Back when Marc and I were first planning the sorts of things we'd make as Freetronics, I thought I'd be like a kid in a candy store: I'd have enough TwentyTens, Ethernet Shields, Prototyping Shields, and other random stuff to let me build whatever I felt like. The problem is that even when I have a box of 200+ Ethernet shields and nearly 1000 prototyping shields sitting in my lounge room, the opportunity to use them just never seems to arise!
Now at last I've managed to do something personal. The front door lock at my house has been controlled by a Diecimila for a very long time, with an RFID reader connected via USB to a Linux host. Now I've taken the Linux host out of the equation and combined the RFID reader and the strike plate controller onto the prototyping area of an Ethernet Shield, along with a PoE Voltage Regulator.
The blue screw terminals on the bottom right go to the electric strike plate. The relay on the right uses 12V from the Power-over-Ethernet feed to trigger the strike plate. The 3-pin header on the top right goes to the status LEDs on the panel beside the door, and the 4-pin header goes to the RFID module.
The actual circuit is a direct implementation of the RFID Access Control System project from Practical Arduino.
It feels good to do something just for the fun of it!
