RFID Based Attendance System

Attendance in colleges is generally paper based which may sometimes cause errors. Taking attendance manually consumes more time. So the proposed attendance system uses RFID technology to take attendance. In this system, each student is issued an RFID tag. Controlling unit is in the institute. Whenever the card is placed near the reader, it will take the attendance. This article explains the same.

RFID Based Attendance System Circuit Principle:

RFID based attendance system consists of RFID Reader, RFID Tag, LCD display and microcontroller unit. RFID can be interfaced to microcontroller through USART. Data is transferred from RFID cards to reader and from there to microcontroller.

Radio frequency technology is used in many applications. RFID tags are of two types – 1) Passive Tags and 2) Active Tags. Passive tags contain 13 digit number tag inbuilt in it, where as active tag is read/write tag i.e. one can read from the tag and write to the tag. This project uses passive tag. In real time, one can issue active tags to the students, with their roll numbers as their tags. RFID reader contains a copper winding in it. This winding acts as an antenna.

When the tag is placed near the reader, due to the induced mutual inductance energy, data is transferred to reader. Reader then transfers data to the microntroller. Microcontroller checks for the data continuously, if any data is received, microcontroller compares the data in data base. If the tag is authenticated, microcontroller takes the attendance.

RFID Based Attendance System Circuit Diagram:

Circuit Diagram of RFID Based Attendance System – Electronics Hub

Circuit Components:

• ATMEGA8 Microcontroller.
• RFID Reader
• RFID Tags.
• LCD display

Circuit Design of RFID Based Attendance System:

RFID based attendance system has very simple circuit design. The RFID Reader has transmit and receive pins. These pins are connected to the transmit and receive pins of the micro controller i.e. PD0 and PD1 pins of microcontroller.VCC is connected to 5v and GND is connected to ground. If pins are not available to the module, connect it using DB9 connector. PD0 pin is receiver and PD1 pin is transmitter.

RFID module communicates with the controller using USART, where USART is a communication protocol. USART is acronym for Universal Synchronous and Asynchronous Receive and Transmit. Serial data can be transmitted from RFID module to microcontroller using UART.

ATMEGA8 microcontroller has USART registers internally. One should declare these registers in order to transmit or receive data serially.

LCD display is connected to Port B of the microcontroller. Interfacing of LCD in 4 bit mode is in to microcontroller which is shown in the circuit diagram. D4 – D7 data pins are connected to the PB0 – PB3 pins of microcontroller. RS pin is connected to PB4, RW pin is connected to PB5 and enable pin is connected to PB6 of microcontroller. To display data on LCD, initially set the LCD in 4bit mode. Then make Rw pin low, RS pin high, enable pin high. Send the data on data pins and make enable pin low.

How to Operate RFID Based Attendance System Circuit?

1. After making all the above connections, Switch on the circuit.
2. On LCD it is displayed “PLEASE SWIPE THE CARD”.
3. Place the RFID tag near the reader.
4. Reader then reads the data in the tag and transmits to the controller.
5. Microcontroller compares the tag with the database. If the tag is matched LCD displays “authenticated” and takes your attendance
6. Now place another card which is not present in the database and check for authentication.
7. Now LCD displays “Un authorized” and it will never take the attendance.
8. In this way, we can use implement this circuit.

Applications of RFID Based Attendance System:

• RFID based attendance system can be used in educational institutions, industries, anywhere.
• RFID is emerging technology and is used in applications where authentication is needed.

Limitations of RFID Based Attendance System:

• RFID attendance system is secured, but there is a chance of misusing the cards. One person can give another person’s attendance if he/she had RFID card.
• If the card was swiped for more than once, there is a chance of giving attendance for next days also if code is not written properly.

source:http://www.electronicshub.org