On Thu, Nov 16, 2023 at 02:41:42AM -0000, jo...@sdf.org wrote:
> Hello -- Does NetBSD support PPS output from a USB GPS? I'm
> using NetBSD 10 RC1.
>
> I have a USB GT-U7 GPS module attached, and I have gpsd running on
> /dev/ttyU0 and receiving GPS data. This looks good.
>
> After configuring ntpd, when I run ntpshmmon, I'm seeing NTP0, but no
> NTP2. If I understand correctly, NTP2 is PPS. This seems to be confirmed
> with ntpq -p, where I don't see a PPS peer.
>
> I unfortunately couldn't find anything when searching on this topic.
>
> My goal is to replace an aging RPi3 with a Rock64 running NetBSD as an NTP
> stratum 1 server.
If it's a pure USB device (with no additional wriring for a PPS signal)
it won't make a good stratum-1 server. USB signals have a 1ms jitter (minimum)
so I don't think you can get a clock more precise than +-1ms with this.
--
Manuel Bouyer <bou...@antioche.eu.org>
NetBSD: 26 ans d'experience feront toujours la difference
--
