#include <xc.h>    //Use this to include the device header for your PIC.
                    //In our case, this will include pic16f690.h.
                    //Do not directly include pic16f690.h to avoid issues if you
                    //change your device later on. Always use <xc.h>.
					
//set the configuration bits: internal OSC, everything off except MCLR
#pragma config FOSC=INTRCIO, WDTE=OFF, PWRTE=OFF, MCLRE=ON, CP=OFF, \
                CPD=OFF, BOREN=OFF, IESO=OFF, FCMEN=OFF

#define _XTAL_FREQ 4000000  //4MHz, which is default
                            //This is used by the compiler to calculate how many
                            //instructions to delay in the calls to __delay_ms().
							
#define LED1        PORTBbits.RB7       //Create meaningful names for our pins
#define LED1_TRIS   TRISBbits.TRISB7
#define LED2        PORTCbits.RC7
#define LED2_TRIS   TRISCbits.TRISC7

void interrupt isr()
{
    //reset the interrupt flag
    INTCONbits.INTF = 0;

    LED2 = ~LED2;   //flip the bit
                    //The ~ (tilde) is the complement operator
}

int main()
{
    TRISA = 0xFF;   //set all digital I/O to inputs
    TRISB = 0xFF;
    TRISC = 0xFF;

    ANSEL = 0x00;   //disable all analog ports
    ANSELH = 0x00;

    LED1_TRIS = 0;      //LED1 is an output
    LED2_TRIS = 0;      //LED2 is an output

    INTCONbits.INTF = 0;        //reset the external interrupt flag
    OPTION_REGbits.INTEDG = 1;  //interrupt on the rising edge
    INTCONbits.INTE = 1;        //enable the external interrupt
    INTCONbits.GIE = 1;         //set the Global Interrupt Enable

    ///////////////////////
    // Main Program Loop //
    ///////////////////////
    while(1)
    {
        LED1 = 1;           //Flash LED1
        __delay_ms(500);
        LED1 = 0;
        __delay_ms(500);
    }

    return 0;
}