Reader then transfers data to the microntroller. When the tag is placed near the reader, due to the induced mutual inductance energy, data is transferred to reader. RFID reader contains a copper winding in it. In real time, one can issue active tags to the students, with their roll numbers as their tags. one can read from the tag and write to the tag. Passive tags contain 13 digit number tag inbuilt in it, where as active tag is read/write tag i.e. RFID tags are of two types – 1) Passive Tags and 2) Active Tags.
Radio frequency technology is used in many applications.
Data is transferred from RFID cards to reader and from there to microcontroller. RFID can be interfaced to microcontroller through USART. RFID based attendance system consists of RFID Reader, RFID Tag, LCD display and microcontroller unit. DIY Project Kit : RFID based Attendance System » RFID Based Attendance System Circuit Principle
