[time-nuts] Synchronization

[Bob kb8tq]

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 <agstrydom at gmail.com> wrote:
> 
> HI Bob
> 
> I do not require timing on the USB at all
> 
> 
> On Thu, Dec 5, 2019 at 6:00 PM Bob kb8tq <kb8tq at n1k.org> 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 <agstrydom at gmail.com> 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 <hmurray at megapathdsl.net>
>> wrote:
>>> 
>>>> 
>>>> agstrydom at gmail.com 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 -- time-nuts at lists.febo.com
>>>> To unsubscribe, go to
>>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>> 
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at lists.febo.com
>>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>> 
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.