[OT] Time sync of arbitrary consumer devices
Robin Laing
Robin.Laing at drdc-rddc.gc.ca
Mon Apr 18 14:45:28 UTC 2005
Don Russell wrote:
> Michael A. Peters wrote:
>
>> Something that has bugged me for years - I have to manually set the time
>> on my microwave, on my stove, on my VCR (it will auto-sync if I pay for
>> cable, but cable does not offer me what I consider to be programming
>> worth what they want to charge - well, I would watch the sci-fi channel,
>> had I the time to watch it ...), my wall clocks, etc.
>
>
> [snip]
>
> That's been around for as long as I can remember... at least 30 years...
> in North America the WWV time signal and it's associates WWV-B all
> shortwave signals, synch'd to the US Naval Observatory Atomic (Cesium)
> clock which is the "official" time in the USA.
>
> I'm seeing more and more consumer-grade devices that listen for that
> signal.
>
> Walmart sells "ATOMIC CLOCKS", well, of course the clocks are not
> atomic... but they have a short wave receiver in them, and a switch on
> the back to set your UTC offset (since WWV broadcasts UTC) and something
> to indicate whether you participate in Daylight Saving Time or not.
>
> So.... why isn't that technology in every consumer device with a clock?
> Because it costs $1 to add it at the mfg level and not enough people
> want it.
>
> Now that technology is being usurped by GPS... a GPS unit in a vehicle
> could set it's own timezone... it know where it is (from the GPS
> signals) and it knows what time it is (from the GPS signals)
>
> Except GPS is strictly line-of-sight.... so unless I keep all my
> appliances in an open field... they won't get the GPS signals. :-)
>
> <paranoia>
> Beside, then the gov't would start stealing time.... they'd slow the
> clocks during working hours so you work longer for the same pay, and
> they'd speed the clocks up during off hours so you get back to work sooner.
> </paranoia>
>
> :-)
>
This may all become pretty obscure as I believe MIT has developed a
real atomic clock that will fit in a cell phone and is quite cheap to
make. As a single chip, it may endup in all types of devices.
One thing to remember is WWV is not always available in all locations
at all times. I use WWV to set my watch once in a while as a
reference but there are times I just cannot pick it up.
--
Robin Laing
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