Forums

Seeking for a wall clock

Started by Carlos E.R. November 19, 2021
Hi,

I'd like to find a wall clock, say kitchen clock, that instead of 
syncing using the DCF radio station 
(https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync.

I may have asked about this before.

Problem is, that here in Spain the DCF signal is so weak that clocks can 
only sync during 01 to 05 AM, and often not even that, so that my clocks 
can be in error for minutes of even hours, not getting corrected in weeks.

So I wonder if somebody makes some sort of ready made clock that uses 
internet for syncing and which can be put on a wall. Or a kit.

Possibly it would run Android.

For example I found one or two bedside alarm clocks (Lenovo Smart Clock 
Essential, with microphone switched off). But nothing for the wall. I 
really do not want a smart clock with a microphone listening, I just 
want a clock, perhaps with a thermometer or weather app.


A possibility would be dedicate an old tablet to this. Or an ebook 
reader (some have apps)

I heard of people doing things like that with a Pi or whatever, but I 
don't look forward to that, somehow, from scratch. A kit, may be.


Maybe a DCF repeater?

-- 
Cheers, Carlos.
On a sunny day (Fri, 19 Nov 2021 19:48:21 +0100) it happened "Carlos E.R."
<robin_listas@es.invalid> wrote in <l48l6i-qpu.ln1@Telcontar.valinor>:

>Hi, > >I'd like to find a wall clock, say kitchen clock, that instead of >syncing using the DCF radio station >(https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. > >I may have asked about this before. > >Problem is, that here in Spain the DCF signal is so weak that clocks can >only sync during 01 to 05 AM, and often not even that, so that my clocks >can be in error for minutes of even hours, not getting corrected in weeks. > >So I wonder if somebody makes some sort of ready made clock that uses >internet for syncing and which can be put on a wall. Or a kit. > >Possibly it would run Android. > >For example I found one or two bedside alarm clocks (Lenovo Smart Clock >Essential, with microphone switched off). But nothing for the wall. I >really do not want a smart clock with a microphone listening, I just >want a clock, perhaps with a thermometer or weather app. > > >A possibility would be dedicate an old tablet to this. Or an ebook >reader (some have apps) > >I heard of people doing things like that with a Pi or whatever, but I >don't look forward to that, somehow, from scratch. A kit, may be.
Yes I did: http://panteltje.com/panteltje/raspberry_pi_FDS132_matrix_display_driver/index.html
> >Maybe a DCF repeater?
Much simpler is use GPS time: http://panteltje.com/panteltje/pic/gm_pic2/ http://www.panteltje.com/pub/GPS_time_IXIMG_0745.JPG it can also measure radiation and tracks location.... If you get a 30$ GPS module and connect it to a raspberry the C code to get the time from it and add time offset for CET is in http://panteltje.com/panteltje/xgpspc/index.html But raspberry will normally sync its system time automaticaly from the internet if connected to it, you do not normally need GPS. So maybe for you a simple raspberry and LCD display? And my cellphone gets its time from the phone network. An alternative would be a sundial.
On 19.11.21 20.48, Carlos E.R. wrote:
> Hi, > > I'd like to find a wall clock, say kitchen clock, that instead of > syncing using the DCF radio station > (https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. > > I may have asked about this before. > > Problem is, that here in Spain the DCF signal is so weak that clocks can > only sync during 01 to 05 AM, and often not even that, so that my clocks > can be in error for minutes of even hours, not getting corrected in weeks. > > So I wonder if somebody makes some sort of ready made clock that uses > internet for syncing and which can be put on a wall. Or a kit. > > Possibly it would run Android. > > For example I found one or two bedside alarm clocks (Lenovo Smart Clock > Essential, with microphone switched off). But nothing for the wall. I > really do not want a smart clock with a microphone listening, I just > want a clock, perhaps with a thermometer or weather app. > > > A possibility would be dedicate an old tablet to this. Or an ebook > reader (some have apps) > > I heard of people doing things like that with a Pi or whatever, but I > don't look forward to that, somehow, from scratch. A kit, may be. > > > Maybe a DCF repeater? >
There are schematics around, at least for WWW and WWWH (60 kHz), which can be changed for 77.5 kHz. You'll need to place the reception antenna far enough to prevent feedback and oscillation of the unit. If you find a clock, please tell us. I'm 1540 km from Mainflingen, but opposite direction compared to you (Helsinki, Finland). -- -TV
In article <l48l6i-qpu.ln1@Telcontar.valinor>,
Carlos E.R. <robin_listas@es.invalid> wrote:

>Problem is, that here in Spain the DCF signal is so weak that clocks can >only sync during 01 to 05 AM, and often not even that, so that my clocks >can be in error for minutes of even hours, not getting corrected in weeks. > >So I wonder if somebody makes some sort of ready made clock that uses >internet for syncing and which can be put on a wall. Or a kit. > >I heard of people doing things like that with a Pi or whatever, but I >don't look forward to that, somehow, from scratch. A kit, may be.
A small Pi system (or one of the many similar SOCs) would almost certainly be the way to go. You could have it time-sync in either of two ways: (1) Over the Internet, via NTP. The necessary NTP software is almost certainly available in the standard Pi software repo. (2) Using GPS - buy a cheap GSP module, wire it to a cheap USB-to-serial adapter, and plug it into the Pi's USB port. The GPS-management program "gpsd" plays pretty well as a time source for either ntpd or Chrony. For the time display, you have all sorts of options... use a small text-only or graphic LCD, or connect a larger display screen to the Pi and write an X Window display application. I don't know of kitted versions for any of the above, though. My home network uses Chrony to talk to NTP servers as a secondary time reference, and has a GSP module as the primary. I have no practical need to have my home network time-sync'ed to better than a millisecond with "standard time", but I do it anyway :-) It's probably not beyond the realm of possibility to make some sort of DCF transmitter, driven from a Pi or a home PC which uses NTP or GPS.
On Fri, 19 Nov 2021 19:48:21 +0100, "Carlos E.R."
<robin_listas@es.invalid> wrote:

>Hi, > >I'd like to find a wall clock, say kitchen clock, that instead of >syncing using the DCF radio station >(https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. > >I may have asked about this before. > >Problem is, that here in Spain the DCF signal is so weak that clocks can >only sync during 01 to 05 AM, and often not even that, so that my clocks >can be in error for minutes of even hours, not getting corrected in weeks. > >So I wonder if somebody makes some sort of ready made clock that uses >internet for syncing and which can be put on a wall. Or a kit. > >Possibly it would run Android. > >For example I found one or two bedside alarm clocks (Lenovo Smart Clock >Essential, with microphone switched off). But nothing for the wall. I >really do not want a smart clock with a microphone listening, I just >want a clock, perhaps with a thermometer or weather app. > > >A possibility would be dedicate an old tablet to this. Or an ebook >reader (some have apps) > >I heard of people doing things like that with a Pi or whatever, but I >don't look forward to that, somehow, from scratch. A kit, may be. > > >Maybe a DCF repeater?
A cheap modern XO clock should be stable to a few PPM. Replace the batteries and set it every 6 months. -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
On 19/11/2021 20.59, John Larkin wrote:
> On Fri, 19 Nov 2021 19:48:21 +0100, "Carlos E.R." > <robin_listas@es.invalid> wrote: > >> Hi, >> >> I'd like to find a wall clock, say kitchen clock, that instead of >> syncing using the DCF radio station >> (https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. >> >> I may have asked about this before. >> >> Problem is, that here in Spain the DCF signal is so weak that clocks can >> only sync during 01 to 05 AM, and often not even that, so that my clocks >> can be in error for minutes of even hours, not getting corrected in weeks. >> >> So I wonder if somebody makes some sort of ready made clock that uses >> internet for syncing and which can be put on a wall. Or a kit. >> >> Possibly it would run Android. >> >> For example I found one or two bedside alarm clocks (Lenovo Smart Clock >> Essential, with microphone switched off). But nothing for the wall. I >> really do not want a smart clock with a microphone listening, I just >> want a clock, perhaps with a thermometer or weather app. >> >> >> A possibility would be dedicate an old tablet to this. Or an ebook >> reader (some have apps) >> >> I heard of people doing things like that with a Pi or whatever, but I >> don't look forward to that, somehow, from scratch. A kit, may be. >> >> >> Maybe a DCF repeater? > > A cheap modern XO clock should be stable to a few PPM. > > Replace the batteries and set it every 6 months.
Yeah, well, that's what I use, a plain analog clock, Xtall controlled. Still, goes of more than a minute by the time I have to adjust summer/winter time again. I want improvement :-) -- Cheers, Carlos.
On 19/11/2021 20.46, Dave Platt wrote:
> In article <l48l6i-qpu.ln1@Telcontar.valinor>, > Carlos E.R. <robin_listas@es.invalid> wrote: > >> Problem is, that here in Spain the DCF signal is so weak that clocks can >> only sync during 01 to 05 AM, and often not even that, so that my clocks >> can be in error for minutes of even hours, not getting corrected in weeks. >> >> So I wonder if somebody makes some sort of ready made clock that uses >> internet for syncing and which can be put on a wall. Or a kit. >> >> I heard of people doing things like that with a Pi or whatever, but I >> don't look forward to that, somehow, from scratch. A kit, may be. > > A small Pi system (or one of the many similar SOCs) would almost certainly > be the way to go. You could have it time-sync in either of two ways: > > (1) Over the Internet, via NTP. The necessary NTP software is almost > certainly available in the standard Pi software repo. > > (2) Using GPS - buy a cheap GSP module, wire it to a cheap USB-to-serial > adapter, and plug it into the Pi's USB port. The GPS-management > program "gpsd" plays pretty well as a time source for either ntpd > or Chrony.
Yes, I use NTP on my computers, that's why I said "sync over WiFi". That's a minor problem, compared to setting up a Pi with a suitable display (I have never played with a Pi).
> > For the time display, you have all sorts of options... use a small > text-only or graphic LCD, or connect a larger display screen to the > Pi and write an X Window display application. > > I don't know of kitted versions for any of the above, though.
Yep.
> > My home network uses Chrony to talk to NTP servers as a > secondary time reference, and has a GSP module as the primary. > I have no practical need to have my home network time-sync'ed to > better than a millisecond with "standard time", but I do it > anyway :-) > > It's probably not beyond the realm of possibility to make some > sort of DCF transmitter, driven from a Pi or a home PC which uses > NTP or GPS.
That would be another idea... -- Cheers, Carlos.
On 19/11/2021 20.35, Tauno Voipio wrote:
> On 19.11.21 20.48, Carlos E.R. wrote: >> Hi, >> >> I'd like to find a wall clock, say kitchen clock, that instead of >> syncing using the DCF radio station >> (https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. >> >> I may have asked about this before. >> >> Problem is, that here in Spain the DCF signal is so weak that clocks >> can only sync during 01 to 05 AM, and often not even that, so that my >> clocks can be in error for minutes of even hours, not getting >> corrected in weeks. >> >> So I wonder if somebody makes some sort of ready made clock that uses >> internet for syncing and which can be put on a wall. Or a kit. >> >> Possibly it would run Android. >> >> For example I found one or two bedside alarm clocks (Lenovo Smart >> Clock Essential, with microphone switched off). But nothing for the >> wall. I really do not want a smart clock with a microphone listening, >> I just want a clock, perhaps with a thermometer or weather app. >> >> >> A possibility would be dedicate an old tablet to this. Or an ebook >> reader (some have apps) >> >> I heard of people doing things like that with a Pi or whatever, but I >> don't look forward to that, somehow, from scratch. A kit, may be. >> >> >> Maybe a DCF repeater? >> > > There are schematics around, at least for WWW and WWWH (60 kHz), which > can be changed for 77.5 kHz. You'll need to place the reception antenna > far enough to prevent feedback and oscillation of the unit.
I feared that :-(
> > If you find a clock, please tell us. I'm 1540 km from Mainflingen, but > opposite direction compared to you (Helsinki, Finland).
Ok! :-)
>
-- Cheers, Carlos.
On 19/11/2021 20.22, Jan Panteltje wrote:
> On a sunny day (Fri, 19 Nov 2021 19:48:21 +0100) it happened "Carlos E.R." > <robin_listas@es.invalid> wrote in <l48l6i-qpu.ln1@Telcontar.valinor>: > >> Hi, >> >> I'd like to find a wall clock, say kitchen clock, that instead of >> syncing using the DCF radio station >> (https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. >> >> I may have asked about this before. >> >> Problem is, that here in Spain the DCF signal is so weak that clocks can >> only sync during 01 to 05 AM, and often not even that, so that my clocks >> can be in error for minutes of even hours, not getting corrected in weeks. >> >> So I wonder if somebody makes some sort of ready made clock that uses >> internet for syncing and which can be put on a wall. Or a kit. >> >> Possibly it would run Android. >> >> For example I found one or two bedside alarm clocks (Lenovo Smart Clock >> Essential, with microphone switched off). But nothing for the wall. I >> really do not want a smart clock with a microphone listening, I just >> want a clock, perhaps with a thermometer or weather app. >> >> >> A possibility would be dedicate an old tablet to this. Or an ebook >> reader (some have apps) >> >> I heard of people doing things like that with a Pi or whatever, but I >> don't look forward to that, somehow, from scratch. A kit, may be. > > Yes I did: > http://panteltje.com/panteltje/raspberry_pi_FDS132_matrix_display_driver/index.html > >> >> Maybe a DCF repeater? > > Much simpler is use GPS time: > http://panteltje.com/panteltje/pic/gm_pic2/ > http://www.panteltje.com/pub/GPS_time_IXIMG_0745.JPG > it can also measure radiation and tracks location.... > > If you get a 30$ GPS module and connect it to a raspberry > the C code to get the time from it and add time offset for CET is in > http://panteltje.com/panteltje/xgpspc/index.html > But raspberry will normally sync its system time automaticaly from the internet > if connected to it, you do not normally need GPS. > So maybe for you a simple raspberry and LCD display?
But prices go up. A complete kitchen clock with DCF can be 20&#2013266084;. Plus the time to build all those.
> > And my cellphone gets its time from the phone network. > > An alternative would be a sundial.
LOL. With a repeater to show inside the kitchen :-D -- Cheers, Carlos.
On 19/11/2021 18:48, Carlos E.R. wrote:
> Hi, > > I'd like to find a wall clock, say kitchen clock, that instead of > syncing using the DCF radio station > (https://en.wikipedia.org/wiki/DCF77), uses WiFi (ie, internet) to sync. > > I may have asked about this before. > > Problem is, that here in Spain the DCF signal is so weak that clocks can > only sync during 01 to 05 AM, and often not even that, so that my clocks > can be in error for minutes of even hours, not getting corrected in weeks.
A decent quartz crystal clock should be good to a few tens of seconds a month at most. There is something wrong if it runs out more than that. The only thing I have with a similar fault is a Meade LX200 where they failed to put the right load around the RTC xtal and it gains about 30s a month. They solved this design error by adding GPS sync to the next generation rather than adding the right capacitors to the load network!
> So I wonder if somebody makes some sort of ready made clock that uses > internet for syncing and which can be put on a wall. Or a kit. > > Possibly it would run Android. > > For example I found one or two bedside alarm clocks (Lenovo Smart Clock > Essential, with microphone switched off). But nothing for the wall. I > really do not want a smart clock with a microphone listening, I just > want a clock, perhaps with a thermometer or weather app. > > A possibility would be dedicate an old tablet to this. Or an ebook > reader (some have apps) > > I heard of people doing things like that with a Pi or whatever, but I > don't look forward to that, somehow, from scratch. A kit, may be. > > Maybe a DCF repeater?
These days it is very hard to find a quartz crystal based clock that doesn't keep good time although I expect if you try hard enough you can. Wrist watches do even better since they are thermally regulated by us. My antique 400 day torsion pendulum clock is good to seconds a week provided I keep the ambient temperature reasonably stable. It has a couple of small counter weights on the main block that tweak the moment of inertia and null out the first order thermal expansion. -- Regards, Martin Brown