[time-nuts] Form factor

[Chris Albertson]

On Wed, Dec 22, 2010 at 3:32 PM, Poul-Henning Kamp <phk at phk.freebsd.dk> wrote:

> I used a shared opto-isolated async bus.  You need two optocouplers
> per microcontroller, and one place you power the shared bus, and
> you're all set.
>
> I have yet to see an microcontroller without an async port.

Opto-isolater?   Why not just use fiber cable between cards.    I know
it sounds exotic but also seems to have half the parts count.  those
s/pdif jacks are so cheap and I bet you can use them as pretty much
drop in replacements for opto-isolators.  Would s/pdif jacks work as a
physical layer?

Really I just used I2C in my write-up as a place holder.  I you say
nothing no one ever says a blank paper is wrong and suggests something
better.

s optical isolation required when all the modules are sharing a common
power supply?  Does this means all the coax connectors need to be
isolated.  I guess some one better step up and propose a grounding
scheme.  That's not going to be me.
=====
Chris Albertson
Redondo Beach, California