I have an old house that is full of these antique push-button dimmer switches. The actual switches are reproductions but the covers and such are original. I think the look complements the house and I don’t want to remove them, but I would like to find a way to control the dimming of smart bulbs and inline z-wave smart controllers with the switch knobs. I know keeping the existing button panel is a big ask, so let’s presume I really want to this to work even if its overly complicated.
The dimmer switches are fairly standard mosfet driven, trailing edge A/C dimming switches. The line voltage goes into a standard switch controlled by the top button and is then routed to the dimming circuit controlled by a potentiometer on the bottom button. I have no idea how I would read anything from them, so my thought was to do the following:
- Remove the dimming circuit from the switch altogether and simply wire the return out of the switch.
- Run a thin two wire line from something like a telephone cable to the potentiometer on the bottom button.
- Poll the resistance on the potentiometer from an Arduino placed somewhere further down the line so I don’t have to place it in the gang box.
- Send the converted values to Home Assistant and read them as a dimmer value.
- Add the dimmer value to the light/Z-wave dimmer as a control.
So, I have two questions:
First, is there an easier way to do this? I haven’t managed to find any existing solutions that poll an in wall dimmer circuit directly, but if that’s possible I’d probably be better off doing that.
Second, if there are no turnkey solutions, is this a reasonable approach? Has anyone tried anything like this and posted about it? Also, I’m a pretty lousy programmer, so if this basic approach is reasonable, is there any existing code (microcontroller code and/or Home Assistant code) that is a good solution for reading potentiometer values and sending them to Home Assistant as dimmer?