On 2017-02-02, sean <s...@sean.eternal-september.org> wrote: > On 2017-02-01, David Taylor <david-tay...@blueyonder.co.uk.invalid> wrote: >> >> Sean, >> >> Thanks for your comments - much of the Web site is comprised of my own >> notes to remind me what to do next time! Still waiting for one minor >> operation, and then to see if (or should it be when?) the Crohn's returns. >> > > Well your self made notes for yourself have proven to have a rich amount > of helpful information. :) Keep the faith with your healing. > >> Unfortunately I can't be part of the pool as my ISP doesn't offer static >> addresses. >> > > I posted a followup whether a hostname could be used in lieu leui of an > IP address. I understand it can't change every few hours/days. Does your > changed that frequently? > >> I don't know whether FreeBSD is better than Linux any more, others will >> need to answer that. My FreeBSD box refused to update from FreeBSD 7 to >> FreeBSD 8, so I stuck Linux on it in desperation! > > Wow, those versions are well before my time with FreeBSD. I'm not sure > if I'll be that concerned about the OS, and rather focus on the GPS > equipment you linked to below. > >> >> Another low-cost device is the Sure evaluation board: >> >> http://www.satsignal.eu/ntp/Sure-GPS.htm >> >> >> http://www.ebay.com/itm/SKG16A-Bluetooth-RS232-USB-UART-GPS-Module-Demo-Board-/230844194302 >> > > Thanks for the link! That's about half the price of the garmin and would > likely get me better precision than just syncing to the NTP pool.
Yes. > >> Windows uses NTP but not with the reference implementation, so of >> unknown quality, and not manageable in the same way. It used to be >> lousy, and I've not tested since then. >> > > I think I'll install the ntp client on my windows machine and see what > kind of time I can get. You would probably be better off syncing a linux machine to the gps board and then syncing the windows machine to that over the local Lan. > >> What will be good enough depends on your needs. The lowest cost might >> be the Sure board attached to an existing FreeBSD box, running 24 x 7 >> and in as stable a thermal environment as necessary. Both the Raspberry >> Pi and BeagleBone Black are low-power devices and therefore low-cost to >> run 24 x 7, with the BBB having a slightly better Ethernet >> implementation if you need to get down to the tens of microseconds >> level, but with the Raspberry Pi have a much wider support even though >> it might offer (approx) fifties of microseconds. Judge for yourself here: >> >> http://www.satsignal.eu/ntp/BBB-vs-RPi.html >> >> If you already have an RPi doing something, adding a NTP server to its >> tasks will make little extra load for an environment with a thousand or >> more clients.... >> > > Incidentally I do have a BBB and a few raspberry pis. The BBB goes back > and forth to/from work so I won't be able to use that as the NTP host. > > As an aside, have you done anything with SDR? You may be interested in > this: > https://github.com/flightaware/piaware > _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
