[PIC] AC Voltage measurement by using ADC

#define DC_Offset1 2042 	
#define DC_Offset2 2042		//for Analog Pin 
#define DC_Offset3 2042		//For analog pin 

#define OPV 5.035 			//operating controller voltage 
#define Gain 244.442		//gain = (OPV)* Fluke Voltage measurement at the end of OPAMP (Converted DC vlotage)

#define Mul_fact_B 0.325	//Multifiaon Factor =  (gain*OPV)/4096 //here 4096 is for 12 bit adc 2^12 (Offset max expected)
#define Mul_fact_Y 0.300
#define Mul_fact_R 0.330




void Adc_Init(void)
{
	ADPCFG	=	0xFFFF;		//configuring channels
	ADPCFGbits.PCFG13 =0;  		//Blue	
	ADPCFGbits.PCFG14 =0;		//Yellow
	ADPCFGbits.PCFG15 =0;		// Red 
	ADCHS             = 0;
	ADCON3bits.ADCS   = 31;		//A/D Conversion Clock Select bits.
	ADCON3bits.SAMC   = 1; 		//sample for 1 Tad cycles 
	ADCON3bits.ADRC   = 0; 		//Clock derived from system clock
	ADCSSL	=	0x0000;		 
	ADCSSLbits.CSSL13 =1;	
	ADCSSLbits.CSSL14 =1;
	ADCSSLbits.CSSL15 =1;	
	ADCON2bits.ALTS=0;			  //0 = Always use MUX A input multiplexer settings, (bit 0)
	ADCON2bits.BUFM=0;		//0 means Buffer configured as one 16-word buffer (bit 1)
	ADCON2bits.SMPI=2;			//Sample/Convert Sequences Per Interrupt Selection bits (bit 5-2)
	ADCON2bits.CSCNA=1;		//1= scan i/p, 0= dont scan (bit 10)
	ADCON2bits.VCFG=0;			//Voltage ref Config (bit 15-13)
	ADCON2bits.BUFS=0;			//0 means BUF select any one of set 8-16 resgisters,0r 0-7 (bit 7)
	ADCON1bits.ADON=0;		//on or off A/D (BIT 15)	
	ADCON1bits.ADSIDL=0;		//IDEAL MODE RUN BIT(BIT 13)
	ADCON1bits.FORM=0;		//OUTPUT FORM 00 (16 BIT UNSIGNED INT)
	ADCON1bits.SSRC=7;			//111 = Internal counter ends sampling and starts conversion (auto convert).       
ADCON1bits.ASAM=1;			//1 is for auto sample,0 Sampling begins when SAMP bit set (BIT 2)
	ADCON1bits.SAMP=0;			//ASAM = 0, writing ‘1’ to this bit will start sampling	(BIT 1)
								
	ADCON1bits.DONE=0;			//Done Coversion (BIT 0)
	ADCON1bits.ADON=1;			
}

void Display(unsigned long int root1,unsigned long int root2,unsigned long int root3)
{
		Mean_sqrt1 = sqrt(root1/Samples);	//applying mean and square root to the result of value1
		Mean_sqrt2 = sqrt(root2/Samples);	//applying mean and square root to the result of value2
		Mean_sqrt3 = sqrt(root3/Samples);	//applying mean and square root to the result of value3
		
		digi_result1 = ((float)Mean_sqrt1*Mul_fact_B);
		digi_result2 = ((float)Mean_sqrt2*Mul_fact_Y);	
		digi_result3 = ((float)Mean_sqrt3*Mul_fact_R);

	
		printf("\nBLUE = %.2f V      \t", (digi_result1));
		printf("\tYELLOW = %.2f V    \t", (digi_result2));
		printf("\tRED = %.2f V", (digi_result3));
		digi_result1=0;	digi_result2=0; 	digi_result3=0;


int main()
{
	Adc_Init();

	while(1)
	{
		while(!ADCON1bits.DONE);

		buf_read1 = ((signed int)ADCBUF0 - DC_Offset1);	//To get the exact DC 
		buf_read2 = ((signed int)ADCBUF1 - DC_Offset2);	//To get the exact DC 
		buf_read3 = ((signed int)ADCBUF2 - DC_Offset3);	//To get the exact DC 


		////////To get RMS (ROOT MEAN SQUARE)//////////////////////

		root1 += pow(abs(buf_read1),2);		//applying root to the buf0 value
		root2 += pow(abs(buf_read2),2);		//applying root to the buf1 value
		root3 += pow(abs(buf_read3),2);		//applying root to the buf2 value
		
		j++;
		if(j >(Samples-1))
		{
			Display(root1,root2,root3);
			root1 =0,root2=0,root3=0;
			j=0;
		}
	}
}