Embedded System Project: RFID Based Attendance System

RFID Based Attendance System Using 8051 Microcontroller

Nowadays, attendance in schools and colleges is based on paper. Sometimes this process causes errors and takes more time.

This project uses RFID technology for making a note of every student entering in a classroom and also calculates the time resides in a class.

In this system every student is allotted with an RFID tag. The attendance can be done by placing card near RFID reader.

What is RFID?

The Radio Frequency Identification (RFID) is an electronic device which includes a small antenna and a chip. This device is used for transmitting information between reader and RFID tag using radio frequency electromagnetic fields.

The operating frequency ranges of these devices include low, mid and high ranges. The low frequency range is from 30 KHz to 500 KHz, middle frequency range is from 500 KHz to 900 KHz and high frequency range is from 2.4 MHz to 2.5 MHz

Block Diagram of RFID Based Attendance system

The attendance system in most of schools and colleges is mostly documented based. For automatic attendance system a wireless technology based RFID system is proposed. Every student is provided with an RFID tag, which uses inbuilt IC for storing and processing the information.

The block diagram of this system includes preset circuit, a microcontroller, an oscillator circuit, LCD display and an RFID reader.

Microcontroller-The microcontroller used in a RFID based attendance system is AT89C52 from the family of 8051. It includes 4-I/O ports and 40-pins.
Oscillator Circuit-Oscillator circuit is connected in between the pins of 18 and 19 of a microcontroller. This circuit is built with a combination of oscillator and two 33 pF capacitors at 11.0592 MHz operational frequency.
Preset Circuit-The microcontroller AT89C52 9th pin is reset pin. The circuit of the preset is built with a capacitor, a resistor and a switch. When switch is pressed, the reset pin is connected with and the microcontroller becomes reset.
LCD Display-LCD display is consists of 16 pins, where 3 pins are connected with and remaining all pins are connected with the port-2 of the microcontroller.
RFID Reader-RFID reader is used for reading the information which is stored in the RFID tags. It incorporates with any type of hardware design.

Working of Attendance System Circuit

After connecting all the components of attendance system, give the power supply to switch on the circuit. Then LCD will displays, please swipe the card. The information contain in the RFID tag is stated as the ID and attendance of the student. When person placed card in front of RFID reader, it reads the information and start matching with the information stored in the AT89S52 microcontroller. Before operation microcontroller is preprogrammed with embedded C language.

If the data of the card matches with RFID reader, then information will display on LCD. By using this system the operational time can be save as all the information is stored directly inside the database.

Source Code:

Consider the embedded system program required for operating the microcontroller system as RFID based attendance system is:-

#include<reg51.h>
#include<string.h>

//0000 to 7FFF

sbit RS = P0^7;
sbit EN = P0^6;

sbit SDA = P1^0;
sbit SCL = P1^1;
sbit RELAY = P1^2;

code unsigned char RFID_1[] = "34006C9C04C0"; //34006C9C04+NULL
code unsigned char RFID_2[] = "34006C549C90";
code unsigned char RFID_3[] = "1300F8FAC1D0";
code unsigned char RFID_4[] = "34006CD5AD20";
code unsigned char RFID_5[] = "420061231E1E";

code unsigned char name_1[] = "SANJAY JAIN";
code unsigned char name_2[] = "SHEKHAT HARSH";
code unsigned char name_3[] = "DHOLARIYA RAKSHIT";
code unsigned char name_4[] = "DIVYANG SINGH ";
code unsigned char name_5[] = "NAKUL JAIN";

unsigned char rs[15];

unsigned int no_of_records;

void delay()
{
	int j;
	for(j=0;j<500;j++);
}

void long_delay()
{
	unsigned int j;
	for(j=0;j<65000;j++);
}

void idelay()
{
	unsigned int j;
	for(j=0;j<10000;j++);
}

void lcd_command(char lc)
{
	P2 = lc;
	RS = 0;
	EN = 1;
	delay();
	EN = 0;
}

void lcd_data(char ld)
{
	P2 = ld;
	RS = 1;
	EN = 1;
	delay();
	EN = 0;
}

void lcd_init()
{
	lcd_command(0x38);
	lcd_command(0x0E);
	lcd_command(0x01);
}

void serial_init()
{
	 TMOD = 0x20;
	SCON = 0x50;
	TH1 = 0xFD;
	TR1 = 1;
}

void transmit(unsigned char tx)
{
	SBUF = tx;
	while(TI==0);
	TI = 0;
}

void send_string(unsigned char *str)
{
	int j;
	for(j=0;str[j]!='\0';j++)
		transmit(str[j]);	
}

unsigned char receive()
{
	char rx;
	while(RI==0);
	RI = 0;
	rx = SBUF;
	return(rx);
}

void lcd_string(char add,char *str)
{
	int j;
	lcd_command(add);
	for(j=0;str[j]!='\0';j++)
		lcd_data(str[j]);	
}

void start()
{
	SDA = 1;
	SCL = 1;
	SDA = 0;
}

void stop()
{
	SDA = 0;
	SCL = 1;
	SDA = 1;
}

void write(unsigned char w)
{
	int j;
	SCL = 0;
	for(j=0;j<8;j++)
	{
		if((w & 0x80)==0)
			SDA = 0;
		else
			SDA = 1;
		SCL = 1;
		SCL = 0;
		w = w << 1;
	}
	SCL = 1;
	SCL = 0;
}

unsigned char read()
{
	int j;
	unsigned char r = 0x00;
	SDA = 1;

	for(j=0;j<8;j++)
	{
		SCL = 1;
		r = r << 1;
		if(SDA == 1)
			r = r | 0x01;
		SCL = 0;
	}
	return(r);
}

void ack()
{
	SDA = 0;
	SCL = 1;
	SCL = 0;
}

void nack()
{
	SDA = 1;
	SCL = 1;
	SCL = 0;
}

void rtc_read()
{
		unsigned char ss,mm,hh,day,mn,date,yr;
		start();
		write(0xD0);
		write(0x00);		
		stop();
		start();
		write(0xD1);
		ss = read();
		ack();
		mm = read();
		ack();
		hh = read();
		ack();
		day = read();
		ack();
		date = read();
		ack();
		mn = read();
		ack();
		yr = read();
		nack();
		stop();

		rs[0] = hh/0x10 + 48;
		rs[1] = hh%0x10 + 48;
		rs[2] = ':';
		rs[3] = mm/0x10 + 48;
		rs[4] = mm%0x10 + 48;
		rs[5] = ',';
		rs[6] = date/0x10 + 48;
		rs[7] = date%0x10 + 48;
		rs[8] = '/';
		rs[9] = mn/0x10 + 48;
		rs[10] = mn%0x10 + 48;
		rs[11] = '/';
		rs[12] = yr/0x10 + 48;
		rs[13] = yr%0x10 + 48;
		rs[14] = '\0';
}

void rtc_init()
{
	start();
	write(0xD0);
	write(0x00);
	write(0x00);
	write(0x00);
	write(0x13);
	write(0x05);
	write(0x12);
	write(0x04);
	write(0x12);
	stop();

}

void write_records(unsigned char *str);
void read_records();

void main()
{
	unsigned char rec_data[13],i,t;

	RELAY = 0;

	lcd_init();
	serial_init();
	rtc_init();
	idelay();
	start();
	write(0xA0);
	write(0x7F);
	write(0xFF);
	stop();
	start();
	write(0xA1);
	no_of_records = read();
	nack();
	stop();

//	no_of_records = 0;

	while(1)
	{
	start:
		lcd_command(0x01);
		lcd_string(0x80,"RFID ATTENDANCE");
		lcd_string(0xC5,"SYSTEM");

		j = 0;
		while(1)
		{
			if(RI==1)
			{
				RI = 0;
				t = receive();
				if(t == '+')
				{
					read_records();
					goto start;
				}
				else
				{
					rec_data[j] = t;
					for(j=1;j<12;j++)
						rec_data[j] = receive();
					rec_data[j] = '\0';	
					break;
				}
			}
		}

		j = strcmp(RFID_1,rec_data);	//match => j = 0

		lcd_command(0x01);

		if(j==0)
		{
			RELAY = 1;
			lcd_string(0x80,name_1);
			rtc_read();
			lcd_string(0xC0,rs);
			long_delay();
			write_records(name_1);
			RELAY = 0;
			goto start;		
		}

//
		j = strcmp(RFID_2,rec_data);	//match => j = 0

		if(j==0)
		{
			RELAY = 1;
			lcd_string(0x80,name_2);
			rtc_read();
			lcd_string(0xC0,rs);
			long_delay();
			write_records(name_2);
			RELAY = 0;
			goto start;		
		}

//
		j = strcmp(RFID_3,rec_data);	//match => j = 0

		if(j==0)
		{
			RELAY = 1;
			lcd_string(0x80,name_3);
			rtc_read();
			lcd_string(0xC0,rs);
			long_delay();
			write_records(name_3);
			RELAY = 0;
			goto start;		
		}

		j = strcmp(RFID_4,rec_data);	//match => j = 0

		if(j==0)
		{
			RELAY = 1;
			lcd_string(0x80,name_4);
			rtc_read();
			lcd_string(0xC0,rs);
			long_delay();
			write_records(name_4);
			RELAY = 0;
			goto start;		
		}

		j = strcmp(RFID_5,rec_data);	//match => j = 0

		if(j==0)
		{
			RELAY = 1;
			lcd_string(0x80,name_5);
			no_of_records = 0;
			start();
			write(0xA0);
			write(0x7F);
			write(0xFF);
			write(0x00);
			stop();
			lcd_string(0xC0,"MEMORY CLEARED");
			long_delay();
			RELAY = 0;
			goto start;		
		}
		lcd_string(0x80,"ERROR");
		lcd_string(0xC0,rec_data);
		long_delay();
	}
}

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