Werner Almesberger werner at openmoko.org
Sun Apr 12 07:50:40 CEST 2009

Steve Mosher wrote:
> or more generally what is the next Open 
> source/open hardware phone that the community can build?.

I think "can" is the key word here. A lot of the discussion
I've seen so far reminds me of what we did with GTA01: blissfully
ignorant of what it means to mass-produce something, we treated it
as if all it took was to make an engineering prototype. Once that
one "worked", we'd be okay, right ?

Unfortunately, a lot more is needed to make a real product. It
starts with finding parts that are actually available throughout
the whole product lifecycle [1], that are available at a tolerable
price in mass quantities [2], and that are supported by the vendor

A lot of the problems Openmoko had to deal with weren't even
publicly visible. E.g., Sean must have spent months negotiating
with LCM vendors.

And once you have the parts, you need to find a factory that can
actually build the device. Some parts had yield rates as low as
50%. Quite obviously, while this may be okay for an engineering
prototype, you'll have a hard time being profitable if you have to
bin half of your hardware.

And that means that you have to find the bad apples in the first
place. In GTA01, we just proudly presented the factory with the
bringup and testing process process we had cooked up in
engineering and expected them to use this. In fact, they did as
they were told. So the factory workers plugged in debug board
cables and then manually ran the devirginator. If it failed, they
did it again. (In GTA02, things were a little smoother.)

There's a lot more. The bottom line is that it's hard to
mass-produce something and that the experience one gets from making
some prototypes or small "hobbyist" runs doesn't really prepare for
industrial production. It's very easy to overlook this difficulty
but reality will catch up when things enter the production stage.
Naturally, that is a really bad time for "surprises".

[1] E.g., Calypso almost got changed to a more restricted revision,
    Calypso's memory got changed, the CPU got changed to different
    chip revisions several times during the development of GTA02
    and GTA03.

[2] E.g., CPU, LCM, GSM, WLAN, and GPS aren't parts you can just
    order from Digi-Key. And if you can, the price will be very
    different from what you can sustain for production. In fact,
    we once had to order LCMs for a larger HXD8 prototype run from
    Mouser at the price of a small car because sourcing had failed
    to stock them at the agreed-upon price in time.

[3] E.g., consider the ridiculous amounts of time we had and still
    have to sink into AR6k, Calypso, both with deficiencies in
    vendor support, and to a lesser extent GPS and the CPU itself.
- Werner

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