Re: gEDA-user: Outsourcing PCB layout

[msokolov@xxxxxxxxxxxxxxx (Michael Sokolov)]

Kai-Martin Knaak <kmk@xxxxxxxxxxxxxxx> wrote:

> That is, you already did the initial gsch2pcb run? 

I did the uEDA equivalent thereof.  I use uEDA rather than gEDA, but the
output PCB elements and PCB netlist format are exactly the same.  All
nets are meaningfully named.

> My rule of thumb for an economical size, that is still no pain to layout 
> is twice the combined area of all components.

Would having 2 extra layers make it less pain to fit into a smaller size
or not?

Here is my issue, and it's a sentimental one: my SDSL modem design is
the functional equivalent of a CSU/DSU (sync serial on the other end, no
Ethernet), whereas all competing SDSL CPE devices are full routers.  One
particular SDSL CPE router that has caused me an untold amount of grief
in the past was the (in)Efficient Networks 5851, and my project's goal
has basically been to replace that abomination.  The PCB inside EN 5851
has 6 layers (I can tell by the layer stackup markings on the side), and
its functional section is approximately 130x165 mm.

I have previously thought about fitting my OSDCU board into that form
factor and putting it into the enclosure from a gutted EN, but I have
subsequently rejected that plan for a number of reasons.  I now want to
make it a simple rectangular PCB, but I'm keeping the 130x165 mm
dimensions.  (EN's design probably wasn't metric and their PCB was an
odd non-rectangular shape anyway, but I'm approximating and I like
metrics.)

I suppose I could make the PCB bigger than 130x165 mm if that makes the
layout labor cost much cheaper, but then we'll have a device with
CSU/DSU functionality that is physically larger than a competing device
which is a full router, and that somehow feels "wrong" psychologically.

> > Again because the project is non-commercial, mass production is not a
> > consideration.
>
> Maybe small series :-)

There is one ISP I am currently in negotiations with, they say they have
some existing customers with an SDSL-to-V.35 arrangement, but those
customers are served from some very very old DSLAMs.  The ISP says they
would like to migrate those customers to a newer DSLAM platform (still
old, but not as old as the other one), but apparently their existing
SDSL-to-V.35 CPE won't work with the other DSLAM.  I am trying to
convince the ISP to fund the NRE cost of my OSDCU (basically the cost of
the layout labor I'm soliciting right now) so they can use it as their
new SDSL-to-V.35 CPE solution that works with all DSLAM flavors.  The
ISP's response so far is that *if* they are interested (it's still an
if), they will want "maybe 100 units".  Well, 100 units is not a low
quantity in my book - but again the whole deal is still hypothetical.

I still consider my project to be non-commercial though because I want
to build it regardless of whether or not that 100 unit ISP deal comes
through, just because *I* want to have the toy for my own use on my own
SDSL line.

MS


_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user