Thermostat / HVAC contol system

Hi !

I am quite new in Openhab world and trying to implement control system for heater, so simply thermostat + time zones. Finally I wish to have possibility of adjustment for two independent time period with day temp and rest time will be night temp.
I have temperature data gather from 1wire and would like to send signal on/off over GPIO based on particular temperature + temp set point.
Thermostat itself is maybe not such difficult to implement, more complex for me is time zones. Ideally will be to use time crone, but it can not include variable :confused:
I have found example of alarm clock, but it looks complex and I have a feeling when I put 4 such rules GUI will works slow.
Can I use just simple condition with time comparison ie now and set point ?
Maybe you have seen such simple time set for diff zones with or withour thermostat rule ?

What about control via the CalDAV/Google calendar bindings? These should be able to send a command to an item to enable/disable your heating control.

Yes, I read about such possibility. Do you know how it works practically ?
I need to create permanent 2xevents and when I would like to change it, just edit it ?
Have you seen any implementation examples ?

A big questions is how important is it that you be able to change the start/end of the time periods through the GUI? Ask yourself, how often are you likely to need to do this? Will someone besides you need to do it? If it is infrequently and you will be the only one changing it I’d say you don’t need the GUI at all.

I have four time periods that I track in my setup to control my lighting, three of which use the Astro binding so they adjust to actual sunrise and sunset. And I have yet to have a need to change them so I don’t even put anything about the time periods on my sitemap.

I’ve posted my items and rules for this here.

I doubt it will work any slower with one or 50 on the GUI. If that is your concern I wouldn’t worry about it.

But if you really do need to be able to change the start and stop times through a UI, @robconnolly’s suggestion to use the calendar bindings will be your best bet.

I’m afraid I haven’t tried either binding, so I can only point you at the relevant wiki pages:


From what I understand either binding should allow you to create a (potentially recurring) set of event which contain a command to update the item in question. You would then need to change these events to change the timing.

Rich, you are right, usually it is something that we initially set and not touch any more, but … I have a new house and still doing adjustment of my central heating. So now I am changing it quite often.
Thank you for a link. I must read about now() function, it looks like a I can combine if and now to achieve time comparison.

During tests with 4 time sets I had a feeling that GUI via web has much bigger delay with refreshing counters, so if I changed ie 6 to 21, by clicking “+”, first it showed 10, 14 and after 10-15s 21. Sometimes I had to back to main frame and back to see refreshed value, so that was my doubts.

Keep in mind that there is a bug in the UI that can cause it to refresh slowly or not at all. In short, it might be working just fine (i.e. the plus clicks are getting to the server) but the UI isn’t kept up to date. Unfortunately we have to wait for OH2 for a fix. So what you are seeing probably has nothing to do with the UI being slow and it is just a side effect of the bug.