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Re: [Xylo-SDR] Some design thoughts requested
Cecil
I don't think you will find any 'motherboards' based on this connector,
however it is cheap, high density, available for the foreseeable future and
we have designers on hand to make it work as a mother board. Fairly easy to
design since it is an open buss with all (or most) pins undedicated. Kicad
makes buss design pretty easy with labels. I think even with a suitable
perhaps aluminum extruded enclosure of the right depth this would be more
than 50 bux (cost) to produce. Spacing of motherboard connectors would, and
should be dependent on the project box. Raw power should come in from the
'back' (front?) on to the mother board, and pick up traces, +/- 12 and 5 DC
further regulation and filtering done by the board designer. Buss
termination could also go on daughter boards.
Symstik is an example of a hobby designed buss which gained favor, and
probably sold quite a few boards and kits.
I think with a little thought from this group, looking for a 'means to an
end' that we could produce a viable solution to many other groups looking
for something like this. I sure have not seen anything but Symstik.
We could look further in the commercial world. GE 90/30 series has a pretty
slick backplane for mounting their standard 'cards', with power supply, but
EXPENSIVE and LARGE!
At the moment we need a readily available side rail enclosure open front and
back which will fit the slide in boards.
Thanks!
Eric
-----Original Message-----
From: xylo-sdr-bounces@lists.ae5k.us [mailto:xylo-sdr-bounces@lists.ae5k.us]
On Behalf Of KD5NWA
Sent: Tuesday, January 03, 2006 6:58 PM
To: Xylo-SDR Discussion
Subject: Re: [Xylo-SDR] Some design thoughts requested
I looked for quite a while and did not find any breadboards using
this connector, this style board is a good idea if you are not going
to have very large boards. But like you mentioned there would be a
need for a motherboard and a some breadboards. Either a group
purchase or at least someone that can layout the boards makes the
files available so we could order our own boards. Actually a group
buy would be way cheaper, but also have the art available as a
starting point for any new design.
As far as connectors, if you put a lot of them, lets say .25" apart,
you can chose where to put a socket and have narrow or wide spacing
according to the project needs. One motherboard for all occasions.
As far as grounds in-between lines, you don't always need that, if
you have a group of signals that change together then they can be
grouped together without interference, clocks though need to be kept
away from control or data signals.
You should have a could of connectors at the end of the bus that are
not bussed except for power and grounds, the other pins should have pads.
The bottom line if you make the art available, people can make custom
versions that have a section that is compatible with everyone else's,
and a custom side if needed.
Either something like this or the Eurocard is workable, the Euro has
the advantage that there is a huge selection of already available
cards, cages, and motherboards.
At 05:14 PM 1/3/2006, you wrote:
>Phil
>
>Thanks! I'll take a look at this again. The only reason I did not proceed
>along this track, is that "Hunt as I might" I could not find commercial
>riser cards, and symstik had too few connections. Even If I did find a
riser
>the spacing would be too close. The sockets are available, but we would
have
>to design our own motherboard. I don't think is that farfetched an idea
>since we could define the spacing and put the raw voltage regulators (5,
12,
>and perhaps -12) on the motherboard.
>
>I am sort of tired of sending out stuff without the forthought for
>packaging. I think in this project it is especially important, since we can
>do A LOT of things with the PGA if we think about the project design from
>the outside - in, and create something which can be an anything design
based
>on the FPGA like a Scope card, a Spectrum analyzer card, a Radio etc!
>
>I think that 184 pins should give us all we need even if we ground every
>other pin for better noise immunity.
>
>Comments?
>
>Eric
>
>
>
>
>-----Original Message-----
>From: xylo-sdr-bounces@lists.ae5k.us
[mailto:xylo-sdr-bounces@lists.ae5k.us]
>On Behalf Of Philip Covington
>Sent: Tuesday, January 03, 2006 1:12 PM
>To: Xylo-SDR Discussion
>Subject: Re: [Xylo-SDR] Some design thoughts requested
>
>Hello all,
>
>I considered using DDR SIMM sockets for a project. You get 184
>contacts and they give you a card width of 5.25". The height of the
>card is not restricted (within reason).
>
>http://www.molex.com/pdm_docs/sd/876362002_sd.pdf
>
>It is kind of like the SIMMStick idea, but with more contacts (184 vs
>30). 30 pin SIMM sockets are very hard to get these days and I see
>that Molex has scheduled the 72 pin SIMM sockets for obsolescence.
>The DDR DIMM sockets should be around for a while yet. They are
>relatively cheap ($1.92 ea Digikey).
>
>73 de Phil N8VB
>
>
>On 1/2/06, Eric Ellison <ecellison@comcast.net> wrote:
> >
> >
> >
> > Cecil
> >
> >
> >
> > Yes, I'll go back and look at Eurocard standard. This looks great. GUD
> > HUNTING! Thanks for all the links. One way or tother I think we need a
>buss
> > for our end product. Your point about size of the boards we might want
to
> > manufacture is well taken. They should be able to go on a little more
than
>a
> > postage stamp, and be VERY inexpensive to produce - external connectors
> > being the limiting size factor! One reason I was looking at Memory Chip
> > risers.
> >
> >
> >
> > I moused around a little today, and really can't see where I can justify
> > Eagle Software in any serious production version. So I'll probably
monkey
> > around with Kicad, which is a really nice GPL product. I mentioned
earlier
> > that there was some problem with the Drill files, which they have
>corrected.
> > Only benefit of Eagle IS the plethora of template files available. I
don't
> > mind eating on my lunchtime and creating new parts! Good exercise and I
am
> > getting fatter! (No Testosterone!)
> >
> >
> >
> > Sparkfun has a pretty good batch deal for prototype boards and also a
lot
>of
> > interesting new products. I like their little 3 buck power supplies.
Also
> > have a some 28 pin SOIC to DIP experimenter stuff for about the same
>price.
> >
> >
> >
> >
>http://www.sparkfun.com/shop/index.php?shop=1&cart=525299&cat=1&PHPSESSID=a
b
>ce58b426cb8d0d0c3cf4b1495f0312
> >
> >
> >
> > Other prototype boards can be had at:
> >
> >
> >
> > http://protoboards.theshoppe.com/index.html
> >
> >
> >
> > Will return!
> >
> >
> >
> > Viva the Project
> >
> >
> >
> > Eric
> >
> >
> >
> > ________________________________
> >
> >
> > From: xylo-sdr-bounces@lists.ae5k.us
>[mailto:xylo-sdr-bounces@lists.ae5k.us]
> > On Behalf Of KD5NWA
> > Sent: Monday, January 02, 2006 2:06 PM
> > To: Xylo-SDR Discussion
> > Subject: Re: [Xylo-SDR] Some design thoughts requested
> >
> >
> >
> >
> > I'll second the DIN connectors,they are very reliable, and come in
>different
> > sizes, single, and dual connector cards. I have used them in an
industrial
> > environment and they worked flawlessly for years. But I'll go one more
>step
> > forward.
> >
> > The Eurocard standard allows for mix of one 96 pin connector, two
> > connectors or even three connectors (not needed). Prototype boards are
> > cheap, most PCB houses have specials on Eurocard size boards. Card cages
>are
> > available for low prices for the Eurocard format
> >
> > Like Leon said the connectors are expensive but they are self aligning,
>and
> > I've seen then for under $3 on the Internet.
> >
> > Although the PCI is tempting and cheap for the backplane, it's a bus
that
> > is designed for digital logic, all pins are tied to the same pins in all
> > cards. Prototype cards tend to be large and expensive.
> >
> > A brief blurb on Eurocards;
> >
> > < http://www.yotor.org/wiki/en/eu/Eurocard.htm >
> >
> > Cheap prototype boards are available for $10 or less, a very important
> > point, $50 to $60 for a PCI card is very expensive, maybe I'm too cheap,
>but
> > the blank board should not cost more than the components.
> > < http://www.sbszoo.com/ve6sbs/sale/cct-brds.htm >
> >
> > Here are some available at Mouse;
> > <
> >
>http://www.mouser.com/index.cfm?handler=data.getPcodes&pcode=BPS%2BPrototyp
e
>%2BBoards&pcodenumber=85400
> > >
> >
> > Sample enclosure, can be home made from aluminum extrusions.
> > < http://www.busboard.net/bps-enc.htm >
> >
> >
> >
> > At 03:34 AM 1/2/2006, Leon Heller wrote:
> >
> > ----- Original Message -----
> >
> > From: Eric Ellison
> >
> > To: 'Xylo-SDR Discussion'
> >
> > Sent: Monday, January 02, 2006 5:17 AM
> >
> > Subject: [Xylo-SDR] Some design thoughts requested
> >
> > Folks
> >
> >
> >
> > Even since the PIC 4550 days I have been thinking on how we might
conduct
> > experiments as well as have a reasonable environment for addingon to
>the
> > project. The obvious answer is a buss of some sort. I have looked at
> > everything from Simm riser boards to ISA buss stuff. PCI risers might be
>the
> > way to go since they are inexpensive ($15) for 3 slot extenders. Also in
>an
> > end product they fit into the L-brackets of a computer case, or 2U
mounts.
> > They have assignedpower busswe can use, fairly inexpensive
>prototyping
> > boards. ($50 - $60), are four layer and designed to minimize intra trace
> > noise. The buss wouldnt be used for PCI, however it would allow power,
>(on
> > designated standards based lines), intra board connections, and FPGA,
> > I2C,signals etc.
> >
> >
> >
> > PCI seems to be a little largefor what we are proposing, and the
>product
> > boards would cost more to produce, however, with an established buss we
> > could put a radio on one card, FPGA on another Audio on another etc.
> >
> >
> >
> > $15 Board amongst others:
> >
> >
> >
> >
> >
> > http://www.plinkusa.net/riser.htm
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > Am I off the wall here?
> >
> >
> >
> > That's the sort of thing I was thinking of doing. I used to work for
Racal
> > and they used to build their military radios from separate screened
>plug-in
> > modules on a backplane.
> >
> >
> >
> > I favour DIN41612 connectors for this sort of thing. They are
expensive,
> > but very reliable, and have pins on 0.1" centres. They can even
accomodate
> > co-axial connectors. They are more commonly used in Europe than the USA,
>but
> > you can get them over there without any problems.
> >
> >
> >
> > 73, Leon
> >
> > --
> > Leon Heller, G1HSM
> > leon.heller@bulldoghome.com
> > http://www.geocities.com/leon_heller
> > _______________________________________________
> > Xylo-SDR mailing list
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> > Subscription help:
> > http://lists.ae5k.us/listinfo.cgi/xylo-sdr-ae5k.us
> > Xylo-SDR web page: http://xylo-sdr.ae5k.us
> > Forum pages: http://www.hamsdr.com/hamsdrforum/
> >
> >
> > Cecil Bayona
> > KD5NWA
> > www.qrpradio.com
> >
> > "I fail to see why doing the same thing over and over and getting the
>same
> > results every time is insanity: I've almost proved it isn't; only a few
>more
> > tests now and I'm sure results will differ this time ... "
> > _______________________________________________
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> > Subscription help:
> > http://lists.ae5k.us/listinfo.cgi/xylo-sdr-ae5k.us
> > Xylo-SDR web page: http://xylo-sdr.ae5k.us
> > Forum pages: http://www.hamsdr.com/hamsdrforum/
> >
> >
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Cecil Bayona
KD5NWA
www.qrpradio.com
"I fail to see why doing the same thing over and over and getting the
same results every time is insanity: I've almost proved it isn't;
only a few more tests now and I'm sure results will differ this time ... "
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