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| − | {{Note|Much of the information in this page is duplicated at [[GPS Problems]]; these pages should probably be merged one way or the other}}
| + | #REDIRECT [[GPS Problems]]. |
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| − | The GTA02 has a problem with signals to the SD card causing interference to the GPS receiver, effectively reducing its sensitivity by 20dB and making it slow or impossible to get an initial fix.
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| − | There has been much discussion of this on the mailing lists. On Wed, Jul 16, 2008 at 12:38 PM, Alasal <info@alasal.be> posted a summary of everything related to the GPS problem to the openmoko-community list.
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| − | ; What is the problem?
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| − | : The Openmoko Freerunner has a long TTFF with the SD card in the phone. So it takes a long time (10min+) before you get your initial GPS data.
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| − | ; Do the Openmoko people know about the problem?
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| − | : Yes.
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| − | ; Are they currently working on the problem?
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| − | : Yes, they are actively searching for a solution.
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| − | ; What is TTFF?
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| − | : This is the time to first fix of the GPS. This is the time the GPS needs 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.
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| − | ; So if we have a first fix, the SD card isn't blocking the GPS anymore?
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| − | : Yes, the SD card isn't blocking the GPS if we have a first fix. (Some people even claim it's more stable)
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| − | ; Do they have a solution?
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| − | : Yes. There is already a highly alpha software workaround. The software just disables the SD card when the GPS tries to get it's first fix. While a hardware solution has already been found it is unclear what can be done for all Freerunners currently out there.
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| − | ; Do we have to return our Freerunners to Openmoko?
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| − | : Probably not, because the software solution should be a sufficient workaround.
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| − | ; So you're saying we can't read the SD card when the GPS is on?
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| − | : No, you will be able to read the SD card when the GPS is on, just not when you're trying to get an initial fix (first starting the GPS). So the GPS will block reading from the SD card in the first moments (appr 30sec), while it acquires an initial fix, after that you will be able to read from the SD card again as normal.
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| − | ; Is there a better software solution?
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| − | : 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 - 2 days old and the bug is also young, so I suspect they can fine tune the software workaround and make it only slow down the SD card, or possibly something better.
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| − | ; Did Openmoko test the GPS with a SD card in it?
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| − | : Yes
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| − | ; Whey didn't they find it while testing the Freerunner?
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| − | : 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 have already modified the test, so it corresponds to the [real] GPS signal better.
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| − | Summary:
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| − | You will be able to use the SD card at the same time the GPS is on except for
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| − | the first 30 seconds or so. (And that's the worst case, because maybe
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| − | Openmoko can find better hacks/fixes)
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| − | [[Category:GTA02 Hardware]]
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| − | [[Category:GPS]]
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