RFID playing cards

Christian Floerkemeier and Friedemann Mattern
Institute for Pervasive Computing, Department of Computer Science,
ETH Zurich, 8092 Zurich, Switzerland

The author in this article created a card game that has been augmented by information technology. The augmentation focuses on automatic bookkeeping (score keeping) as well as offer tips to novice players regarding legal moves and bad moves that can be made. In the system the mobile phones act as user  interfaces. (show the scores as well as give advice at the same time) The phone itself communicate with the computer which keeps track of the game state. This will allow the phones to connect to the game server with their phones at any time during the game.

The game state itself is kept track of by utilizinig a RFID label on each of the playing cards available. A short range RFID reader is utilized to determine what cards each of the players hold. In order to keep track of the cards when they are in a stack form, the tags choosen were tuned to a resonance frequency greater than the operating frequency. Placing them close together reduced the resonance frequency to a value close to the operating frequency.