ADC programming on PIC16f886

[anj]

Hi... all..

i am working on my college project and currently i am trying to sample the AC signal(0-12V) 50Hz and then from sampled values i want to calculate RMS value of signal.
my code is:

#include<htc.h>
#include<pic.h>
#include<conio.h>
#include<stdio.h>
#include<math.h>
#include "func.h"

void main()
{	

	int i;
 	long s1[20];

        i=0;
        TRISB = 0;										//Set PORTB to inputs
        TRISC = 0;

ADCON0= 0b10000001;
ADCON1=0b10001000;
init_rs232();
delay_ms(20);
for(i=0;i<20;i=i+2)
{
GO=1;
while(GO==1);
s1[i]=ADRESL;
s1[i+1]=ADRESH;
delay_ms(2);  // 10 samples at 2ms delay so 10*2=20ms i.e. 1 cycle. of 50 hz
}

txdat("adc value:  "); // serial tx of string

for(i=0;i<20;i=i+2)
{

Serial_Hexbyte(s1[i+1]); // hex conversion of samples 
Serial_Hexbyte(s1[i]);
delay_ms(2);
txdat("  ");
}

now after sampling what to do for getting rms value. vref+=12V, vref-=gnd and 10 bit conversion is going on. please help. Regards.