To show one LED no. But what I think they were implying by multiplexing is now suppose you wish to show 2 LEDS at the same time, that may be very difficult unless they are both on the same layer. As if you turned two layers and two Led items you would turn on 4 LEDS not two. So instead alternate turning on one and then the other really really fast and your eyes were perceive that both are on at the same time.
Kurt
Man will ya look at the kind of threads that happen when one is not paying attention. 
Looks like Kurt has been working his butt off trying to, uh, enlighten you guys… 
Thank you all, that was really helpful. Once the LEDs arrive, i will get started and show you guys
Great project sonierm.
I’ve been looking at some of these a while ago. Would be fun to make one! I would like to try one myself one day.
Thanks for sharing!
not a problem Xan,
its a really cheap project, 120 LEDS was less the 5 bucks on ebay.
Good deal! 8)
Single color right?
yes, i dont know to , much about the multi colour ones, i guess there would be a third pin?
Yeah usually there is a “shared” ground pin, and two voltage pins. apply voltage to one of the two pins to change color. I haven’t really tried yet but I think you could also apply power to both pins to get a third color.
Could be a third pin. Or you can connect them back-to-back as I mentioned earlier.
Alan KM6VV
EDIT:
Here’s an RGB chip LED (digikey):
365-1227-2-ND OVSRRGBBC9 LED RED/GRN/BLUE SMD 1.0 X 2.7
data sheet:
media.digikey.com/pdf/Data%20Sheets/Optek%20PDFs/OVSRRGBBC9.pdf
Can’t buy it yet.
Alan KM6VV
so I finally got the LED’s
but now i have one more question, how do I use the AX0 - AX3, I need to be able to set them from high to low.
I am going to start building soon, i will post some pics as I go
For now I assume that this is a Basic Atom Pro 28. In that case AX0-AX3 are simply IO pins P16-P19. Use them like the other 16.
Good Luck, will be fun to see pictures when it get it up and running.
Kurt
lol thats easy!! thank you!
perhaps I missed it but I don’t see where you stated what LEDs you bought. might help to know for further discussion.
I got 120 x 5MM 18000MCD LEDs
what, uh, is the operating current those are rated for? and are they single, bi, or tri color?
(this is where manufacturer and part number potentially saves a lot of time)
This is the info i got
light Colour :blue
Size(diameter):5mm
Lens Color : Water Clear
Forward Voltage :3.2V-3.4V
Forward Current :20MA
View Angle: About 30 degree
Operating life span:100,000Hours
Product Shape:hat type
Interesting. I find the 18000MCD at 20mA tough to imagine but who is to say. Will be fun to see what you come up with.
Actually for a cube a frosted LED would work better. Defuses the directional aspect of a clear and would perform better in this type of array. My 2 cents. I showed my boss the video of the cube and he went nuts. He is one of those campers that has to have the coolest light displays in his camp site. So this gives me a free ride to prototype cubes for him… Muhahaha
Will be using the AVR Atmega32 chip to play with.
