Slashdotted

[Lothar Behrens]

Am 05.04.2009 um 23:21 schrieb Steve Mosher:

> Good comments All.
>
> Let me inline some answers/explanations.
>
>

Snip

>>
>> My education in 1987 till 1990, was electronics engineering. I do not
>> any more practice in that area. So I stuck in some conflict
>> not to start any electronics projects, because I have the glue the
>> project will be a one man show and keep a hobby project. But
>> if there would be a collerative project I could join, I propably
>> would. And may it only getting more practice in laying out PCB boards
>> whose schematics other developers have created.
> Ok.. here comes a question. What layout tools? are there open source
> layout tools ( one hopes) and if not then what tool do we pick?

I mentioned KICAD (http://kicad.sourceforge.net/wiki/index.php/DE:Main_Page 
).
It is capable to handle up to 16 layers, has a basic autorouter  
engine, but also could
use an external one I think.

It is multiplatform (Windows, Linux, Mac OS X and probably others).  
There is a 6 layer
PCB board as a sample that is a video grabber.

As a plus, it could display boards in 3D and supports wings 3D models  
to be used for
the parts.

Also the schematics is organized in scheets and subsheets, so one  
could divide a project
in sub projects. The scheets therefore could get connectors to enable  
inter scheet connections.
(In my words :-)

I think the same would be possible if we design PCB components with  
prelayouted stuff, but this
is only an idea with the component as is in mind - why should it not  
possible to couble a component
with a layout except the interconnection wires.

To pick up the colerative aspect of PCB design, I could ask the dev  
team, if it is possible to add
a color scheme to show the differences in layout to be a helper to  
spot differences between versions.

>
> Essentially, you are pitching the idea I'm going to try to get going.
> I'll make an announcement about it shortly, but my plate is pretty  
> full
> and I can only volunteer a couple hours a day to help organize and  
> guide it.
>>
>> If that would be possible, then it would be a real open phone :-)
>>
>> End of arsing around. Is there a potential to create a hardware
>> development comunity?
>  I think so. no harm in trying.
>>
>> To avoid that each individual will start its own variant we could
>> using a vote system before any direction is done, say wich  
>> formfactor is
>> used, for sample.
>  The voting approach will be discussed. Basically I dont believe in
> letting idiots vote. You dont want me voting on your layout and
> convincing everyone with my superb rhetoric that your 8 layer design
> can be accomplished in 2 layers.. you get my drift. The community will
> have to have SME ( subject matter experts) They will have to have some
> undemocratic powers. my view at least.

My knowledge is a bit away (Eagle, HP UX DS ??), but I know, Ill do  
something wrong, if I used 8 layers
but these are 20% filled only each.

OTOH, some guides could be applied like this: This board is a  
candidate for two layers. Don't use more than 4.

I participated layouting in motor control circuits, backplanes for  
computer systems and also
computer systems (the Transputer processor).

I got more knowledge by often doing a review and do layouts in steps.  
First the power and block capacitors then
the group of data signals and then the remaining stuff.

Critical stuff is HF and that sould be a separate step. Keep versions.  
Also an assisting layout would be helpful, like this:
I do one signal I think how it should done, an you do the rest of this  
signals (bus).

That way you avoid the risk, someone forgots the capacity in the  
signals and do wire them in paralell, but shouldn't.
Also signal length is an issue, but that is an HF issue.

About the voting: When one makes his / her first try in layouting, the  
core team should not
spend much time on it. A layouter first should get points of trust,  
thus other layouter with
some more experience should / could review the work of less  
experienced layouters, but not vica versa.

I think, this funnel also will help in finding good layouters that may  
get payd later and is fair.

I know that a hobby electronics guy will have it harder to get points,  
but others with some background
and the willing to help is a help. The hobby electronics guy could  
learn from the more experienced.

Snip

The cost:

What I didn't know is the cost for, say, 20 phones. I know there is  
the cost for the
equipment and the staff at all, but compare prototype costs with that  
here:

http://www.eurocircuits.com/index.php/PCB-production-service-overview/PCB-proto-the-new-PCB-prototype-service-from-Eurocircuits.html
and
http://www.eurocircuits.com/index.php/Service-overview/Service-Overview.html

>
>>
>> Sean: This would propably help continue GTA3 development. The risk to
>> produce it, would only invest some inspections of a new design
>> and doing integration tests. And even this could be donated.
>
> I asked sean the same. We are going to set up a mailing list at
> openmoko.org to get this started.

We don't let the press in the glue we can't manage this. Beat them :-)

-- | Rapid Prototyping | XSLT Codegeneration | http://www.lollisoft.de
Lothar Behrens
Heinrich-Scheufelen-Platz 2
73252 Lenningen