marcosartore
Posts: 14
Joined: Thu Jan 15, 2015 3:07 pm

CM3 vertical socket

Wed Mar 15, 2017 8:35 am

Hello,
does anybody know if it exists, where to buy and which ordering code of a CM3 socket "vertical mount", i.e. so that the CM3 module will result orthogonal to the board where it fits instead of parallel as in the usual way ?

Many thanks in advance,
Marco

PiGraham
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Re: CM3 vertical socket

Wed Mar 15, 2017 8:49 am

Like this?

http://uk.farnell.com/te-connectivity-a ... dp/2396418

Image

You should confirm compatibility, but it seems to match the CM spec:
The Compute Modules conform to JEDEC MO-224 mechanical specification for 200 pin DDR2 (1.8V) SODIMM modules

marcosartore
Posts: 14
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Re: CM3 vertical socket

Wed Mar 15, 2017 9:30 am

Thanks for your answer, but I believe that it is one of the usual horizontal mounting sockets.
The 200 pins solder on top of the PCB as for any SMD device, but the CM3 is then inserted and locked in a horizontal position with this connector.
They did this way because these sockets are widely used in laptops where the vertical spacings are an issue. Instead in an application with the Compute Module I would prefer a vertical mounting.
Marco

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RaTTuS
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Re: CM3 vertical socket

Wed Mar 15, 2017 9:34 am

I think that one is right angled to the board
see also
http://uk.farnell.com/webapp/wcs/stores ... ,113188599
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marcosartore
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Joined: Thu Jan 15, 2015 3:07 pm

Re: CM3 vertical socket

Thu Mar 16, 2017 10:42 am

Hello,
many thanks for your answers.
Unfortunately, what they mean with "right-angled" is that the socket is 90° angled with respect to the PCB where the pins are soldered. This yields to a setup where the SODIMM module results parallel to the PCB, not right-angled.
With right-angled I mean something like the personal computer's PCI sockets, where the plug-in cards (and not the socket itself) result perpendicular to the main board's PCB.
Anybody else has a suggestion about ?
Many thanks in advance,
Marco

PiGraham
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Re: CM3 vertical socket

Thu Mar 16, 2017 4:46 pm

You may be right. Did you check the datasheets? I just assumed they were illustrating all sockets as the sit on a PCB.

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RaTTuS
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Re: CM3 vertical socket

Fri Mar 17, 2017 8:00 am

aha I think your right - most all SODIMM sockets I've seen are like that
http://www.te.com/usa-en/products/conne ... ckets.html
looks like 200pin ones are always right angled
others are vertical :-(
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PiGraham
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Re: CM3 vertical socket

Fri Mar 17, 2017 11:18 am

I see that some "blade cluster" designs for CM use the standard SODIMM connector on a "blade" carrier that plugs into a vertical socket on the baseboard. The flat SODIMM making a slim two board "blade".
https://4.bp.blogspot.com/-TWlh44WY6-Q/ ... 8_orig.jpg

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red_mamba
Posts: 39
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Re: CM3 vertical socket

Sat Mar 18, 2017 2:57 pm

I used this one, but it's for DDR. So you need to widen the gap on the module to fit

https://www.digikey.co.uk/product-detai ... ND/4732027

Still looking for a better fit for my cluster project if anyone finds one :lol:

aBUGSworstnightmare
Posts: 1492
Joined: Tue Jun 30, 2015 1:35 pm

Re: CM3 vertical socket

Mon Mar 20, 2017 4:50 pm

You're looking for TE Connectivity part no 2040910-2 or 2040910-3
http://www.mouser.com/ds/2/418/NG_CD_20 ... 620686.pdf

Problem is finding someone selling it in small quantities.

http://www.te.com/usa-en/product-2040910-2.html


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red_mamba
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Re: CM3 vertical socket

Sat Apr 15, 2017 10:32 am

Just finished soldering mine and I'm happy to report it's working :mrgreen:

Image

MH6
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Joined: Wed Aug 26, 2015 2:26 am

Re: CM3 vertical socket

Tue Apr 18, 2017 2:40 pm

red_mamba wrote:Just finished soldering mine and I'm happy to report it's working :mrgreen:

Image
Which part did you end up going with? I long ago gave up trying to find a decent source for cheap, low quantity vertical SODIMM connectors outside of China. The horizontal ones are much more abundant thanks to laptops.

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red_mamba
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Re: CM3 vertical socket

Tue Apr 18, 2017 3:23 pm

MH6 wrote:
red_mamba wrote:Just finished soldering mine and I'm happy to report it's working :mrgreen:

Image
Which part did you end up going with? I long ago gave up trying to find a decent source for cheap, low quantity vertical SODIMM connectors outside of China. The horizontal ones are much more abundant thanks to laptops.
The one I posted in my previous post. It's for 2.5V modules. So does not fit the CM unless you widen the gap.

Would be great if factory CM would have wide gap so that would fit both 1.8 and 2.5V version of connectors.

Next step is to build the cluster board.

brianjaod
Posts: 5
Joined: Thu Aug 03, 2017 4:34 pm

Re: CM3 vertical socket

Fri Aug 04, 2017 7:21 pm

Just wanted to chime in to share my experience, doing the same hack on the CM3 as a result of the same TE connector, in case it's helpful to anyone. More details here of my solution viewtopic.php?f=98&t=190048.

I modded a pi module the same way, by cutting the key notch just slightly (with a dremel) to allow for placement of the pi module in the DDR (vs DDR2) connector. I then powered up the system and it booted great and I thought all was great, but then I started having problems with booting. Some power ups would boot fine, and others (more than half the time) would not boot up at all, nothing over the serial at all. So apparently I must have slightly dinged an important internal layer trace (or two) from my cutting, to cause the booting (and who knows what else) to become unreliable. For a short term proto hack and more careful notch trimming, this still might make the readily available DDR TE connector work ok-ish, but it's not a production solution, which is probably the use case for a lot of compute module users/integrators.

The other risk of trimming the key notch approach, is even if it doesn't damage any internal layer traces, it now means that the module contacts don't align automatically with the connector pins. With them being only 0.6mm pitch, it doesn't take much side to side sliding for them to not align correctly.

Anyway, my solution (thanks to another's generous sharing) was to find this correct DDR2 connector from JST: http://www.jst-mfg.com/product/detail_e.php?series=520. Unfortunately, it wasn't readily in stock from Digikey, but I was still able to get some samples from JST and now it's working.

Killertechno
Posts: 177
Joined: Wed Jan 02, 2013 8:28 am

Re: CM3 vertical socket

Tue Apr 02, 2019 10:52 am

I don't know if any news...
I found this from JST website (UK), why not make a buy group?
DM-7D4-H2500
Uk users could then sell It to other european users...

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