Can you make a 3d LED cube with an Picaxe 28x1. Like a 3x3x3 or bigger. It something second I would love to do. Robot is the first thing I want to do but learning more about LED and wanted to know if it is possible to do something like this. I can't wait till I place my order in soon to get this and share my project with everyone.
DIO count
How many digital outputs do you have on this chip? 3x3x3=21 LEDs. I can see a way of controlling 25 LEDs with 10 output lines. Alternatively you can multiplexors and such.
Uh, Mr Math please, 
3 x 3 x 3 = 27 LEDs. Make mag had an article using 9 lines if wired in a cube, with some multiplexing you mentioned. Here is a Make magazine podcast that went through this with another controller.It could probably be adapted to the PICAxe
http://blog.makezine.com/archive/2007/09/make_a_pocket_led_cube_we.html
http://cachefly.oreilly.com/make/wp_ledpocketcube.pdf
Testing, testing, 123…
D’uh. I knew that. I just wanted to check if you were awake.
Here’s an interesting option. That said, THIS is the beggar I’d use (if I coud find one for sale anywhere…)
**There may be a few **
I checked http://www.findchips.com searching for M545 that showed Mouser and Newark have some. I think Newark is worldwide, does Farnell have them over on your side of the pond? They appear to be about $3 or $4 each. This might work well with some 5x7 matrix LEDs I’ve got to experiment with.
FOUND ONE!
I have one. At the bottom of my sock drawer. Still in the little baggie. I just need an application!
Hmmm…
I’m not even gonna ask why you have an LED driver IC in your sock drawer. Something are just better left unknown.