Known Button limit for SmartLighting?

Recently I ran into an issue with the Zen30, which has 21 total scene actions. Normally I would create a button for each but it turns out that at 20, the smartlighting app just bombs, although at 19 it seems to be fine.

Is this a known thing? Or am I just doing something wrong?

Tagging @TheSmartestHouse

Probably not, but check here just in case:

I didn’t think Smart Lighting was impacted by these, but I’m not sure since I have no idea what happens on the back end since SL is usable in both Classic and the new app.

@Brad_ST, any insight?

@JDRoberts, @TheSmartestHouse I don’t actually see this as a Zen30 issue. I just offered that as a frame of reference. Smart lighting just doesn’t seem to be able to handle 20 buttons with one single device.

It’s most likely a ST limitation, the Fibaro Home Center Lite which is the only hub we know of that recognizes the central scene command out of the box, creates 21 different actions for the devices automatically without any problems.


Understood, I just thought @TheSmartestHouse might have heard reports from other customers one way or the other as to whether there’s a ST limit of 20 buttons. :sunglasses:

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What do you mean by “the smartlighting app just bombs”? I am able to create a Smart Lighting automation that is controlling 20+ devices. I also checked the logs and didn’t see an obvious error logged.

@Brad_ST - if a single device has 20 buttons, you cannot select that device’s buttons as the trigger in smart lighting

Hi @doncaruana,

I see the button number state, like this:

But, don’t you still have to call out the buttons as child devices like the Aeon Minimote DTH?


Based on the live logging this is the error:

groovy.lang.MissingMethodException: No signature of method: java.util.ArrayList.getAt() is applicable for argument types: (java.math.BigDecimal) values: [2]

Looking at the source code, it seems there is an issue handling values greater than 19. I’ll try to get a bug report filed but I’m not sure when it’ll get addressed as I’m guessing it isn’t encountered extremely frequently.


@johnconstantelo - The new app needs the buttons separately (I don’t even think they need to be child devices actually) where you can assign them directly, but in the classic app those buttons are just available in the automation without a child device. If there are buttons available as an attribute on the device like your screenshot, smart lighting will see them. And, as brad pointed out, there’s a code limitation in smartthings.

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Thanks!! Now that I know, I’ll just work around it. :slight_smile:

I’m curious though if you know if there’s a similar issue with the new app on buttons. I noticed with some handlers, the extra buttons are available for assignment right in the device itself, without going to smart lighting or anything. I’m kind of guessing that’s different code and wouldn’t be affected…thoughts?

I’m not certain. I know the SmartThings button (1 button device) has a plugin on the device page which allows for button assignment but I haven’t seen it on other devices, such as the Sylvania Dimming Switch (technically a 2 button device).

Stupid question: why isn’t it defined as 3 buttons, with supportedButtonValues filled with
“double", "pushed_3x", "pushed_4x", "pushed_5x", etc

You can only assign a trigger to a button, not to a button state. So that would only give you 3 assignable triggers when there are technically 21 possible.

@Automated_House - I may have spoken too soon! I was looking at the minimote handler and threw a sim device in and started goofing around with it. I think I can do this with just the 3 buttons, like you suggested. And it will be a lot cleaner, etc and shouldn’t violate the button limit thing. Thanks for making me think about this differently!! More to come!


check out the z-wave button handler too. It has some Fibaro devices that support up to 5x push


Thanks!! I have a feeling by the time I’m done, I’m going to be embarrassed by how wrong I’ve been doing this!! LOL


Nah, don’t say that! Your development efforts are greatly appreciated!

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@Brad_ST somewhat related question: is there a reason that the automations setup in the new app doesn’t support choosing a button number in the trigger for multiple button devices (like the Sylvania you mentioned)?