Having a linux box (Pi) dedicated as a time server should mean you have
consistent delays?
To offload time server requests so they don't affect disciplining
response/timing, would it be worthwhile having one Pi dedicated to being
disciplined by the GPS, then have that pi discipline a second Pi
I have the NEO-M8T-0-01, which doesn't have Galileo, but I'm running
with GPS and GLONASS enabled.
(I was shipped old stock by a supplier. I'd love to upgrade the firmware
to 3.01 TIM 1.10 to be able to get the Galileo constellation, but I'm
just an individual. All my emails offering to sign an
Would it be too simple a project to have a GPS demonstration:
* GPS time, leap seconds (need for)
* UTC time
* Local Time Zone time (rise, set, noon)
* Solar Time (rise, set, noon)
* Solid Earth Tides
* and a custom sun dial, marked for solar time and local time (a lamp
can simulate
Yo Gary!
With a strictly SSE skyview, I still regularly get signals from sats to
my NW. When they're at the right elevation and heading, their signals
pass over me and reflect back at me from a tall building. When running
my M8T with the position unlocked, and those NW sats are getting a
ure module?
- a more stable module temperature?
I'm tempted to add some thermal mass (block of Al) to the top of the M8T
and a chunk of insulation on top of that.
Michael
p.s.
As I finish this, LH is showing five sats, 23, 30, 31, 32 & 34 dBc, Accu
6 ns
On 01/11/2017 9:55 AM, MLewis wrote:
I h
Is this a workable or worthwhile strategy?:
- RTC providing date & time to second to system on boot
- RTC frequency output driving a counter/divider to produce PPS
- GPS module providing UTC PPS
- GPS module's secondary PPS disciplining the RTC-counter-divider PPS by
resetting the RTC's
/2017 4:57 PM, Chris Caudle wrote:
On Wed, November 1, 2017 3:17 pm, MLewis wrote:
hadn't got there yet
Your RTC is not likely to be tightly synchronized to NTP time, so there is
a high probability that trying to use RTC as a secondary time source will
actually make the system worse than just
hadn't got there yet
likely using NTPsec, as the codebase is available if a driver or generic
driver won't work
https://docs.ntpsec.org/latest/driver_howto.html
On 01/11/2017 12:38 PM, Chris Caudle wrote:
On Tue, October 31, 2017 9:27 pm, MLewis wrote:
I'm intending to add a "prec
, Bob kb8tq wrote:
Hi
Ok, local RF interference sounds like a significant part of the problem. I would
suggest that swapping antennas might make sense. Not all “super interference
rejecting” antennas are created equal.
Bob
On Nov 1, 2017, at 9:55 AM, MLewis <mlewis...@rogers.com> wrote:
e source” even under your extreme conditions.
Bob
On Oct 31, 2017, at 11:14 PM, MLewis <mlewis...@rogers.com> wrote:
I'm stuck with a near ground level antenna site (~16" above grade?), with half
a sky view (thankfully to the SSE), less some low blocking buildings with regular
mutlipa
(I suspect this is drifting from the original thread too much, so new
subject)
Temperature ranges from 65F to 78F, with the potential for drafts, but
is more typically 76F.
I read about the NTPsec runs with insulating a Pi and running a load
generating program to better maintain a stable
ct 31, 2017, at 10:27 PM, MLewis <mlewis...@rogers.com> wrote:
I'm intending to add a "precision" (well, precision to the Pi world) RTC to my
Pi 3 to use for a holdover source when it hasn't got PPS from the GPS module.
On 31/10/2017 10:04 PM, Chris Caudle wrote:
On Tue, October 31,
I'm intending to add a "precision" (well, precision to the Pi world) RTC
to my Pi 3 to use for a holdover source when it hasn't got PPS from the
GPS module.
On 31/10/2017 10:04 PM, Chris Caudle wrote:
On Tue, October 31, 2017 7:19 pm, MLewis wrote:
...the "better&quo
If one is building a GPS disciplined NTP Stratum 1 server from a Pi or
Beaglebone, the "better" quality RTCs seem to be
DS3231 based (DallasSemi/Maxim), Accuracy ±2ppm from 0°C to +40°C,
±3.5ppm from -40°C to +85°C
or
NXP:
PCF2127AT: ±3 ppm from -15 °C to +60 °C
PCF2127T: ±3 ppm
Or any change in land tide as everyone ran to google "my eyes hurt".
On 22/08/2017 3:58 PM, Mike Cook wrote:
Hi you guys over the pond.
Don’t be shy.
Did anyone measure their oscillators stability over the eclipse totality?
Please share.
How about GPS?
Did you record the crickets?
Did the
On 18/05/2017 4:34 PM, cdel...@juno.com wrote:
I think I might do it myself and go with a 1/2" hole depth and 1/4"
threaded depth.
Or go back to the shop and get a new quote with them knowing it's not
bottom tapping, only 1/4" threaded depth.
Michael
Rather than commercial passenger flights, it used to be one could get
connections and fly along on transport, ferry or private flights,
typically for a (no-frills) low fee.
There are also flights made for testing equipment at altitude, including
radio, satellite, imaging or other sensing
On 22/03/2017 10:56 AM, jimlux wrote:
On 3/22/17 4:04 AM, Angus wrote:
No tall mountains in Australia, but...
Pikes Peak in the US is 14114 ft, 4304m and has a road to the top. Of
course the base is at about 5000 ft/1600 m
In EU, there's probably a Seilbahn of some sort pretty high up in
On 15/02/2017 1:17 PM, Chris Albertson wrote:
Why set up a dedicated NTP server if you only have two computers that
will use it? ... You could save some money and just run NTP on the two
computers. ... NTP is almost zero load on the CPU and the best thing
is the NTP accuracy is not effected by
On 14/02/2017 9:23 PM, Chris Albertson wrote:
On Tue, Feb 14, 2017 at 7:31 AM, MLewis <mlewis...@rogers.com> wrote:
- a dedicated machine/box for unencumbered acceptance of PPS, and
- for systems with a business need, a dedicated NTP server/box disciplined
by the PPS source (with ded
On 14/02/2017 7:26 AM, Bob Camp wrote:
Hi
A direct port might be a +/- 100 ns sort of thing most of the time and a +/-10
us
thing every so often under some OS’s. Most desktop operating systems are not
designed to prioritize random pin interrupts. A dirt cheap MCU coded with a few
(hundred)
On 14/02/2017 12:24 AM, Chris Albertson wrote:
Pretty dramatic difference between a "real" serial port and USB. Like two
orders of magnitude or more.
If you computer lacks a serial port, just buy a new computer. The
Raspberry Pi or the like costs about $40 the serial port has a pin that
On 12/02/2017 6:49 PM, David Witten wrote:
Is this perhaps the reason this firmware is marked "Not for Timing Use"?
The 2.01 Release at this location is similarly marked.
Dave
According to posts in the ublox forum, there are specific issues
regarding timing specific features in the timing
On 12/02/2017 1:50 PM, Pete Stephenson wrote:
What firmware version are you using? Are you sure it's an authentic
u-blox receiver? There's a bunch of fakes out there that identify as
u-blox but lack some functionality. I recently purchased an M8T and
the UBX-MON-VER message shows the firmware
Interesting.
My guess wasn't a material made for RF but a carbon added to give a
decent black colour.
"It is not inconceiveable that off-spec or scrap materials from the
production might end up as mousemats." and "stealth material".
Very interesting.
At an airshow many years ago, these
My TW4722 GNSS active antenna is on a 100 mm stainless ground-plane,
placed on 2" of wood on a window sill behind two panes of glass, between
metal blinds and the glass, almost touching the glass. Feeds a NEO-M8T.
Late yesterday I placed old neoprene rubber mouse pads, rubber side
outwards,
With this NEO-M8T, I've even turned off everything but min=4/max=8 for
GPS & GLO, and it won't accept any configuration for Galileo, let alone
enable.
And that's with the required NEMA of 4.1.
Specifically, from u-center, the Signals checkbox for E1 - with a
Signals selection listed as a
wow
Five M8Ts.
And here I was feeling extravagant having splurged for one...
I'm only seeing between 20 and 25 signals, but there's a bank of
concrete brick-clad buildings opposite. And typically with the
majority of signals coming from north of my building, they're coming in
off those
Anticipating issues with multipath, signal levels and a limited skyview,
along with discovering that the tallest building in my skyview with a
military computer centre has various stealth antennas around its roof, I
went with:
- u-blox NEO-M8T, mainly for its sensitivity, multi-GNSS (GPS, GLO &
Those hobby packs are typically LiPO, chosen for the energy density, and
they often (usually?) run them with minimal protection circuits to
reduce weight. Not recommended practice for building devices.
BMS
When I built a 12 cell series 10Ah pack, I went with LiFePO4 and a
custom-configured
According to the builder, it was selling well (he was on version 5 of
the board). He said he just decided (no feedback) that no one would use
the dial more than once, so he removed it.
For money talks, I would have thought having a capability to use any
numeric offset, so it could be used by,
It's assumptions on how a product will be used that end up ruining so
many potential products for me.
Like the GPS modules with a PPS pin and people build breakout boards for
them that either don't use the PPS or use the PPS for flashing an LED,
but there's no pin nor contact point for
On 03/12/2016 12:33 PM, Bob Camp wrote:
For an “antenna challenged” location, the T is the better choice. It is simply
an update (as the M8Q) of the earlier uBlox parts. The function is very similar
to the earlier parts. You nail down the antenna location (like with duct tape)
and put the
Use a video codec in a container to record your audio?
On 01/12/2016 9:19 AM, Tim Shoppa wrote:
... Is there a common digital audio format that embeds in the digital stream, a
timestamp marker of real-world-clock-time that the audio was recorded at?
...
I know that in the TV/video editing
On 30/11/2016 4:23 PM, Bob Camp wrote:
3) Unless you can reasonably expect 4 sat’s in view at all time, don’t bother
with setting up a GPS
timing system. It will just make you angry with all the issues.
I'm hoping a timing GPS module, with their claims of being successful
(to the precision I
On 30/11/2016 4:23 PM, Gary E. Miller wrote:
Yo MLewis!
I suggest you take this over to NTPsec:de...@ntpsec.org, or
on gpsd:gpsd-us...@nongnu.org
Looks interesting. Thanks!
On 01/12/2016 1:51 AM, Chris Albertson wrote:
First question: How accurate does your local NTP server need
On 30/11/2016 4:36 PM, Mark Sims wrote:
... V.KEL SIRF=III modules (I paid $15-$20 for three)...They don't do GLONASS.
I think I should have GLONASS, to maximize my chances.
The NEO M8 is a decent device. I've seen mine tracking over 24 sats. The
module that I have has a U.FL antenna
(resending as I tried posting in html...)
Hello,
I'm a novice at time issues. I've been gathering info and I think I'm
ready to start asking questions.
I'm after a time solution for my personal computer. It looks like I need:
*a standalone box to be my own local personal NTP server (so
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