steve at openmoko.com
Mon Apr 6 03:35:04 CEST 2009
sean announced the mailing list at openexpo. also talked about our
long term view. I read through your other comments below. Thanks.
On the Proto boards. PCB is just one component of the cost of a EVT
board. I know with the Voodoo II I spent at least 1000 per board to get
a 2 day turn back in 1998 or so. The difficulty with a cell phone PCB,
and the GTA03 in particular, was the small number of houses who could
actually build the PCB, laser drilled, the 6410 BGA required a very
specialized PCB, cant recall all the details.. hey Im marketing.
Plus components for a short run tend to be very expensive. Granted I
didnt go over all the costs with a fine tooth comb. (task belongs to
engineering) In any case I think with something like Dr. N approach and
the one rattling inside my head
we could probably get through EVT with a volunteer effort. let me see
about the progress on getting the list set up.
Lothar Behrens wrote:
> Am 05.04.2009 um 23:21 schrieb Steve Mosher:
>> Good comments All.
>> Let me inline some answers/explanations.
>>> 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
> 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.
> 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:
>>> 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
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