[sdiy] Which programable chip?

[Joe Grisso]

On 4/15/09, Scott Nordlund <gsn10 at hotmail.com> wrote:
>
>  Why would you need to run the audio through the processor?
>
> If I'm not mistaken, are you wanting to route one input (of 8 total)
> to one output (of 8 total)?  You can do that with 2 4051 multiplexers,
> and not have to worry about any ADCs or DACs or high speed processors
> or anything.  You only need to send 6 bits to control everything.

That would be a selector - if it's a full patch matrix the first
topology to mind is to use 16x CD4066s, 8 74HC573s, and op-amp summing
buffers at each output. With a complicated setup like that, it would
be more cost-effective hardware wise to have 8 channels of ADC and
DAC, then perform all the summing in the MCU.

Then again, the description of Ian's module is a bit nebulous. I could
also see the topology being an input bus of 8 signals wired into 8
4051s. That routes one of 8 inputs to each output, and keeps each
output independent of one another.

-- 
Joe Grisso
Detachment 3 Engineering