su, 2008-07-13 kello 03:48 -0700, Russell Sears kirjoitti:
quoted text
> The current software drivers do not save any state between GPS locks, so 
> the GPS device is needlessly re-downloading information from the 
> satellites each time it turns on.  Downloading the data seems to require 
> a much better/more consistent signal than calculating the phone's 
> current position.

Doesn't just seem to, it does need a better signal. And yeah, being able
to restore that data and/or get it from the network should provide much
quicker first fixes. From #openmoko:
<DocCod> cold start: like 10 minutes for a fix
<DocCod> agps data feeded immediately after start: fix in 1 minute or less
<DocCod> between 2 tall buildings, btw

Anyway, as for the GPS problems some are having, I got a fix relatively
quickly on a phone another guy had problems with from the first Finnish
group batch. The difference mostly that he used some of the frontends
and I grepped the device node directly. So there might've been some
software glitches at work with eg. gsmd getting confused at the chip
output (which includes large amounts of those spurious error messages
and stuff). (Of course, it _might_ have been a flaky but not
consistently faulty connection too; we'll keep an eye on the device if
it starts acting up again.)

So anyone who's having GPS problems should probably make sure it's
hardware by checking out the GPS chip output at the lowest level by
doing something like:

echo 1 > /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/neo1973-pm-gps.0/pwron
grep GPGGA /dev/ttySAC1

And seeing if there'll be fix-looking data within, say, 10 minutes to be
sure, on a decent exposure of the sky. (You can do that remotely in a
screen session and then attach to it with "screen -dr" from the OpenMoko
terminal to make it easier to type it in but still get the output from
the Neo.) See http://wiki.openmoko.org/wiki/GPS on what a fix looks
like.

Hope this helps someone.

-- 
Mikko Rauhala   - mjr@iki.fi     - <URL:http://www.iki.fi/mjr/>
Transhumanist   - WTA member     - <URL:http://www.transhumanism.org/>
Singularitarian - SIAI supporter - <URL:http://www.singinst.org/>




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