[time-nuts] More ES100 WWVB Measurements
Lady Heather has DST code. It has rules for USA, Europe, and Australia or the user can specify a local rule. The code is not very complicated, but getting it right (and testing) can be tricky. >Has anybody looked into how much code it takes to implement DST? ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
Hi Wayne:
The problem is that when and how DST is implemented is a political decision at the state level. When those rules that
apply today are implemented in firmware (easy to do) the product tells the wrong time when those rules change.
In the case of the Heathkit GC-1000 the DST firmware changed the time when Colorado changed, but for me in California
that clock was wrong twice a year for a couple of hours.
https://www.prc68.com/I/HeathkitGC1000.shtml
--
Have Fun,
Brooke Clarke
https://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how
well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.
Original Message
> GPS has no bits for Daylight Savings
It isn't that hard to compute when DST changes and GPS has the advantage that, since it also knows position, a wall
clock could also automatically set the timezone, much as our cellphones do.
> Has anybody looked into how much code it takes to implement DST?
In my WWVB generator for Arduino it took me about about 15 lines of C code and a small table (daysToMonth[]). The main
function is getNthSundayOfMonth() which, in turn, use two other functions, getDayOfYear() and isLeapYear(). The
daysToMonth[] table is used by getDayOfYear(). Then, the main code uses getNthSundayOfMonth() to get the 2nd Sundays
of MARCH and NOVEMBER.
Wayne
On Tue, Jan 1, 2019 at 12:34 PM Brooke Clarke mailto:bro...@pacific.net>> wrote:
Hi Wayne:
DST.
GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB
have those bits.
So for a clock displaying local time WWVB is the way to go.
--
Have Fun,
Brooke Clarke
https://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by
how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.
Original Message
> While reading this thread and pondering whether to buy and fool around
with
> an ES100-based module from Universal Solder, I suddenly found myself
> wondering if there was any advantage to using the time received from WWVB
> vs just using an inexpensive GPS receiver. The ES100 module costs about
> $70, but I can get a GPS receiver, with antenna, for far less than that
and
> I've had no trouble receiving GPS signals indoors with most modern
receiver
> modules.
>
> I suppose the low power requirements of the ES100 might be an advantage
> when building battery powered clocks to mount on the wall, but it seems
> like some of the newer, ultra low power GPS modules intended for use in
> smart watches could also work in a battery-powered wall clock, especially
> if the receiver was only powered on a few times a day to update the time.
>
> And, finally, if GPS modules are (or will some become) a suitable
> replacement for WWVB receiver modules, do we really need WWVB in the
modern
> age? Perhaps there's some critical advantage to using WWVB to get the
time
> but, offhand, I cannot think of it. What am I missing?
>
> Wayne
>
> On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke mailto:bro...@pacific.net>> wrote:
>
>> Hi Joseph:
>>
>> Thanks for the patent link. I've added it to my WWVB phase modulation
>> info at:
>> https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic
>>
>> --
>> Have Fun,
>>
>> Brooke Clarke
>> https://www.PRC68.com
>> http://www.end2partygovernment.com/2012Issues.html
>> axioms:
>> 1. The extent to which you can fix or improve something will be limited
by
>> how well you understand how it works.
>> 2. Everybody, with no exceptions, holds false beliefs.
>>
>> Original Message
>>> On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com
<mailto:time-nuts-requ...@lists.febo.com>
>>> wrote:
>>>
>>>> time-nuts Digest, Vol 173, Issue 44
>>>> Message: 7
>>>> Date: Mon, 31 Dec 2018 04:04:22 -0800
>>>> From: "Tom Van Baak"
>>>> To: "Discussion of precise time and frequency measurement"
>>>> mailto:time-nuts@lists.febo.com>>
>>>> Subject: Re: [time-nuts] More ES100 WWVB Measurements
>>>> Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52>
>>>> Content-Type: text/plain; charset="UTF-8"
>>>>
>>>&
Re: [time-nuts] More ES100 WWVB Measurements
It appears Canada tries to match the US to save confusion. The US changed the dates starting in 2007 (making clocks in earlier systems like VCRs obsolete) and Canada followed suit. Who knows what Congress will do in the future (abolish DST? I hope!), so programming a system to be good to 2100 seems optimistic! David N1HAC On 1/1/19 5:31 PM, Graham / KE9H wrote: >> Does anybody know how many other places use the same rules? What does > Canada do? > > https://en.wikipedia.org/wiki/Daylight_saving_time_by_country > > --- Graham > > == > > On Tue, Jan 1, 2019 at 4:05 PM Hal Murray wrote: > >>> GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB >>> have those bits. So for a clock displaying local time WWVB is the way to >> go. >> >> WWVB's DST data is targeted at the US. >> >> Does anybody know how many other places use the same rules? What does >> Canada >> do? >> >> Has anybody looked into how much code it takes to implement DST? If you >> are >> willing to stick to one set of rules, you could pre-compute a small table >> to >> cover the next 20 (or 100) years. That's probably not good enough for a >> product, but OK for most home brew clocks. Can I get to 2100 with only 28 >> slots? (7 for day-of-week, and 4 for leap years) >> >> The full Unix time conversion package is pretty big if you are of running >> it >> on a tiny SOC. Has anybody implemented a slimmed down version? How slim >> can >> you get if all you want is DST? >> >> Besides, GPS gives you leap second warning. >> >> A while ago, somebody asked why use WWVB rather than GPS? One answer is >> so we >> can monitor what it does when a leap second happens. >> >> >> >> >> -- >> These are my opinions. I hate spam. >> >> >> >> >> ___ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=02%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C25a013efe21a47a2cfc308d670673875%7C995b093648d640e5a31ebf689ec9446f%7C0%7C1%7C636819985982409036sdata=BKBILOKTdOaPsSSz%2FezRuZ8His6jcRnp5TePARLlIYs%3Dreserved=0 >> and follow the instructions there. >> > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.comdata=02%7C01%7Cdavid.g.mcgaw%40dartmouth.edu%7C25a013efe21a47a2cfc308d670673875%7C995b093648d640e5a31ebf689ec9446f%7C0%7C1%7C636819985982419040sdata=N7yW%2BmbXlKj47WIeCBKMSjT7628E1dkj33yfQ8yqyjg%3Dreserved=0 > and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
> Does anybody know how many other places use the same rules? What does Canada do? https://en.wikipedia.org/wiki/Daylight_saving_time_by_country --- Graham == On Tue, Jan 1, 2019 at 4:05 PM Hal Murray wrote: > > > GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB > > have those bits. So for a clock displaying local time WWVB is the way to > go. > > WWVB's DST data is targeted at the US. > > Does anybody know how many other places use the same rules? What does > Canada > do? > > Has anybody looked into how much code it takes to implement DST? If you > are > willing to stick to one set of rules, you could pre-compute a small table > to > cover the next 20 (or 100) years. That's probably not good enough for a > product, but OK for most home brew clocks. Can I get to 2100 with only 28 > slots? (7 for day-of-week, and 4 for leap years) > > The full Unix time conversion package is pretty big if you are of running > it > on a tiny SOC. Has anybody implemented a slimmed down version? How slim > can > you get if all you want is DST? > > Besides, GPS gives you leap second warning. > > A while ago, somebody asked why use WWVB rather than GPS? One answer is > so we > can monitor what it does when a leap second happens. > > > > > -- > These are my opinions. I hate spam. > > > > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
> GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB > have those bits. So for a clock displaying local time WWVB is the way to go. WWVB's DST data is targeted at the US. Does anybody know how many other places use the same rules? What does Canada do? Has anybody looked into how much code it takes to implement DST? If you are willing to stick to one set of rules, you could pre-compute a small table to cover the next 20 (or 100) years. That's probably not good enough for a product, but OK for most home brew clocks. Can I get to 2100 with only 28 slots? (7 for day-of-week, and 4 for leap years) The full Unix time conversion package is pretty big if you are of running it on a tiny SOC. Has anybody implemented a slimmed down version? How slim can you get if all you want is DST? Besides, GPS gives you leap second warning. A while ago, somebody asked why use WWVB rather than GPS? One answer is so we can monitor what it does when a leap second happens. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
Hi Wayne: DST. GPS has no bits for Daylight Savings. As far as I know only WWV and WWVB have those bits. So for a clock displaying local time WWVB is the way to go. -- Have Fun, Brooke Clarke https://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html axioms: 1. The extent to which you can fix or improve something will be limited by how well you understand how it works. 2. Everybody, with no exceptions, holds false beliefs. Original Message While reading this thread and pondering whether to buy and fool around with an ES100-based module from Universal Solder, I suddenly found myself wondering if there was any advantage to using the time received from WWVB vs just using an inexpensive GPS receiver. The ES100 module costs about $70, but I can get a GPS receiver, with antenna, for far less than that and I've had no trouble receiving GPS signals indoors with most modern receiver modules. I suppose the low power requirements of the ES100 might be an advantage when building battery powered clocks to mount on the wall, but it seems like some of the newer, ultra low power GPS modules intended for use in smart watches could also work in a battery-powered wall clock, especially if the receiver was only powered on a few times a day to update the time. And, finally, if GPS modules are (or will some become) a suitable replacement for WWVB receiver modules, do we really need WWVB in the modern age? Perhaps there's some critical advantage to using WWVB to get the time but, offhand, I cannot think of it. What am I missing? Wayne On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke wrote: Hi Joseph: Thanks for the patent link. I've added it to my WWVB phase modulation info at: https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic -- Have Fun, Brooke Clarke https://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html axioms: 1. The extent to which you can fix or improve something will be limited by how well you understand how it works. 2. Everybody, with no exceptions, holds false beliefs. Original Message On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com wrote: time-nuts Digest, Vol 173, Issue 44 Message: 7 Date: Mon, 31 Dec 2018 04:04:22 -0800 From: "Tom Van Baak" To: "Discussion of precise time and frequency measurement" Subject: Re: [time-nuts] More ES100 WWVB Measurements Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> Content-Type: text/plain;charset="UTF-8" Hi Graham, That's very nice work. And you have uncovered several unusual effects in the ES100. Bugs? Features? If we time nuts keep up the good work to evaluate this chip, we are likely at some point to get an informative response from the guys who designed it. They read time-nuts. I didn't see this mentioned, but I think I have found the relevant US patent application: US20130051184A1, Real-time clock integrated circuit with time code receiver, method of operation thereof and devices incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed 2013-02-28. .<https://patents.google.com/patent/US20130051184> Found this by chasing stuff from the EverSet website: .< http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf . Joe Gwinn So now both you and Tim have observed the off-by-one-second (or off-by-N-seconds) effect in the ES100. I wonder if this explains why some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are off by a second sometimes. My main question: in your "Time Plot.PNG" plot, what is the cause of the sawtooth pattern? The points are almost all on a clear negative slope, though bounded by roughly +/- 75ms. Looking on the far left, I see a time drift of +50 ms to -25 ms over an hour, which is equivalent to a -20 ppm frequency offset; about -2 seconds/day. Do you think this is due to the 16 MHz onboard xtal? If so, how about changing the temperature of the eval board by a lot (say, several tens of degrees) for an extended time (say, 4 hours) and see if the sawtooth slope changes convincingly. Also, just to be sure, can you put a known independent timing signal (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / ntpd time server / Python 3 / Excel stack to establish the validity of your measurement methodology? Very likely you did it right, but I always cringe when I hear "Linux" or "NTP" and "precise time" in the same sentence. Yes, sorry, forgive me; I grew up in the "trust, but verify" generation [1]. It applies pretty well to metrology also ;-) /tvb [1] https://en.wikipedia.org/wiki/Trust,_but_verify End of time-nuts Digest, Vol 173, Issue 44 ** ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
[time-nuts] More ES100 WWVB Measurements
On Mon, 31 Dec 2018 17:47:56 -0800 Wayne Holder wrote: Interesting thought. I wonder if anyone has tested WWVB reception in a deep underground location such as a sub sub level in a building or parking garage? * * * Many years ago when the San Francisco rapid transit system (Bart) was getting ready to open a tunnel under San Francisco Bay, a radio station I was affiliated with, operating on 560 kHz, was preparing to do an underground broadcast at the east end of the tunnel. Radio reception was desired for timing and coordination as telephone lines, other than the broadcast circuit, were not yet available. Portable radios produced no trace of a signal -- only noise. I took down what I called a resonant-ring antenna, basically a three-food diameter ring of one-inch copper pipe with mica capacitors in the gap and tuned to 560 kHz. The feed connections were loaded with resistance to produce a 10 kHz bandwidth as the natural response of this loop was only about 1 kHz between 6 dB points. With the loop underground, bringing a transistor radio within a couple of feet of the loop produced a strong clear signal. I believe a similar loop would provide underground WWVB reception. Bruce, KG6OJI ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
Hi Go indoors in the basement inside an inner room. You can at some times of day get WWVB. With a normal building, GPS isn’t going to make it. Even if it does, the signals will be degraded enough that you will have a tough time using in. Bob > On Dec 31, 2018, at 8:47 PM, Wayne Holder wrote: > >> If you are fairly deep inside a building, GPS isn’t going to get there. > WWVB likely >> will make it to an internal location. > > Interesting thought. I wonder if anyone has tested WWVB reception in a > deep underground location such as a sub sub level in a building or parking > garage? > > Wayne > > On Mon, Dec 31, 2018 at 5:29 PM Bob kb8tq wrote: > >> Hi >> >> If you are fairly deep inside a building, GPS isn’t going to get there. >> WWVB likely >> will make it to an internal location. >> >> If you are convinced that WWVB is un-jamable and that GPS is easily >> jammed, WWVB >> would be more robust. >> >> That’s about it. >> >> Bob >> >>> On Dec 31, 2018, at 7:56 PM, Wayne Holder >> wrote: >>> >>> While reading this thread and pondering whether to buy and fool around >> with >>> an ES100-based module from Universal Solder, I suddenly found myself >>> wondering if there was any advantage to using the time received from WWVB >>> vs just using an inexpensive GPS receiver. The ES100 module costs about >>> $70, but I can get a GPS receiver, with antenna, for far less than that >> and >>> I've had no trouble receiving GPS signals indoors with most modern >> receiver >>> modules. >>> >>> I suppose the low power requirements of the ES100 might be an advantage >>> when building battery powered clocks to mount on the wall, but it seems >>> like some of the newer, ultra low power GPS modules intended for use in >>> smart watches could also work in a battery-powered wall clock, especially >>> if the receiver was only powered on a few times a day to update the time. >>> >>> And, finally, if GPS modules are (or will some become) a suitable >>> replacement for WWVB receiver modules, do we really need WWVB in the >> modern >>> age? Perhaps there's some critical advantage to using WWVB to get the >> time >>> but, offhand, I cannot think of it. What am I missing? >>> >>> Wayne >>> >>> On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke >> wrote: >>> >>>> Hi Joseph: >>>> >>>> Thanks for the patent link. I've added it to my WWVB phase modulation >>>> info at: >>>> https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic >>>> >>>> -- >>>> Have Fun, >>>> >>>> Brooke Clarke >>>> https://www.PRC68.com >>>> http://www.end2partygovernment.com/2012Issues.html >>>> axioms: >>>> 1. The extent to which you can fix or improve something will be limited >> by >>>> how well you understand how it works. >>>> 2. Everybody, with no exceptions, holds false beliefs. >>>> >>>> Original Message >>>>> On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com >>>>> wrote: >>>>> >>>>>> time-nuts Digest, Vol 173, Issue 44 >>>>>> Message: 7 >>>>>> Date: Mon, 31 Dec 2018 04:04:22 -0800 >>>>>> From: "Tom Van Baak" >>>>>> To: "Discussion of precise time and frequency measurement" >>>>>> >>>>>> Subject: Re: [time-nuts] More ES100 WWVB Measurements >>>>>> Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> >>>>>> Content-Type: text/plain;charset="UTF-8" >>>>>> >>>>>> Hi Graham, >>>>>> >>>>>> That's very nice work. And you have uncovered several unusual effects >>>>>> in the ES100. Bugs? Features? If we time nuts keep up the good work >>>>>> to evaluate this chip, we are likely at some point to get an >>>>>> informative response from the guys who designed it. They read >>>>>> time-nuts. >>>>> I didn't see this mentioned, but I think I have found the relevant US >>>>> patent application: US20130051184A1, Real-time clock integrated circuit >>>>> with time code receiver, method of operation thereof and devices >>>>> incorporating the same, Oren Eliez
Re: [time-nuts] More ES100 WWVB Measurements
> If you are fairly deep inside a building, GPS isn’t going to get there. WWVB likely > will make it to an internal location. Interesting thought. I wonder if anyone has tested WWVB reception in a deep underground location such as a sub sub level in a building or parking garage? Wayne On Mon, Dec 31, 2018 at 5:29 PM Bob kb8tq wrote: > Hi > > If you are fairly deep inside a building, GPS isn’t going to get there. > WWVB likely > will make it to an internal location. > > If you are convinced that WWVB is un-jamable and that GPS is easily > jammed, WWVB > would be more robust. > > That’s about it. > > Bob > > > On Dec 31, 2018, at 7:56 PM, Wayne Holder > wrote: > > > > While reading this thread and pondering whether to buy and fool around > with > > an ES100-based module from Universal Solder, I suddenly found myself > > wondering if there was any advantage to using the time received from WWVB > > vs just using an inexpensive GPS receiver. The ES100 module costs about > > $70, but I can get a GPS receiver, with antenna, for far less than that > and > > I've had no trouble receiving GPS signals indoors with most modern > receiver > > modules. > > > > I suppose the low power requirements of the ES100 might be an advantage > > when building battery powered clocks to mount on the wall, but it seems > > like some of the newer, ultra low power GPS modules intended for use in > > smart watches could also work in a battery-powered wall clock, especially > > if the receiver was only powered on a few times a day to update the time. > > > > And, finally, if GPS modules are (or will some become) a suitable > > replacement for WWVB receiver modules, do we really need WWVB in the > modern > > age? Perhaps there's some critical advantage to using WWVB to get the > time > > but, offhand, I cannot think of it. What am I missing? > > > > Wayne > > > > On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke > wrote: > > > >> Hi Joseph: > >> > >> Thanks for the patent link. I've added it to my WWVB phase modulation > >> info at: > >> https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic > >> > >> -- > >> Have Fun, > >> > >> Brooke Clarke > >> https://www.PRC68.com > >> http://www.end2partygovernment.com/2012Issues.html > >> axioms: > >> 1. The extent to which you can fix or improve something will be limited > by > >> how well you understand how it works. > >> 2. Everybody, with no exceptions, holds false beliefs. > >> > >> ---- Original Message > >>> On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com > >>> wrote: > >>> > >>>> time-nuts Digest, Vol 173, Issue 44 > >>>> Message: 7 > >>>> Date: Mon, 31 Dec 2018 04:04:22 -0800 > >>>> From: "Tom Van Baak" > >>>> To: "Discussion of precise time and frequency measurement" > >>>> > >>>> Subject: Re: [time-nuts] More ES100 WWVB Measurements > >>>> Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> > >>>> Content-Type: text/plain;charset="UTF-8" > >>>> > >>>> Hi Graham, > >>>> > >>>> That's very nice work. And you have uncovered several unusual effects > >>>> in the ES100. Bugs? Features? If we time nuts keep up the good work > >>>> to evaluate this chip, we are likely at some point to get an > >>>> informative response from the guys who designed it. They read > >>>> time-nuts. > >>> I didn't see this mentioned, but I think I have found the relevant US > >>> patent application: US20130051184A1, Real-time clock integrated circuit > >>> with time code receiver, method of operation thereof and devices > >>> incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed > >>> 2013-02-28. > >>> > >>> .<https://patents.google.com/patent/US20130051184> > >>> > >>> Found this by chasing stuff from the EverSet website: > >>> .< > >> > http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf > >>> . > >>> > >>> Joe Gwinn > >>> > >>> > >>>> So now both you and Tim have observed the off-by-one-second (or > >>>> off-by-N-seconds) effect in the ES100. I wonder if this explains why > >>>>
Re: [time-nuts] More ES100 WWVB Measurements
Hi If you are fairly deep inside a building, GPS isn’t going to get there. WWVB likely will make it to an internal location. If you are convinced that WWVB is un-jamable and that GPS is easily jammed, WWVB would be more robust. That’s about it. Bob > On Dec 31, 2018, at 7:56 PM, Wayne Holder wrote: > > While reading this thread and pondering whether to buy and fool around with > an ES100-based module from Universal Solder, I suddenly found myself > wondering if there was any advantage to using the time received from WWVB > vs just using an inexpensive GPS receiver. The ES100 module costs about > $70, but I can get a GPS receiver, with antenna, for far less than that and > I've had no trouble receiving GPS signals indoors with most modern receiver > modules. > > I suppose the low power requirements of the ES100 might be an advantage > when building battery powered clocks to mount on the wall, but it seems > like some of the newer, ultra low power GPS modules intended for use in > smart watches could also work in a battery-powered wall clock, especially > if the receiver was only powered on a few times a day to update the time. > > And, finally, if GPS modules are (or will some become) a suitable > replacement for WWVB receiver modules, do we really need WWVB in the modern > age? Perhaps there's some critical advantage to using WWVB to get the time > but, offhand, I cannot think of it. What am I missing? > > Wayne > > On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke wrote: > >> Hi Joseph: >> >> Thanks for the patent link. I've added it to my WWVB phase modulation >> info at: >> https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic >> >> -- >> Have Fun, >> >> Brooke Clarke >> https://www.PRC68.com >> http://www.end2partygovernment.com/2012Issues.html >> axioms: >> 1. The extent to which you can fix or improve something will be limited by >> how well you understand how it works. >> 2. Everybody, with no exceptions, holds false beliefs. >> >> Original Message >>> On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com >>> wrote: >>> >>>> time-nuts Digest, Vol 173, Issue 44 >>>> Message: 7 >>>> Date: Mon, 31 Dec 2018 04:04:22 -0800 >>>> From: "Tom Van Baak" >>>> To: "Discussion of precise time and frequency measurement" >>>> >>>> Subject: Re: [time-nuts] More ES100 WWVB Measurements >>>> Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> >>>> Content-Type: text/plain;charset="UTF-8" >>>> >>>> Hi Graham, >>>> >>>> That's very nice work. And you have uncovered several unusual effects >>>> in the ES100. Bugs? Features? If we time nuts keep up the good work >>>> to evaluate this chip, we are likely at some point to get an >>>> informative response from the guys who designed it. They read >>>> time-nuts. >>> I didn't see this mentioned, but I think I have found the relevant US >>> patent application: US20130051184A1, Real-time clock integrated circuit >>> with time code receiver, method of operation thereof and devices >>> incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed >>> 2013-02-28. >>> >>> .<https://patents.google.com/patent/US20130051184> >>> >>> Found this by chasing stuff from the EverSet website: >>> .< >> http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf >>> . >>> >>> Joe Gwinn >>> >>> >>>> So now both you and Tim have observed the off-by-one-second (or >>>> off-by-N-seconds) effect in the ES100. I wonder if this explains why >>>> some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are >>>> off by a second sometimes. >>>> >>>> My main question: in your "Time Plot.PNG" plot, what is the cause of >>>> the sawtooth pattern? The points are almost all on a clear negative >>>> slope, though bounded by roughly +/- 75ms. Looking on the far left, I >>>> see a time drift of +50 ms to -25 ms over an hour, which is >>>> equivalent to a -20 ppm frequency offset; about -2 seconds/day. >>>> >>>> Do you think this is due to the 16 MHz onboard xtal? If so, how about >>>> changing the temperature of the eval board by a lot (say, several >>
Re: [time-nuts] More ES100 WWVB Measurements
While reading this thread and pondering whether to buy and fool around with an ES100-based module from Universal Solder, I suddenly found myself wondering if there was any advantage to using the time received from WWVB vs just using an inexpensive GPS receiver. The ES100 module costs about $70, but I can get a GPS receiver, with antenna, for far less than that and I've had no trouble receiving GPS signals indoors with most modern receiver modules. I suppose the low power requirements of the ES100 might be an advantage when building battery powered clocks to mount on the wall, but it seems like some of the newer, ultra low power GPS modules intended for use in smart watches could also work in a battery-powered wall clock, especially if the receiver was only powered on a few times a day to update the time. And, finally, if GPS modules are (or will some become) a suitable replacement for WWVB receiver modules, do we really need WWVB in the modern age? Perhaps there's some critical advantage to using WWVB to get the time but, offhand, I cannot think of it. What am I missing? Wayne On Mon, Dec 31, 2018 at 4:30 PM Brooke Clarke wrote: > Hi Joseph: > > Thanks for the patent link. I've added it to my WWVB phase modulation > info at: > https://prc68.com/I/Loop.shtml#La_Crosse_UltrAtomic > > -- > Have Fun, > > Brooke Clarke > https://www.PRC68.com > http://www.end2partygovernment.com/2012Issues.html > axioms: > 1. The extent to which you can fix or improve something will be limited by > how well you understand how it works. > 2. Everybody, with no exceptions, holds false beliefs. > > Original Message > > On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com > > wrote: > > > >> time-nuts Digest, Vol 173, Issue 44 > >> Message: 7 > >> Date: Mon, 31 Dec 2018 04:04:22 -0800 > >> From: "Tom Van Baak" > >> To: "Discussion of precise time and frequency measurement" > >> > >> Subject: Re: [time-nuts] More ES100 WWVB Measurements > >> Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> > >> Content-Type: text/plain;charset="UTF-8" > >> > >> Hi Graham, > >> > >> That's very nice work. And you have uncovered several unusual effects > >> in the ES100. Bugs? Features? If we time nuts keep up the good work > >> to evaluate this chip, we are likely at some point to get an > >> informative response from the guys who designed it. They read > >> time-nuts. > > I didn't see this mentioned, but I think I have found the relevant US > > patent application: US20130051184A1, Real-time clock integrated circuit > > with time code receiver, method of operation thereof and devices > > incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed > > 2013-02-28. > > > > .<https://patents.google.com/patent/US20130051184> > > > > Found this by chasing stuff from the EverSet website: > > .< > http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf > >. > > > > Joe Gwinn > > > > > >> So now both you and Tim have observed the off-by-one-second (or > >> off-by-N-seconds) effect in the ES100. I wonder if this explains why > >> some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are > >> off by a second sometimes. > >> > >> My main question: in your "Time Plot.PNG" plot, what is the cause of > >> the sawtooth pattern? The points are almost all on a clear negative > >> slope, though bounded by roughly +/- 75ms. Looking on the far left, I > >> see a time drift of +50 ms to -25 ms over an hour, which is > >> equivalent to a -20 ppm frequency offset; about -2 seconds/day. > >> > >> Do you think this is due to the 16 MHz onboard xtal? If so, how about > >> changing the temperature of the eval board by a lot (say, several > >> tens of degrees) for an extended time (say, 4 hours) and see if the > >> sawtooth slope changes convincingly. > >> > >> Also, just to be sure, can you put a known independent timing signal > >> (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / > >> ntpd time server / Python 3 / Excel stack to establish the validity > >> of your measurement methodology? Very likely you did it right, but I > >> always cringe when I hear "Linux" or "NTP" and "precise time" in the > >> same sentence. Yes, sorry, forgive me; I grew up in the "trust, but > >> verify" generation [1]. It applies pretty well to metrology also ;-) &
Re: [time-nuts] More ES100 WWVB Measurements
Good detective work. Oren is who I used to talk with at everset. Regards Paul WB8TSL On Mon, Dec 31, 2018 at 4:32 PM Joseph Gwinn wrote: > On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com > wrote: > > > time-nuts Digest, Vol 173, Issue 44 > > > Message: 7 > > Date: Mon, 31 Dec 2018 04:04:22 -0800 > > From: "Tom Van Baak" > > To: "Discussion of precise time and frequency measurement" > > > > Subject: Re: [time-nuts] More ES100 WWVB Measurements > > Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> > > Content-Type: text/plain; charset="UTF-8" > > > > Hi Graham, > > > > That's very nice work. And you have uncovered several unusual effects > > in the ES100. Bugs? Features? If we time nuts keep up the good work > > to evaluate this chip, we are likely at some point to get an > > informative response from the guys who designed it. They read > > time-nuts. > > I didn't see this mentioned, but I think I have found the relevant US > patent application: US20130051184A1, Real-time clock integrated circuit > with time code receiver, method of operation thereof and devices > incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed > 2013-02-28. > > .<https://patents.google.com/patent/US20130051184> > > Found this by chasing stuff from the EverSet website: > .< > http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf > >. > > Joe Gwinn > > > > So now both you and Tim have observed the off-by-one-second (or > > off-by-N-seconds) effect in the ES100. I wonder if this explains why > > some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are > > off by a second sometimes. > > > > My main question: in your "Time Plot.PNG" plot, what is the cause of > > the sawtooth pattern? The points are almost all on a clear negative > > slope, though bounded by roughly +/- 75ms. Looking on the far left, I > > see a time drift of +50 ms to -25 ms over an hour, which is > > equivalent to a -20 ppm frequency offset; about -2 seconds/day. > > > > Do you think this is due to the 16 MHz onboard xtal? If so, how about > > changing the temperature of the eval board by a lot (say, several > > tens of degrees) for an extended time (say, 4 hours) and see if the > > sawtooth slope changes convincingly. > > > > Also, just to be sure, can you put a known independent timing signal > > (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / > > ntpd time server / Python 3 / Excel stack to establish the validity > > of your measurement methodology? Very likely you did it right, but I > > always cringe when I hear "Linux" or "NTP" and "precise time" in the > > same sentence. Yes, sorry, forgive me; I grew up in the "trust, but > > verify" generation [1]. It applies pretty well to metrology also ;-) > > > > /tvb > > > > [1] https://en.wikipedia.org/wiki/Trust,_but_verify > > > > > > End of time-nuts Digest, Vol 173, Issue 44 > > ** > > ___ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
On Mon, 31 Dec 2018 12:00:02 -0500, time-nuts-requ...@lists.febo.com wrote: > time-nuts Digest, Vol 173, Issue 44 > Message: 7 > Date: Mon, 31 Dec 2018 04:04:22 -0800 > From: "Tom Van Baak" > To: "Discussion of precise time and frequency measurement" > > Subject: Re: [time-nuts] More ES100 WWVB Measurements > Message-ID: <96BB388753294278A9CDE96C1EA7D9AE@pc52> > Content-Type: text/plain; charset="UTF-8" > > Hi Graham, > > That's very nice work. And you have uncovered several unusual effects > in the ES100. Bugs? Features? If we time nuts keep up the good work > to evaluate this chip, we are likely at some point to get an > informative response from the guys who designed it. They read > time-nuts. I didn't see this mentioned, but I think I have found the relevant US patent application: US20130051184A1, Real-time clock integrated circuit with time code receiver, method of operation thereof and devices incorporating the same, Oren Eliezer et al, Oren Eliezer et al, filed 2013-02-28. .<https://patents.google.com/patent/US20130051184> Found this by chasing stuff from the EverSet website: .<http://everset-tech.com/wp-content/uploads/2014/11/ReceiverRadioClocks.pdf>. Joe Gwinn > So now both you and Tim have observed the off-by-one-second (or > off-by-N-seconds) effect in the ES100. I wonder if this explains why > some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are > off by a second sometimes. > > My main question: in your "Time Plot.PNG" plot, what is the cause of > the sawtooth pattern? The points are almost all on a clear negative > slope, though bounded by roughly +/- 75ms. Looking on the far left, I > see a time drift of +50 ms to -25 ms over an hour, which is > equivalent to a -20 ppm frequency offset; about -2 seconds/day. > > Do you think this is due to the 16 MHz onboard xtal? If so, how about > changing the temperature of the eval board by a lot (say, several > tens of degrees) for an extended time (say, 4 hours) and see if the > sawtooth slope changes convincingly. > > Also, just to be sure, can you put a known independent timing signal > (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / > ntpd time server / Python 3 / Excel stack to establish the validity > of your measurement methodology? Very likely you did it right, but I > always cringe when I hear "Linux" or "NTP" and "precise time" in the > same sentence. Yes, sorry, forgive me; I grew up in the "trust, but > verify" generation [1]. It applies pretty well to metrology also ;-) > > /tvb > > [1] https://en.wikipedia.org/wiki/Trust,_but_verify > > > End of time-nuts Digest, Vol 173, Issue 44 > ** ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] More ES100 WWVB Measurements
This is good work and I have been following. What caught my attention was the 2 X very fast codes. I remember talking to the everset folks early on and the high speed code could be turned on. It had not been. The ES100 will not track that code as mentioned. Did not think they actually ever turned it on. More likely a power cycle left the system turned on. A bit of humor. If John Lowe is still around send him a email he could turn it off. Regards Paul WB8TSL On Mon, Dec 31, 2018 at 7:05 AM Tom Van Baak wrote: > Hi Graham, > > That's very nice work. And you have uncovered several unusual effects in > the ES100. Bugs? Features? If we time nuts keep up the good work to > evaluate this chip, we are likely at some point to get an informative > response from the guys who designed it. They read time-nuts. > > So now both you and Tim have observed the off-by-one-second (or > off-by-N-seconds) effect in the ES100. I wonder if this explains why some > of my ES100-based La Crosse 1235UA Ultratomic wall clocks are off by a > second sometimes. > > My main question: in your "Time Plot.PNG" plot, what is the cause of the > sawtooth pattern? The points are almost all on a clear negative slope, > though bounded by roughly +/- 75ms. Looking on the far left, I see a time > drift of +50 ms to -25 ms over an hour, which is equivalent to a -20 ppm > frequency offset; about -2 seconds/day. > > Do you think this is due to the 16 MHz onboard xtal? If so, how about > changing the temperature of the eval board by a lot (say, several tens of > degrees) for an extended time (say, 4 hours) and see if the sawtooth slope > changes convincingly. > > Also, just to be sure, can you put a known independent timing signal > (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / ntpd > time server / Python 3 / Excel stack to establish the validity of your > measurement methodology? Very likely you did it right, but I always cringe > when I hear "Linux" or "NTP" and "precise time" in the same sentence. Yes, > sorry, forgive me; I grew up in the "trust, but verify" generation [1]. It > applies pretty well to metrology also ;-) > > /tvb > > [1] https://en.wikipedia.org/wiki/Trust,_but_verify > > > - Original Message - > From: "Graham / KE9H" > To: "Discussion of precise time and frequency measurement" < > time-nuts@lists.febo.com> > Sent: Sunday, December 30, 2018 6:03 PM > Subject: [time-nuts] More ES100 WWVB Measurements > > > > Attached are three graphs, plotting the results of two 24 hour runs of > the > > ES100 board. > > > > The ES100 can run in two modes. One for time acquisition, which takes 134 > > seconds, and a second mode for "tracking" which only takes 24 seconds to > > execute, and returns only the "seconds" value. > > > > The tracking mode is intended for time sync of a receiver that already > > knows > > the time, and may need to compensate for oscillator drift. It can only > sync > > over a +/- 4 second correction interval, and must be started just before > > the > > top of the minute. > > > > The first plot, entitled Time Plot, is a plot of sequential time > > acquisition > > commands, which shows the time returned by the ES100, versus nptd time, > on > > a Linux (Debian 9.4) computer connected to the network. Due to > asymmetrical > > latency in a cable modem system, there might be some bias in the > > Network time, but the bias should be constant for the 24 hour run. > > > > If the ES100 returned a "No Decode" for any single command, the value was > > forced to -100 ms in the plot, and plotted on the line labeled "NO > DECODE". > > > > The WWVB signal sends a 6 minute long highly encoded time signal at 10 > > Minutes > > and 40 Minutes after the hour, which this chip can not decode, which are > > the > > clearly occurring repetitive "NO DECODE" bursts, twice per hour. To the > > best of > > my knowledge, there is no commercially available receiver or that can > > decode this > > 6 minute signal. > > > > The first time acquisition was within a few seconds of 0300 UTC, and ran > > for > > 24 hours. After each acquisition, whether successful or unsuccessful > > decode, > > the logging computer waited one second then requested another time > > acquisition. > > A total of 495 samples were captured and plotted. > > > > -- > > > > The second test exercised the "tracking" mode. > > > > In this case, the logging computer requested a tracking upd
Re: [time-nuts] More ES100 WWVB Measurements
Hi Graham, That's very nice work. And you have uncovered several unusual effects in the ES100. Bugs? Features? If we time nuts keep up the good work to evaluate this chip, we are likely at some point to get an informative response from the guys who designed it. They read time-nuts. So now both you and Tim have observed the off-by-one-second (or off-by-N-seconds) effect in the ES100. I wonder if this explains why some of my ES100-based La Crosse 1235UA Ultratomic wall clocks are off by a second sometimes. My main question: in your "Time Plot.PNG" plot, what is the cause of the sawtooth pattern? The points are almost all on a clear negative slope, though bounded by roughly +/- 75ms. Looking on the far left, I see a time drift of +50 ms to -25 ms over an hour, which is equivalent to a -20 ppm frequency offset; about -2 seconds/day. Do you think this is due to the 16 MHz onboard xtal? If so, how about changing the temperature of the eval board by a lot (say, several tens of degrees) for an extended time (say, 4 hours) and see if the sawtooth slope changes convincingly. Also, just to be sure, can you put a known independent timing signal (e.g., GPS/1PPS) into your complex BeagleBone Black / Debian 9.4 / ntpd time server / Python 3 / Excel stack to establish the validity of your measurement methodology? Very likely you did it right, but I always cringe when I hear "Linux" or "NTP" and "precise time" in the same sentence. Yes, sorry, forgive me; I grew up in the "trust, but verify" generation [1]. It applies pretty well to metrology also ;-) /tvb [1] https://en.wikipedia.org/wiki/Trust,_but_verify - Original Message - From: "Graham / KE9H" To: "Discussion of precise time and frequency measurement" Sent: Sunday, December 30, 2018 6:03 PM Subject: [time-nuts] More ES100 WWVB Measurements > Attached are three graphs, plotting the results of two 24 hour runs of the > ES100 board. > > The ES100 can run in two modes. One for time acquisition, which takes 134 > seconds, and a second mode for "tracking" which only takes 24 seconds to > execute, and returns only the "seconds" value. > > The tracking mode is intended for time sync of a receiver that already > knows > the time, and may need to compensate for oscillator drift. It can only sync > over a +/- 4 second correction interval, and must be started just before > the > top of the minute. > > The first plot, entitled Time Plot, is a plot of sequential time > acquisition > commands, which shows the time returned by the ES100, versus nptd time, on > a Linux (Debian 9.4) computer connected to the network. Due to asymmetrical > latency in a cable modem system, there might be some bias in the > Network time, but the bias should be constant for the 24 hour run. > > If the ES100 returned a "No Decode" for any single command, the value was > forced to -100 ms in the plot, and plotted on the line labeled "NO DECODE". > > The WWVB signal sends a 6 minute long highly encoded time signal at 10 > Minutes > and 40 Minutes after the hour, which this chip can not decode, which are > the > clearly occurring repetitive "NO DECODE" bursts, twice per hour. To the > best of > my knowledge, there is no commercially available receiver or that can > decode this > 6 minute signal. > > The first time acquisition was within a few seconds of 0300 UTC, and ran > for > 24 hours. After each acquisition, whether successful or unsuccessful > decode, > the logging computer waited one second then requested another time > acquisition. > A total of 495 samples were captured and plotted. > > -- > > The second test exercised the "tracking" mode. > > In this case, the logging computer requested a tracking update at 4 seconds > before the top of the minute, every minute for 24 hours. > > The same results are plotted twice, once labeled "Track Plot ALL" which is > scaled to show all data, which includes some seconds returned as "valid" > but > are in error up to three seconds in time. It should be noted that there > were > only 13 of these events, and they all occurred during one of the six minute > highly encoded time signals, which this chip can not decode. I let the > tracking sync requests run during these 6 minute signals. If a real > application > knew not to ask for tracking sync during this time, the false "valid" would > not > occur. But it does suggest a problem within the error detection/correction > processes within the ES100 chip. > > To give a better view of the time "tracking" performance of the chip, I > plotted > the same data on a scale of +150, -100 milliseconds. This pl
