Compiler/EK-TM4C1294XL: Hardware interrupt on SW1 and SW2 on launchpad

Alesh Mahajan

Part Number: EK-TM4C1294XL

Tool/software: TI C/C++ Compiler

Hello,

I have been trying a solution in a thread to get GPIO interrupt working on EK-TM4C1294XL launchpad ( https://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/p/332605/1786938 )

The solution is given for TM4C123 so I have changed the port and pin to match with my board but it doesn't work. I already have a lot going on in my work-space (UARTs/ADC/Web server) so i am adding a few important things to verify:

Clock:

    g_ui32SysClock = SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
    SYSCTL_OSC_MAIN |
    SYSCTL_USE_PLL |
    SYSCTL_CFG_VCO_480), 120000000);
    //
    // Configure the device pins.
    //
    // Configure SysTick for a 100Hz interrupt.

    SysTickPeriodSet(g_ui32SysClock / 100);
    SysTickEnable();
    SysTickIntEnable();

Interrupt configuration:

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOJ);        // Enable port J
    GPIOPinTypeGPIOInput(GPIO_PORTJ_BASE, GPIO_PIN_0);  // Init PJ1 as input
    GPIOPadConfigSet(GPIO_PORTJ_BASE, GPIO_PIN_0,
                     GPIO_STRENGTH_4MA, GPIO_PIN_TYPE_STD_WPU);  // Enable weak pullup resistor for PJ1


    //---------------------------------------------- Interrupt setuü -----------------------------------------
    GPIOIntDisable(GPIO_PORTJ_BASE, GPIO_PIN_0);        // Disable interrupt for PJ1 (in case it was enabled)
    GPIOIntClear(GPIO_PORTJ_BASE, GPIO_PIN_0);      // Clear pending interrupts for PJ1
    GPIOIntRegister(GPIO_PORTJ_BASE, onButtonDown);     // Register our handler function for port J
    GPIOIntTypeSet(GPIO_PORTJ_BASE, GPIO_PIN_0,
        GPIO_FALLING_EDGE);             // Configure PF4 for falling edge trigger
    GPIOIntEnable(GPIO_PORTJ_BASE, GPIO_PIN_0);     // Enable interrupt for PJ1

ISR:

void onButtonDown(void) {
    if (GPIOIntStatus(GPIO_PORTJ_BASE, false) & GPIO_PIN_0) {
        // PF4 was interrupt cause
        UARTprintf("Button Down\n");
//        GPIOIntRegister(GPIO_PORTJ_BASE, onButtonUp);   // Register our handler function for port F
//        GPIOIntTypeSet(GPIO_PORTJ_BASE, GPIO_PIN_0,
//            GPIO_RISING_EDGE);          // Configure PF4 for rising edge trigger
        GPIOIntClear(GPIO_PORTJ_BASE, GPIO_PIN_0);  // Clear interrupt flag
    }
}
void onButtonUp(void) {
    if (GPIOIntStatus(GPIO_PORTJ_BASE, false) & GPIO_PIN_0) {
        // PF4 was interrupt cause
        UARTprintf("Button Up\n");
        GPIOIntRegister(GPIO_PORTJ_BASE, onButtonDown); // Register our handler function for port F
        GPIOIntTypeSet(GPIO_PORTJ_BASE, GPIO_PIN_0,
            GPIO_FALLING_EDGE);         // Configure PF4 for falling edge trigger
        GPIOIntClear(GPIO_PORTJ_BASE, GPIO_PIN_0);  // Clear interrupt flag
    }
}

The Switch on launchpad SW1 and SW2 connected to J0 and J1, here i have tried to configure interrupt only of one button. Please let me know the valid method to initialize the GPIO interrupts and their priority.

over 7 years ago

0 Genatco over 7 years ago

Guru 55663 points

Perhaps clear the INT source first and outside the if test. Would it not seem reasonable SW1 is true if or when the interrupt was being serviced?

0 Ralph Jacobi over 7 years ago

TI__Guru*** 135045 points

Hello Alesh,

Do you have the following enable interrupt calls being used (they don't have to be ROM calls if you aren't using that):

ROM_IntMasterEnable();
ROM_IntEnable(INT_GPIOJ);

Also I would recommend starting a new project focused only on SW1/SW2 interrupts so you don't have anything else going on, and once you have the operation validated that way, you can then import it back into your main project and work on the priority aspect at that time.

0 Alesh Mahajan over 7 years ago in reply to Ralph Jacobi

Prodigy 80 points

Hello Ralph Jacobi,

Thank you for your valuable suggestion.

Ralph Jacobi said:
IntEnable(INT_GPIOJ);

It lead me to to a relevant post which solved the problem.

( e2e.ti.com/.../2323238 )

Although the week pull-up enabled by the line :

GPIOPadConfigSet(GPIO_PORTJ_BASE, GPIO_PIN_0, GPIO_STRENGTH_2MA,GPIO_PIN_TYPE_STD_WPU);

didn't worked out for me(max voltage with week pull up at J0 was 180mV ). I had to add an external pull up to the J0 pin.

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Compiler/EK-TM4C1294XL: Hardware interrupt on SW1 and SW2 on launchpad