SmartThings Community

Switch / Hue Bulb State Change Toggle


(Mike Hendriks) #1

Hi Everyone,

I’m looking for a solution, and so far haven’t found one.

I have a Konnected board that I’ve connected a low voltage (dry contact) switch to. This switch is in SmartThings, no problem there.

I also have a Hue bulb that works in SmartThings.

I want to create or (ideally) find a SmartApp that will induce a state change in the bulb when there’s a state change in the switch. I want the switch and bulb to behave like a three-way switch would. I’ve looked in Smart Lighting, and I can lock the switch and bulb state together, but that doesn’t help me if another routine turns the bulb off.

Does something like this already exist somewhere, or am I going to have to start investigating writing my own?

Thanks in advance


#2

I’m not sure what you’re asking. If you use the “mirror” function in the official smart lights feature, it doesn’t matter how the trigger device is turned on: it could be physically at the wall, it could be through a routine, it could be through another smart app, it could be through a voice assistant like echo… It will always be caught by the smart light feature and the other device will then mirror the first one.

You can also set up two where A mirrors B and B mirrors A.


(Mike Hendriks) #3

Right, but that locks the switch and bulb state together. Consider this scenario:

Switch turned on, bulb comes on
Timer or other routine turns bulb off
Switch turned off, no state change in bulb

What I want is this scenario

Switch turned on, bulb comes on
Timer or other routine turns bulb off
Switch turned off, bulb turns on


#4

I don’t understand what you’re trying to describe. That doesn’t sound like a typical three-way set up.

Why do you want the bulb to turn on again after the switch is turned off?


(Mike Hendriks) #5

To give my wife local control of a Hue bulb. In a three way switch, any state change of any one switch produces a state change in the bulb.


#6

There are about eight different ways to physically wire a dumb three-way in the US, and one of them is a “lazy eight“ (where the current moves through only one loop depending on the position of the switches) but we don’t wire smart switches that way.

In the lazy eight, “up” and “down” No longer mean “on” and “off.” The light can be engaged in either position.

With smart switches, the switch doesn’t latch into an up or down position. It’s always in neutral, ready for the next command. So it rests in neutral.

If you try to use a lazy 8 with a smart switch, it won’t work. That’s because the switches always need to have current to operate the radio so they can hear the next “on“ command. If you cut them out of the current loop, they don’t operate. So you change the wiring. That’s why most of them require a neutral.


#7

You might find the FAQ on what switches to use with Hue bulbs helpful as well. Remember that we don’t want to actually cut the current to the hue bulb or we have the same problem as the lazy eight switch: the bulb needs current in order to be able to hear the next “on” command from a timer or a routine.


#8

Oh, and if you really want to make it look like a lazy eight even when it isn’t, then make sure that changing the switch does not in any way control the current to the hue bulb.

There are a couple of ways to then create a toggle that takes into account the previous state of the bulb. I think the easiest way is going to be web core.


(Mike Hendriks) #9

Yeah, I’m not wiring a three way, 120 VAC smart switch. I recognize that the Hue bulb requires constant current. As I’ve said above, I want a state change in the Konnected switch (not the mains switch) to produce a state change in the bulb


(Mike Hendriks) #10

I suppose another way to describe it would be: I want a state change in the Konnected switch to act like a button press in SmartThings. The mains switch will (of course) remain powered on all the time.

I could use a momentary switch or button (via Konnected) to accomplish the same thing. But for my use case, I want to use a switch.


#11

You should be able to do this with webcore. For example, here’s a very similar use case. I know the poster in that thread is using a button, but I don’t think it will matter. Webcore has a toggle option which should do what you want. Just ask the experts in the webcore forum. :sunglasses:

And if you need more information about webcore, start here: