Fantastic Planet LED Sign
I helped run a huge party called Fantastic Planet in Norfolk, VA, for which the we typically outsourced the lighting arrangements. We grew tired of hiring light guys several times a year and I was asked to built our own mega display for the New Years show.
The LED sign consists of 1,474 LEDs that output well over 10,000 lumens. The sign was produced for just about $800, which is very reasonable for a display of its size. The whole thing is controlled by a pair of Arduino Megas paired with 34 MIC5891 shift registers to drive the LEDs in a Matrix pattern, all mounted on custom designed PCBs that I etched produced in my apartment.
2 Arduino Megas
2 PC PSUs