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

[Ian McLaughlin]

On 2013-01-17, at 10:20 PM, Dave McGuire <mcguire at neurotica.com> 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.

Wrapping the data in UDP is simple.   The HDLC layer could deal with
error detection/correction.

Yes!

The problem is finding surplus time to embark on this.   Maybe a few
of us could collaborate on it?

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

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... :)

                          -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA


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