On 02/19/2015 07:47 PM, Sharath Ananth wrote: > 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.
There's no jumper or hardware way (short of taking out the GPSDO). You can call set_clock_source() (see the manual: http://files.ettus.com/manual/classuhd_1_1usrp_1_1multi__usrp.html#a73ed40009d0d3787c183d42423d25026) If you're using GNU Radio & Python, that won't require a recompile (see the GR manual: http://gnuradio.org/doc/doxygen/classgr_1_1uhd_1_1usrp__sink.html#aac2a32bcaa207c18a0b8c037760508e6). > (ii) Does the active antenna work of USB power? You should be good, but in general, GPSDO+2x2 MIMO pushes what bus power can provide and is considered unreliable. > (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 just had a very brief look at the gpsd man page, and it seems it works with devices that are directly connected to the PC -- this isn't how the B2x0 + GPSDO where intended to be used (you won't find an 'attached GPS device' on USB anywhere). If you want to use gpsd, you'll probably need to 'fake' such a device by polling the NMEA strings. Maybe someone out here has done that before? Cheers, M > 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 > > > > > > > > > _______________________________________________ Discuss-gnuradio > mailing list [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
