I’m looking for a 12vDC dimmer switch to operate my camper LED’s, that I can physically interact with even if HA is down.
I currently have touch switches that work great, but would love to integrate them into HA. I have the 12v shelly, but don’t feel comfortable having my lights reliant on the uptime of the RPi and my local network. I’m open to zigbee, z-wave, wifi, bt, anything. I’ve scoured the internet, and found tons of physical or remote only dimmers, and 120vAC dimmer switches, but none that allow physical input, remote input, on 12vDC.
Any direction would be great, thanks!
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I use Shelly 1’s in my RV, and they work great both for HA control as well as local use. If my HA instance is down or whatever, it still works.
The Shelly 1 has a center terminal that is for switched ground. Basically, here is how you wire them up.
- Remove the wires from the switch - one is the 12+ and the other is the + line to the light.
- Tap the local 12+, and run that to the “N” terminal on the Shelly, and the “I” terminal.
- Run the “O” terminal to the line to the light.
- Tap the 12- and run it to the “L” terminal on the shelly, and then to one side of the switch. Run a lead from the other terminal on the switch to the “SW” terminal on the shelly.
Here is how it works. The “L” and “N” terminals provide power to the Shelly. The relay inside the Shelly controls the connections between “I” and “O”. If you leave it this way, you have remote control of the light, but now local control. The open/close is controlled by HA (or whatever).
However, if you ground “SW”, then it LOCALLY controls the Shelly. So if you attach the “SW” terminal to the existing switch, and the other side of the switch to the 12- line, then operating the physical switch functions like a 3-way switch would in your home. You get both local and remote control, and more importantly, if you use the local switch, it updates the state to HA, so you always have the correct state in HA whether you is it locally or remotely. They are pretty small, and can also usually fit inside the wall without much hassle.
I have used these in my last 3 RV’s and they work awesome. I personally prefer Tasmota firmware over the stock firmware, so i flash them with Tasmota
This is what my Shelly’s look like before I install them.
And I use a few of them 
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I agree with Bob on the Shelly 1’s, but if you want a dimmer, I’ve played around with the Shelly RGB with success so far. You won’t be able to dim using a physical switch, but it’ll work through HA (or from the Shelly app). The Shelly RGB is intended for RGB lights (as the name suggests), but it works great with a regular white light, supports 12v, and is dimmable. Even if HA is down, you’ll still be able to physically actuate the switch, but wouldn’t be able to control dimming through HA, obviously.
I’ve never found (but would love) a physical 12v smart dimmer switch like those common for household applications.
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I actually bought a Shelly RGB early in my HA journey, but with the frequency that my HA instance is unreachable and I have to hard restart the Pi, or my Netgear Nighthawk network is randomly unreachable, I decided to wait for a version allowing physical control. The Shelly 1 (awesome tutorial Bob!) doesn’t seem to dim, which is an LED feature I was hoping to preserve.
After a good bit of research I landed on these Tuya WZ1 devices. I only need 1 one channel per device, so the second channel and the 2.4gHz remote control ability are both redundant, but its the best I could find. I would’ve loved to use these generic ZigBee devices (SR-ZG9101CS) which are more streamlined for my particular application (1ch and no remote support / power draw), but no US stores carry that Swiss tech - EU people, enjoy them!
Once the Tuya devices finish their 2 month journey from China I’ll wire them up with these momentary touch switches which identically replace my current ‘dumb’ dimmer switches, and see how it goes! Will report back.
Hope you update on progress. Looking for the exact same control for my camper lighting (and was asking on the esphome forum how to integrate the exact same switch you want to use). Have to have a physical switch and it has to look good so no rotary style dimmers for me. My fallback is to use regular switch with an 8266 with relay sheild and then figure out how to dim in HA but this is less than ideal. Hope we can get this sorted!
Hi, I know this is super late sorry, just noticed the notification. I actually did end up going with the Tuya device. I have 2, with these momentary push switches. They work great, both with HA and the physical buttons.
Complaints:
- HA doesn’t recognize changes made by the physical buttons, so if I press to turn on, I have to click “on” then off in HA to turn off. Same with dimming levels
- I don’t need 2 channels per device, or RF, or the ability to control different LED strip setups, and I hate overkill…
- They took several weeks to ship from China
- I now need a Zigbee dongle hanging off my Pi
So I wouldn’t say its perfect and I’m always on the lookout for replacements, but since these are the literal only devices in the universe apparently (like… how?) that can handle this combination of simple/classic requirements, they’re working alright for now.