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Topic: Clocks using DS3231 or similar? (Read 1 time) previous topic - next topic

odometer

I am aware that DS3231 is expensive, and I expect that other, similar high-precision RTC chips are also expensive.

It seems to me that, if I want a clock with this kind of chip in it, I have to either build it as an electronics kit, or buy a clock which someone has already built as an electronics kit or homemade electronics project.

What if I really do care more about than the destination than the journey?

It is quite reasonable to want to put up a clock in a place with poor reception, or no reception, for radio time signals. It is also reasonable to want the clock to keep very good time so as not to require frequent maintenance, especially if one must climb a ladder to reach it, or if there are many clocks such as in a large building. If nothing else, it is one less job for the maintenance crew.

Even for ordinary home use, one might well want the piece of mind of being able to trust one's wall clock.

Are clocks with high-precision RTC chips sold for use in homes, small offices, etc.? I am not counting clocks that are so expensive that one might as well just use the money to pay someone to set the time on an inferior clock. What I mean is a clock with the external appearance of an ordinary analog wall clock, or digital alarm clock, but with a high-precision RTC in it. Or maybe it has some "extras" such as the seconds and the date, but it is still meant for use primarily as a time-of-day reference.

Or is it that, for marketing reasons, such clocks simply do not exist.

I am thinking of one building in New York City which I have been to. One floor of this building has at least 20 radio-controlled digital clocks, which last time I checked, showed times spanning a range of several minutes at least. This in a situation in which people pay to reserve a room for a block of time, and so one wants to know exactly when one's reserved time begins and ends. As the clocks are not receiving the radio signal, the situation essentially cries out for clocks such as I am asking about.

Coding Badly

I am aware that DS3231 is expensive, and I expect that other, similar high-precision RTC chips are also expensive.


$15 doesn't seem that expensive to me.  Where do you put the "is expensive" threshold?

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Are clocks with high-precision RTC chips sold for use in homes, small offices, etc.?


I've never noticed any but I've never looked for them either.  The radio ones work great in my house.  They are freakishly well synchronized.

Jack Christensen

That is a really good question. I'm happy building my own, but there does seem to be a gap in the consumer-type products available. I'm in the same camp as CB, haven't noticed any but haven't gone looking particularly either. Still, seems like I might have seen something. I am starting to notice inexpensive clock radios that evidently have battery-backed RTCs in them. Don't think there were any extraordinary claims to accuracy, though. Maybe the average consumer isn't all that worried about accuracy. Clocks that derive their timing from the AC mains actually have very, very good long-term accuracy, but won't necessarily be within a second or two at any given point. And then there are power outages to deal with. There has also been some talk about changing the way the grids are managed that may affect the accuracy of mains-synchronized clocks, I'm not sure where this currently stands, however.

We have several of the WWVB-controlled radio clocks here, too. Being in Michigan, the signal from Fort Collins isn't terribly strong, but they work quite well. I believe they are programmed to synchronize at night when propagation is favorable, but in the fall when we change from daylight to standard time, this usually results in a few missed syncs, not that it matters much.

So the radio clocks seem to be the consumer-oriented solution for accuracy, although they don't necessarily work well everywhere as you have noted.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

Boffin1

We dont have a broadcast time signal here in South Africa, so I just use a cheap GPS module with inbuilt antenna for about $17  Fastrax UP501.

You dont need any buttons to set the time, and its always right time ...........
With my mobile phone I can call people and talk to them -  how smart can you get ?

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