[Noisebridge-discuss] Big LED Screen - potential upgrade?

[nils at shkoo.com]

On Fri, 10 Apr 2009, d p chang wrote:
>> nils at shkoo.com writes:
>>> If you're interested in more of the technical details you can check
>>> out the wiki page:
>>>
>>> https://www.noisebridge.net/wiki/Big_LED_Screen
>
> reading this, the panel almost looks like an 'isa smart panel' that some
> lcd controlers do (or the last lcd controller i was involved w/).

I think I'd charactarize it as very far from smart. :)  We use SPI to 
drive the shift registers directly.  There's no controller involved. 
There are 3 pins, "data", "clock", and "latch"/"strobe".

> w/ your dma idea, are you thinking of building a controller in front of
> the existing controller or replacing the shift register stuff completely?

It would be a lot of work to replace the shift register stuff, since it's 
384 pins that need to be individually controllable as to whether they can 
drain current or not.  Plus, some of the daughterboards are glued down.

I wouldn't characterize the shift register stuff as a "controller"; it's 
quite a bit dumber than that. :)

If you're asking as to whether I'd want to replace the boarduinos with an 
ARM, then yes.

I've uploaded some pictures to flickr of the equipment involved and 
updated the wiki if you want to look at the old logic and how things fit 
together. Search for "picture" in the wiki page.  There are mouse-over 
notes on the pictures too.

-nils