this is the code..
#include<absacc.h>
#include<reg52.h>
sbit rs=P2^0;
sbit rw=P2^1;
sbit e=P2^2;
unsigned char c[11];// to receive tag Id
const unsigned char Tag1[11]= {‘0′,’0′,’1′,’5′,’3′,’9′,’7′,’6′,’5′,’1’};// to store tag numbers
const unsigned char Tag2[11]= {‘0′,’0′,’1′,’5′,’3′,’9′,’7′,’6′,’5′,’0’};
const unsigned char Tag3[11]= {‘0′,’0′,’1′,’5′,’3′,’9′,’4′,’7′,’9′,’8’};
unsigned int bn; // to store bus number
unsigned char area[4];// to store area number
unsigned int n=11; // no. of bytes in tag id
void delay(unsigned int );
void lcdinit(void);
void rtcinit(void);
void lcdcmd(unsigned char);
void welcome(void);
void receive(void);
void bus1(void);
void bus2(void);
void bus3(void);
void nomatch(void);
void rtc(void);
void bcdconv(unsigned char) ;
void lcddata(unsigned char );
void lcdstring(unsigned char * );
void main()
{
unsigned int i;
unsigned int v1,v2,v3,vn; // variables in switch cases
TMOD=0x20;
TH1=0xFD;
SCON=0x50;
TR1=1;
lcdinit();
delay(25);
welcome();
delay(25);
while(1)
{
receive(); // function to recieve tag id into array
v1=v2=v3=vn=0;
for(i=0;i<n;i++) // loop to compare the recieved tag and the id’s stored in tags
{
if(c==Tag1)
v1++;
else
if(c==Tag2)
v2++;
else
if(c==Tag3)
v3++;
else
if(c!=(Tag1&&Tag2&&Tag3))
vn++;
} // end of for loop
//if value of any variable is n i.e., the number of bytes then the coresponding fumction is called
if(v1==n)
bus1();
else
if(v2==n)
bus2();
else
if(v3==n)
bus3();
else
if(vn==n)
nomatch();
//Function to initialize the Real Time Clock (RTC)
rtcinit();
delay(25);
//Funtion to Obtain the Time From the RTC
rtc();
}// end of while loop
}//end of main function
// Welcome function
void welcome()
{
unsigned int i=0;
unsigned char c[]=”WELCOME TO RFID”;
unsigned char d[]=”BUS ID SYSTEM”;
lcdcmd(0x01);
delay(1);
lcdcmd(0x80); //
delay(1);
for(i=0;c!=’ ’;i++)
lcddata(c);
lcdcmd(0xc0);
delay(1);
for(i=0;d!=’ ’;i++)
lcddata(d);
}
// function to recieve the tag id from reader
void receive()
{
unsigned char t;
for(t=0;t<n;t++)
{
while(RI==0); //wait until value of RI is set to 1
c[t]=SBUF; //load SBUF value into array ‘c’
RI=0; //clear value of RI to 0
}
}
// Function to send the details of bus 1
void bus1()
{
lcdcmd(0x01);
delay(10);
lcdcmd(0x80);
delay(10);
lcdstring(“Bus Number : 1” );
delay(10);
lcdcmd(0xc0);
delay(10);
lcdstring(“Area : RJY”);
delay(10);
}
//function to store area of bus 2
void bus2()
{
lcdcmd(0x01);
delay(10);
lcdcmd(0x80);
delay(10);
lcdstring(“Busnumber : 2” );
delay(10);
lcdcmd(0xc0);
delay(10);
lcdstring(“Area : KKD”);
delay(10);
}
//Function to store Bus 3 details
void bus3()
{
lcdcmd(0x01);
delay(10);
lcdcmd(0x80);
delay(10);
lcdstring(“Busnumber : 3” );
delay(10);
lcdcmd(0xc0);
delay(10);
lcdstring(“Area : ABC”);
delay(10);
}
//Function to display the unauthorized entry of buses into the arena of the college
void nomatch()
{
lcdcmd(0x01);
delay(10);
lcdcmd(0x80);
lcdstring(“Unauthorised entry”);
delay(10);
}
// function to display time from the RTc
void rtc()
{
unsigned char hr,min,sec;
hr=XBYTE[4];
bcdconv(hr);
delay(10);
lcddata(‘:’);
min=XBYTE[2];
bcdconv(min);
delay(10);
lcddata(‘:’);
sec=XBYTE[0];
bcdconv(sec);
}
//Function to convert hex values into BCD
void bcdconv(unsigned char v)
{
unsigned char x,y;
x=v&0x0F;
x=x|0x03;
y=v&0xF0;
y=y>>4;
y=y|0x30;
lcddata(y);
lcddata(x);
}
//LCD initialisation function
void lcdinit()
{
lcdcmd(0x38);
delay(1);
lcdcmd(0xE0);
delay(1);
lcdcmd(0x01);
delay(1);
lcdcmd(0x06);
delay(1);
}
//function to display string
void lcdstring(unsigned char *str)
{
int i=0;
for( ;str!=’ ’;i++)
{
lcddata(str);
delay(1);
}
}
// lcd function to display a single character
void lcddata(unsigned char value)
{
P1 = value;
rs= 1;
rw=0;
e=1;
delay(1);
e=0;
}
void lcdcmd(unsigned char value)
{
P1 = value;
rs= 0;
rw=0;
e=1;
delay(1);
e=0;
}
// Function to initialize the Real Time clock
void rtcinit()
{
delay(200);
XBYTE[10]=0x20; //turn ON the oscillator
XBYTE[11]=0x83;
XBYTE[0]=0x55;
XBYTE[2]=0x58;
XBYTE[4]=0x16;
XBYTE[7]=0x19;
XBYTE[8]=0x10;
XBYTE[9]=0x04;
XBYTE[11]=0x03;
}
//Function to generate delay
void delay(unsigned int count)
{
unsigned int i,j;
for(i=0;i<count;i++)
for(j=0;j<1275;j++);
}