GPS testing on 2008.12

Ed Kapitein ed at kapitein.org
Wed Dec 24 09:09:53 CET 2008


Hi Jan,

You could try to work on the low level first:
If you activated gps in the settings, try to do
cat /dev/ttySAC1
this should give you some output like this:

root at freerunner:~# cat /dev/ttySAC1
NMEA unknown msg*58

$GPTXT,01,01,01,NMEA unknown msg*58

$GPTXT$GPRMC,,V,,,,,,,,,,N*53

this would indicate that the unit is in fact powered on and working.

Next you could try to start gpsd ( /etc/init.d/gpsd start )
make sure the device in /etc/default/gpsd is /dev/ttySAC1
now you can use gpspipe -r to check if gpsd is getting data.
(gpspipe is in the gps-utils package, so you might have to use opkg
install gps-utils first)
it should look something like this:

root at freerunner:~# gpspipe -r
GPSD,R=1
$GPZDA,,,,,00,00*48
$GPTXT,01,01,01,PSRF inv format*2B
$GPTXT,01,01,01,PGRM inv format*34
$GPTXT,01,01,01,PFEC inv format*2C
$GPRMC,,V,,,,,,,,,,N*53
$GPVTG,,,,,,,,,N*30
$GPGGA,,,,,,0,00,99.99,,,,,,*48
$GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30

this would indicate that gpsd is running.

Time to first fix might take a while, please read the wiki about that.
The assisted gps tool (agps-onlinec) really makes the TTFF much faster,
so give it a try.
If you swich of the gps unit the almanac info received with agps-onlinec
seems to be lost, so run it again after each power up of the gps unit.

with tango gps in the "trip" section you can see how many satelites
should be in view and how many are in view. something like 10/6.

I hope this will get you on your way.
I can recomend navit as an gps application, it is a bit like tomtom and
i find it very usefull.

Kind regrads,
Ed
 


2008-12-24 at 01:37 +0000, Jan Henkins wrote:
> Hello all,
> 
> I hope somebody here might have an idea or two that might shed some 
> light. I've trawled for HOWTO's and recipes on how to get the GPS 
> working on my FR, but to no avail, none of them worked at all. In order 
> to to some low-level testing to acertain whether I have a possible 
> hardware problem or not, is there a way to check the GPS device for 
> activity of some sort? I've left agpsui running for almost half a day 
> (with GPS enabled in Settings of course), but I get no good fixes or any 
> TTFF.
> 
> The rest of the phone seems to be working OK, I  manage to make/receive 
> calls and SMS's reliably. I have even managed to sort-of stabilise 
> 2008.12 with regards to suspend, and also managed to get Enlightenment 
> to stop crashing all the time with Illume (thanks to Yaroslav's WIKI 
> entry!). Any ideas how I can do some low-level testing on the GPS device?
> 
> Thanks in advance!
> 





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