[time-nuts] Re: NIST 60KHz message

[rcbuck at atcelectronics.com]

Jeffry,

Yes, the sync once per day is due to the Arduino software. The ES100
needs to be told when to start receiving the WWVB signal and when to go
to sleep. You can modify the software to change the time and number of
syncs per day. I would suggest you change it to 2am CA time. The daily
sync is used to update the RTC (DS3231) that is on the board. The clock
gets the time from the DS3231. I really try to avoid Arduino code so I
can't tell you where the code needs to be modified. The 8pm you see
corresponds to midnight UTC. Since DST started today your clock should
update around 7pm tonight depending on WWVB signal strength at your
location.

The sync will happen each time the module is powered up. It usually
takes about 3 minutes at my location in Phoenix.

In the Arduino .ino file the interrupt count is updated every time the
ES100 generates an interrupt. The interrupt code also makes an
adjustment to the milliseconds variable value.

There is a millis() function somewhere that updates the milliseconds
value. I have looked and can't find that function in any of the code
supplied with the kit. It may be in the Time library but I haven't
looked there. The milliseconds value is used to calculate the time when
a valid data string is received from the ES100.

There is a note in the ES100.h file that says this: "// This hold the
millis() when the interrupt occured, will be useful in the user code to
handle the second boundary. New valid data should be handled within
65536 milli seconds, after that the variable will overflow and the user
won't be able to calculate the right second boundary."

Daylight savings time started at 2 AM this morning. The "NDST 11/07
02:00" means daylight savings time ends at 2am on 11/07, first Sunday in
November. "(N)o (D)aylight (S)avings (T)ime".

Ray, AB7HE


-------- Original Message --------
Subject: [time-nuts] Re: NIST 60KHz message
From: Jeffrey Pawlan <pawlan at runbox.com>
Date: Sun, March 14, 2021 7:52 am
To: time-nuts at lists.febo.com

I have been using the new BPSK receiver for NIST. There are two strange 
things that perhaps others can explain.
It only syncs one and only one time per day, usually around 8pm. It also

shows an interrupt count anywhere between 2 and 50 every day. I am sure 
it can receive the signal more frequently than once in a day. Is that 
caused by the design of the arduino software?

I also saw last night they sent a message "DST starts at 11/07 0200".  
This morning it says "DST in effect" and "NDST at 11/07". Why are they 
showing that date?

Regards,

Jeffrey Pawlan  WA6KBL

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