Al Johnson openmoko at
Sat Jul 12 14:49:18 CEST 2008

On Saturday 12 July 2008, William Kenworthy wrote:
> Does it make any difference to leave the gps running 15 minutes plus
> (probably a few multiples of 15 minutes is best) then power off for a
> few minutes and then back on?

No. Every time you power off the GPS it loses the data from the sats. At 
present every start is a cold start. It is possible to save the data before 
shutdown and send it back after a restart, but AFAIK here is no app to do 
this on the Freerunner yet. I'm working on this, as an excuse to learn 
python, but details of everything needed are on the wiki.

> My freerunner isnt here yet, but my experience on a cheap bluetooth gps
> that I though just had occasional conniptions was actually operating
> according to design
> On the first fix (or a fix after a few weeks on the shelf powered off),
> it would take some time (once being over a day with poor signal) to get
> a fix, after which it would be fine getting a nearly instant fix on
> startup.
> Turns out the device needs information downloaded from a satellite and
> can take ~13 minutes to do so.  And at least one article mentioned that
> any problem/lost/corrupted data caused it to start again at the next
> start point.  So if you have a poor signal, something blocks it at a
> critical point, you can scratch that 15 minutes.
> As the freerunner has come straight from the factory, probably with none
> of this data, it will need at least 15 minutes with a good signal to get
> its data up to date.  This data is also valid for 6 weeks which explains
> the erratic operation after extended periods of non-use of my bluetooth
> unit.
> Learnt a lot reading up on this :)
> A good thread!
> BillK
> On Sat, 2008-07-12 at 10:25 +0100, Jonathan Spooner wrote:
> > I've been playing with my GPS and finally got a fix using agps diag
> > tool. I stood the gta02 up on my garden table using a pop bottle :-)  I

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