David Lord <[email protected]> writes: >James Browning wrote: >> On Sep 17, 10:52 pm, "David J Taylor" <[email protected] >> this-part.nor-this.co.uk.invalid> wrote: >>> Don't worry about trees - a modern GPS such as the GPS 18x LVC is very >>> sensitive, and can work with a lot of obscuration. Although my GPS 18 LVC >>> is sitting on the roof, the GPS 18x LVC works just as well sitting in a >>> room on the top floor of the house. >> >> I have a SiRF star III based USB dongle (US GlobalSat BU-353)</plug> >> that I got a location off of in a basement room about 6 feet from the >> window. currently it's attached to box whos' ntpd crashes every time >> I >> mention it. I think it's talking in the binary mode and the kernel >> device >> is tuck at the wrong speed. (I probably just need to restart it.)
>You can check with minicom or similar as to output. I used >Telix from DOS with my BR304 to set to just give a single >RMC sentence per second output. The codes needed to switch >modes were in the br304 manual I downloaded. >Having said that the br304 is now in pieces to be explored >with scope probe in case it's possible to locate any signal >usable for ntp. Best I had was +/- 0.5 sec but it is much >less sensitive than the Garmin GPS18x-LVC that early in year >maintained an offset within 4us (that's until sats in view >reduced by tree growth so it became unusable). Since the usb line has nothing to which a PPS interrupt could attach AFAIK, you are not going to get even ms timing from a usb dongle. You should certainly get better than .5 sec however. ><http://support.ntp.org/bin/view/Support/InexpensiveOemGps#Globalsat_BR_355_BU_353_and_othe> >David _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
