A bit of a long post, but I have several behaviours that I need to outline in detail to get across what is going on…
I use “Mirror” behaviour in three setups in my home. In each case, the “Mirror” acts differently. Two work well enough that I have no complaints but only one of those works exactly as I would expect. The third is completely broken when I enable it and I have had to change the rule to “Turn On (and also off)”.
They are as follows:
- GE Zigbee Dimmer switch is mirrored by GLEDOpto RGBW strip (set up as a ZLL device). When I turn on or off the GE dimmer, the GLEDOpto strip follows exactly; it doesn’t matter if the action is at the GE Dimmer, through a Smart Lighting automation or just through the standard app (not classic) on Android. This is acceptable but if I turn the GLEDOpto strip on or off in the app then the behaviour is not mirrored to the GE dimmer; such behaviour seems to be described by this answer - How to set up a virtual 3 way between 2 master switches?, but I do not expect to have to mirror in both directions.
- Virtual Living Room Lights device is mirrored by a Logitech Harmony Activity and a separate mirror by a Cree Connected Dimmable Bulb. In this case, I can use the Virtual Living Room Lights device or the Harmony Activity to control the living room lights and one activates the other so that both switches are in the same state at all times. If I turn on the lights with the Virtual Device in the SmartThings app and then open the Harmony app, the activity is ‘on’. Turning it off there turns off the Virtual Device and the living room lights with it. This is precisely what I would expect of a mirrored behaviour and I only have the one mirroring rule between the Virtual Lights and the Harmony Activity.
- GE Zigbee Dimmer mirrored by two Cree Connected Dimmable bulbs and a separate mirror for a Logitech Harmony Activity. In this case, turning on the GE Dimmer turns on the bulbs but does not activate the Harmony Activity. Turning off the GE Dimmer starts to turn off the Cree bulbs but then they immediately turn back on again despite the GE Dimmer registering as off (it is this behaviour I have had to “fix” by setting the behaviour to “Turn on (and also off)” instead of “Mirror” - hinted at but not resolved here Osram / Sylvania Lightify Strip - Smart Lighting Mirror Switch Behavior) and if I replace the Cree Blubs with a GLEDOpto strip to mirror the GE Dimmer, that works exactly as in case (1) above. If I turn on the Harmony Activity, the GE Dimmer does not respond but if, subsequently, I turn on the GE Dimmer and then turn off the Harmony Activity, there seems to be a race condition where the GE Dimmer and the Harmony Activity turn each other off and on repeatedly with the Cree bulbs following as best they can.
So, what is the designed function of “Mirror”?
Is there some incompatibility with GE Zigbee Dimmers?
Why do Cree Connected bulbs fail to respond correctly to mirroring a GE Zigbee Dimmer device but are fine mirroring a virtual lighting device?
As I stated, case 1 is fine as that is my hallway lights on the GE Dimmer and a hidden coat rack light turns on and off with it; case 2 for my living room lights functions perfectly; case 3 is for my bedroom lights, where I have tried making a virtual bedroom light device to control the individual lights and I can control that with the Harmony Activity just fine, but mirroring the GE Dimmer produces the same strange race condition results (except the Cree Bulbs don’t turn back on when they should be off). For the bedroom, I’d prefer not to have a virtual device since that runs in the cloud and I’d like the GE Dimmer to have direct control over the bedroom lights at all times in case of any internet issues. All I want is for the GE Dimmer and the Harmony Activity to remain in sync and the lights to follow.