Testing ntpd and/or timing from gpsd

[Frank Nicholas]

> On May 10, 2016, at 6:22 PM, Hal Murray <hmurray at megapathdsl.net> wrote:
> 
> 
> esr at thyrsus.com said:
>>> This seems like a good opportunity for an experiment.  What do you have in 
>>> the way of a place to stand while can monitor other NTP servers?
>> The Pi might be it.  I have it set up to monitor four pool servers with
>> noselect.  I get output like this: 
> 
> Begin rant...
> 
> If you are going to be playing this game, you need a few toys.  The primary 
> one is a PC with a real serial port and a good GPS receiver.

Eric - if you are serious about this testing, ping me directly and I’ll go through some of my old hardware.  I should have some fan-less systems (except the PS), with real serial ports, that draw < 30w while running Gentoo linux (I have one as an NTP dev box now, using the Adafruit breakout board).

With the Adafruit breakout & a real serial port, you’ll have to have a serial level converter, and some soldering will be required - the parts come as “kits” for the headers, etc.  I can send you specific links to models of level converters at Adafruit or Sparkfun.  These serial level converters *might* (I don’t think so, from my research) introduce some timing delays.  Those more knowledgable about electronics might want to chime in about how a MAX232 or equivalent chip will/won’t affect timing for PPS.

Thanks,
Frank