2CMDR.all != 0x2C20)
{
I2caRegs.I2CMDR.all = 0x2C20; // 0x2C20 --Send restart as master receiver
}

return I2caRegs.I2CDRR;
}

PLEASE help me