Sync serial bridging over Ethernet, was Re: [HECnet] Multi-floor household (DECnet) routing help needed

[Dave McGuire]

On 01/18/2013 01:37 AM, Ian McLaughlin wrote:
I'd do it with an HDLC/SDLC-capable chip like a Z8530...offload as 
much from the firmware as possible, leave those cycles for
protocol handling.   Unless you meant wrapping bare ?DLC frames in
packets?

I was thinking that we don't even need to decapsulate the serial
frame at all - just detect the start and end.   All we're doing is
emulating a piece of wire, after all.   Unless we're putting in a
fancy LCD status display, but I think that's overkill.

  Ohhhh ok, that's an interesting idea; make it a "dumb" transparent
bridge.   I was thinking we could do interesting translational stuff at
the protocol level, but one can't beat the utility of a dumb
get-bits-from-here-to-there bridge.   I like this idea!

I have that problem as well, but I got really excited when you 
mentioned it, because I am doing a lot of designs with Ethernet
now.   I have a "base" design, a "hardware macro" if you will, that
I've recycled several times.   It's a Philips..erm, NXP
LPC2300-series ARM7 with an on-chip Ethernet MAC, and all
supporting hardware.   I typically run FreeRTOS and uIP on them.

The only things I have dev platforms are on my end are PIC and Atmel.

  I do a lot of AVR stuff for work, but mostly that's maintenance of
previous controllers.   All of our current stuff (and my personal stuff)
is ARM7 now.   If (and I'm not pushing, or even suggesting!) you ever
want to get into it, I can give you a big head start.

I have some Zilog stuff, but I gave up on them several years ago.

  Same here...after a significant investment in time, code, and blank
PCBs.   Their management is incredibly, unbelievably bad.   I used the
eZ80F91 in several commercial products.   Great chip.   Crappy tools.
Crappy company management.

However, if you're able to put together the hardware layer, and
there's a C compiler available for your platform, I can help on the
software side.   I've also done some software work for a local company
that uses a TI Davinci processor.

  I am, and there is, that would be great, and...wow that's cool! :-)

  What sort of hardware interface would you envision?

Interfacing an ?DLC engine to that would be a cakewalk starting
from that base design as a head-start.   I have a few tubes of
Z8530s in PLCC-44 packages here.

Oh oh.   I think there's another project starting... :)

  Oh there are just too many. ;)

                      -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA