xc8 - 16F887A - MPX2 CC - 74HC595

#include <xc.h>
#include <stdio.h>
#include <stdlib.h>

#define _XTAL_FREQ 1000000

#pragma config FOSC = XT // Oscillator Selection bits (HS oscillator)
#pragma config WDTE = OFF // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF // Power-up Timer Enable bit (PWRT disabled)
#pragma config BOREN = OFF // Brown-out Reset Enable bit (BOR disabled)
#pragma config LVP = OFF // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)
#pragma config CPD = OFF // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off)
#pragma config WRT = OFF // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control)
#pragma config CP = OFF // Flash Program Memory Code Protection bit (Code protection off)

unsigned int volume, value, f, ADCvalue, voltage;
int i, x;
int mask;

const unsigned char DIGIT[10] = {0X3F,0X06,0X5B,0X4F,0X66,0X6D,0X7D,0X07,0X7F,0X6F};

void ADCinit(void){
    ADCS2= ADCS1= 0; ADCS0= 1; //Set Fosc/8
    ADFM= 1; //right justified
    CHS2= CHS1= CHS0= 0; // Choose AN0
    PCFG3= PCFG2= PCFG1= 1; PCFG0= 0;
}

unsigned int atod(void){
    ADON= 1; //A to D on
    GO= 1;
    __delay_ms(1);
    while (GO);
    return (int) ADRESH* 256 + ADRESL; // Dich 8 bit
}

 shift_out(){
     int numero;
    value= DIGIT[numero];
    mask= 1;
    RC3= 0; //Set ST_CP= 0 , open latch
    RC0= 0; // Set SH_CP=0 , enable to write to shift register

    for(i=0; i< 7; i++){
        if (value & mask)
         RC1= 1; //DS= 1;
      else
         RC1=0; //DS= 0;

    RC0= 1;
    __delay_us(5);
    RC0= 0; // Next bit
    __delay_us (5);

    mask = mask << 1;
    }
    RC3= 1; // Shift out to Qn gate
    __delay_us(125);

}

void main (){
    TRISA= 0xff;
    TRISC= 0x00;
    ADCinit ();
    unsigned int ones,tens=0;
while(1)
{
__delay_ms(1);
ADCvalue = atod();
voltage = ADCvalue *5000 /1023;
f = voltage / 10 - 273;
ones= f%10;
tens= (f/10)%10;

shift_out();
PORTC = DIGIT[tens];
__delay_us(50);
PORTC = DIGIT [ones];
__delay_us(50);
}
}