jim...@earthlink.net said: > I've got a bunch (a pack?) of beaglebones that are connected via ethernet > (wired) and I want them to be (roughly) synchronized.
How rough? > Running NTP (in some flavor) would be the obvious approach, but I'm in an > environment where there's no "outside" connectivity.. Could I make one of > the beaglebones be the NTP server, and the others be the clients? Yes. Search for orphan mode. I've never tried it. Let e know if you can't figure out how to make it work and I'll use that as an excuse to learn more. > (I've seen some "add a GPS to a Rpi to make a NTP server" projects, and I > could probably leverage that) That should work. I haven't found a GPS with PPS for the beaglebone. What level of accuracy do you want? If you only need 100 ms or so, then a normal junk GPS (no PPS) on USB should work. There is at least one GPS+PPS over USB. The GPS breakout board plus FTDI USB 2.0 breakout with a few wires gives you PPS with improved accuracy. (Not great, just 8x better than PPS over old/slow USB.) I got mine from Sparkfun. > I've also got a laptop (a mac, as it happens).. what's involved in making > *that* be a NTP server (e.g. the Mac might get its time from a NTP server > at some higher stratum, and then it propagates it down). That should work too. I don't know much about the Mac environment. If it's running a normal-enough ntpd it is already a server and you don't have to do anything. If not, you will have to build/install your own and/or poke holes in the firewall rules. -- These are my opinions. I hate spam. _______________________________________________ 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.