ADC INTERFACING WITH PIC12F683

#include "Includes.h"



void InitADC(unsigned char Channel)
{
ANSEL   = 0x10;     // Clear Pin selection bits
ANSEL  = 0x34;   // Select Channel
TRISIO  = 0x40;      // GP3 input, rest all output
TRISIO |= Channel; // Make selected channel pins input
ADCON0 = 0x81; // Turn on the A/D Converter

VRCON  = 0x00;
    GPIO=0x00;     // Shut off the Voltage Reference for Comparator
}



unsigned int GetADCValue(unsigned char Channel)
{
ADCON0 &= 0xf3;      // Clear Channel selection bits

switch(Channel)
{
case AN0: ADCON0 |= 0x00; break;      // Select GP0 pin as ADC input
case AN1: ADCON0 |= 0x04; break;      // Select GP1 pin as ADC input
case AN2: ADCON0 |= 0x08; break;      // Select GP2 pin as ADC input
case AN3: ADCON0 |= 0x0c; break;      // Select GP4 pin as ADC input

default: return 0; //Return error, wrong channel selected
}
   
    __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 ((ADRESH<<8)+ADRESL);   // Return 10 bit ADC value
}

MAIN.C 

#include "Includes.h"

// Config word

__CONFIG(FOSC_INTOSCIO & WDTE_OFF & PWRTE_ON & MCLRE_OFF & BOREN_ON & CP_OFF & CPD_OFF);

#define LED  GP5   //RED LED

#define LED1 GP4    //GREEEN LED 

#define BUZZER GP0     //BUZZER

unsigned int ADC_Value,ADC_Value1;

unsigned int ADC_Total, ADC_Total1,ADC_Total2,ADC_Average,ADC_Average1;

unsigned int flag,count,ADC_Average2;

unsigned int ADCValue1,Lowerlimit,Upperlimit;

// Main function

void main()

{

OSCCON=0x61;

InitADC(AN2);       // Initialize GP2 as ADC input pin CHANNEL 2    

while(1)

{

    LED=0;

    LED1=0;

    count=0;

    ADC_Value = GetADCValue(AN2);   //taken reading for .2mv   to read

    __delay_ms(250);

    count++;

if((ADC_Value>70) &&(ADC_Value<650) && (count==1))   

   {            

 

    __delay_ms(2000);

    ADC_Value = GetADCValue(AN2);               // Initialize GP2 as ADC input pin CHANNEL 2    

ADC_Average1=ADC_Value;                       

 

Upperlimit=ADC_Average1+30;               

Lowerlimit=ADC_Average1-30;                

 

LED=1;                                  //Referance Obtained RED LED && BUZZER ON

  GP0=1; 

__delay_ms(1000); 

GP0=0;              

LED=0;

count++;

}

if(count==2)

{

while(1)

{

    //__delay_ms(2000);

ADCValue1= GetADCValue(AN2);                // GET a first ADC value to make calculation

 

                    

ADC_Average1=ADCValue1;                //STORE In A variable 

if((ADC_Average1>Upperlimit) ||(ADC_Average1<Lowerlimit))       

{

LED=0;

LED1=0;

}

else

{

GP0=1; 

__delay_ms(500); 

GP0=0;

LED=1;

LED1=1;

}

}

}

}

}