Solatube dimmer integration?

I found one post from last year regarding someone wanting to integrate the butterfly flapper style dimmer in their Solatube with their ST automation.
Unfortunately, for whatever reason, in a years’ time, he did not get a single response to his query. I am also interested in doing this integration, and not sure which category my post should be in.

Some of you might be wondering why someone would want a dimmer on a Solatube to begin with. If you have ever tried to take a nap in a room where there is no dimmer on a Solatube, then you will understand. Also, a Solatube can literally light a room completely in the middle of the night during a full moon.

I just got off the phone with Solatube International. While speaking to their support department, I was able to get some technical information about how this dimmer controller works and the voltage needed to operate the motor.

The factory actuator switch is a in-wall assembly designed to look similar to a in-wall light switch. Inside the assembly, there is a transformer which is connected to a supply voltage of between 90-210v AC. The transformer output feeds a momentary DPDT rocker-style switch with ±5v DC when the switch is activated. The motor operates between ±5v DC.

My thinking is that if someone makes a ±5v DC switch which will work with ST to supply ±5 volts DC and be able to reverse the current to operate the motor both directions, then it could be used with ST. I was unable to get the amperage rating of the motor, but was told that is probably very small.

The explanation of my goal, is probably a bit over-simplistic? I’m wondering if there might be some other issues involved in this integration. These issues might have to deal with:
-Figuring out partial open/close percentages
-Having the ST controller mimic a momentary switch
-Having the controller “know” when the flaps are completely opened or closed to
avoid overloading the motor or controller.

Rumor has it that Solatube R&D is currently developing a wireless controller for this dimmer, but it is not yet in production, and a production date is not set. I also don’t know if it will be an add-on or if the entire design of the motor assembly will change once R&D finishes the new design.

Any “takers” on this? Since the dimmer can be added on after the initial installation, I may wait until the new wireless design comes out and see if there is an easier method of doing this integration.

My guess would be that you could wire a dual-output relay in parallel with the switch that would simulate a button press - something like this (but suitable for your location if you’re not in the UK).

If there’s no issue overloading the motor by pushing the button, then there shouldn’t be an issue with ST doing it for you either (the motor probably contains a limit switch that shuts off current when it reaches max travel in either direction).

The challenging part would be partial dimming - due to network traffic, you can’t rely on the relay close and relay open commands from the hub to arrive at a fixed time. So if you currently have to press the button for 5 seconds to fully close the dimmer, you might want to set up your automation to press it for 8-10 seconds so that if the “on” command is delayed, there’s still enough time to close the dimmer before the “off” command arrives - that would give you full open / full close. And you’ll need to use WebCore or write your own smartapp to control it, since your times will be below the threshold you can set for any of the built in functions like Smart Lighting.