[Arm-netbook] Just a thought...

[Scott Sullivan]

On 10/22/2013 01:35 PM, Christopher Havel wrote:
> It occurred to me, just now, that if the MEB (or any other EOMA-68
> carrier board) is put in a housing with built-in guides for the CPU
> Card, then we don't necessarily need a proper PCMCIA slot -- just a 2x34
> right-angle pin header with 1.27mm spacing. Have the bezel of the CPU
> card stick out just a touch from the housing, so that someone can get
> their fingernail (or a small slot screwdriver) under it and pry just
> enough so that they can yank it out.

There are instances in some of my ideas for custom enclosures where I'd 
like to have the EOMA-68 card vertical relative to the PCB. I have not 
yet found a PCMICA connector that does that. This would be a justifiably 
place to put in some guides and a pin header as you describe.

Last time I looked down this path I had only minimally encouraging 
results (limited to searching digikey). If I recall I found a 80pin 
header with the right spacing, but the pins were too short. If they had 
been longer, I could justify buying a few and cutting them down to size 
for one-offs.

> Seems to me that it'd be a cheaper option as well, because of the
> wonders of injection-molded plastic... even making the housing out of
> something fairly sturdy, say 2mm ABS, surely wouldn't cost too terribly
> much... plus, it's potentially possible to 3d print such a thing, which
> would make this stuff even more accessible to the (far richer than me)
> hobbyist. (Of course it'd also be possible to 'jerry-rig' it with scrap
> materials and lots of fussing.)

Depending on the model of PCMICA socket your looking at, that can be all 
they are. I know the socket on MEBv1 would be close to fitting under 
this definition of injection-moulded plastic guide. It had the added 
benefit of being cheap and off the shelf and no need for an extra pin 
header.

http://rhombus-tech.net/community_ideas/micro_engineering_board/

It's easy to consider custom options based on 'it will be good enough 
for me', but that logic doesn't fly with a product where you expect to 
sell more then any where from a dozen to a few thousand. When ordering 
that and larger quantity of parts it does become cost effective to ask 
for a custom part from a manufacturer of PCMICA connectors. That cost 
effectiveness is also including the weeding out of manufacturing 
defected parts!

Case in point, the blue 0.1" headers on the Netduino.

http://netduino.com/hardware/

You can not go to digi-key and get hearers in any colour you like. But 
if you have the capital and a large enough _direct_ order, anything is 
possible, including a branding statement like blue pin headers.

This is a case where if there is enough of uses cases for wanting such a 
vertical header, we could pool resources for an order. But I don't see 
that happening until there is a regular production runs of EMOA-68 cards 
to justify it.

> I'd love to see a housing like that, with a small carrier board (perhaps
> a VGA-enabled version of the MEB?) and a VESA 75mm mounting option. It
> would enjoy a permanent placement on the back of my spare LCD for sure.
> (The carrier board would definitely have to support VGA through some
> means, though, to work with that screen.)

I think I'm starting to ramble.

-- 
Scott Sullivan