[ntp:questions] Is there an easier way to hook a GPS clock to NTP or a free shortwave audio line level out?
ntp at universal-mechanism.org
Wed Dec 16 01:11:45 UTC 2015
OK! I'm going with the Raspberry PI B+ with a plug in GPS receiver.
So on the http://ava.upuaut.net store it list the GPS receiver then down
below it list the nine related products. So if I understand right I
want the B+ version. The case looks cool and I just need the case and
the 25mm M3 Standoff Kit for Geaux Robot Case. What about Stacking
header kit for Raspberry Pi+ do I need it and do I need this one too,
11mm Stand off kit for Raspberry Pi+? Which of those three GPS antennas
do I need and what's the difference between them.
On 12/16/2015 1:20, Mike Cook wrote:
> Hi Nate,
> I think you can forget about using your radio as the E1’s lowest
> band is from 100KHz and WWVB which is what you want for timing is on
> 60KHz. I don’t know of any FM station time decoders.
> After that cold shower, the options are limitless wth quite a number
> entailing gluing small bits.
> I have gone the way of gluing bits and I have a lot of them.
> Your stats are are bad, due probably to the >2:1 asymmetry in
> upload/download rates on 4G plus latency on the WIFI. You might also
> be compounding that with power saving on your system though you don’t
> say how that is configured.
> If you want low budget, and have no better internet access you might
> get by with a cheap PCI-E GPS such as Ublox GPS B39 PCI-5S-1-500 at <
> $10 delivered from the auction site, coupled to a mini PCI-E to PCI-E
> adapter (ex 181622523046 on the same site) for $5 delivered, an
> SMA antenna with say 5m of cable , another $10 plus
> an SMA pigtail to replace the RP-SMA at a couple of $
> Link all that up and you will have an NMEA ref clock (over what will
> look like a USB serial port to your OS) that should give you low ms
> accuracy and stability for less than $50.
> The GPS receiver seems to have a 4Hz update rate which is not useful,
> but it can be reconfigured to 1Hz (see
> ) with Ublox’s U-Center free software. That runs on windows only, but
> should run under wine in linux or maybe you can dual boot your system
> or ask a friend.
> I prefer to have my time servers independent of application workload
> , so I have many minis dedicated to that.
> A good cheap one is a Raspberry PI B+ with a plug in GPS receiver
> such as
> which has few bits and only one connector to solder. If you ask
> nicely, the seller will probably do it for you. If you add a usb wifi
> dongle you won’t need cabling but you get better latency with cable,
> so I would use that as you have ethernet on your box. The advantages
> here are that you can leave it on all the time, and it will have 1PPS
> ref clock, so you have microsecond accuracy and stability. Well I do
> with that config. With a case, antenna etc I think you can get a
> clean setup for < $150.
> Of course you can do cheaper with bits. Take your choice.
> As you have a crappy internet connection , even with a really
> accurate inboard or external time source, it will be only ONE. This
> not a good config . You really need a minimum of 3 .
> How much would a proper internet connection cost you?
> You seem to be between a rock and a hard place.
>> Le 13 déc. 2015 à 17:06, Nate Homier <ntp at universal-mechanism.org> a
>> écrit :
>> I am using a system76.com Wild Dog Pro desktop computer running
>> Ubuntu 15.10, I bought it in December 2015. It has no serial port. I
>> have a Shortwave radio if that will work to hook up to NTP.
>> Researching the net reveals many howto for hooking up GPS OEM radios.
>> This usually involves soldering, cutting and working with little tiny
>> things, all of which I am terrible at. I have heard of GPS radios
>> that plug into your PCI-E slot, now that sounds cool, but pricey.
>> Does anybody have any recommendation as to how I can turn myself
>> into an accurate stratum 0 or 1 client, I am not interested in being
> Stratum 0 is the reference clock, Atomic, GPS, WWVB or whatever . It
> is what makes an NTP source Stratum 1, so if you have a ref clock
> your box will default to stratum 1 while the ref clock is reachable.
> You can fudge stratum levels in the config, but it is unusual outside
>> a server. In case your wondering why, I don't know why, I do have
>> an official diagnosis of OCD, that might explain it. Not accurate
>> time bothers me a lot.
>> I have an Eton E1 HF receiver that keeps it's clock accurate via the
>> HF time bands, but not the LF band, strange, on the other hand your
>> guaranteed to get an HF signal worldwide as opposed to LF. It also
>> has an audio line out and does anybody have any experience with line
>> level audio for time keeping. Maybe I should start there before
>> forking over the cash for some project I can't finish.
>> Here's what I'm willing to do.
>> Do the shortwave radio thing first. Free and what I learn from it I
>> can apply to below.
>> Buy an PCI-E port serial card, one that you guys tell me to buy,
>> budget $75
>> Buy an GPS PCI-E card or external device. I can't give you a figure
>> for what I'm willing to pay because I have no idea what they cost.
>> Just doing this for fun. Love NTP.
>> Currently I am getting Internet through my Verizon Samsung Galaxy S6
>> Edge WiFi hotspot. -102 dBm and 38 asu signal, poor signal for 4G
>> LTE. Once I get up in the morning I turn off the Internet at about 11
>> am and the computer won't see a connection again until 8 or 9 pm. So
>> NTP is only connected during the night when I'm sleeping. Anybody
>> know how I can keep track of clock drift when NTP gets woken up at
>> night, be interesting to see how accurate the motherboard is.
> NTP’s drift file will give you that info , though your connection
> looks so bad that it may not be that good a figure. You really need
> stable sources for to enable NTP to calculate it.
>> My current NTP stats.
>> First one is from peer.awk
>> ident cnt mean rms max delay
>> dist disp
>> 184.108.40.206 21 30.724 60.139 161.716 103.967
>> 989.601 149.718
>> 2604:a880:800:10::bc:c00d 19 8.736 16.624 32.476 134.039
>> 499.117 42.186
>> 220.127.116.11 18 19.069 23.196 46.512 141.819
>> 495.233 44.446
>> 2001:67c:1560:8003::c7 17 -2.631 18.085 41.863 204.340
>> 173.570 23.222
>> 18.104.22.168 18 37.286 26.949 50.019 147.775
>> 174.419 39.181
>> nate at frontier:~$ ntpq -p
>> remote refid st t when poll reach delay
>> offset jitter
>> +deekayen.net 22.214.171.124 2 u 554 1024 377 135.533
>> -23.196 82.525
>> *time.tritn.com 126.96.36.199 2 u 531 1024 377 82.637
>> -26.905 62.751
>> +2604:a880:800:1 188.8.131.52 2 u 592 1024 377 149.243
>> -23.740 63.528
>> +184.108.40.206 220.127.116.11 2 u 1007 1024 377 109.755
>> 5.461 87.911
>> +golem.canonical 18.104.22.168 2 u 488 1024 377 182.265
>> -44.495 158.015
>> Sincerely Nate.
More information about the questions