CC2650: CC2650 register setting for I2C slave

Hi Hae,

Have you configured the IO pins for I2C operation as well? Could you maybe provide some code snippets on what you are doing or even better, a small example project that I can run?

Thanks for your response,

please refer to following code snippets

for main.c

/*******************************************************************************
 * LOCAL VARIABLES
 */
PIN_Handle i2cPinHandle;
PIN_State  i2cPinState;
/*******************************************************************************
 * GLOBAL VARIABLES
 */
PIN_Config i2cPinTable[] = {
    Board_I2C0_SDA | PIN_INPUT_EN | PIN_PULLUP | PIN_OPENDRAIN,
    Board_I2C0_SCL | PIN_INPUT_EN | PIN_PULLUP | PIN_OPENDRAIN,
    PIN_TERMINATE
};

int main()
{
  /* Register Application callback to trap asserts raised in the Stack */
  RegisterAssertCback(AssertHandler);

  Board_initGeneral();

  PRCMPowerDomainOn(PRCM_DOMAIN_PERIPH);

  Power_setDependency(PowerCC26XX_PERIPH_I2C0);
  // Set Power dependecies & constraints
  Power_setDependency(PowerCC26XX_PERIPH_GPIO);

  /* Set constraints for Standby, powerdown and idle mode */
  Power_setConstraint(PowerCC26XX_SB_DISALLOW);
  Power_setConstraint(PowerCC26XX_IDLE_PD_DISALLOW);

  PRCMLoadSet();
  PRCMPeripheralRunEnable(PRCM_PERIPH_I2C0); // Enable I2C module
  PRCMPeripheralRunEnable(PRCM_PERIPH_GPIO);
  PRCMLoadSet();

  PINCC26XX_setMux(i2cPinHandle, Board_I2C0_SDA, IOC_PORT_MCU_I2C_MSSDA);
  PINCC26XX_setMux(i2cPinHandle, Board_I2C0_SCL, IOC_PORT_MCU_I2C_MSSCL);

#ifndef POWER_SAVING
  /* Set constraints for Standby, powerdown and idle mode */
  Power_setConstraint(PowerCC26XX_SB_DISALLOW);
  Power_setConstraint(PowerCC26XX_IDLE_PD_DISALLOW);
#endif // POWER_SAVING

  /* Initialize ICall module */
  ICall_init();

  /* Start tasks of external images - Priority 5 */
  ICall_createRemoteTasks();

  /* Kick off profile - Priority 3 */
  GAPRole_createTask();

  SimpleBLEPeripheral_createTask();

  i2cPinHandle = PIN_open(&i2cPinState, i2cPinTable);
  if(!i2cPinHandle) {
      System_abort("Error initializing board LED pins\n");
  }

  /* enable interrupts and start SYS/BIOS */
  BIOS_start();

  return 0;
}

add slave init at task init function

  I2CSlaveInit(I2C0_BASE, 0x74); // 7bit address

add I2C receive function at TaskFxn

    // read Slave status register
    if(I2CSlaveStatus(I2C0_BASE) == I2C_SLAVE_ACT_RREQ_FBR)
    {
  	  int i;
  	  uint8_t b_char[4];
  	  uint32_t reg_addr=10;

  	  reg_addr = I2CSlaveDataGet(I2C0_BASE);
  	  for(i=0; i<4; i++)
  	  {
  		  while(I2CSlaveStatus(I2C0_BASE) == I2C_SLAVE_ACT_RREQ);
  		  i2cRecvData[i] = I2CSlaveDataGet(I2C0_BASE);
  		  b_char[i] = (uint8_t)(i2cRecvData[i]&0x000000FF);
  	  }
     }

I think this is all that I have added for I2C slave feature.

if you need anything else, just let me know.

Best Regards,

Hae Ryong

Hi Hae,

Your code seems OK to me, as you use the internal pull-up resistors, have you made sure there is no external pull-ups in play as well? What I2C speed are you running at?

Hi M-W,

I have external pull-ups in F28069 board, CC2650 board is connected via 5 lines cable, since F28069 and CC2650 are in different boards.
cable length is just around 10 cm.
What is the setting for external pull-ups for SCL and SDA ? I'd like to try to change it.

I have tried I2C speed as 400k and 100k, both are same situation.

Best Regards,
Hae Ryong

To disable the internal pull-ups you need to include the I2CCC26XX.c driver file to the project and make changes to the internal PIN setup. Look for I2CCC26XX_initIO, in that function change from "PIN_PULLUP" to "PIN_NOPULL".

Hi M-W,

sorry for late response.

I have tried pin setup as follows

PIN_Config i2cPinTable[] = {
Board_I2C0_SDA | PIN_INPUT_EN | PIN_NOPULL | PIN_OPENDRAIN,
Board_I2C0_SCL | PIN_INPUT_EN | PIN_NOPULL | PIN_OPENDRAIN,
PIN_TERMINATE
};

I got still same waveform as before, seems nothing changed.

however, I'm not sure I am using I2CCC26XX.c, since I cannot find I2CCC26XX_init() called in my files.
I think I am using only i2c.h in C:\ti\tirtos_cc13xx_cc26xx_2_18_00_03\products\cc26xxware_2_23_03_17162\driverlib

what could be the problem ?

Best Regards,
Hae Ryong

HI Hae,

You are completely right, I must have slipped and thought we were talking about the I2C Master driver again. Do you have another device you could use as a master to try with (another launchpad for example)? If you can reproduce it with two launchpads then I can try it out as well.

Hi Hae,

Have you been able to try this out and reproduce it on two launchpads?