[dorkbotpdx-blabber] Advice on large LED matrix

[dalas v.]

ShiftBrite looks like it might be a good place to start.

-dalas


--- On Tue, 12/9/08, Hans Lindauer <armatronix at sbcglobal.net> wrote:

> From: Hans Lindauer <armatronix at sbcglobal.net>
> Subject: Re: [dorkbotpdx-blabber] Advice on large LED matrix
> To: "A discussion list for dorkbot-pdx (portland,  or)" <dorkbotpdx-blabber at dorkbot.org>
> Date: Tuesday, December 9, 2008, 11:19 AM
> As Mykle already mentioned, shift registers seem to be the
> way to go for this.  There are ones like the Texas
> Instruments 5940 which are specifically made for controlling
> LEDs - they have on-board pulse width modulation for
> controlling brightness and are able to drive a high enough
> load that you don't need external drivers (for standard
> LEDs).  There are other versions without the PWM, if you
> don't need the brightness control.  You can chain them
> together to get as many pinouts as you need.  There may be
> simpler options than the 5940 - I experimented with them a
> little bit, but I thought they were a little more cumbersome
> than they needed to be.
> 
> There's a kit available for a 25x25 LED array, although
> it's not RGB:
> http://evilmadscience.com/tinykitlist/35-tinykitcat/75-peggy2
> That one must be doing multiplexing, because you'd need
> forty 5940 chips to control each LED directly.  For RGB
> you'd need 120, and that might be prohibitive.  Of
> course, multiplexing cuts your brightness at the same time
> as it decreases the number of pinouts you need.
> 
> You could also do a grid of ShiftBrite modules:
> http://www.macetech.com/blog/
> 
> LED dance floor projects might be a good place to look. 
> There are others trying to do large RGB grids - I've
> seen a lot of similar inquiries on other forums when doing
> my own research.
> 
> -Hans
> 
> 
> dalas v. wrote:
> > I'm thinking of building a matrix of RGB LEDs.
> Brightness is a priority. Size would be maybe 1 or 2 square
> feet. Battery power would be preferred, but if there is a
> need for AC power, I'd need to use a prebuilt power
> supply, because I don't want to attempt making one.
> Minimum control would be 32 color options (preferably more),
> maybe you can program 8 - 12 sequences and switch between
> them?
> > 
> > It seems like the arduino might be able to handle
> this? It would be my first arduino project. I know that it
> can control LED matrices and sequences, how would it be for
> a large matrix and how big / bright can I get?
> > 
> > I'm in the really early stages with this, so any
> advice or links to kits would be appreciated.
> > 
> > -dalas
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