Smartthings Button Teardown (and more!)

[adamkempenich]

I have some switches that aren’t wired for neutral, and I wanted digital switches to control my lights.

I decided to use SmartThings buttons to communicate between my Leviton switches, which aren't wired up to mains power. The lights themselves are always on. It feels nice to have a hub that's so reliable—I don't worry if pressing the switch will work or not, which isn't something I've said about other hubs or platforms in the past.

If this type of post isn't allowed, please let me know. Just figured I'd share my story of creating some unpowered wall switches with these buttons.

The teardown...

The buttons themselves look pretty nice. The click feels good, as well!

Prying off the front plate is somewhat easy. There are plastic tabs that create the forward tension for the button.

The cat wasn't happy that I was working on her table.

The buttons are held together using plastic clasps. A metallic spudger worked just fine to pry it open.

On the back side of the device, you'll notice a battery door (that can be opened with a coin) and a reset button.

The battery itself is actually held in with a magnetic back--what a good idea! The underside of the battery connects to this wire to complete the circuit. You'll also notice a coil on the top (to connect the positive terminal of the battery) and a button on the bottom --- which is what is depressed through the pinhole on the back of the device.

The opposite side of the board reveals the button itself, in addition to an LED. Nothing too strange here.

This chip reads
EFR32
MG13P732HG
1832C00QOM

I haven't looked into it at all, yet.

Looks like I have the first revision of the sensor. I do wonder what future revisions will have changed.

The LED seems to be RGB. I haven't tested for voltage or anything, but I may revisit this in the future.

I figured I should probably make sure the board still works, at this point.

The next step was to solder my connection wires to the button contacts.

How does the soldering look?

My best soldering work
Not my best soldering work <<< Survey says

And then route the wire through a melt-cut hole.

Finally, I tested the contacts in HE to ensure they'd work as intended (they did).

And then, I re-assembled the unit. I kept messing up my cutting, but got it right in the end.

I soldered the other side of the wire into a non-smart Leviton Decora switch. These are my favorites, and a few friends have commented on how good they feel to press (which, we honestly don't do a lot thanks to presence sensors.) One day, I may revisit wiring the LED from the button to the switch, but for now, it's nice to only have 3 switches in the entire house that aren't smart.

Here’s how the switch itself is wired. NO wires go to the mains.

[keithcroshaw]

Huh... beware the firmware! Let me know if you loose connectivity in three days or so.
I had to buy a new (clearance ST Hub V2) from Home Depot to update the firmware OTA...
Good idea though!

[bertabcd1234]

Neat! Since these switches aren't wired to the house electrical, what do you do with them when you're done? Stuff them in a low-voltage old-work box in the wall to make it look like a switch anyway? (Or I guess maybe box the "dumb" switch used to be in with everything capped, but I'm not sure about mixing that with some sort of barrier.)

I haven't figured out a use for my ST button yet. Despite liking it so much and it being probably the cheapest thing out there besides Xiaomi, it's still just paired to my hub but sitting on my desk, and I haven't bought more. It may be because I've also got a Lutron Smart Bridge Pro and bought a bunch of Picos since then (easily wall mountable, supposedly long battery life, and probably about the same price as this setup in the end, minus the cost of the bridge--but no need to solder).

I'll definitely put this on my list of things to consider doing with it.

[adamkempenich]

@bertabcd1234

box the "dumb" switch used to be in with everything capped

This is exactly what I do It’s totally a preference, but I love the look and feel of the old-style z-wave Leviton switches & dimmers. There’s something to be said for only having the individual button on the wall, instead of a paddle or switch, that I love. I realize a lot of people don’t like this (hence, why they moved away from that design), but this is what led me down this path instead of Lutron. Connectivity seems fine—I have a pretty strong zigbee and z-wave mesh in my house, though.

@keithcroshaw

Let me know if you loose connectivity in three days or so

My fiancé will let me know if that happens, and then I’ll let you know

Thankfully, I’ve had them running for over a week with no hiccups, aside from the hub thinking multiple button presses were received. I also have my ST hub, and I might end up trying to update the firmware at some point (if they stop working).

I also considered soldering in a bigger battery connector, but I can’t imagine these ones will die very quickly.

[stephack]

@adamkempenich

aside from the hub thinking multiple button presses were received

Known issue with these bad boys and apparently updating the firmware doesn't help. If it gets too annoying you can try this mode driver. It's been helping me avoid the duplicate events until Samsung or HE release a fix.

"New" SmartThings 2018 sensors

I have made a mod to @jp0550's mod for this driver. This will be my interim driver till Hubitat/Samsung resolve the duplicate events that occur after these button devices have been unused for a period of time. Essentially it will ignore multiple button press events that occur with a specified timeframe. When I receive duplicates my logs show that they occur within 2 seconds of each other. I have found that 2500ms to be the sweet spot for me. Your mileage may vary and so I made this an adjustable…

[adamkempenich]

Thank you for posting that. I started noticing duplicate presses, and the new driver fixed it. No worrying about complaints, now

[jwetzel1492]

Very cool! When you soldered the leads to the leviton switch, is it simply attaching them to the line and load? Nothing else? In that case, when you turn the switch on, does the button report a "hold" event? What events are being reported by the button?

[adamkempenich]

The leviton switches seem to work a bit differently, seeing as there is only one button. Line and load are isolated from the button I soldered on to. I'm guessing most digital switches act in this same way.

The switch itself acts as a relay, as far as I can tell, with the toggle switch on the front acting as the controller to turn the AC relay off and on. I'm only using the button portion---nothing with the AC wire at all, so the switch's button essentially replace's the button's button in parallel --- I've simply added another button to the circuit ... if that makes sense? I can add a wiring diagram if that will help

I was thinking about this last night---and realize that I could have kept the AC wire running through the switch so I could use the air gap in the switch to toggle the power, and I could have cut the traces on the switch's button to not send false reports/fry the button's circuitry. I have 3 more switches to do this with... perhaps I will change that in the next iteration

[jwetzel1492]

So is this a smart switch? Or just a standard leviton light switch? Can you show a picture of how you have it wired in?

[adamkempenich]

I'm using a VP0SR-10Z dumb switch---although, dumb probably isn't the best way to describe it.

This switch can act as an auxiliary/remote switch for a Leviton smart switch of the same era. Since it only has one button that triggers the relay inside the switch, there is some additional circuitry controlling that.

I had a picture on my phone of the wiring, but it's seemingly disappeared. I'm going to order another smart button to wire this into... give me 6 days and I will re-capture that image for you

[jwetzel1492]

Gotcha! That's a lot like the GE add-on switches that I'm familiar with. It's basically a smart switch, but without the radio, because it pairs with a full smart switch, right?

What events does the Smartthings button end up reporting back to the hub? Is it pushes, or does it report hold and release?

[adamkempenich]

@jwetzel1492

Gotcha! That's a lot like the GE add-on switches that I'm familiar with. It's basically a smart switch, but without the radio, because it pairs with a full smart switch, right?

Exactly!

@jwetzel1492

What events does the Smartthings button end up reporting back to the hub? Is it pushes, or does it report hold and release?

It reports the same values as the normal button would, since it's just passing through open/closed contact to the button's circuit. Pushes/Double Push/Hold all work exactly as expected. I had an issue with the native driver, but @stephack's driver has been working perfectly as a fix.

No connectivity issues, despite it being in a 2-gang box.

[jwetzel1492]

Does it report the pushes when you toggle the switch up, or down, or both? (Sorry for asking so many questions)

[stephack]

If you are asking whether it reports pushed and released events...then no. It only reports pushed.

[adamkempenich]

And if you are asking how the switch reports--it only reports on button-down events (the switch is normally open).

[adamkempenich]

I’ve updated with a picture of the wiring on the switch itself

[jwetzel1492]

Aha! I finally get it! The Leviton decora switch is a momentary button itself. All this time I had been thinking it was a switch with on/off.

[adamkempenich]

Whoops! My apologies. I should have outright said it was one momentary switch