Dear colleagues, i've made some tests and wrote an article about Raspberry Pi as a timeserver. I think we can trust on it and this board can keep a good time from GNSS PPS. I'm open to suggestions. I hope this can help in the decision making process. The link: rpi_article <https://www.researchgate.net/publication/334179026_Credit_card_size_computer_Stratum_1_NTP_Server>
Also, in our tests as you can see in the article, for general purposes the RPI has a good dealing with high loads. The difference is we've removed the crystal oscillator and put a signal from a synthesizer, you can keep the crystal and trust on pps signal too. I'm using a server at home with a cheap module NEO-6M and also one with SAM-M8Q. For comparsions effect i've put the NEO-6M to compare the ntp time of the rpi that this receiver is connected to with the server from the article: you can see in the thingspeak: thingspeak_channel <https://thingspeak.com/channels/691405/> If you want the source code for the 1 PPS generation thats it: 1pps_generation_src_code <https://github.com/LuizPauloDamaceno/rpi_pps_out/blob/master/ppsout.c> Best regards, Luiz Em seg, 22 de jul de 2019 às 11:05, wildylion via time-nuts < [email protected]> escreveu: > Hello there, > > I wanted to ask for advice regarding NTP > > Situation 1: > What I currently have is a uBlox M8N GPS puck I'm planning to use with the > Raspberry PI. Seems like it should work almost out of the box with some > kernel tuning, but I have a question about short term stability in the > event of GPS loss - how well will the board hold over if it's lost GPS for, > say, 24 hours? > > Situation 2: > Also, there's a need for more dependable NTP time sources for our > colocated spaces. > > What we have is about 100 servers, some of them running DBMS that wouldn't > like clock drift at all. After a recent incident involving NTP I've got an > idea to install GPSDO time servers in each datacenter and slave them to > stratum2's that will be actually distributing time to clients. > > All the certified GNSS disciplined clocks are really expensive (way more > than the management would approve), so what I'm planning to do is possibly > getting a couple LeoNTP units and using them as the root time sources, > would this be a good plan? Of course, all the NTP infrastructure will be > monitored, and possibly we'll use Stratum 2 servers which would be slaved > to GPSDO S1's AND the public NTP pool for sanity checks. > > Maybe BG7TBL's units instead of LeoNTP? > Is that a good idea? > > Sent with [ProtonMail](https://protonmail.com) Secure Email. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
