The passive RFID tags do not have any power source and hence they have indistinct operational life span. The power needed for functioning is taken from the reader when the tag comes in the vicinity of the reader. They are available in a variety of sizes ranging from sizes which can fit into adhesive label.…

The active RFID tags have their own source of power. They can transmit stronger signals over long distances and can operate in rugged environment for many years. Because of the on-board source of power they are larger in size and expensive. Then too Active RFID and Real-Time Location solutions (RTLS) are saving millions of dollars…

RFID tag is a small device which stores and sends data to RFID reader. They are categorized in two types – active tag and passive tag. Active tags are those which contain an internal battery and do not require power from the reader. Typically active tags have a longer distance range than passive tags. Passive tags are smaller and lighter in size than the active tags. They do not contain an internal battery and thus depend on RFID reader for operating power and certainly have a low range limited up to few meters. There are two important components of a RFID tag – A microchip and a coil (antenna). The antenna receives power and RF signals from the RFID reader and sends those signals to the chip. The chip receives those signals, computes them and sends back the data to RFID reader. We can figure out the précised working of a RFID tag through this diagram. 

This project aims to automate the process of talking attendance on pen and paper and prevent any fraudulent entry. It uses RFID tags to record attendance. Each student is assigned a unique tag, which he/she is required to swipe over the reader to give his/her attendance. This system benefits both the teacher and student as its quick and hassle free. This setup can be used in any educational institution regardless of whichever board they follow. Data is stored in a CSV file which keeps track of each day’s attendance. The main component of the system is the RFID reader which transmits a 12-byte ASCII string via the TTL-level SOUT pin. This helps to identify a student from the rest, as each TAG generates a unique ASCII string. This String is then fed to the AVR’s RX line which processes it for marking his/her attendance.