ADC in PIC 16F1503

#include <xc.h>                                                                                    // edit MCB data at 3 places
// Config word
//__CONFIG(FOSC_INTRCIO & WDTE_OFF & PWRTE_ON & MCLRE_OFF & BOREN_ON & CP_OFF & CPD_OFF);

// Define CPU Frequency
// This must be defined, if __delay_ms() or
// __delay_us() functions are used in the code
#define _XTAL_FREQ   4000000  

#define AN1  1
#define AN2  2
#define AN3  3
#define AN7  7

#pragma config FOSC = INTOSC    // Oscillator Selection Bits (INTOSC oscillator: I/O function on CLKIN pin)
#pragma config WDTE = OFF        // Watchdog Timer Enable (WDT enabled)
#pragma config PWRTE = OFF      // Power-up Timer Enable (PWRT disabled)
#pragma config MCLRE = OFF       // MCLR Pin Function Select (MCLR/VPP pin function is MCLR)
#pragma config CP = OFF         // Flash Program Memory Code Protection (Program memory code protection is disabled)
#pragma config BOREN = ON       // Brown-out Reset Enable (Brown-out Reset enabled)
#pragma config CLKOUTEN = ON    // Clock Out Enable (CLKOUT function is enabled on the CLKOUT pin)

// CONFIG2
#pragma config WRT = OFF        // Flash Memory Self-Write Protection (Write protection off)
#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable (Stack Overflow or Underflow will cause a Reset)
#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (Vbor), low trip point selected.)
#pragma config LPBOR = OFF      // Low-Power Brown Out Reset (Low-Power BOR is disabled)
#pragma config LVP = ON 


int ADC_Val;


unsigned int GetADCValue(unsigned char Channel)
{
    ADCON0 |= Channel<<2;      // Clear Channel selection bits

    if(Channel > AN7) return 0;
   
    __delay_ms(10);      // Time for Acqusition capacitor to charge up and show correct value
    GO_nDONE  = 1;         // Enable Go/Done
    while(GO_nDONE);     //wait for conversion completion
    return (int)(ADRESH<<8)+ ADRESL ;   // Return 10 bit ADC value
}

void InitADC(unsigned char Channel)
{
    ANSELA   = 0x00;
    ANSELC   = 0x00;        // Clear Pin selection bits
    if(Channel < 4)    
        ANSELA  |= Channel;       // Select Channel
    else
        ANSELC  |= Channel;


    ADCON1 = 0b11110000;  
    ADCON0 = 0x01;         // Turn on the A/D Converter
    CM1CON0  = 0x07;         // Shut off the Comparator, so that pins are available for ADC
    FVRCON  = 0x00;         // Shut off the Voltage Reference for Comparator
}

void main() {
    OPTION_REGbits.nWPUEN = 1;
    //APFCON=0x20;
    //ANSELA = 0x08;
    //ANSELC=0X04;
    //ADCON0 = 0x08;
    TRISCbits.TRISC3 = 1;
    TRISAbits.TRISA0  = 0;
    RA0=0;
    InitADC(AN7);
   
    while(1)
    {
        ADC_Val = GetADCValue(AN7);
        if(ADC_Val<500)
        {
            RA0=0;
        }
        else
        {
            RA0=1;
        }
    }
}

// PIC16F1503
// Config word
//__CONFIG(FOSC_INTRCIO & WDTE_OFF & PWRTE_ON & MCLRE_OFF & BOREN_ON & CP_OFF & CPD_OFF);
// these should be before any '#include'
#pragma config FOSC = INTOSC    // Oscillator Selection Bits (INTOSC oscillator: I/O function on CLKIN pin)
#pragma config WDTE = OFF        // Watchdog Timer Enable (WDT enabled)
#pragma config PWRTE = ON       // Power-up Timer Enable (PWRT enabled)
#pragma config MCLRE = OFF       // MCLR Pin Function Select (MCLR/VPP pin function is MCLR)
#pragma config CP = OFF         // Flash Program Memory Code Protection (Program memory code protection is disabled)
#pragma config BOREN = ON       // Brown-out Reset Enable (Brown-out Reset enabled)
#pragma config CLKOUTEN = OFF   // Clock Out Enable (CLKOUT function is disabled CLKOUT pin)

// CONFIG2
#pragma config WRT = OFF        // Flash Memory Self-Write Protection (Write protection off)
#pragma config STVREN = ON      // Stack Overflow/Underflow Reset Enable (Stack Overflow or Underflow will cause a Reset)
#pragma config BORV = LO        // Brown-out Reset Voltage Selection (Brown-out Reset Voltage (Vbor), low trip point selected.)
#pragma config LPBOR = OFF      // Low-Power Brown Out Reset (Low-Power BOR is disabled)
#pragma config LVP = ON

#include <xc.h>                                                                                    // edit MCB data at 3 places

// Define CPU Frequency
// This must be defined, if __delay_ms() or
// __delay_us() functions are used in the code
#define _XTAL_FREQ   4000000

#define AN0  0
#define AN1  1
#define AN2  2
#define AN3  3      // RA4
#define AN4  4
#define AN5  5
#define AN6  6
#define AN7  7      // RC3

unsigned int GetADCValue(unsigned char Channel)
{
    if (Channel > AN7) return 0;

    ADCON0 = (ADCON0 & 0x03) | (Channel<<2);   // select channel

    __delay_ms(1);                  // Time for Acqusition capacitor to charge up and show correct value
    GO_nDONE  = 1;                  // Enable Go/Done
    while(GO_nDONE);                // wait for conversion completion
    return (ADRESH<<8) | ADRESL;    // Return 10 bit ADC value (uses unsigned int operation)
}

void InitADC(unsigned char Channel)
{
    // all pins default to analog mode with TRISx = 1, so this isn't
    // required, but...
    switch (Channel) {
        case AN0: ANSELAbits.ANSA0 = 1; TRISAbits.TRISA0 = 1; break;    // RA0
        case AN1: ANSELAbits.ANSA1 = 1; TRISAbits.TRISA1 = 1; break;    // RA1
        case AN2: ANSELAbits.ANSA2 = 1; TRISAbits.TRISA2 = 1; break;    // RA2
        case AN3: ANSELAbits.ANSA4 = 1; TRISAbits.TRISA4 = 1; break;    // RA4
        case AN4: ANSELCbits.ANSC0 = 1; TRISCbits.TRISC0 = 1; break;    // RC0
        case AN5: ANSELCbits.ANSC1 = 1; TRISCbits.TRISC1 = 1; break;    // RC1
        case AN6: ANSELCbits.ANSC2 = 1; TRISCbits.TRISC2 = 1; break;    // RC2
        case AN7: ANSELCbits.ANSC3 = 1; TRISCbits.TRISC3 = 1; break;    // RC3
    }

    ADCON1 = 0b11110000;    // right-justified, FRC clock, VREF=VDD
    ADCON0 = 0x01;          // Turn on the A/D Converter
    // these are not needed... comparator off by default
    // CM1CON0  = 0x07;         // NOT CORRECT FOR 16F1503
    // FVRCON  = 0x00;         // Shut off the Voltage Reference for Comparator
}

void main() {
    unsigned int ADC_Val;

    OPTION_REGbits.nWPUEN = 1;
    //APFCON=0x20;
    TRISAbits.TRISA0  = 0;
    RA0=0;
    InitADC(AN7);

    while(1)
    {
        ADC_Val = GetADCValue(AN7);
        if(ADC_Val<500)
        {
            RA0=0;
        }
        else
        {
            RA0=1;
        }
    }
}