Setup NTP server on the pi. The BBB should have the ntpd (NTP daemon) already setup. Change the ntp configuration to point to the IP of your pi. Let ntp maintain the time by itself no need for cron. Any scripts or custom implementation will had a delay which will increase the time drift between your systems.
To maintain the clock between reboots or when the pi is unavailable, purchase an i2c real time clock like the DS1307 and use ntp to keep the time sync'ed. I hope this helps. On Thursday, July 2, 2020 at 9:27:23 AM UTC-7, [email protected] wrote: > > Yeah, GGB has its own power supply. And I am connecting raspberry pi and > BBG through ethernet. For transmitting the message, it is done by LCM. > I think LCM is faster because at least there's no password issue and I > hope to let the BBG time sync quite often(like every 1 min), but not too > often because that would be unnecessary. > > What I now have is a program(c or python) that can get the time sending by > a raspberry pi. Now I plan to read the output and set the time using think > command: date -s "2 OCT 2006 18:00:00" > in the shell script. But I don't know how to do that. > > > 在 2020年7月2日星期四 UTC-4上午11:03:20，Dennis Bieber写道： >> >> On Wed, 1 Jul 2020 22:45:25 -0700 (PDT), in >> gmane.comp.hardware.beagleboard.user >> [email protected] wrote: >> >> >Hi, >> > >> >I am doing a project using both beaglebone and raspberry pi. Now only >> the >> >pi has internet connection and I have to sync their time. Currently I >> can >> >send the pi's time to beaglebone green every second, but I don't know >> how >> >to use this data to set the system time on Beaglebone. I plan to write a >> >shell script so it can be running all the time from boot. Anyone knows >> how >> >to do that? Thanks. >> > >> >> "Information... We want... Information" >> >> How is the BBG connected to the R-Pi for this transfer? If the >> R-Pi is >> sending time data, there has to be something on the BBG that is reading >> it. >> >> It would probably be easier to have the BBG /ask/ the R-Pi for >> the >> time, and that could be done using a cron job on the BBG. Of course, that >> means now the R-Pi has to have running process to accept the requests... >> >> It all comes down to how the two devices are communicating. If >> the BBG >> is connected to the R-Pi via USB (hope you are using an external power >> supply on the BBG -- don't think an R-Pi USB can provide the power draw) >> you might just need to configure the R-Pi as a gateway, and let the BBG >> NTP >> (or whatever recent Debian/systemd sets up) do normal time sync through >> the >> R-Pi's network connection (or run a tier 3 NTP server on the R-Pi and let >> the BBG time sync to it). >> >> >> -- >> Dennis L Bieber >> >> -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/c55500c6-a8ce-446b-a07e-2b7b2cfaa0ado%40googlegroups.com.
