Re: [time-nuts] looking for low-power system for gps ntp timekeeping NANOSG20
On Wed, Jul 3, 2013 at 4:14 PM, folkert wrote: > > > Oh for convenience. I need to patch ntpd to use linux pps (afaik) and on > other systems I successfully run gpsd with ntpd (read: low jitter). Using gpsd with ntpd reduces the jitter versus just using ntpd by itself? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] The "auction site"?
Hello, Why do people go out of their way to avoid writing ebay on this list? The statements are purposely written so that it is obvious that the "insert mystical phrase" is ebay and not a generic auction site. What history am I not aware of? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] BBC Precision: Measure of All Things
On Wed, Jun 26, 2013 at 10:07 PM, Dan Rae wrote: >> > And BBC tv shows are not available (legitimately) for download or on demand > outside the UK anyway. What is your point? Would you prefer that I only post things that are relevant to time nuts on this side of the pond? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] BBC Precision: Measure of All Things
The BBC recently did a three part series titled Precisoin: The Measure of All Things. Part 1 is Time and Distance Part 2 Mass and Moles Part 3 Is Heat, Light and Electricity Probably nothing ground breaking for any time nuts but may be interesting to watch with friends and amily. http://www.bbc.co.uk/programmes/b02xbjmf ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] What is the deal with li...@lazygranch.com
On Tue, Jun 18, 2013 at 5:14 PM, Alan Melia wrote: > Hi Doug what software are using as your mail client, and under what OS. I > have had similar effects on an older system. I seem to get the "lists" > postings ok. > > Alan > G3NYK Of course I accidentally deleted the messages in the process of trying to figure out what is going on. I found the most recent two on the archived list page: http://www.febo.com/pipermail/time-nuts/2013-June/077483.html http://www.febo.com/pipermail/time-nuts/2013-June/077524.html ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] What is the deal with li...@lazygranch.com
Time Nuts, Is something messed up on my end with mail from li...@lazygranch.com? I seem to get an iawful lot of blank emails from this address to the t-n list. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Beaglebone NTP server
Can you explain what is different in this approach versus the traditional gps/pps without needing a custom clocksource? On Fri, Jun 14, 2013 at 8:13 PM, Gabs Ricalde wrote: > As an alternative to the Net4501, the AM335x in the Beaglebone has > timers that accept an external clock up to 25 MHz (TCLKIN) and can > timestamp events on an input pin (TIMER4-TIMER7). Both sets of pins are > available on the headers after an appropriate pinmux configuration. > > I'm finishing the clocksource driver for Linux, I'm testing it using the > 10 MHz and PPS outputs of a LEA-6T. ntpd loopstats show +/- 0.1 us > offsets, frequency is a flat 0.000 PPM as expected. > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Unit tests for time calculations
On Sun, Jun 9, 2013 at 11:29 PM, Bill Hawkins wrote: > Hi, Thanks in advance. > > Since this is a list for precise things, could you make your questions > more precise? > > What sort of test cases? > > What sort of calculations? Do you mean conversions? > > What do you mean by "catching" an error - where would you catch it? > > What do T1 and T2 have to do with it? > > What do you mean by timescale? Is a timescale a neighborhood? > > The work involved in clarifying those questions may make the answers > clear to you. > > Best regards, Are you familiar with the concept of a unit test? I can clariy those questions but I am not sure how that is going to make the answer clear to me. I am writing some software that reads input from users and a number of disparate systems and I have no control over the incoming time formats. I would like to make sure that my time calculatoins/conversions work and continue to work after i make changes during development. T1 and T2 are example time date strings. Calculations: T1(UTC) - T2(EST) = Time delta in seconds 12/31/1998 00:00:00 EST + 5184001 seconds = Time Date in UTC Conversions: 01/01/1991 11:01 AM EST = XX/XX/ XX:XX UTC As far as "what do you mean by catching an error - where would you catch it" I cant tell if you are being snide. By catching an error I mean identifying that the calculation my program made was incorrect. Maybe you are unfamiliar with unit tests? What was unclear about what catch errors? What else came to mind when you read the sentence. Has anyone ever used "time scale" to describe a neighborhood? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Unit tests for time calculations
Hello, My google-fu is failing me. Does anyone have a collection of test cases for date and time calculations? I am especially interested in catching errors when T1 comes from a different timescale than T2. Thanks in advance. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Cheap 1588 cards Was: Re: Net4501
On Thu, Jun 6, 2013 at 8:48 PM, Bob Camp wrote: > 1588 compatible network cards are capable of time stamping everything > that goes in and out. They are pretty common these days both as stand > alone cards and as peripherals on MCU's. There's no real need to do > hardware, just come up with drivers (and all the other software goop) > to make them work with NTP. More or less the same work you would have > had to do once the FPGA was done and debugged. > > Bob > Can anyone recommend a cheap 1588 compatible card? I just recently saw that the linux kernel PPS support for the cards. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Traceability after loss of LORAN and WWVB
On Sat, Jun 1, 2013 at 3:02 PM, Scott McGrath wrote: Since the demise of LORAN and WWVB (although d-PSKer may allow us to bring > spectracoms and 117a's back. > What/Who is d-PSKer? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] NTP Clock suggestions?
Your message is the only place google has ever seen "OnTime dial clock" Did you mean "a dial clock that displays the correct time" and left out the space between on and time? On Mon, May 27, 2013 at 11:21 AM, Eric Williams wrote: > If you want a project, you should be able to get an older Android tablet or > a Chumby 8 for $100 or less and hack it to do what you want. Hard to beat > the price for the hardware you get. > > I'm happy with my OnTime dial clock. > > > On Mon, May 27, 2013 at 8:14 AM, Bob Camp wrote: > > > Hi > > > > On May 27, 2013, at 10:56 AM, Miguel Barbosa Gonçalves wrote: > > > > > Hi Bob! > > > > > > On 27 May 2013 14:56, Bob Camp wrote: > > > > > >> Hi > > >> > > >> Correct answer: > > >> > > >> I don't think there is such a beast. Once you get away from the radio > > >> controlled (WWVB etc) clocks the cost goes up quickly. > > >> > > > > > > I don't understand why a microprocessor with an Ethernet controller and > > a 7 > > > segment display would cost so much to manufacture... I think I'll build > > my > > > own. > > > > … and that's really my point. You can build one easier than you can buy > > one. > > > > > > > > >> Also correct, but a bit of a joke answer: > > >> > > >> Raspberry PI driving your television set. Alternatively make the Pi > > feed > > >> control signals to a hacked normal clock. > > >> > > > > > > Good joke :-) I imagine the electricity bill at the end of the month. > > > > The Pi isn't all that power hungry. The TV set - yes it's going to be a > > bit of a hog. Even with the Pi's i/o limitations you should be able to > get > > it to run some sort of low power external display. > > > > Bob > > > > > > > > I would like to have a clock sync with my super precise stratum 1 > servers > > > :-) what's the point in having them if I can see the time anywhere? :-) > > > > > > Cheers, > > > Miguel > > > ___ > > > time-nuts mailing list -- time-nuts@febo.com > > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > and follow the instructions there. > > > > ___ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] iPhone keeping better time?
On 11/16/2011 11:14 AM, Mike S wrote: > At 10:03 AM 11/16/2011, David J Taylor wrote... > >> A pity that there isn't a port of the reference NTP for the Mac, such >> as we have on Windows. > > macmini-2:~ mikes# ntpd --version > ntpd - NTP daemon program - Ver. 4.2.4p4 > > Seems to be the "standard" implementation. Works fine for me. > > I think that is not the most recent OSX release right? The opensource.apple.com page seems like 4.2.6 is the most recent... ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] iPhone keeping better time?
On 11/16/2011 12:28 PM, David J Taylor wrote: >> Apple run their own NTP servers and ship their Macs configured to use >> them >> to sync time. > > Last time I looked those servers were either not working, or very > broken! Apple should use the pool rather than create single poinst of > failure. > Their servers were not so bad the last time i monitored them. the time.apple.com servers are stratum 2s. I think they sync to tick and tock.apple.com in the us and the euro hosts sync with truetime.euro.apple.com. I never bothered looking for the stratum one server for the time.asia group. dfc@ronin:/var/repos/ntp-dev$ host time.apple.com time.apple.com has address 17.151.16.23 time.apple.com has address 17.151.16.22 time.apple.com has address 17.151.16.21 time.apple.com has address 17.151.16.20 time.apple.com has address 17.151.16.30 time.apple.com has address 17.151.16.28 time.apple.com has address 17.151.16.31 time.apple.com has address 17.151.16.29 time.apple.com has address 17.171.4.24 time.apple.com has address 17.171.4.22 time.apple.com has address 17.171.4.23 time.apple.com has address 17.171.4.21 dfc@ronin:/var/repos/ntp-dev$ host time.euro.apple.com time.euro.apple.com has address 17.72.255.11 time.euro.apple.com has address 17.72.255.12 dfc@ronin:/var/repos/ntp-dev$ host time.asia.apple.com time.asia.apple.com has address 17.82.253.7 time.asia.apple.com has address 17.83.253.7 Apple should use the pool? Apple should support/donate/take part in the pool. But it would not be apple if they did not "think different":) >> I believe the Mac NTP client is shipped with a very large maximum polling >> interval. Try reducing it. > > In which case they are not running the reference implementation, as the > polling interval should automatically adjust to suit the need, and not > normally require the user to fiddle with the settings. > It is still the reference implementation just with different defaults. I also think the minpoll is ridiculously high. If you add your own servers / config directives below the line that the GUI adds to /private/etc/ntp.conf things work fine. I had autokey working on one up until the most recent autokey change. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] iPhone keeping better time?
On 11/16/2011 10:03 AM, David J Taylor wrote: >> I own a Mac Mini and a MacBook. Their NTP implementation is simply a >> joke. >> Even with a local stratum 1 I can't get decent accuracy. :-( >> >> David, weren't you interested in a LED clock I was going to build? >> >> Cheers, >> Miguel > > A pity that there isn't a port of the reference NTP for the Mac, such as > we have on Windows. > What? OSX has a slightly dated version of the NTP ref implementation. It looks like it is 4.2.6: http://opensource.apple.com/source/ntp/ ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] List Threading Behavior?
On 10/25/2011 05:10 AM, Attila Kinali wrote: On Tue, 25 Oct 2011 01:29:07 -0400 Doug Calvert wrote: Am I the only one whose email client has trouble putting threads together for this list? All of my other lists appear to be working correctly. Am I missing something? This is not an issue of the mailinglist itself, but of mail clients that do not conform to the RFC's. Especially webclients and MS stuff are known to miss the "In-Reply-To" and "References" header fields which are needed to get threading working correctly. Ie if someone with an incorrectly working mailclient replies to a mail you will get a "split" thread, because the In-Reply-To field is missing. Attila Kinali Thanks that makes sense. Most of the other mailing lists I am on are mainly populated by n*x users. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] List Threading Behavior?
Hello, Am I the only one whose email client has trouble putting threads together for this list? All of my other lists appear to be working correctly. Am I missing something? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SLIP vs Ethernet for NTP
On 10/24/2011 12:26 AM, Magnus Danielson wrote: On 10/24/2011 05:14 AM, Doug Calvert wrote: On 10/23/2011 08:37 AM, Tijd Dingen wrote: I seriously doubt that piping it through slip is going to help. You still get to deal with slip + tcp protocol stack. I would expect gbit ethernet with possibly some fifo/buffering setting adjusted gets you better performance that RS232 (with or without slip). Just assemble some raw frames on the source side and go. I think gig ethernet has a higher delay for smaller packets (ntp's udp datagram is tiny) than 100mbit ethernet. There is very little to support this claim. The line-encoding could possibly cause a small difference, but other than that I suspect implementation issues rather than protocol by itself. Even if you said that gigabit ethernet cards tend to have a higher delay for smaller packets I would react, but then not on the technical aspect but rather that I would like to see some statistics supporting the claim. Only real technical issue is that datagram size needs to be 64 bytes and that the header, trailer and inter-packet gap has the same size, but behaves like larger relative parts than for larger packets. However, this effect would be valid for fast ethernet too. I am off to bed so i do not have time to track down some of the links. I too was skeptical the first time I heard this. It has something to do with the framing (among others) if memory serves me. It was recently discussed on ntp-questions or ntp-hackers. The one link I do remember is from mysql-clusters: http://lists.mysql.com/cluster/3976 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] SLIP vs Ethernet for NTP
On 10/23/2011 08:37 AM, Tijd Dingen wrote: I seriously doubt that piping it through slip is going to help. You still get to deal with slip + tcp protocol stack. I would expect gbit ethernet with possibly some fifo/buffering setting adjusted gets you better performance that RS232 (with or without slip). Just assemble some raw frames on the source side and go. regards Fred I think gig ethernet has a higher delay for smaller packets (ntp's udp datagram is tiny) than 100mbit ethernet. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Google NTP Servers and smearing leap seconds...
Time Technology and leaping seconds http://googleblog.blogspot.com/2011/09/time-technology-and-leaping-seconds.html "The solution we came up with came to be known as the “leap smear.” We modified our internal NTP servers to gradually add a couple of milliseconds to every update, varying over a time window before the moment when the leap second actually happens. This meant that when it became time to add an extra second at midnight, our clocks had already taken this into account, by skewing the time over the course of the day. All of our servers were then able to continue as normal with the new year, blissfully unaware that a leap second had just occurred. We plan to use this “leap smear” technique again in the future, when new leap seconds are announced by the IERS." ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Averaging Location for Position Hold
>> As far as Lady Heather not working with other GPSDO's... well, She has >> good taste. The Trimble Thunderbolt is far and away the best time-nut GPSDO >> out there. It is highly configurable and controllable, comes with a very >> good OCXO, and is dirt stinkin' cheap. If you dot all your i's and cross >> all your t's and pay very close attention to the details you can coax >> ridiculously high performance out of the tiny little box... rivaling the >> best cesium references made for under $200. Far and away better than the M12+ or M12M? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 60hz west coast electric grid gone berserk
The OP mentioned something about pulling data from Washington (i think he was in nevada/utah). Where can you access power grid data like that over the internet? On Fri, Sep 9, 2011 at 1:17 PM, Hal Murray wrote: >> What software do you use for the monitoring? > > Things are pretty simple if you have a Linux box. Here is the code I'm using: > http://www.megapathdsl.net/~hmurray/time-nuts/60Hz/60Hz.py > > Kernel support to capture PPS info into NTP was developed many years ago. > The API gives you a time stamp and a count. Although the intention was 1 Hz, > it works fine at 60 Hz. It's available on recent Linux kernels and has been > available on most/all *BSD systems for a long long time. > > Linux also makes that info available via /sys/class/pps/pps0/assert so you > can get at it with scripts and don't need to write/compile c code. > [murray@shuksan]$ cat /sys/class/pps/pps0/assert > 1315583280.57314#763070 > [murray@shuksan]$ > > It wouldn't be hard to write something similar in c that would run on a BSD > box. > > > > -- > These are my opinions, not necessarily my employer's. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
