I am going to build 8x8x8 LED cube. Before I do I need to figure out a good driver circuit. I came here because I have very little knowledge about how a lot electronic parts fit together.
So here's my plan.
I will be using the Arduino UNO to run the animations.
The cube itself will be made with 512 3mm Diffused Blue LEDs. These LEDs have a
Vf = 3.4vand maximum current of
20mA. I want to be able to provide that maximum current. The cube will be setup so that the 64 columns will be the anodes of the LEDs and the 8 layers will contain all the cathodes of the 64 LEDs in that layer.
I have decided to use nine 74HC595 shift registers to expand the Arduino's I/O to the required 72 outputs. From here I don't know what to use to connect the shift registers to the cube. The first 8 registers will control the columns (anodes) and the last will control the layers (cathodes).
Some have suggested I use the UNL2803 to "anti-drive" the 64 anodes and 8 transistors or MOSFETs to turn the layers on and off.
I don't understand how to connect the UNL2803 or the other parts so could someone provide me with some clarity, a simple schematic perhaps? I just don't get how to use a UNL2803 to source current...
Schematic Below For CubeDriver: