Chicago hackerspace Pumping Station: One uses BeagleBoard to control door access:

door.jpg

 

There is BeagleBone Black on the Front Door and the Back Door:

door2.jpg

door3.jpg

 

The BeagleBone is a connected to a Sparkfun USB RFID breakout with a ID-12 RFID Reader.  This scans the RFID keys:

rfid.jpg

[More photos]

 

PS1 president Derek Bever and other members are collaborating on this GitHub repo:

 

Client-side RFID authentication (and general access control)

This system is built on a BeagleBone Black and Sparkfun's USB board for RFID readers for hardware, and PS1Auth's server-side RFID authentication on the backend.

Client-side software is written in Go.