Reason for GPS problems found!
openmoko at mazikeen.demon.co.uk
Tue Jul 15 14:53:21 CEST 2008
On Tuesday 15 July 2008, thomasg wrote:
> Hi ppl,
> I write this to community, not to devel or owners because everyone should
> *sbeh*, one of the people in #neo1973-germany IRC-channel found the reason
> for the GPS problems.
> The problem only occurs if a SD card is set in. Doesn't matter if it's
> mounted or in use, it just has to sit in the socket.
> The TTFF went from no fix at all to TTFF 120 seconds indoor(!!!), and about
> 40 seconds outdoor.
> Two other people could verify this with about the same results.
> We'll do more tests later, but for now we surely know what's causing the
> problem (and it seems to be a EMC problem).
> First results show at the same devices, even outdoor, that there is no fix
> in over 400 seconds with SD card, the signal seems to be at least 10 to 20
> dB worse (so bad, that most satellites don't even appear).
> Testresults from other people appreciated.
Another confirmation. Unassisted TTFF outdoors close to buildings and trees is
consistently ~45s with card removed, 2 to 10 minutes with card present.
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