Easy Link Issue with I2C

Rick,

we forgot to add a macro for Board_I2C() in Board.h (since we didn't have any I2C examples and prepopulated it with a I2C_config[] structure).

This will be added in the next release, but these code snippets should help you out.

You'll have 3 files to make changes. "Board.h", "EK_TM4C123GXL.h", and "EK_TM4C123GXL.c"

Board.h:

#define Board_I2C  EK_TM4C123GXL_I2C3
#define Board_I2C1 EK_TM4C123GXL_I2C0

EK_TM4C123GXL.h:

/*!
 *  @def    EK_TM4C123GXL_I2CName
 *  @brief  Enum of I2C names on the EK_TM4C123GXL dev board
 */
typedef enum EK_TM4C123GXL_I2CName {
    EK_TM4C123GXL_I2C1 = 0,
    EK_TM4C123GXL_I2C3,

    EK_TM4C123GXL_I2CCOUNT
} EK_TM4C123GXL_I2CName;

EK_TM4C123GXL.c:

#if TI_DRIVERS_I2C_INCLUDED
#include <ti/drivers/I2C.h>
#include <ti/drivers/i2c/I2CTiva.h>

/* I2C objects */
I2CTiva_Object i2cTivaObjects[EK_TM4C123GXL_I2CCOUNT];

/* I2C configuration structure, describing which pins are to be used */
const I2CTiva_HWAttrs i2cTivaHWAttrs[EK_TM4C123GXL_I2CCOUNT] = {
    {I2C1_BASE, INT_I2C1},
    {I2C3_BASE, INT_I2C3},
};

const I2C_Config I2C_config[] = {
    {&I2CTiva_fxnTable, &i2cTivaObjects[0], &i2cTivaHWAttrs[0]},
    {&I2CTiva_fxnTable, &i2cTivaObjects[1], &i2cTivaHWAttrs[1]},
    {NULL, NULL, NULL}
};

/*
 *  ======== LM4F120H5QR_initI2C ========
 */
Void EK_TM4C123GXL_initI2C(Void)
{
    /* I2C1 Init */
    /* Enable the peripheral */
    SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C1);

    /* Configure the appropriate pins to be I2C instead of GPIO. */
    GPIOPinConfigure(GPIO_PA6_I2C1SCL);
    GPIOPinConfigure(GPIO_PA7_I2C1SDA);
    GPIOPinTypeI2CSCL(GPIO_PORTA_BASE, GPIO_PIN_6);
    GPIOPinTypeI2C(GPIO_PORTA_BASE, GPIO_PIN_7);

    /* I2C3 Init */
    /* Enable the peripheral */
    SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C3);

    /* Configure the appropriate pins to be I2C instead of GPIO. */
    GPIOPinConfigure(GPIO_PD0_I2C3SCL);
    GPIOPinConfigure(GPIO_PD1_I2C3SDA);
    GPIOPinTypeI2CSCL(GPIO_PORTD_BASE, GPIO_PIN_0);
    GPIOPinTypeI2C(GPIO_PORTD_BASE, GPIO_PIN_1);

    /*
     * These GPIOs are connected to PD0 and PD1 and need to be brought into a
     * GPIO input state so they don't interfere with I2C communications.
     */
    GPIOPinTypeGPIOInput(GPIO_PORTB_BASE, GPIO_PIN_6);
    GPIOPinTypeGPIOInput(GPIO_PORTB_BASE, GPIO_PIN_7);

    I2C_init();
}
#endif /* TI_DRIVERS_I2C_INCLUDED */

Hey Tom:

Trying this right now.  Thank you for the quick reply.  Will keep you posted.

Thank you.

Rick

I forgot you also need to add in "Board.h":

#define Board_initI2C                EK_TM4C123GXL_initI2C

Hey Tom:

Everything looked great except...  this popped up as soon as Linking started.

undefined             first referenced                                                                                                    

  symbol                   in file                                                                                                         

---------             ----------------                                                                                                    

__TI_decompress_none                                                                                                                      

__TI_decompress_rle24                                                                                                                     

__TI_zero_init                                                                                                                            

_args_main           

I understood the portions of code that you gave me. 

Any thoughts about this?  I was wondering if I should start afresh or if you had further insight.

Again, thank you very much for helping.

Rick

Rick,

it's rather difficult to determine what might be causing this link error.. I'm working if something was inadvertently changes in the linker settings. In your CCS project settings, check if the "Runtime support library" is to "<automatic>".

Also, which version of CCS 5.4 are you using?

Does a stock TI-RTOS example compile for you with the ARM compiler 5.06? We only tested it with version 5.0.4.

Hey Tom,

Thank you for the response.  I decided to start from scratch.  All is well.

I noticed that the Board_initI2C(); line gets flagged with "function declared implicitly" on compile.  The program does Compile and Link.

I did insert this line on Boards.h

#define Board_initI2C EK_TM4C123GXL_initI2C    Any thoughts?

For now, all seems well...  Thank you again for helping.

Rick

Rick,

I knew I forgot something....

That warning will go away once you add the function prototype in EK_TM4C123GXL.h:

extern Void EK_TM4C123GXL_initI2C(Void);

All of these changes will be in the next TI-RTOS release.