[time-nuts] Serial port server .. any interest in a write up on using ?

[Michael Tharp]

On 05/22/2012 06:37 PM, Pete Lancashire wrote:
> I've never though about using one to distribute the 1PPS for NTP. Its
> a pity there isn't enough umph inside one of these
> little Linux boxes to implement NTP.

Don't get too excited because this is many months out, but I'm working 
towards designing a single-board ARM linux computer to run a NTP server. 
It'll connect to a GPS receiver via UART and PPS, using a hardware timer 
peripheral in input capture mode to compensate the PPS for interrupt 
latency (maybe overkill), and the CPU can be clocked by your favorite 
GPSDO or OCXO. I've seen this done by hacking up x86 hardware, but 
purpose-built will do even better and will consume very ltitle power. 
Your OCXO on the other hand, well I can't do anything about that :)

I also need to look into whether there's specialty ethernet hardware 
needed to make an ideal PTP source, I barely know anything about it. 
Hopefully it's available for a reasonable cost. As it is the board 
should be < 40 USD, but I'm still working on the schematic and there's 
always room to bloat the project with more features.

But first I need to finish the Resolution SMT interface boards I've 
promised to make. Sent for 9 PCBs yesterday, should arrive in 2-3 weeks.

Here's to feature creep,
-- m. tharp