[time-nuts] Some ES100 WWVB BPSK success

[Tim Shoppa]

I got the ES100 from Universal Solder that TVB pointed us towards. It came
in the mail (from Canada) last week. It uses a 6-pin 0.1inch JST header for
connection - I bought a bunch and will be glad to send my extra via USPS to
any time-nuts who wants one. TVB pointed out that any old 0.1inch header
can fit too.

I cabled it up to a Arduino Nano. I used the Nano 3.3V out to power the
ES100 and arbitrarily chose 1.8K resistors on all 4 data lines to give some
current limiting for the 3.3V vs 5V I/O differences. I ran the supplied
sketch to interface to it.

In my Maryland basement during broad daylight, no lock at all.

A bit after my sundown (but way over an hour before Colorado sunset) from
the 2nd floor on a west-facing window, it locks in a couple minutes. See
picture below.

Keep in mind that at my Maryland location, the PWM-modulated WWVB signal is
not necessarily reliable at 2AM. My Seiko Waveceptor most always locks at
2AM but other household WWVB clocks are more hit-or-miss each night.

So getting a lock on WWVB via the ES100 without common darkness between me
and Colorado, that seems like a success to me!

I will be endeavoring to to time the IRQ edge from ES100 vs GPS PPS. The
IRQ edge is supposed to be within 100ms (that's not microseconds, that's
not nanoseconds, that's milliseconds) of actual time according to ES100
specs.

[image: image.png]

Tim N3QE
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