We turned 12 table top decorations into an interactive game and light show!
Pickled Electronics. These were jars with lights and old electronics in them, an early deco to be found at DEF CON.
DC26 I found myself adding the ability to sync light shows across 12 with no persistent connection utilizing Network Time Protocol (NTP).
For DC27, we added the ability to communicate and play a little war game! Between the 12 stations that were no longer jars, but locking metal pyramids, one was always the controller of the show.
11 of 12 towers play a coordinated light show, while one of the tower determines the show via its number pad! Its own lights are displaying its "phone number" encoded by color. If another station dials that number, they take control on the show. Each station has it own shows, and there are of course easter egg numbers!
The game was written in python, using websockets and NTP to sync the stations.