Again on lighting. This time it is a 4x4x4-LED-cube I had laying around for several month. Building such a thing takes a bit of patience, but turned out to be relaxing as playing with lego. Programming it can get challenging, but the software provided does a good job in simplifying it by providing graphics primitives.

parts and sources original author, printed parts/tools, software modifications, pinout correction,… HippyNerd’s step-by-step instructions

Mainly I wanted to have one, because they look so great. On the other hand this is also an interesting project, because the exercise is to control 192 light emitting diodes (LEDs) with a single microcontroller. LEDs are polarity sensitive. We take advantage of that fact by controlling another LED by using the same pair of wires with opposite polarity and therefore save wires. That was meant to draw a rudimentary picture on how this is working. However that wasn’t completely accurate, because in real charlieplexing gets used here, which saves even more wires. But it is also more complicated and implies, that not all LEDs can be lid up at the same time. Instead they flicker fast enough to trick the human eye not to see it.