I2C on CC2650 - SCL issue

Siddharth,

Can you share your I2C driver configuration and Board files for CC2650? The I2C address defined in board.h have to be updated for the SHT30 peripheral address.  Also, the bit-rate from your logic analyzer for CC2650 is set at 100KHz which differs from your Arduino setup.  The TI-RTOS I2C driver supports two bit rate modes: 100kHz and 400kHz. Have you tried the 400kHz mode since the peripheral supports fast mode?

Vikram

Hello Vikram,

The problem isnt solved yet. I tried again with TI RTOS 2.16, please find attached board files and the i2c driver configuration below: 

uint8_t rxBuffer3[6];

   uint8_t txBuffer3[] = {0x24,0x00};

   I2C_Handle      i2cHandle;

   I2C_Params      i2cParams;

   I2C_Transaction i2cTransaction;

   //I2C_Transaction readTransaction;

   /* Create I2C for usage */

   I2C_Params_init(&i2cParams);

   i2cParams.bitRate = I2C_400kHz;

   i2cParams.transferMode = I2C_MODE_BLOCKING;

   i2cParams.transferCallbackFxn = NULL;

   i2cHandle = I2C_open(CC2650_LAUNCHXL_I2C0, &i2cParams);

       if (i2cHandle == NULL) {

           System_abort("Error Initializing I2C\n");

       }

       else {

           System_printf("I2C Initialized!\nValue of handle %d \n", i2cHandle);

           System_flush();

       }

           i2cTransaction.slaveAddress = SHT30_SLAVE_ADDRESS;

           i2cTransaction.writeBuf = txBuffer3;

           i2cTransaction.writeCount = 2;

           i2cTransaction.readBuf = rxBuffer3;

           i2cTransaction.readCount = 6;

           //System_printf("pre \n");

           //System_flush();

    int i = 0;

    for(i = 0 ; i < 20 ; i++) {

    if(I2C_transfer(i2cHandle, &i2cTransaction)){

    System_printf("Success\n");

    System_flush();

    }

    else{

    System_printf("bus fault\n");

    System_flush();}

    }

       Task_sleep(1000000);

I2C_close(i2cHandle);

//end of code

The output shows "bus fault". please also note that same code works for opt3001 by changing device address and tx data. 

0552.CC2650_LAUNCHXL.h

2553.CC2650_LAUNCHXL.c

1805.Board.h

Is your hardware wiring ok? The SHT30 supports switching its address between 0x45 and 0x44 using the ADDR pin. Is that pin always connected to VDD? What about nRESET?

Did you issue any write command prior to the read that you show? When a read is issued, the SHT30 will apparently send NACK if it has no data to send. I know you say that the response is fine with the Arduino library, but maybe there is some other difference in your code?

Also, how did you set up your logic analyzer? I am asking because to me both I2C requests look the same (read from 0x45).

Hi,

I am working with CC2650 to access, by I2C, the MAXIM 30100 HeartRate chip and I had problems to use I2C with sensortag CC2650 too.  The SCL is correct but the function "I2C_transfer()"  it i s not sending all data inside the buffer. Only the first one because the I2C driver is writing a slave address 0x5C always in front my correct ID address data 0xAE. Until now I did not get to access the MAXIM CI.  The function I2C_transfer() is not increasing the buffer automatically and it is not send the slave ID address 0xAE.

My  C code is similar to your. I think that I2C SensorTag driver is prepared to work only with onboard sensors. The 0x5C in front my data stream is blocking my access to MAXIM.

 Did you have success in your test ? 

/********** My code ***********/

bool transferir()

{

  // Store new slave address

  I2C_Transaction i2cTrans;

  I2C_Handle handle;

  I2C_Params params;

  unsigned char i;

  unsigned char buffer1[9];

   buffer1[0] = 0x01;

   buffer1[1] = INTENABLEREG;

   buffer1[2] = 0xF0;

   buffer1[3] = ADDCONF;

   buffer1[4] = (MODEUSED + SP2ENABLE + TEMPENABLE);

   buffer1[5] = SP02_CONF_REG;

   buffer1[6] = (SP02REG + LEDPW_200 + SP02SR_200);

   buffer1[7] = LED_CONF_REG;

   buffer1[8] = (LEDREG + REDPA11_0MA +  IRPA11_0MA);

   I2C_Params_init(&params);

   //params.transferMode = I2C_MODE_CALLBACK;

   params.transferCallbackFxn = writeCallbackDefault;

   params.bitRate = I2C_100kHz;

   handle = I2C_open(CC2650STK_I2C0, &params);

    // Initialize master I2C transaction structure

    i2cTrans.writeCount   = 9;

    i2cTrans.writeBuf     = buffer1;

    i2cTrans.readCount    = 0;

    i2cTrans.readBuf      = rxBuffer;

    i2cTrans.slaveAddress = 0xAE;

************* it is a test ******************

*********** the for() is not necessary if  I2C_transfer() to increase the buffer by itself ********************

       for( i = 0; i < 9; i++)

       {

     // Do I2C transfer (in callback mode)

     if(!I2C_transfer(handle, &i2cTrans))

     {

     PIN_setOutputValue(led1PinHandle, Board_DP2, 1); //Erro

     //return false;

     }else

     PIN_setOutputValue(led1PinHandle, Board_DP3, 1); //Correto

       }

       //System_printf("I2C Initialized!\nValue of handle %d \n", handle);

   I2C_close(handle);

 return true;

}