Thanks! Thats exactly what I was looking for. This is faster and easier then writing 0's to the shift registers.

Ok...Another question. For now I have my Master Reset/Reclear tied to 5v. However I want to control the MR.
Now is it right when I pull the MR to LOW that all the shift registers will be cleared, and the bytes that were in the shift registers are gone(even when I set it to HIGH again)?

Got it fixed, I was so stupid to shift out B00001 instead of B00000 at the void setup(I shift out B00000 to clear out all the shift registers). So I got it fixed !

So I tried 1k, still some very faint flashes on powering up

So I tryed it on a single shift register but no luck, its still flashing when getting powered up. However when I put a 10k resistor on the latch to ground on a single shift register on my breadboard it won't flash at all, but on my cube with 6 registers it will flash when using a 10k pull down resistor.

Im going to try a 10k from OE to 5V and see if that works, ill report back!

Btw, i wrote a piece of code in the void setup to put all latches to low and shift out B00000 (each zero is a LED in off state) to all shift registers

The problem is not with latching data out, but the leds are flashing when i connect my arduino to my laptop via usb (so when the arduino gets powered up). So im already using a pull down resistor on the latch I get significant less flashing on powering up. However its not completely gone(like 1ms flash or so).

So i got my cube working and all . Only thing is that i still get a really faint flash on all leds (pretty hard to see because its maybe on for a millisecond or so). I tried lowering my pull down resistor to 3k but i still see the flashes. Maybe someone know why I still get flashes??

I absolutely agree with the statement you made. However I think a good meter will be a good investment though (for my study and other projects in the future) even if it isnt really meaningful for now yet.

I did a measurement with a cheap digital volt meter and it came around 2.5V. I think I should invest in a better multimeter in the first place (a buddy of mine has an industrial fluke that works really well he said, maybe I should look for something like that) to get some accurate readings  

The digital pins from the arduino can only sink(/source) up, up to 40mA. If I turn on 25 LEDs on one layer the total current that need to be sinked by the digital pin would be 25*13mA = 325mA, this is far too much for a digitalpin. Instead I use NPN transistors, the collector from the transistor is connected to each layer of the cube. The emitter is connected to ground from the arduino (Ground from the arduino can sink up to around 450 mA on USB) and the base is connected to a digital pin on the arduino (in my case to the shift register). Now I am able to turn on 25 LEDs on one layer without frying something. The other advantage from transistors is the way how the ground is turned on/off, I send a HIGH signal to the base from the transistor so it switches the selected layer to ground. Because I can use HIGH instead of LOW (what you mentioned) it makes it easier to program.

Yes there quite a few parts in this one, here a list of all things I used:

-125 LEDs
-Copper wire to give the layers more thoughness
-5 NPN 800mA (2n2222) transistors
-5 x 150 ohm resistor for the transistors
-2 experiment boards to solder the components on
-14 male, 5pin connectors
-13 female, 5 pin connectors
-1 male, 3 pin connector
-2 meter 10wires ribbon cable
-6 meter white wire
-2 meter black wire
-2 meter red wire
-1 meter blue wire
-2 meter green wire
-2 meter yellow wire
-6 shift registers and 6 ic-sockets
-6 100nF ceramic capacitors
-25x 220 ohm resistors
-1x 10K resistor

This is all I used. I use 5 shift registers to control 5 LEDs per shift register, the 6th shift registers is for controlling the layers via the NPN transistors.

Here are some pics :















Next time I'm gonna design a PCB and etch it at school.

Sorry for the delay but I have been on vacation lately. Tommorow I will post some pics of it. I still have some struggling with the code but I almost figured out. So the videos will be posted within a week .

I figured out the brightness issue though. Its because the duty cycle is around 1/5 if I multiplex 5 layers. To fix it I should pulse my leds with much more current then I do right now. I dont really mind about the brightness loss so I keep it in its original state:).

So after 3 days I finished my 5x5x5 LED cube. Now everything is working fine, however if I multiplex more then three layers my LEDs goes less bright then when I'm only multiplexing 3 layers. It's not a big deal but if someone has an explanation for it it would be great!

pics comming soon!