[time-nuts] NTP Clock suggestions?

[Bob Camp]

Hi

Is there a price shown somewhere on that sheet?

Bob

On May 27, 2013, at 2:23 PM, Chris Albertson <albertson.chris at gmail.com> wrote:

> One more idea:   Buy one of those "Atomic Clocks" that run off WWVB.  Then
> use time code to modulate a very low power 60KHz radio transmitter.  The
> clocks will pick up your signal and sync to it.    The clocks run on
> battery power and you don't need wires.
> 
> But then I did notice you can buy exactly what you asked for $99.
> /DS%5FTimeDisplays.pdf<http://www.symmetricom.com/media/files/downloads/product-datasheets/DS%5FTimeDisplays.pdf>
> 
> 
> 
> 
> On Mon, May 27, 2013 at 9:40 AM, Bob Camp <lists at rtty.us> wrote:
> 
>> Hi
>> 
>> If you are doing this from scratch today, would you go IRIG or would you
>> go RS-485 for a wall clock? Both will drive more cable than you are likely
>> to have in a house. Both are reasonably noise immune. With RS-485 there's
>> less to do. It's a serial stream like any other bunch of "stuff" into a
>> UART.
>> 
>> Some math:
>> 
>> YYMMDDHHMMSSCR  = 13 ASCII characters. With one check byte it would be 14.
>> A baud rate of 115.4K isn't stretching things on RS-485 or on most UART's
>> these days.
>> Sent it at 7N1 you have 9 bits per character, 126 bits in the message.
>> Message takes a bit over 1 ms.
>> 
>> Time it to anywhere in the string and the clock should be within <+/- 2
>> ms. That's better than I can see on a clock. Better yet, time it to the
>> first (or last) character in the string. More or less a 10X improvement.
>> You could also drop the year / month / day if the clock isn't going to use
>> them.
>> 
>> Take any of the Arduino (or what ever) LED display boards and drive them
>> with something cheap. I doubt the "clock" end plus the drivers would be
>> over $30. I suspect IRIG would cost a bit more once you got it all worked
>> out.
>> 
>> Bob
>> 
>> On May 27, 2013, at 11:03 AM, Chris Albertson <albertson.chris at gmail.com>
>> wrote:
>> 
>>> I've seen LLCD computer monitors used as clocks.  Seems this would be
>>> the perfect use for a Rasbury Pi. and a cheap monitor. $100 or maybe a
>>> low-end Android tablet.
>>> 
>>> The way it is more commonly done is you have you computer that is
>>> using NTP produce an IRIG time code.  Then there are any number of
>>> commercial clocks and large digital LED displays that will use IRIG.
>>> IRIG displays are not cheap but they sure are easy to find.
>>> 
>>> On Mon, May 27, 2013 at 6:29 AM, Miguel Barbosa Gonçalves <m at mbg.pt>
>> wrote:
>>>> Hi!
>>>> 
>>>> I was wondering if anyone knows about a not so expensive wall digital
>> clock
>>>> that gets its time from an NTP server...
>>>> 
>>>> TIA,
>>>> Miguel
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>> 
>>> 
>>> 
>>> --
>>> 
>>> Chris Albertson
>>> Redondo Beach, California
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> 
> 
> 
> -- 
> 
> Chris Albertson
> Redondo Beach, California
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.