PIC12F683 XC8 Digital Input Example

#pragma config FOSC = INTOSCIO // IO function on GP4 & GP5
#pragma config WDTE = OFF // Disable watchdog timer
#pragma config PWRTE = OFF // Disable power-up timer
#pragma config MCLRE = OFF // Disable reset on GP3
#pragma config CP = OFF // Disable code protection
#pragma config CPD = OFF // Disable data code protection
#pragma config BOREN = ON // Enable brown out detection
#pragma config IESO = OFF // Disable oscillator switching
#pragma config FCMEN = ON // Enable fail-safe clock monitor

#define _XTAL_FREQ 4000000 // Define 4Mhz frequency for compiler

#include <xc.h>
#include <stdbool.h>

void init(void) {
    OPTION_REGbits.nGPPU = 0; // Enable internal IO pull-ups
    OPTION_REGbits.T0CS = 0; // Internal instruction cycle clock
    OPTION_REGbits.PSA = 0; // Assign prescaler to internal Timer0 module
    OPTION_REGbits.PS = 0b000; // 1:1 prescaler rate
    OSCCONbits.IRCF = 0b110; // 4MHz internal oscillator
    OSCCONbits.OSTS = 0; // Device is running from internal oscillator
    OSCCONbits.HTS = 1; // HFINTOSC is stable 8MHz to 125kHz
    OSCCONbits.LTS = 0; // LFINTOSC is not stable 31 kHz or below
    OSCCONbits.SCS = 1; // Internal oscillator for system clock
    ANSELbits.ADCS = 0b000; // FOSC/2 AD conversion clock
    ANSELbits.ANS = 0b0000; // Set all AN pins to digital mode
    CMCON0bits.COUT = 0b00; // Set comparator output bits
    CMCON0bits.CINV = 0; // Do not invert output
    CMCON0bits.CIS = 0; // CIS has no effect so we'll just make it zero
    CMCON0bits.CM = 0b000; // Disable comparator output
    CMCON1bits.T1GSS = 0; // Timer1 gate source is comparator output
    CMCON1bits.CMSYNC = 1; // Comparator output synced with falling edge of Timer1 clock
    WDTCONbits.WDTPS = 0; // Watchdog timer period 1:32
    WDTCONbits.SWDTEN = 0; // Disable watchdog timer

    return;
}

int main(void) {
    init(); // Initialize hardware

    TRISIO = 0b00100000; // Only GP5 as input
    GPIO = 0; // All IO low

    while(true) {
        if(GP5 == 0) { // If GP5 is brough low (connected to ground)
            GP0 = 1; // Bring GP0 high and light the LED
        }
        else { // If GP5 is brought high
            GP0 = 0; // Bring GP0 low to turn off the LED
        }
    }

    return 0;
}