The one thing that hasn't yet happened is making the beaglebone timestamp on the linux side in a way that works for ntp.
Custom code no problem. Freebsd PPSAPI no problem. Linux, nothing there yet. I have been working on it but if anyone has some insight its appreciated. On Monday, October 20, 2014, Bob Camp <kb...@n1k.org> wrote: > Hi > > There is a *lot* of detail on this in the archives. > > Quick rundown - the Soekris has some custom code and “stuff” that makes it > better for NTP than any of the other boards. > > For any normal use, a couple of microseconds is likely “good enough. For > that, many boards and GPS’s will do just fine. Yes people have gotten NTP > running on just about every board that will run Linux. > > Bob > > > On Oct 20, 2014, at 9:39 PM, Joseph Gray <jg...@zianet.com > <javascript:;>> wrote: > > > > What does everyone think of this GPS module for ntp use? According to the > > specsheet, it uses a Ublox Neo-7N. > > > > > http://www.ebay.com/itm/RY725AI-10Hz-UART-USB-interface-GPS-Glonass-QZSS-antenna-module-flash-memory-/181562403752 > > > > I'm thinking about using it for a Beaglebone ntp server. I know there was > > some discussion about Beaglebones a while back. Has anyone gotten ntpd > with > > PPS and time stamping running on a Beaglebone yet (like on the Soekris > > Net4501)? > > > > Does anyone want to take a wild guess as to the best/worst case UTC > offset > > I might get with such a setup? I realize that I'd have to try it to > really > > find out, but guesses and advice from those more knowledgeable is always > > appreciated. > > > > What I'm really after is to eventually have several Beaglebones scattered > > around the area as part of a TDOA DF network. I have spare radios to > > dedicate to the task. Each fixed node will timestamp incoming > transmissions > > and then relay that information to a central location. The central system > > will use the data to calculate the location of the transmitter. > > > > Does anyone here have any experience with this sort of thing? Would you > > recommend a better way of accurately timing the transmissions vs using > ntp > > on each Beaglebone? > > > > I know that TDOA is used by the cellular companies. Is anyone aware of > some > > "user level" projects or source code for this? I've Googled a bit, but > > haven't turned up much. There was one thesis about an Amateur doing part > of > > this, but he didn't have much detail on the satellite nodes and didn't > > describe anything about the centralized processing part. > > > > I have one Beaglebone White that I got cheap, so I have something to get > > started with. Later, as I figure out things, I'll buy a few Beaglebone > > Blacks. > > > > Joe Gray > > W5JG > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com <javascript:;> > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com <javascript:;> > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
