Modify main.c

main.c

The main.c file requires a few lines to be uncommented for the interrupt to work properly. To enable the interrupt to work, Global Interrupts and the Peripheral Interrupts need to be enabled. MCC already has the control commands in the default main.c file, they are just commented out with two forward slashes (//). The forward slashes need to be removed to enable these lines of code.

    // Enable the Global Interrupts
    INTERRUPT_GlobalInterruptEnable();

    // Enable the Peripheral Interrupts
    INTERRUPT_PeripheralInterruptEnable();

The main loop does not require any additional code beyond the default while(1) loop. The Interrupt Service Routine (ISR) will handle the changing of the I/O pin.

while (1)
    {
        // Add your application code

    }

tmr0.c

The tmr0.c file contains the ISR that will run when the interrupt occurs. This is where a function to toggle the LED pin is entered. The function used is the D2_LED_Toggle() macro that is created by MCC and placed in the pin_manager.h file. This D2_LED_Toggle() is added to the ISR as shown below.

void TMR0_ISR(void)
{
    // clear the TMR0 interrupt flag
    PIR0bits.TMR0IF = 0;
    if(TMR0_InterruptHandler)
    {
        TMR0_InterruptHandler();
    }

    // add your TMR0 interrupt custom code
    D2_LED_Toggle();
}

In addition to the ISR modification, the tmr0.c file also needs to know where the definitions are for the toggle function. By adding the line #include "mcc.h" to the tmr0.c file, the definitions generated by MCC can be compiled with the tmr0.c file without errors. The #include "mcc.h" is added just after the #include "tmr0.h"

#include <xc.h>
#include "tmr0.h"
#include "mcc.h"