Can not take Analog read in PIC 12F675 - c

Question

In my code I want to read voltage from a battery and if the voltage greater than 3V then it off the LEDs.But the LED always on even when the voltage is 5v and when I add more LED in different GPIO and turn them 0/1 then the GPIO2 become off. I am using PIC12F675.
AN1 is my analog reader pin which is GPIO1.
GPI02 is my LED output pin.
// CONFIG
#pragma config FOSC = INTRCIO // Oscillator Selection bits (INTOSC oscillator: I/O function on GP4/OSC2/CLKOUT pin, I/O function on GP5/OSC1/CLKIN)
#pragma config WDTE = OFF // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF // Power-Up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = ON // MCLR
#pragma config BOREN = OFF // Brown-out Detect Enable bit (BOD disabled)
#pragma config CP = OFF // Code Protection bit (Program Memory code protection is disabled)
#pragma config CPD = OFF // Data Code Protection bit (Data memory code protection is disabled)
// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.
#include <xc.h>
#define _XTAL_FREQ 4000000 // 4MHZ crystal
void main(void) {
unsigned int adcVal;
double voltage;
int i=0;
TRISIObits.TRISIO1 = 1;
TRISIObits.TRISIO2 = 0;
TRISIObits.TRISIO3 = 0;
ANSELbits.ADCS0 = 1;
ANSELbits.ADCS1 = 0;
ANSELbits.ADCS2 = 1; //FOSC/16
ANSELbits.ANS1 = 1; //channel 2
ADCON0bits.CHS0 = 1;
ADCON0bits.CHS1 = 0; //AN1
ADCON0bits.ADON = 1; //Turn it on
ADCON0bits.GO = 1;
ADCON0bits.ADFM = 1;
while (1) {
__delay_us(5);
ADCON0bits.ADON = 1;
GO_nDONE = 1;
while (GO_nDONE); //Wait for ADC to complete
adcVal = (((unsigned int) ADRESH << 8) + ADRESL);
ADCON0bits.ADON = 0;
voltage = ((double) (adcVal / 1023)*5.0);
if (voltage >= 3.0) {
GPIObits.GP2 = 0; //LED off
} else {
GPIObits.GP2 = 1; // LED On/
}
}
}

Answer 1

Your calculation adcVal/1023 is an integer calculation and for a range 0 ... 1023 for adcVal always 0 (or 1 for 1023).
Best thing is to avoid the float calculatin at all:
// CONFIG
#pragma config FOSC = INTRCIO // Oscillator Selection bits (INTOSC oscillator: I/O function on GP4/OSC2/CLKOUT pin, I/O function on GP5/OSC1/CLKIN)
#pragma config WDTE = OFF // Watchdog Timer Enable bit (WDT disabled)
#pragma config PWRTE = OFF // Power-Up Timer Enable bit (PWRT disabled)
#pragma config MCLRE = ON // MCLR
#pragma config BOREN = OFF // Brown-out Detect Enable bit (BOD disabled)
#pragma config CP = OFF // Code Protection bit (Program Memory code protection is disabled)
#pragma config CPD = OFF // Data Code Protection bit (Data memory code protection is disabled)
// #pragma config statements should precede project file includes.
// Use project enums instead of #define for ON and OFF.
#include <xc.h>
#define _XTAL_FREQ 4000000 // 4MHZ crystal
void main(void) {
unsigned int adcVal;
double voltage;
int i=0;
TRISIObits.TRISIO1 = 1;
TRISIObits.TRISIO2 = 0;
TRISIObits.TRISIO3 = 0;
ANSELbits.ADCS0 = 1;
ANSELbits.ADCS1 = 0;
ANSELbits.ADCS2 = 1; //FOSC/16
ANSELbits.ANS1 = 1; //channel 2
ADCON0bits.CHS0 = 1;
ADCON0bits.CHS1 = 0; //AN1
ADCON0bits.ADON = 1; //Turn it on
ADCON0bits.GO = 1;
ADCON0bits.ADFM = 1;
while (1) {
__delay_us(5);
ADCON0bits.ADON = 1;
GO_nDONE = 1;
while (GO_nDONE); //Wait for ADC to complete
adcVal = (((unsigned int) ADRESH << 8) + ADRESL);
ADCON0bits.ADON = 0;
if (adcVal >= 614) { //value for 3.0V
GPIObits.GP2 = 0; //LED off
} else {
GPIObits.GP2 = 1; // LED On/
}
}
}