The cube described on this page uses a 5 x 5 x 5 matrix of single colour LEDs. This is a good size to experiment with as the number of LEDs required at 125 keeps the cost down, does not take too long to assemble and just fits onto a eurocard sized PCB. The power requirement is under 1 amp and the use of just one colour keeps both the hardware construction and control software fairly simple.
The project includes a ready to program HEX file with some demo cube animations and also the source code. The firmware implements a simple macro drawing processor command set so if you’ve got some programming skills you can create your own animations for the cube.
Although the project on this page uses a PCB, the original prototype (see below) was constructed on a prototype pad board so if you’re not able to make your own PCB it’s still possible to make this project yourself.
The cubes made with 3mm LEDs in diffused packages work best, there is more space within the cube body which makes it visually more effective and the diffused body distributes the light better.
Water clear packaged LEDs are not very effective since the LED illuminates the one directly above it. High brightness LEDs are even worse in this respect and LEDs with 15o viewing angle are hopeless in my experience. LEDs with outputs around 50-150mcd seem to work quite well.
If you can get LEDs in a milky white diffused package these are ideal, however they are generally not that easy to find.
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