Constant lighting - how to implement?

Here is the scenario: the bird refugee maintains a “fixed day” for organizational issues. Let’s say that day dawns at 7:00 and dusk out at 8:00. So the flood light should dim in/out comparable to the duration of a sun rise/set. After 100% flood light and an additional time, lights with a specific spectrum are switched on and again switched off a while before dusk. The same with UVB for a few hours within day.

So, the switching I plan to do with a KNX clock (for my lack of a better translation of “Schaltuhr”) but for dimming in/out over a longer period of time (at least 20min) I haven’t found anything in the KNX realm.

The utmost thing would be a constant lighting approach based on the flood lights. I do have access to the Siemens building control system and that features a sophisticated weather station. The access is done by the way of BACNet with a gateway from MDT. The cool thing would be to map the outside LUX to a value sent to the DALI Dimmers for the light required in addition to the daylight in order to archive a constant brightness. I was thinking about the OpenHab rule engine as the basis. I don’t want to equip the entire facility with photosensors -I just want a ballpark dim value based on what is delivered by the sun. Is this feasible and did someone have any experience with this?

If you use the astro binding you will get datetime of begin / end of sunrise / sunset as well as the duration and an event happening (you can use the event to trigger a rule).

E.g. If you want to dim your lights from 0% to 100% you can use timers to set your dimmer item accordingly as you need it

There’s a couple of people who implemented this using the astro binding as the main input, it tells you about sunrise (various, also start and end) and amount of current solar radiation; there’s also weather bindings to tell about UVB. There’s also a BACnet binding should these inputs not be sufficient.
Search this forum for threads to find out about existing implementations; keyword “circadian” lighting e.g. Circadian Lighting / calculate colortemp and brightness according to circadian rythm
Eventually there’s already something on the marketplace, too.

Matthias, well the Astro Binding provides me with the correct sun set/rise but this isn’t what I need - I have the luxury to define my private sun rise/set. This necessary because of feeding time and, most importantly, the sound… especially the Aras and Kakadu are extremely noisy and we have to make sure it doesn’t happen at the “wrong” time because of the neighbors - this is downtown Vienna:-)

So, we define daylight, regardless if the sun provides us with energy or not. I’m rather unsure how to establish a 20min dim period, where ist starts with 5% up to 100%. I’d need something that deliveres a constant ping, like a clock the is sending out a pulse every 10 sec, or so. Than I might be able to take this pulse as an action eveluating a rule that finally calculates teh dim value.

Does this make any sense to you guys?

Here we go, Markus - thank you. In the thread you linked I’ve learned, that I may create a rule that fires continuously every (5 min there) so hopefully 30 sec. in my case. Within this rule, I may check the system clock and act on this accordingly. That should do the trick… thinking it to the end: wouldn’t this render any switch clock (“Schaltuhr”:slight_smile: obsolete when I use such rules as trigger for continuous time-based actions?

There’s a couple of rules-based solutions to that on this forum. The principle is simple enough; set a target, and every N minutes take another step towards it.

You’ll observe that setting the target is a function of your ‘fake daylight’ scheduling task, and actually doing the work is a seperate function.

Note that Astro binding is capable of native ‘earliest/latest’ settings e.g. ‘latest’ fire a trigger when the sun comes up, but if isn’t up by 6am fire the trigger anyway. This may have uses in your daylight scheduler.

why not try the pid controler and dim your lights based on the lux of the weather station

Because the weather station delivers the “actual day” and that goes with the seasons. I have a fixed day regardless what the sun is doing. So in winter, theday is far longer than the actual daylight an in sommer it’s vice versa. So for the winter, I have to simulate sun rise/set always at the same time of the day. Finally, I’ll care for the sun light and apply only as much light from the LED’s as required for a constant amount of light. But right now, I’m perfectly happy if the automation runs in the most easy configuration:-)

What i did for a small indoor garden was using this to record a day of good light done manually also the rgb led and play back everyday the same thing . keep in mind there was no sun coming in that room

Not bad, not at all - will have a closer look! Thank you.

Yes. You can implement any logic in OH rules, and the linked thread is just one way of implementing.

Thank you all in this regard too - now I use a central continuous timer every 30 seconds that calculates a set of Items and based on that Items, other rules are being triggered controlling the lights and maintaining the UI states.