Attendance System using AVR and RFID

This project aims to automate the process of taking 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.
System Design: 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.

The start byte and stop byte are used to easily identify that a correct string has been received from the reader (they correspond to a line feed and carriage return characters, respectively). The middle ten bytes are the actual tag’s unique ID. This ID is then matched with the ID stored on MCU’s flash memory to get the name, roll no and other details. Once a match has been found it is then dumped to the SD card along with the date and time stamp.

Data entry and retrieval: For this project to work Student name and roll number along with their tag ID must be preconfigured in the program. To get the Tag ID of a new RFID card I have written a simple program which can be used when the database is been updated. Adding or editing any info is as simple as modifying the array. All information is stored in 3 different arrays namely “tag”, “name”, “roll”. Care must be taken while editing the information with respect to array index. Whenever there’s a hit with the tag ID the corresponding name and roll number is returned.
Data is stored on a SD card for convenience. Every day a new file gets created with date as the filename (e.g. 5102013.CSV) and records the attendance. File extension is comma separated value (CSV) which can be imported by Excel or MS Access.
Usage: Usage is fairly simple. The Tag card must be brought close to the RFID reader so that the student can record his/her attendance. An LED on board the RFID reader blinks to acknowledge the same.
For more detail:  Attendance System using AVR and RFID