[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:
>> I'd much prefer to use DMA since we're going to spend so much of our
>> time doing this, and we'll waste a lot of processing power if we have
>> to output byte-by-byte.
>
> out of curiosity, what is the interface to the led boards like? a
> 'controller' that supports serial and dma sounds 'interesting'.

The old controller was a custom board hooked up to a 386 motherboard, and 
we think the custom boared was FPGA based.  But, the socket which we think 
might have been a FPGA chip (and to which most of the traces terminate) is 
missing a chip, so we're not really sure.

Our current kludge is to use two boarduinos and use one SPI interface on 
each of them for clocking out.  They don't do DMA so they spend most of 
their time clocking out bits, which is what I'd want to make sure we had 
DMA if we're going to redo it.

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

-nils