The Open Heart is an LED matrix of individually addressable LEDs. It can be used to create a broach or bag light with highly customizable animations. It can be configured so that you can temporarily attach it to fabrics with headers that you simply push through, or you can sew it into a project using conductive thread/wire for a more permanent setup. I have also created a simple flash programmer that you can design animations with, and it will generate the Arduino code for you. That way you just copy, paste, upload, and enjoy.
I am using a Charliplexing technique for addressing the LEDs. What this means is that you only need 6 wires from a micro controller to light things up. I’ve chosen to support the Arduino micro controller, because it has a low cost of entry, it is easy to program for, and it is easy to find information on. An Arduino can run up to three of these at once, as well as take input. You can also store up to 1,000 frames of animation(with an Atmega328, but only 500 with the Atmega168), which could lead to some very complex animations. There are many versions of the Arduino out there, including the Lilly pad, which can be used for sew-able projects.
You can check out the instructable to built it yourself, or you can save yourself some time and buy a kit from me. The new version 2.0 kit is easier to assemble with a high quality blue PCB, has brighter LEDs, and comes with a pre-made cable all for the same price as the previous kit!