[time-nuts] PPS for NTP Server - How Close Is "Good Enough"?
hmurray at megapathdsl.net
Sat Jun 13 02:02:38 EDT 2015
eds_equipment at verizon.net said:
> Is it possible to modify the kernel so the USB is polled more often, and
> would that significantly reduce the jitter?
Modifying the kernel may not be enough if the timing parameters are in the
microcode for the USB device.
Whether any improvement is significant probably depends upon your goals.
It's unlikely to become a great NTP server.
If I wanted a good low power NTP server, I'd probably start with a BeagleBone
Black. I haven't seen a low cost no-assembly-required GPS board for the BBB
(There is at least one GPS board for the BBB, but it includes a cell phone
modem which doubles the cost.) I'd probably try the GPS breakout board from
SparkFun. It should take 5 wires: power, ground, trans, recv, and PPS. (and
then the appropriate software hacking)
These are my opinions. I hate spam.
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