GPIO interrupt on the CC3200(TI RTOS)

Hi John,

    First thing, I'll recommend looking at the CC3200 Datasheet (look at Table 3-1) to understand the pin-multiplexing. P08 is the package pin number and has it's GPIO pin alias (GPIO17) that is used to configure the pins. In CC3200_LAUNCHXL.h , you'll need to add a new enum type to CC3200_LAUNCHXL_GPIOName for your new pin. In the corresponding CC3200_LAUNCHXL.c file you'll add a new entry for GPIOCC3220_GPIO_17 (P08) to the gpioConfigs array. Since you want P08 to be an interrupt input pin, look at the lines for CC3200_LAUNCHXL_SW2 as examples. Now you can provide your interrupt function as a GPIO callback using the gpioCallbackFunctions array (note the order should match the order of pins in your gpioPinConfig array).

   In Board.h, you can add a define (e.g #define Board_Pin08   CC3200_LAUNCHXL_P08)  for your new pin using the enum type you added in CC3200_LAUNCHXL.h. The Board.h name is what you use in your application.

   I'll recommend reading section 5.5 of the TI-RTOS User Guide to understand better the GPIO driver.

Let me know if this helps.

Moses

Hi Moses,

Thanks for the reply.Actually I have seen the GPIO interrupt example and did the required changes in the project and it works fine.But I want to use HWI API from BIOS.

Any help regarding the code given below.

#include <xdc/std.h>
#include <xdc/cfg/global.h>
#include <xdc/runtime/System.h>

/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>
#include <ti/sysbios/hal/Hwi.h>

/* TI-RTOS Header files */
#include <ti/drivers/GPIO.h>
#include <ti/drivers/ports/HwiP.h>

/* Example/Board Header files */
#include "Board.h"

/* variable to be read by GUI Composer */
int count = 0;

/*
* ======== gpioButtonFxn0 ========
* Callback function for the GPIO interrupt on Board_BUTTON0.
*/
void gpioButtonFxn0(void)
{
/* Clear the GPIO interrupt and toggle an LED */
GPIO_toggle(Board_LED0);

if (count++ == 100) {
count = 0;
}
}

/*
* ======== gpioButtonFxn1 ========
* Callback function for the GPIO interrupt on Board_BUTTON1.
* This may not be used for all boards.
*/
void gpioButtonFxn1(void)
{
/* Clear the GPIO interrupt and toggle an LED */
GPIO_toggle(Board_LED1);

if (count++ == 100) {
count = 0;
}
}

void myIsr (void)
{
GPIO_toggle(Board_LED1);
}
/*
* ======== main ========
*/
int main(void)
{
/* Call board init functions */
Board_initGeneral();
Board_initGPIO();
Board_initUART();

HwiP_Params hwiParams;
HwiP_Handle myHwi;
//Error_Block eb;

/* Turn on user LED */
//GPIO_write(Board_LED0, Board_LED_ON);

System_printf("Starting the GPIO Interrupt example\nSystem provider is set"
" to SysMin. Halt the target to view any SysMin contents in"
" ROV.\n");
/* SysMin will only print to the console when you call flush or exit */
System_flush();

/* install Button callback */
//GPIO_setCallback(Board_BUTTON0, gpioButtonFxn0);

/* Enable interrupts */
//GPIO_enableInt(Board_BUTTON0);

/*
* If more than one input pin is available for your device, interrupts
* will be enabled on Board_BUTTON1.
*/
/* install Button callback */
//GPIO_setCallback(Board_BUTTON1, gpioButtonFxn1);
//GPIO_enableInt(Board_BUTTON1);

/* initialize error block and hwiParams to default values */
//Error_init(&eb);

Hwi_enable();
HwiP_enableInterrupt(17);

HwiP_Params_init(&hwiParams);
hwiParams.arg = 10;
//hwiParams.enableInt = FALSE;
myHwi = HwiP_create(17, (Hwi_FuncPtr)myIsr, &hwiParams);
if (myHwi == NULL) {
System_abort("Hwi create failed");
}
else
{
System_printf("Hwi Object Created\n");
System_flush();
}

/* Start BIOS */
BIOS_start();

return (0);
}

Also the number 17 is for the port GPIOA. But does it read the entire port or a particular pin?

Thanks

Regards

John

Hi John,

       The issues you're having is because of mixing the use of the TI-RTOS GPIO driver (GPIO_xxx APIs) with the Hwi you're manually trying to create. If I breakdown in summary the steps to use an interrupt on a GPIO it'll include: configuring the pins (pin direction, pullups, interrupt trigger, etc) , creating an interrupt and registering an ISR, enabling the GPIO interrupt. The first 2 steps are done by the TI-RTOS GPIO driver when you call Board_initGPIO. Hwis for the input pins in the GPIO_pinConfig array (in CC3220_LAUNCHXL.c) are created automatically. So Board_initGPIO in your code has already created a Hwi for that pin if you added it to gpioPinConfig array and this conflicts with you trying to manually create a Hwi in main.

     If you don't want to use the TI-RTOS  GPIO driver you'll need to do without Board_initGPIO as well. The CC3200SDK driverlib (which the TI-RTOS GPIO driver internally uses) has APIs to configure the pins, then you create your Hwi and register your ISR function and to begin receiving interrupts you enable it with the CC3200SDK GPIOIntEnable API. May I ask what you're trying to achieve here? The TI-RTOS GPIO driver does all these things for you and is easy to use.

Let me know if this helps,

Moses

Hi Moses,

Thanks for the reply.Actually the reason I want to choose the Hwi_xxx API's is because it gives me better control over the parameters of the hardware interrupt.I have used the interrupt API's given by the TI RTOS GPIO driver but I do not see anyways of changing the interrupt priority(I want to make one interrupt higher priority than the other).Or is there a way to get finer control over the interrupts using the TI-RTOS GPIO driver?(This is dynamic creation of the interrupt).

Also I would like to know from where the interrupt number on CC3200 has to be found(for the static creation of hwi).As in the video tutorial for HWI it is mentioned as PIE Vector Table for the CC2000 series. Where is the interrupt number mentioned for the CC3200?I have found this post (  )for the CC3200 and it mentions the interrupt sources based on the ports and not pins?Am I missing something here?

Thanks
Regards
John

Hi John,

  If it's the priority you're trying to control then there is the Hwi_setPriority API that you can use to set the priority of an interrupt by just specifying the interrupt number. You'll have to use the family specific Hwi module to access this API, so use "#include <ti/sysbios/family/m3/Hwi.h>" instead of "#include <ti/sysbios/hal/Hwi.h>". Now you can go back to using the TI-RTOS GPIO driver which automatically creates and manages the Hwi for you and you can call Hwi_setPriority from your application just to adjust the priority. I'd recommend taking a look at the Hwi API reference here.

  To find the interrupt number take a look at Table 2-6 and 2-7 in the Technical Reference Manual for the device. Another place is in the hw_ints.h file in <TI-RTOS_INSTALL_DIR>/products/CC3200_driverlib_1.1.0/inc. Also sorry for misleading you about the port vs pin registering of interrupts. For GPIO interrupts are registered on a per port basis and there's a register in the GPIO peripheral where you can read what particular pin triggered it.

Let me know if this helps.

Moses

Hi Moses,

Thanks for the reply.I have implemented as you have said and everything seems to work fine.

Regards

John