This project started out with a bag of LEDs that I had removed from flashlights, to convert to UV flashlights. I knew I would find something fun to use them with, but It was months before I figured out what to do with them. When I saw an LED cube on youtube, I knew what to do.
I had about 70 LEDs, and an arduino. I wanted to build the cube with stuff that I already had, and using as little new stuff as possible. I built my using 64 LEDs, and 4 resistors and I would have used bus wire, but I didnt have any, so I used galvanized steel wire from the hardware store (baling wire?). I had to use wire to connect the LEDs, since had been clipped to about 1/8" lead length. To connect the LEDs to the arduino, I used an old IDE cable, because its so convenient for transferring parallel data. I was going to need 20 wires, so one ribbon cable keeps things tidy, and easy to trace. I did this project on a holiday weekend, and I wasnt able to acquire a SIP header, but I was able to make due with a couple paper clips, straightened, and clipped to about 1/2".
I had some problems finding software that would work, because I made my cube common anode, Instead of common cathode (I was thinking of only using 4 resistors, and thought they should be on the positive side, not the negative side...) Since my cube was made up of 4 layers of 16 columns, I used 4 220ohm resistors on the plane pins instead of 16 resistors on the column pins. I figured I could always change the code, but that turned out more challenging than I had anticipated. I have since revised my cube to use 16 100 ohm resistors, instead of the 4 220s, and It is much more evenly lit.
It should also be noted, that the LEDs that I used were in circuits with 3 batteries, they seem to run at about 4.5v. When re-using IDE cable, every other wire is one side of the connector, so if you only use one side (like Im doing), you only use every other wire, this also turned out to be quite handy when hooking up 2 8-bit shift registers.
This worked great, but it used all the pins on my arduino, and I wanted to try to add things, things that will need some of those precious pins. The arduino had some nice programs for using shift registers (74HC595s specifically), so that is what I used.
There are many examples of using LED cubes, so I wont go over that part, this is about converting the cube from parallel to serial using shift registers. With the new code, and use of shift registers, you can expand this cube to virtually any size, you can also add features (buttons, knobs, sounds, sensors, motors,...)
This project needs:
1 4x4x4(64) LED cube, assembled, and working.
2 74HC595 Shift Registers.
1 IDE cable
9 SIP header pins.
Arduino + USB cable + computer to program.
1 USB cell phone charger (to power the cube when not hooked up to the computer.)
You will also want some kind of container, or board to mount your project.
Soldering iron/solder/flux/alcohol (Soldering and cleanup)
Tweezers, Pliers, Diagonal nose cutters, knife (for wire and chip prep)