Hi On a traditional RPi, many things go over the USB. The ethernet interface connects via USB. On some, the WiFi also connects over USB. It all necks down into a very narrow “pipe”.
Bob > On Dec 5, 2019, at 3:21 PM, Anton Strydom <[email protected]> wrote: > > HI Bob > > I do not require timing on the USB at all > > > On Thu, Dec 5, 2019 at 6:00 PM Bob kb8tq <[email protected]> wrote: > >> Hi >> >> One timing issue could be that USB is not that great for timing. Since it >> is >> packet based it introduces jitter in the link. Running NTP on a >> “traditional” >> RPi is unlikely to produce numbers below a milisecond. >> >> Indeed I’m digging into that for what I’m working on ….. >> >> Bob >> >>> On Dec 5, 2019, at 12:09 AM, Anton Strydom <[email protected]> wrote: >>> >>> Good day Hal >>> >>> Thank you for your contribution >>> >>> The physical setup is as follows, each Rp1 has 2 or more cameras attached >>> to it via a multiplexer or usb depending on the camera, there are a >> number >>> of V2 RPi and also a couple of USB cameras attached to some of the RPi's. >>> All the equipment is powered by solar >>> >>> I will be able to run cable but it is going to be difficult plus the >>> possibility that the cables and equipment attached to it will be stolen >> is >>> 100% hence the WiFi >>> >>> Yours sincerely >>> >>> Anton >>> >>> >>> >>> On Thu, Dec 5, 2019 at 3:01 AM Hal Murray <[email protected]> >> wrote: >>> >>>> >>>> [email protected] said: >>>>> The cameras are pairs sitting on a multiplexer so the problem is not >> the >>>>> camera pair synchronization but the RPi synchronization >>>> >>>> I don't understand the physical setup. Is it possible to run a cable to >>>> wherever you need good time? >>>> >>>> Even if that isn't practical in the long run, it might be useful for >>>> experimenting. >>>> >>>> >>>> -- >>>> These are my opinions. I hate spam. >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> 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. >> >> >> _______________________________________________ >> 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. _______________________________________________ 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.
