Open source hardware, how to build a lightboard: https://sites.google.com/site/northwesternlightboard/
I developed the Lightboard to be able to record attractive online lectures, easily. In technical subjects equations and sketches are important and I use my hands a lot as I write and talk. I’m not writing backwards; the board is videotaped in mirror reflection. This process is direct-to-disk, so you can do it yourself with little or no post-production.