Arduino units have been used to make some pretty interesting things such as a steam powered turntable and a magnetic card reader. Matt Williamson, from App Delegate Inc., has designed a RFID security scanner that uses an Arduino unit that is no less impressive as well. Williams made his security pass by first purchasing an RFID reader from Radio Shack for 8 dollars on clearance rather than the $40 it would have cost. Talk about a bargain! That particular unit came with two tags, a credit card version and also a disc version. To get the reader to work Williamson used an Arduino Decimilia which is old but can be found in various stores, typically in the bargain bin. He connected his scanner, along with a servo mechanism attached to a lock, to a door that when a card is swiped the door unlocks. A small peizo speaker he used emits a different tone depending on weather access was granted or denied. A more advanced version he created is based on this version but also uses Python to make his computer yell at intruders. To see a diagram and to download his source code for Arduino please visit: http://appdelegateinc.com/blog/2010/10/04/arduino-rfid-security-access/
Eavesdropper