I have used a bunch of these things:
http://www.ebay.com/itm/252162780444
From: Forrest Christian (List Account)
Sent: Wednesday, September 06, 2017 9:34 PM
To: af
Subject: Re: [AFMUG] GPS'd NTP
My rough draft here is a USB-serial interface with an isolated DC-DC converter
and a isolated usb-serial interface, so you are at least mostly electrically
and opto isolated from the SBJ. Plug into a USB and then power the SBJT. So
USB to a small box, then cat5 to the SBJ. This is a small enough and fun
project that it will probably just happen and fairly quickly - I need a few of
these after the nightmare of the rackinjector (think of it as a working
vacation).
I've also had on the todo a NTP all in one appliance, probably in the SBJ or
SB12 box. That same code would make it into the rackinjector and any followon
similar products. There are quite a few things ahead of it on the roadmap
though...
On Wed, Sep 6, 2017 at 2:45 PM, George Skorup <george.sko...@cbcast.com> wrote:
Apparently there are USB sticks that are basically a GPS receiver and a
PL2303 for $30-40. So you get the date/time. Cool. Then they take the 1PPS
output to blink a f***ing LED. Really!? I was reading some blogs where folks
have opened them up and wired a super tiny jumper from 1PPS to DCD. That was
about 5-6 years ago using older SiRF receivers, too. Meh.
A GPS+GLONASS SBJ basic and USB kit would be pretty cool. Could the USB
interface also power the box, up to say 20-25 feet? The other thing is, all of
the machines I'm working with have a serial port. So maybe just skip the USB
altogether?
I was thinking, maybe take the daisy-chain output from a
SyncInjector/PowerInjector/RackInjector since those switch the pipe/box to NMEA
anyway, but I don't think I'd want a path from the tower-mounted gear to
server(s). And other funky stuff like noise making it into the timing for the
radios would be ungood.
On 9/6/2017 2:10 AM, Forrest Christian (List Account) wrote:
I could tell you how to wire a syncbox junior up to a usb port if you'd
like. Requires a TTL level usb to serial cable.
I'd you wait a month or so until the gps+glonass version is out it well
even speak nmea. Heck, now I think about this it might make a good
product.... syncbox basic plus a USB dongle.
On Sep 5, 2017 8:19 PM, "George Skorup" <george.sko...@cbcast.com> wrote:
I've got a few CentOS machines running around the network doing various
tasks, one being NTP for radios, routers, switches, etc. I've been having some
issues with us.pool.ntp.org lately. I switched to time-(a,b,c,d).nist.gov.
Apparently those are pretty busy.
So is anyone else using GPS to feed NTPd? From what I've been reading, I
guess I need a 1PPS capable receiver. Does that exist in a simple USB package?
That would be ideal, preferably with an SMA female for an external antenna
where needed. Looks like none of the cheap shit I'm finding on Amazon has PPS
output.
--
Forrest Christian CEO, PacketFlux Technologies, Inc.
Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602
forre...@imach.com | http://www.packetflux.com
