Alternate I2C pins on CC3200 not working.

Hi,

No, setting the Pins 1 and 2 to GPIO also did not solve the problem.

John

Hi,

Try use this:

MAP_PinTypeGPIO(PIN_01, PIN_MODE_0, false);
MAP_GPIODirModeSet(GPIOA1_BASE, 0x4, GPIO_DIR_MODE_OUT);
MAP_PinTypeGPIO(PIN_02, PIN_MODE_0, false);
MAP_GPIODirModeSet(GPIOA1_BASE, 0x8, GPIO_DIR_MODE_OUT);

instead

MAP_PinModeSet(PIN_01,PIN_MODE_0);
MAP_PinModeSet(PIN_02,PIN_MODE_0);

Jan

Hi Jan,

Apology for the late reply.

As suggested by you, we have tested the same configuration on our custom board, but it didnt work. I2C bus faults were still coming.We thought of testing the launchpad once with the same configuration (Pins 3 and 4 configured as SDA & SCL). For this, we have isolated the resistors (R116 & R117) so that switch (SW3) will be completely isolated from the GPIO. Also, we have provided external pull up resistors to these pins which are pulled up to 3.3V.

After verifying the hardware connections of launchpad, we tested the same code and found that I2C is not working and we are getting the same bus faults as earlier.
We measured the I2C lines voltages as well, and both were 3.3V.

We are in big trouble since CC3200 pins 3 and 4 are not working.

Can you please check this at your end by isolating the resistors (R116 and R117) on the launchpad? Let us know your observations.

Also, do you think we have missed out anything in our basic configuration ?

Waiting for your reply.

Thanks
John

Hi,

I think you have something else wrong inside your code. We use I2C at pin 3 and 4 without any issue. In our code we have I2C at 1 MHz. According our observations is I2C peripheral in CC3200 reliable. Only thing which we not able get to work is FIFO buffer for I2C receive. Because it need some testing, we left the FIFO buffers in I2C for later stage.

Did you check the SDA and SCL lines at oscilloscope? Do you see there any activity?

This is my I2C init code. It configure I2C and interrupts for IC:

// Config structure for SW or HW I2C
//
typedef struct {
  // GPIO port for SDA (GPIOA0_BASE, GPIOA1_BASE, GPIOA2_BASE, GPIOA3_BASE)
  unsigned long                    portSDA;
  // pinu number at CC3200 IC for SDA (PIN_02, PIN_04, PIN_06, PIN_17)
  unsigned long                    pinSDA;
  // GPIO mask for SDA
  unsigned char                    maskSDA;
  // GPIO port for SCL (GPIOA0_BASE, GPIOA1_BASE, GPIOA2_BASE, GPIOA3_BASE)
  unsigned long                    portSCL;
  // pinu number at CC3200 IC for SCL (PIN_01, PIN_03, PIN_05, PIN_16)
  unsigned long                    pinSCL;
  // GPIO mask for SCL
  unsigned char                    maskSCL;
  // I2C frequency
  long                             speedI2C;
} I2Ccfg_t;


// Get pinmux mode from pin number
//
static unsigned long I2CgetPinMuxMode(unsigned long pin) {
  switch(pin) {
    // I2C at PIN_01 a PIN_02
    case PIN_01:
    case PIN_02:
      return PIN_MODE_1;
    // I2C at PIN_16 a PIN_17
    case PIN_16:
    case PIN_17:
      return PIN_MODE_9;
  }
  // PIN_03, PIN_04, PIN_05 a PIN_06
  return PIN_MODE_5;
}


// Open I2C hardware
//
void I2COpenHW(I2Ccfg_t *cfg) {

  int i;

  #define I2C_O_MTPR          0x0000000C

  // save config structure
  hwI2Ccfg = cfg;

  // generating pulse at SCL line for "unfreeze" slaves
  MAP_PinTypeGPIO(cfg->pinSCL, PIN_MODE_0, false);
  MAP_GPIODirModeSet(cfg->portSCL, cfg->maskSCL, GPIO_DIR_MODE_OUT);
  MAP_GPIOPinWrite(cfg->portSCL, cfg->maskSCL, 0xFF);
  for (i = 0; i < 2; i++) {
    MAP_UtilsDelay(120);
    MAP_GPIOPinWrite(cfg->portSCL, cfg->maskSCL, 0x00);
    MAP_UtilsDelay(120);
    MAP_GPIOPinWrite(cfg->portSCL, cfg->maskSCL, 0xFF);
  }

  // enable clock for I2C peripheral
  MAP_PRCMPeripheralClkEnable(PRCM_I2CA0, PRCM_RUN_MODE_CLK);
  // switch pinmux for SCL a SDA lines
  MAP_PinTypeI2C(cfg->pinSCL, I2CgetPinMuxMode(cfg->pinSCL));
  MAP_PinTypeI2C(cfg->pinSDA, I2CgetPinMuxMode(cfg->pinSDA));

  // reset
  MAP_PRCMPeripheralReset(PRCM_I2CA0);

  // set frequency
  if (cfg->speedI2C == I2C1MHZ) {
    // 1MHz
    MAP_I2CMasterEnable(I2CA0_BASE);
    HWREG(I2CA0_BASE + I2C_O_MTPR) = 2;
  } else {
    // 100kHz, 400kHz
    MAP_I2CMasterInitExpClk(I2CA0_BASE, 80000000, cfg->speedI2C);
  }
  // clear all interrupts from I2C
  MAP_I2CMasterIntClearEx(I2CA0_BASE, 0xFFF);
  // set irq sources
  MAP_I2CMasterIntEnableEx(I2CA0_BASE, I2C_MASTER_INT_DATA |
                           I2C_MASTER_INT_TIMEOUT);
  // enable I2C master block
  MAP_I2CMasterEnable(I2CA0_BASE);

  // set I2C state byte to idle
  gI2CStateHW = I2C_IDLE_HW;
}

Jan

Hi Jan

Thanks for the reply. My code is working fine on Pins 1 and 2 as well as 5 and 6. I cannot tell if there is a problem with the default driver implementation.As I can understand you have created a custom driver file for yourself.

I will try testing out with this code.

Thanks

Regards

John