If you’re the kind of person who has friends, and/or leaves the confines of the basement from time to time, we hear that these “Escape Rooms” are all the rage. Basically you get locked into a room with a couple other people and have to solve various problems and puzzles until you’ve finally made enough progress that they let you out. Which actually sounds a lot like the working conditions here at Hackaday HQ, except they occasionally slip some pizza rolls under the door for us which is nice.
Whichever side you find yourself on in one of these lighthearted hostage situations, knowledge of this multi-tag RFID lock created by [Annaane] may come in handy. By connecting multiple MFRC522 RFID readers to an Arduino Uno, she’s come up with a method of triggering a device (like an electronic door lock) only when the appropriate combination of RFID tags have been arranged. With a little imagination, this allows for some very complex puzzle scenarios which are sure to keep your prisoners enthralled until you can lower the lotion down to them.
Her code allows you to configure the type and number of RFID cards required to trigger one of the Arduino’s digital pins, which usually would be connected to a relay to fire off whatever device you want. The Arduino sketch is also setup to give “hints” to the player by way of a status LED: fast blinking let’s you know the tag scanned is wrong, and slow blinking means you don’t have enough scanned in yet.
The video after the break shows some highlights of the build, as well as a quick demonstration of how both the RFID “combination” and manual override can be used to trigger the attached relay.