Single player controller w/ RGB LEDs & USB only? Possible?

[shponglefan]

I've got plans to build a pair of single player controllers.  One with 4 buttons, one with 7.  I'd like to use RGB LEDs for the buttons on both.  For the 4 button, I was thinking of just using a LED-wiz+GP controller, as it would have enough outputs to drive the buttons.  But I'm wondering about the feasibility for the 7-button stick, since it will require 21 outputs (more than the 16 on the LEDwiz+GP).

Is it possible to use an LEDWiz or PACLED64 in conjunction with a regular interface controller (i.e. IPAC2 or something) with just a single USB?  I figure @ 20 mA per channel (est.) x 21 channels, that's 420 mA; that leaves not much left over for driving an interface.  Does anyone know the current draw on a typical interface?

I suppose at the end of the day I could just put together a test rig and measure it, but I'm wondering if anyone has experience with this?

[PL1]

Are you planning on animating the LEDs or just leaving them constantly on?

If you want to reduce the current draw, buy 12v LEDs and power them with 5v like this example.


Scott

[shponglefan]

Animated, I suppose.  I'd like to use LEDBlinky to light up button configurations on a per-game basis.

I'm using Seimitsu clear buttons, so I'm trying to figure out LED solutions for those.  I'd like to order the Pele and Uila LEDs (whenever the Pele's come back in stock), but I realize those are 5V LEDs.  Actually I just realized those are two RGB LEDs per board, not just one.  So not sure the current draw on those.

I may look at other DIY solutions as well.  Good point on the 12V LEDs...

[edekoning]

Why not use a usb dual power cable, like:

[shponglefan]

Yeah, I had considered that as an alternative.  Actually I figure the options from most elegant to least elegant would be:

1) Single USB
2) Dual USB
3) USB + battery/AC adapter

Ideally if I can go single USB I'd prefer that, but I'm not adverse to going to a dual-USB solution if need be.  I like the idea of overcoming the single USB challenge though