21 LEDs across 3 circuits controlled by an (underclocked) Adafruit Gemma that can run for days on a small LiPo battery! Source code available at [ github.com [https://github.com/wgbartley/awe-chloe-dress] ]. For the dress, contact my wife at [ facebook.com [https://www.facebook.com/birchavenueapparel] ], [ storenvy.com [http://www.