You too can paint your favorite meme in light with just a few tools. [Skywodd] brought together a couple of different projects to make this happen. He had already built a large POV display and now uses a DSLR with long exposure to create light paintings (translated).
The Arduino-powered display is built from a strip of 35 RGB LEDs. Now, that’s four pins per LED but one of is ground, leaving just 105 pins that need to be addressable. A couple of things make this manageable. First, he etched his own circuit boards for the LED strips. This breaks out the contacts to the edge of the boards and simplifies the soldering a bit by taking care of the ground bus. Secondly, he’s using M5450 LED display drivers for addressing. After the break you can see the video of the prototype hardware (in French but blinky action starts at about 2:30).
If you’re looking for an easier way to do this, check out the light painting that uses manufactured LED strips.