How does the watch keep it's time?

Discussion in 'Apple Watch' started by Piggie, Oct 8, 2014.

  1. Piggie macrumors 604

    Piggie

    Joined:
    Feb 23, 2010
    #1
    Just looked at Apple's site and saw the 50 millisecond comment again.

    Just struck me, how does it do that?
    Is it acting like normal radio controlled watches and clocks do and picking up the time signals given off from stations around the country?

    http://en.wikipedia.org/wiki/Radio_clock

    Using this method ?
     
  2. kdarling macrumors demi-god

    kdarling

    Joined:
    Jun 9, 2007
    Location:
    First university coding class = 46 years ago
  3. Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #3
    This is probably more marketing to the high end watch users/makers rhetoric that about time keeping. Your iPhone sets the time every time it connects to GPS. GPS requires an accuracy of under 100ns in order to work accurately. So just syncing the aWatch to your iPhone every day or so will keep it well within the gigantic 50ms error.

    Didn't remember that thread and I posted twice in it.:D I bet the aWatch is more accurate than my memory.:eek:
     
  4. Piggie thread starter macrumors 604

    Piggie

    Joined:
    Feb 23, 2010
    #4
    Thanks for the link.

    Looked thru that thread, people seem to be suggesting it's only accurate when paired to the iPhone, getting it's time signal from the link?

    I don't know if there is an official logo for what we call Radio Control watches.

    That's what I was wondering I guess, if the watch gets its own time signal independent from the iPhone like a normal radio controlled watch does, as that tech is years old and must be very very mature and solid now for Apple to use.

    I suppose we need to wait for more info from Apple as to if it's the watch that keeps itself accurate or the phone keeps the watch accurate.

    I hope the watch does it, itself personally. The more independent the watch is, the happier I am.

    Again, many thanks to the link to the thread about this :)
     
  5. Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #5
    There is no official logo but they are often called Radio or Atomic clocks. While this is accurate it requires a long antenna and another radio receiver. Also it uses VLF (60kHz) and is less accurate (in absolute terms) than GPS.

    The aWatch will need to piggy back on the iPhone for installing any Apps (the aWatch will only connect to the iPhone and not iTunes or the internet). It's been reported that you will have an App on your iPhone that controls /installs/configures Apps. The aWatch will probably gather data but offload it to the iPhone for processing (to save batt life). Also you will (probably) need to download all types of data like weather from the iPhone. You may need it to pair it to authorize your account for security every day or so. I bet you WILL need to pair your aWatch very often to your iPhone.
     
  6. Piggie thread starter macrumors 604

    Piggie

    Joined:
    Feb 23, 2010
    #6
    Thanks.
    It's almost sounding worse by the minute! :eek:
    But I suppose it will work ok for people who are organised enough to keep both devices happy with each other daily. :)
     
  7. fisha macrumors regular

    Joined:
    Mar 10, 2006
    #7
    I don't see too much of an issue with the watch pairing (or more to the point, syncing) every day ... once it wakes up, it'll probably look for the phone nearby, and probably auto-sync with it for basic data. That pairing will probably be transparent and automatic based on the last sync. In the same way bluetooth car modules auto link and sync contacts to the phone when you jump in the car.

    I do agree that for payments and the like of higher security data, then a security check will be required. I read the comment that for payments, with the watch being worn, you'd do a security check such as entering a pin, and that would be valid for the time that you kept the watch on your wrist. If you were to take the watch off and then put it back on, then the security pin would be required again for you to make a further payment transaction . . . which kind of makes sense . . . so that you couldn't have the watch taken from you to make stolen payments.
     
  8. kdarling macrumors demi-god

    kdarling

    Joined:
    Jun 9, 2007
    Location:
    First university coding class = 46 years ago
    #8
    Every time a notification gets sent from the phone to the watch, it could (and probably will) include the current time down to the millisecond. Thus the watch's onboard time would be constantly updated.

    Hmm. I've read that some $15 quartz watches are good to 1ms a day. So, 50ms could actually be pretty poor for a companion smartwatch :)

    --

    It feels like something that came from an engineer during a brainstorming session with the ad writers.

    Publicist: "Okay, anything else besides the fact that 18kt gold is usually twice as strong as 24kt gold? We can spin that to sound amazing."

    Engineer: "Oh, and it's never off by more than 50ms during the day."

    Publicist: "Cool! Is that good? Never mind! If we just mention it, people will think it is!"

    I think Apple has this down to a science. They can make anything sound magical.
     
  9. APlotdevice macrumors 68040

    APlotdevice

    Joined:
    Sep 3, 2011
    #9

    My understanding is that the accuracy of a Quartz watch can vary considerably by its operating temperature.
     
  10. HereBeMonsters macrumors 6502

    HereBeMonsters

    Joined:
    Jul 5, 2012
    Location:
    Fareham, UK
    #10
    I think you're getting a bit confused here.

    Atomic clocks are ridiculously accurate clocks that typically use Caesium or Rubidium cooled to near absolute zero and calculate their time based on electron decay of the element.

    Radio clocks are a consumer device that synchronise their time from radio signals - in Europe, at least, this is typically RDS radio - the same thing that tells you the name of the FM station you're listening to.

    Neither of them require a massive aerial - I have 4 of the latter at home!
     
  11. Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #11
    No I am not.

    [​IMG]

    [​IMG]
     
  12. HereBeMonsters macrumors 6502

    HereBeMonsters

    Joined:
    Jul 5, 2012
    Location:
    Fareham, UK
    #12
    Yeah, those are not by any stretch of the imagination actual atomic clocks.

    Sorry, I'm not trying to argue with you here, just clarify the information. You will not get an atomic clock in your house. Not unless you live in a science lab.

    They sometimes call radio controlled clocks atomic clocks, as that is where they get their time signals from.

    For a watch, this is indeed possible - I have about five or so that connect to the signal from Anthorn, as well as my bedside alarm clock that does so. The Apple Watch will not do this, however - it will merely have a computer and sync itself to the phone every now and then.
     
  13. rotation macrumors member

    rotation

    Joined:
    Oct 16, 2014
    Location:
    Los Angeles
    #13
    From what I understand it has an internal chronometer and then receives updates from the cell network giving it extremely accurate timekeeping.


    I am not totally sure if it's really possible for it to keep much better time than an analog watch but who knows.
     
  14. Julien macrumors G3

    Julien

    Joined:
    Jun 30, 2007
    Location:
    Atlanta
    #14
    Yeah, and if you would have read my post you would know that was not what I was talking about. I was responding to a question in the previous post.

    And my response.

    My response IS correct and my pics prove it. Is this still not clear what I was talking about?
     

Share This Page