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Hi all,

I'm a new z-uno user about to embark on my first project and I have a question in the planning stages. I've done some searching for the answer to this but haven't found exactly what I'm after. Apologies if this has already been covered and I haven't been able to find it.

My project will need to know the time of day for certain timed events to run (it's an irrigation controller). I am wondering if there is a best-practice way of the z-uno discovering the current time. In particular, I have the following questions;

- Is a real-time clock (e.g. DS3231) necessary, or if I have a way of determining the time regularly can I just do that and use the millis() function to get a current offset?

- Would anyone recommend using a wifi connection (eg ESP8266) to regularly establish the time via a public NTP server? I will have access to a wifi network as the device will be used at my home, but this seems to add a new layer of complexity for e.g. dealing with a change in wifi password.

- Is there a way of regularly sending the time over the z-wave connection from the z-wave controller? I plan on using openHAB as my controller. Would there be a way of the z-uno sending a signal to the controller to request a current time if it has been reset? If this is feasible this seems like the best way to me but I have barely begun to look at the z-wave side of the device so I honestly have no idea.

Thanks for any help/advice you can give.

There is a special Command Class Time in Z-Wave. But Z-Uno do not implement it right now. You can use config parameters to start the time and then use RTC to keep it. Otherwise you can instruct the controller to send it periodically via config parameters.

We will think about implementing it in Z-Uno

That's really useful. Thank you.

I hope you are able to implement the Time Command Class. It looks like it could be useful for me.