If I understand correctly, your Arduino based device is generating the
time code to send to your computer.
In the past I have used GPS NMEA messages and IRIG-B for data
acquisition time stamps. I considered SMPTE, but it did not look useful.
I would expect that making your Arduino device look like a GPS receiver
outputting NMEA messages and a PPS signal would be about the simplest
approach you could take. It has the advantage that there is existing
software to deal with the messages, including NTP drivers.
IRIG-B has the advantages that it has a lower bit rate and only requires
one signal line. I looked at NTP source code and there is a driver for
IRIG-B (and E) using 1 kHz modulation.
Two questions come to mind:
- How is your Arduino going to get time?
- What is the computer going to do with it?
Gary
WA9ZZZ
On 8/7/19 8:13 AM, Ralph Aichinger wrote:
Hi everybody!
I am a newbie and am wondering what options there are for exchanging time
on a more basic level than NTP or PTP (that is for situations when a
full network stack is too complex).
For now I have found:
NMEA (probably ZDA only)
IRIG timecode (this is rather complex, I would rather have a
full network stack than IRIG?)
SMPTE timecode (this too?)
Are there any other obvious candidates I missed? How did e.g.
HP atomic clocks tell their time to connected devices before
there was the NTP protocol? Did they output NMEA or something
else? Did they emit IRIG directly?
I want to create an Arduino based clock that tells time to a computer
it is linked too. For exact seconds alignment I want to use a PPS signal,
but I need a means to tell the computer about second numbers, hours etc.
too.
Of course I could invent a serial protocol, but I suppose if I invented a
text based serial protocol, it would probably end up looking very
similar in structure to NMEA ZDA sentences.
*Is* NMEA the most practical time protocol at the 1 second level
(that is when a PPS pulse takes care of second alignment?) or should
I use something else if I am free to design stuff clean slate?
TIA
/ralph
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
