Author Topic: Fyi: Gps Problems, Summary  (Read 4217 times)


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Fyi: Gps Problems, Summary
« on: July 17, 2008, 01:31:03 am » writes

A summary of everything related to the GPS problem.

Does the people of Openmoko know the problem?
 - Yes.

Do they work on the problem?
 - Yes, they are actively searching for a solution.

What is the problem?
 - The Openmoko Freerunner have a long TTFF with the SD card in the phone.
So it takes a long time (10min+) before you get your first GPS data.

What is TTFF?
 - This is the time to first fix of the GPS. This is the time the GPS has
needed to get the first clue on where you are on planet earth. So you have
to do this only once. After you have a FF (first fix), you can get more
fixes without any problems with the SD card in the phone.

So if we have a first fix, the SD card isn't blocking the GPS anymore?
 - yes, the SD card isn't blocking the GPS if we have a first fix. (Some
people even claim it's more stable)

Does they have a solution?
 - yes. Their is already a highly alpha software workaround. The software
just disables the SD card when the GPS tries to get it's first fix They are
also examine a hardware solution.

Do we have to return our Freerunners to Openmoko?
 - Probably not, because the software workaround should work too.

But we can't read of the SD card when the GPS is on?
 - Wrong, you will be able to read the SD card when the GPS is on. You will
probably not be able to read the SD card when you're starting the GPS (appr.
30 sec), because the GPS will only block the SD card when it's searching
it's first fix. After that you will be able to read the SD card again.

Is their a better software solution?
 - Maybe. From reading the mailing list, I have understood that half the
Openmoko team is looking into this bug. All this information is only 1 à 2
days old and the bug is also young, so I suspect they can finetune the
software workaround and make it only slowdown the SD card or even better.

Did Openmoko test the GPS with a SD card in it?
 - yes

Whey didn't they find it while testing the Freerunner?
 - Because they have to do the tests with a fake GPS signal and with that
signal it worked. (In a fab you haven't a decent GPS signal) They already
have modified the test, so it correspond the GPS signal better.

Summary of the summary:
You will be able to use the SD card in the same time of the GPS except for
the first appr 30 seconds. (And that's the worst case, because maybe
Openmoko can find better hacks/fixes)
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