Long time, no updates! That's not to say I haven't been busy though.
My latest undertaking with Arduino has been to interface with an RFID reader. What's that you say? Pete using Arduino for _real_ radio-frequency work and posting it on his blog? Wonders will never cease ;-)
Anyway, I bought last week one each of these:
Then I proceeded to interface the reader with my existing keyless entry system (see below). This proved to be very easy to do (from a hardware perspective) due to the reader having a built in TTL level UART. Interfacing with the Arduino was a simple matter of providing the reader with 5V, GND and running a single signal wire from reader's TX into Arduino's RX.
Writing the code was more complex, but still only one evening's work. The end result is that I can now unlock & enter simply by waving a token in front of the reader. I plan on sewing one into the shoulder of my favorite vest so I can just shoulder-nudge the reader when walking through. It does beg the question about a medical-grade implant too! Maybe I'll leave that for a future project ;-)
Here is a short video of the system in action:
