nixiebunny watch out! Once bit by the timenut bug you might be surprised where it leads:
For me initially some nice OCXO's, then DOCXO, then Cesium and Rubidium oscillators and frequency standards... oh and then you better have a better counter to measure it all... hopefully with 10's of ps one shot resolution. You'll probably need a good GPS antenna on your roof too! This leads to GPS splitters so you can run multiple GPS disciplined oscillators at the same time o.O! Bill On Friday, October 1, 2021 at 10:06:46 AM UTC-7 Nick wrote: > I also use TinyGPS++, though a version I've modified for the MSP430 and > other processors - I've also made it "const correct" and added conditional > compilation so that a reduced size version can be built if you don't need > the maths stuff (that drags in a whole bunch of libraries that may waste a > load of space). I did provide my modified version back to Mikal at Sundial > plus some comments about handling negative heights (below sea level) etc. - > some of that has made it into the latest version. > > I ignore the RTC when GPS is available but use the NMEA $GPRMC sentences > to discipline the RTC. When I've no GPS for a while, I switch to the RTC, > e.g. when the network is down and my NWTS is not seeing NTP or the GPS puck > just loses its fix. > > Nick > > On Wednesday, 29 September 2021 at 17:34:27 UTC+1 nixiebunny wrote: > >> My latest scope clock uses a DS3232 RTC chip for general timekeeping. >> This chip only keeps time to the nearest second, as far as the >> user-readable registers are concerned. >> I also have a USB port that can read the time from a GlobalSat GPS puck. >> This reports the time once a second through the Arduino TinyGPS library, >> with the age of the time in milliseconds (typically 250). This should let >> me compensate for the read delay by setting the tick (50/60Hz) counter in >> my local time variables. >> What do any of you time nuts do about displaying the time accurately, and >> making the RTC be reasonably accurate compared to the GPS? >> Do you discipline the RTC with GPS? Do you just ignore the RTC when GPS >> is available? Set the RTC occasionally? >> >> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/e0dcddc9-c7a8-48f9-82f0-12a872b977cfn%40googlegroups.com.
