gta02-core and external GPS antenna

Steve Mosher steve at
Fri May 29 17:18:07 CEST 2009

Personally I always thought that a phone targeted at developers out to 
have as
many ins and outs as practicable. That said, On the sales side we never 
did see
much uptake for the external GPS antenna. From a logistics point of view
getting uniques off the board is a good good thing. I would concur with 
the decision
to remove it. However, u may want to check with Tully on the mechanical 
I have his personal email here somewhere in case he doesnt answer the om 

Question: are you considering folding in the A8 changes? and the 1024 fix?
beware on the A8 microphone as it requires an annoying case mod. doable,
but annoying.


Werner Almesberger wrote:
> There's one simplification that looks attractive to make in gta02-core
> and that's to remove the external GPS antenna connector. From what I've
> heard, this antenna is rarely used in the FreeRunner, and for
> stationary use, one could connect an external antenna to the socket for
> the internal antenna.
> There are the following benefits in removing the external antenna:
> - reduced SMT cost by removing about a dozen components, some of them
>   unique. Due to its shape, The antenna connector may also need
>   special treatment in SMT, such as glueing.
> - fewer components means less risk of getting interferences. This goes
>   particularly for the external antenna socket when open.
> - simplifies the layout of the GPS RF circuit and thus reduces the
>   risk of us getting something wrong.
> - when investigating the SD/MMC vs. GPS problem, Andy found that the
>   antenna selection circuit is operating with an incorrect voltage.
>   Apparently, this didn't cause any observable problems, but then
>   you never know what's really behind the occasional glitch ...
> - in case future designs are made based on gta02-core, a smaller GPS
>   subsystem may allow for a smaller PCB size or give more room to
>   other subsystems
> There are also a few disadvantages:
> - if you really need the external GPS antenna along with the internal
>   one, this will not be a welcome change
> - the antenna connector also helps to hold the PCB in place. Without
>   it, there is only USB on that side of the board to assist the
>   snap-in mechanism. (Probably doesn't matter all that much, though.)
> - removing the connector leaves an empty hole in the case
> I think the benefits outweigh the disadvantages, so I'd like to see
> the external GPS connector gone.
> Any thoughts ?
> - Werner
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