How do I go about adding a single tile linked to all lights. If I press it once it turns it all off and again turns it all on and indicates the correct icon on the tile?
I created a virtual dimmer switch that I have my 3 living room lamps mirror using the native Smart Lighting app in SmartThings. When I turn on/off/dim the virtual switch the lamps follow. You can create a tile with the virtual switch on a dashboard and then control all your lights at the same time.