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. 

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. But, before going to read this post, once get an idea about how to interface LCD with AVR Microcontroller as it is also included in this circuit.

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.