Virtual 3 way for dimmers?

I’m so confused. :thinking:

Assume two Meross WiFi dimmer switches, one called “Master” and one called “Accessory.” (Both are the same single pole model, this is not their 3 way kit. I just want to set up a virtual 3 way. Don’t worry about the wiring, I’m just trying to figure out the automation in the SmartThings app.)

Smart Lighting is available.

Is there a simple automation so that when you dim the accessory, the master will match it?

Basically want something like the old groovy Trendsetter smartapp.

Screenshots would be appreciated; I’m really confused.

Bonus question

Is it true that routines will only let you do this with on/off, not dimming?

If so, if you do have two dimmers, what happens if you set up an on/off routine linking them? (If accessory turns on, turn master on.)

Is RulesAPI simple automation?
Using RulesAPI this is possible.

I don’t know if it’s possible to execute RulesAPI rules in cloud. My all RulesAPI rules are local in my SmartThings hub.

Probably not simple enough for this case. I am quadriparetic and use voice dictation and I only use a tablet, not a pc. Dictating anything like code is really tiring and requires lots of time. So again in this instance I am just looking for something that is done within the SmartThings app.

I could also use SharpTools if the dictation isn’t too complicated.

But I am glad to hear that RulesAPI can do it, I am sure there are others who would be interested. :sunglasses:

Smart lighting is the only automation available in the app that can synchronize dimmers. With Smart lighting, you program one device to be “master” and as many others as you wish to sync with it.

My use of this feature has always been “one way” with a virtual dimmer as the "master’ and multiple real dimmers synced to it.

In the screenshot below, Kitchen Ceiling is a virtual dimmer, the others are physical. Note that you select the device(s) to be controlled first.

In conjunction with this, I have a “cleanup” routine in case the physical switches are used. It turns the virtual off if all the physicals are turned off.

Whie this isn’t technically perfect, we use it almost exclusively via Alexa (e.g. “Alexa, kitchen ceiling 50%” or “Alexa, kitchen ceiling off”).


Thanks for the information!

What happens if you just use the on and off features of a regular routine with a dimmer device?

You can synch the dimmers to go on/off as described in the other topic.

What dim level they come on at depends on the available settings in the driver for that particular device. For instance, using the GE/Jasco Motion-Dimmer driver from @philh30 exposes the Default Dim Level setting which determines the behavior when the dimmer is switched on from the button, the ST app, or a Routine that doesn’t explicitly set the dim level.

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That will depend on what your dimmers do when switched on. All of mine (GE, Zooz, and Leviton running stock DTHs or drivers) turn on at the level they were last set to when on.

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Smart lighting causes them to sync the dim levels. If I slide the “master” dim level up or down in the app, when I stop (so the action is sent), the dimmers being controlled immediately change to match.

I see there’s something new in Routines that allows taking an action when a dimmer is set to a specific level. Not at all the same thing but possibly useful in some context.

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@JDRoberts was talking about using just on/off in Routines (not Smartlighting) to mirror behavior and what that might look like. I was just pointing out that the OP in the other topic described how he set that up.

As for the new triggers in Routines, yeah, I talked about that in the other topic as well. You can only trigger on a specific value(s) like “dim level matches 50%” or “dim level is above 50%” or “dim level is in a range”. So while that would allow you to trigger on various scenarios, there is 1) no method of setting one device’s dim level to the value of another; 2) you can only set a discrete value for the dim level in the Actions.

As I also mentioned, Sharptools allows the use of event data which would at least allow the dim level from one switch to be assigned to another switch. But, again, not native and not a perfect mirroring.


Not super useful for syncing dim levels, but opens up some interesting possibilities for using a virtual dimmer as a variable to pass between multiple routines and avoid needing to use Rules… :thinking:


Good point. I know I’m using virtual switches to track state in a number of different situations.


I’m using Number Fields (EDGE Driver-Mc): Aplicaciones Virtuales Mc (virtual Switch Mirror, Virtual Calendar and virtual Switch Board…) - Devices & Integrations / Community Created Device Types - SmartThings Community for state of different situations. More easy to use than multiple virtual switches.


I wasn’t aware of that one - very cool. Now I have to consider which of my virtual switches are worth replacing and whether it would simplify anything…

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If you could name the text and number fields it would help. Otherwise, you have to remember which field is representing which particular state. Virtual devices can be named so having “Nighttime is on” vs “Number field One is 1” is a bit more intuitive :slight_smile: