[time-nuts] new WWVB BPSK dev board

[Tim Shoppa]

Because of the Q of WWVB's transmit antenna (at least 300 by my back of the
envelope estimates), I don't think we could ever claim a WWVB PPS edge
sharper than 5 milliseconds and that might be optimistic.

Tim N3QE

On Tue, Dec 4, 2018 at 11:49 AM Bob kb8tq <kb8tq at n1k.org> wrote:

> Hi
>
> The I2C clock rate is going to matter a bit in terms of what you can
> achieve.
> Since the device is targeted at low power, the max practical baud rate may
> not be very high. I2C can have a lot of wait in it ... There are a lot of
> registers
> dumped after each “reception attempt”.
>
> There also is the basic question of how the IRQ flag relates to the time
> the
> chip “sees”. If it’s actually WWVB time sync’d then that’s a useful thing.
>
> None of this is likely to be an issue in a wall clock. If they can run at
> a “tens of ms”
> sort of level that’s more than good enough. We really want to get to
> microseconds
> don’t we :)
>
> Bob
>
> > On Dec 4, 2018, at 11:25 AM, Majdi S. Abbas <msa at latt.net> wrote:
> >
> > $69 CAD is roughly $50 USD.
> >
> > Expensive for what it is but easier to work with than gutting a working
> clock and no more expensive.
> >
> > I ordered one.  Curious to see what sort of precision we can get from an
> i2c interface.
> >
> > If nothing else I suppose I can toss a six digit i2c 7 segment module at
> it and roll my own WWVB desk clock.
> >
> > —msa
> >
> >> On Dec 4, 2018, at 07:50, paul swed <paulswedb at gmail.com> wrote:
> >>
> >> I assume thats exactly the case. I also thought it was pretty high.
> >> The actual clocks are about $50 or less I believe. So the board seems a
> bit
> >> off.
> >> Regards
> >> Paul
> >> WB8TSL
> >>
>
>
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