Everyone wants to make giant LED displays to show their cool, geometric LED waves, or fuzzy pink Elvis art. However, in order to address a massive wall of LEDs, you have to figure out how to turn your fuzzy pink Elvis art into a string of zeros and ones which get properly buffered, shifted, and sent down a wire at the speed of electricity - no easy feat. However, in this instructable, we're going to demonstrate how to use a PixelPusher LED controller coupled with L.E.D. Labs' iPad software to eliminate that pesky middle step of digital buffoonery.
This instructable focuses on the back end components needed to make this wall work, although we will talk a bit about fabrication of the superstructure as well. This method of controlling LEDs requires the use of a pixelpusher to do the heavy lifting of physically driving the LEDs. The LED Labs software running on the iPad does the heavy lifting of taking your image / video / algorithm and breaking into chunks the PixelPusher can understand.
For this instructable, we are going to be controlling WS2801 LEDs in "pixel" packages instead of "strip" packages. They are very common, and are a bit more expensive than some other options, but are very easily controlled from a wide variety of chipsets. Typically, strip packages are much more common since their installation is substantially simpler, but to get the effect we desired with this piece, we had to go after the pixel versions instead. We ended up getting ours from a bulk supplier in China since we needed around 2000 LEDs, but going local is always simpler and saves your sanity in the long run if you need smaller quantities:
5V WS2801 pixels on Adafruit: http://www.adafruit.com/product/322
Pixelpusher on Illumn: http://www.illumn.com/heroic-robotics-pixelpusher....
Additionally, you'll of course want an iPad, the appropriate 5V power supply, and a wireless router. Our favorite wireless router to use is the Ubiquiti consumer models since they are equipped with some advanced features like auto-resetting and the like which can keep your LED system running nonstop. However, they are a bit more advanced than other consumer level routers, so pick one that suits your expertise level.