Auto-dim LED lights at night?


I’ve recently read about getting better sleep by avoiding bright lights at night. I was going to ask about using SmartThings to do an auto-dim LED setup, but the “your topic is similar to” forum search found this for me:

Which is amazing.

However, it uses color changing bulbs, e.g. it adjusts both dim + color, and right now I’m just thinking of using regular LED bulbs + Lutron Caseta switches and doing auto-dim only.

Does anyone know of a similar project for auto-/time-of-day dimming?

I was pleasantly surprised to see that circadian project has Groovy code in it, as I can hack on that if needed, but just looking to see what I’m getting myself in to, and if this is a “yeah, np, already done” sort of thing or a “eh, quite a few hours/weekends of hacking around” sort of thing.


Why do you need any special project ?
Simply use SmartLighting. Set you automation to turn on xx% during times A and B. Set another to turn on at yy% during B and C .

I have color bulbs in bedroom and hall just for this reason, between 10PM and 5AM lights come on at 10% red. The lights that are white only I have set to turn on 80% while in home mode, 10% when in night mode.

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Thanks for reply!

Your approach sounds great, but my assumption was that sort of rule, “go to
X% dim at Y:00”, if setup as a regular/out-of-the-box rule, would happen
for all the lights, whether they were on or not.

What I want is to only change lights that are currently on/as soon as they
turn on, e.g.:

At 9pm, turn any light that is on down to 20% dim, leave other lights off.
If any light is turned on after 9pm, immediately set it to 20% dim.

At 7am, turn any light that is on up to 100% dim, leave other lights off.
If any light is turned on after 7am, immediately set it to 100%.

Is that possible with SmartLights?

Oh, hm, looking at this:

In theory I could make 1 or maybe 2 automations per dimmer, and have that
automation triggered by mode, and only if mode is on? E.g.:

Automation 1 for dimmer A, trigger on time=9pm, when mode is on, set level
to 20%
Automation 2 for dimmer A, trigger on mode change, when time is >9pm, set
level to 20%
Repeat for each dimmer

And then make these two rules for each dimmer, sounds like that would do
what I want?

Do you know if there would be a large delay for the 2nd rule? E.g. if I hit
the “on” button at 10pm on a dimmer, it’s default action will be “go to
100%”; how long until the SmartLights catches it, and sets it back to 20%?

Ideally there would not be a flash to 100% and then ~X seconds later it
drops to 20%. But maybe that is too fancy, and just using the physical
dimmer +10% button after Xpm is reasonable enough.

Really what I would prefer is if the dimmers were smart enough to tell them
"here is the max level I want you at; I don’t care if you’re on or off, but
if you’re on, or whenever you turn on, here’s your max level".


I failed to mention all my lights are based on motion or contact sensors So no the lights don’t all just turn on at A time at XX%. If motion in the hall between 5AM-10PM lights come on at 80% white. If motion in the hall between 10PM-5AM the lights come on 10% red. When Good night runs it turn off 90% of the lights, turns on 1 light in each room at 10%, turns on the bedroom at 20% red ( Wife goes to bed before me 99% of the time, and light won’t wake her, and I usually won’t trip over dog ) . After 30 minutes with no motion all the downstairs lights turn off. If in night mode motion downstairs turn on the respective lights at 10%.

Oh, wow, that’s a lot more sophisticated than I assumed was possible. And
this is all with just the built-in SmartLights?

I’ll have do start doing some more research then to just learn what is
possible. Do you know of any websites/youtube videos that describe what is
basically your setup? Or is it pretty obvious once you start poking around
in SmartThings/SmartLights?


It is fairly obvious. When you set up a SmartLighting routine, just make sure you expand each of the sections so you can actually see all of your options that you have available. The entire thing is only 4 rules. 1 for " only in home mode" , 1 for " only in night mode". The other 2 are " only between hours of "

The Circadian Daylight app can use non color-changing smart bulbs. I have a mix of color-changing, temperature-changing, and dimmable bulbs around my house and it works just fine.