Re: [gpsd-users] GPS fix last to long

[Krzysztof Drobiński]

Hi Gary,
thanks for replay.

On 21.08.2012 00:44, Gary E. Miller wrote:
> Yo Krzysztof!
>
> On Sat, 18 Aug 2012 14:29:18 +0200
> Krzysztof Drobiński <address@hidden> wrote:
>
> > Hi All,
> > I'm using ISM420 receiver. GPSD version is 2.95. I was wondering why
> > first location reporting by GPSD lasts so long.
> That can take up to 30 mins from a cold start.
>
> > Analysis of output from serial interface shows that time to first fix
> > is more / less 45s but gpsd reports location after 180s.
> Serial or USB connected GPS?  If serial, try settng the port speed
> before starting gpsd.  That saves the auto-baud time.
Do you mean by compile time --enable-fixed-port-speed option? I already 
set it. It's fixed to receiver's default baud (4800)
> > My question is how gpsd decides when position is ready to report?
> When it gets a position, it reports it.  Which is  AFTER it has determined the
> proper port speed and GPS type.
I think now I understand what causes the delay. gpspipe reports NMEA 
sentences after 180s as well (after I restarted gpsd).

# gpspipe -r

netlib_connectsock() returns socket on fd 3

{"class":"VERSION","release":"2.95","rev":"2012-08-21T06:02:44","proto_major":3,"proto_minor":3}

{"class":"DEVICES","devices":[{"class":"DEVICE","path":"/dev/ttyS1","activated":1345532244.64,"native":0,"bps":0,"parity":"N","stopbits":1,"cycle":1.00}]}

{"class":"WATCH","enable":true,"json":false,"nmea":true,"raw":0,"scaled":false,"timing":false}

{"class":"DEVICE","path":"/dev/ttyS1","activated":1345532393.81,"driver":"Generic 
NMEA","native":0,"bps":4800,"parity":"N","stopbits":2,"cycle":1.00}


So the issue could be probing the serial port / receiver settings. Last 
sentence

{"class":"DEVICE","path":"/dev/ttyS1","activated":1345532393.81,"driver":"Generic 
NMEA","native":0,"bps":4800,"parity":"N","stopbits":2,"cycle":1.00}

occur after about 3 minutes, then NMEA sentences are reported.
It is weird because baudrate is already set during compilation and log above
shows that gpsd is still trying to probe terminal parameters..
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
>         address@hidden  Tel:+1(541)382-8588