When Polyhedra Lite was released (in October 2012) one of the platforms it supported was the Raspberry Pi: an ARM-based single board computer which is the size of a credit card. The GPIO lines are brought out to a header to enable easy interfacing with the real world, and we have produced a demo where a Polyhedra client drives some GPIO lines to reflect the state of some records in a database. As these lines are connected to some LEDs on a breadboard, this is literally a flashy demo!
Since the above demo was recorded, the code has been adapted for use with some LEDs and switches mounted on an interface card (pictured left, mounted on a Raspberry Pi and mounted into a clear plastic case into which some holes have been cut to allow access to the switches and to give some clearance to the LEDs). The revised demo is described in a separate article, and appended to that article is a ZIP file containing the schema definitions, source code, compile scripts etc.The switches are used to speed up, slow down and to start and stop the animation of the traffic lights.