[Discuss-gnuradio] GPSDO and B2100

[Sharath Ananth]

Hello,
I recently installed a board mounted GPSDO (TCXO) on my B2100. Specifically I 
am using this in a USB powered mode and the web-site did say that the TCXO 
works off the USB power. I am using a passive antenna at the moment.

Now most of the time I get warning display "No GPRMC message found". Only in 
two cases during the day have I seen the green LED on the GPSDO turn on, in 
which case the warning message went away, so I know all is well with the board 
and the mount.

Now my questions:
(i) Is there a way to force the B2100 to use the internal clock and not wait 
for the GPS fix for all applications? For example I don't want to change the 
uhd_usrp_proble executable, but would like the board to use the internal clock 
and not wait for GPS fix. Is there a way to toggle the mode from automatic to 
internal clock for all applications via a jumper or other means? I don't want 
to recompile other working
 applications just because I have installed the GPSDO.

(ii) Does the active antenna work of USB power?

(ii) Once the GPS actually starts working, how can I use gpsd to get the gps 
data. That is, the web page http://files.ettus.com/manual/page_gpsdo_b2x0.html 
says "Other information can be fetched as well. You can query the lock status 
with the gps_locked sensor, as well as obtain raw NMEA sentences using the 
gps_gprmc, and gps_gpgga sensors. Location information can be parsed out of the 
gps_gpgga sensor by using gpsd or another NMEA parser." The last sentence is 
what I want.

I do have gpsd and gpsdx installed on my Mac. However neither can be configured 
to actually get the data from the GPSDO module. 
For example the options in the gpsdx does not see an external USB GPS to begin 
with.

Any suggestions are welcome.

Thanks, Sharath