/*  Name     : main.c
 *  Purpose  : Source code for RFID Interfacing with AT89C52.
 *  Author   : Gemicates
 *  Date     : 2017-06-21
 *  Website  : www.gemicates.org
 *  Revision : None
 */
#include <regx52.h>
#include <stdio.h>
#include <string.h>

#define lcd P2		                               // LCD data pins

sbit rs=P1^0;		                               // register select pin
sbit rw=P1^1;		                               // read write pin
sbit e=P1^2;		                               // enable pin

unsigned char card_id[4];		               // ID varialble decleration
                                                       // DELAY FUNCTIONS
		void delay (unsigned int);
                                                       // LCD FUNCTIONS
		void lcddata(char t);                  // lcd functions
		void lcdstring( char *l);
		void lcdcmd(unsigned char);
		void com();
                                                       // RECEIVE FUNCTIONS
		void init();              
		unsigned char* receive();
                                                       // MAIN FUNCTION
void main()
{	 
	unsigned char i,j,k,n;
	unsigned char d[12];
	unsigned char C[12];
	unsigned char c1[12]={0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31};
 
	P1=0x00;
	P2=0x00;
	init();
	com();
delay(100);
	lcdstring("ID : ");
	delay(100);
     for(i=0;i<12;i++)		                       // ID value receive function
     {          
			   while(RI==0);
         card_id[i]=SBUF;
				 d[i]=card_id[i];
         RI=0;
     }
	for(n=0;n<12;n++)
	{
		C[n]=d[n];
		lcddata(C[n]);
	}
lcdcmd(0xc0);
k=0;
for(i=0;i<12;i++)
{	
for(j=0;j<12;j++)
	{
			if (c1[i]==d[j])
			{
			 k=k+1;
			}
			else
			{
				k=0;
			}
		}
	}
	if (k>1)
	{
		lcdstring("USER VERIFIED");
		delay(500);
		lcdcmd(0xc0);
	}
	else if (k==0)
	{
		lcdstring("INVALID USER");
		delay(500);
		lcdcmd(0xc0);
	}
}

void init()			                       // UART initialization
{
	TMOD=0x20;
	TH1=0xFD;
	SCON=0x50;
	TR1=1;
}



void delay(unsigned int msec )                         // The delay function provides delay in msec.
{
	int i,j ;
	for(i=0;i<msec;i++)
  for(j=0;j<1275; j++);
}

void lcddata(char t)			               // lcd data function
{
	rs=1;
	lcd=t;	
	rw=0;
	e=1;
	delay(1);
	e=0;
}

void lcdcmd(unsigned char c)		               // lcd command function
{  
	lcd=c;
	rs=0;
	rw=0;
	e=1;
	delay(1);
	e=0;
}

void com()   					       // lcd initialization function
{
	lcdcmd(0x38);
	delay(10);
	lcdcmd(0x0c);
	delay(10);
	lcdcmd(0x01);
	delay(10);
}

void lcdstring(char *d)		                       // lcd string print function
{
	while(*d !=0)
	{
		lcddata(*d++);
	}
}