Declaring GPIO Pins?

Daniel Dichek

I am new to TI-RTOS and CCS and am having a hard time trying to do something quite simple: Read or write binary values to an arbitrary GPIO pin. The board I am working with is the MSP-EXP432P401R

My main question is: What is the "right" way to add a GPIO pin to a task in TI-RTOS?

I read the TI-RTOS manual entry for the GPIO driver and I understand that the GPIO pins and ports need to be configured in MSP_EXP432P401R.c and .h. I am not sure where each of the parameters come from in the GPIO_PinConfig gpioPinConfigs[] definition, or which other definitions I need to be sure to complete and how.

Could someone help me in the right direction by giving an example for how I would set up a pin/port (say, P2.7) as an input/output with TI-RTOS?

Thank you!

over 9 years ago

0 Daniel Dichek over 9 years ago

Prodigy 40 points

Update: I think I've almost got this working but I have tripped one of the asserts in GPIOMSP432.c.

Specifically, this is the error I got:
[CORTEX_M4_0] xdc.runtime.Main: "gpio/GPIOMSP432.c", line 497: assertion failure
xdc.runtime.Error.raise: terminating execution

Here's line 497 (the assertion that failed):
DebugP_assert(initCalled && index < GPIOMSP432_config.numberOfPinConfigs);

So something must be wrong with the way I added the target pin to gpioPinConfigs[] in the board configuration .c file and to "typedef enum MSP_EXP432P401R_GPIOName" in the board configuration header file.

Here is my code, for reference. I am trying to assign P1_6 as a GPIO output:

*~*~*~*~*~*~* in the .c file:
GPIO_PinConfig gpioPinConfigs[] = {
/* Input pins */

GPIOMSP432_P1_4 | GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_RISING,

/* Output pins */
/* MSP_EXP432P401R_LED1 */
GPIOMSP432_P1_0 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,
/* MSP_EXP432P401R_LED_RED */
GPIOMSP432_P2_0 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,

// MSP_EXP432P401R_DIR_LEFT -->Direction Pin for Left motor
GPIOMSP432_P1_6 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,

/*
* MSP_EXP432P401R_LED_GREEN & MSP_EXP432P401R_LED_BLUE are used for
* PWM examples. Uncomment the following lines if you would like to control
* the LEDs with the GPIO driver.
*/
/* MSP_EXP432P401R_LED_GREEN */
//GPIOMSP432_P2_1 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,
/* MSP_EXP432P401R_LED_BLUE */
//GPIOMSP432_P2_2 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW
};

*~*~*~*~*in the header file:

typedef enum MSP_EXP432P401R_GPIOName {
MSP_EXP432P401R_S1 = 0,
MSP_EXP432P401R_S2,
MSP_EXP432P401R_LED1,
MSP_EXP432P401R_LED_RED,
MSP_EXP432P401R_DIR_LEFT,

/*
* MSP_EXP432P401R_LED_GREEN & MSP_EXP432P401R_LED_BLUE are used for
* PWM examples. Uncomment the following lines if you would like to control
* the LEDs with the GPIO driver.
*/
//MSP_EXP432P401R_LED_GREEN,
//MSP_EXP432P401R_LED_BLUE,

MSP_EXP432P401R_GPIOCOUNT
} MSP_EXP432P401R_GPIOName;

0 Michel Solecki over 9 years ago in reply to Daniel Dichek

Mastermind 8415 points

Hi Daniel,

I believe you might be missing the first entry of your pin configuration array.

{
/* Input pins */
/* MSP_EXP432P401R_S1 */


// >>>>>>>>> MISSING THE FIRST ENTRY <<<<<<<<<<<<<//
GPIOMSP432_P1_1 | GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_RISING,
//>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<//


/* MSP_EXP432P401R_S2 */
GPIOMSP432_P1_4 | GPIO_CFG_IN_PU | GPIO_CFG_IN_INT_RISING,

/* Output pins */
/* MSP_EXP432P401R_LED1 */
GPIOMSP432_P1_0 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,
/* MSP_EXP432P401R_LED_RED */
GPIOMSP432_P2_0 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW,

// Your extra gpio here

// MSP_EXP432P401R_DIR_LEFT -->Direction Pin for Left motor
GPIOMSP432_P1_6 | GPIO_CFG_OUT_STD | GPIO_CFG_OUT_STR_HIGH | GPIO_CFG_OUT_LOW

};

You GPIOName table counts up to 5 entries, but you only had 4 because of the first one missing.

Regards,

Michel

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