Hardwiring Motion/Multipurpose Sensors?

Anyone hardwire the motion and/or multipurpose sensor? It’s unfortunate the new motion sensors lacks a USB port.
I bought another house (2nd smartthings location) that is prewired for alarm (two wires) at each door/window and along the walls for motion. All wires go back to a centralized location thus I could possibly use a CCTV like power supply to send the appropriate voltage. How would I connect it to the smartthings sensor? Solder it to the terminal???


You can find project reports from people who have done this kind of project on the quick browse lists in the community – created wiki in the project report section under “power.” :sunglasses:


Do be aware that anything that requires soldering will likely void the warranty on that particular device.

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Appreciate the response, this is the closest thing that I found: 3v Step Down Converters for Sensors

Any alternative to soldering?

Existing hard wired alarm might be able to be modified to be seen by smartthings. As JD mentioned, take a look at the wiki. Here is an example of one that was done with an esp8266, which is very inexpensive.

The Aeotec multi sensor has a USB power option.

Other than that, if you don’t want to solder you would have to look for a dummy battery option, but they aren’t usually made in that size.


Maybe you had more than one question. My last response was for connecting hard wired alarm to ST.

As far as just a battery operated motion sensor, you could always just buy a 3.3v wall plug, cut the end off, and hook the wires to where the battery would normally go. I tape up the a dead battery to hold the wires in place so it requires no soldering.

Totally diy and would void any kind of warranties.

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I am using this solution at my current house and it works great! But at my 2nd location, I would rather just use SmartThing’s sensors since they are the most reliable solution, at least in my experience.

In my experience the Aeotec sensors haven’t really been reliable and I had two that failed on me.

This looks great! Can you still put the cover back one? I suppose I could use a large power supply like this and connect all the sensors??


As long as your voltage is constant, around 3v, then I think that should work, but I can not confirm that.

Yes the cover fits back on this one without any modifications. Doesn’t look great, but I’m sure I could get a better fit modifying it a bit with a drimmel, and have it come out the back.


Instead of using the SmartThings wireless sensor, I would just get an inexpensive wired PIR motion sensor for about $20 and use my nodemcu-smartthings esp8266 project to hook it to SmartThings. You can power it with any 12V transformer. Much cheaper and you never have to worry about batteries.

Guess I should have been more specific. I tape up the battery all the way around/ top and bottom with electric tape so that it doesn’t contact the wires and gets no current. It just holds the wires in place.


Further on @JDRoberts recommendation: my two installations have a total of four Aeon multi-sensors all running on USB power. I use iPhone charger blocks for the power, but you could easily use existing wiring from a central location if you’re comfortable with soldering and making cables.

FWIW, my sensors have all been very reliable. No issues since initial deployment. YMMV, of course :grin:

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There are dummy batteries made for this purpose out of appropriate materials. They’re easy to find in a AA size, but not so easy in other sizes. You can make your own out of nonflammable nonconducting plastics, but that’s a whole other issue.

I would definitely agree with @anon36505037 on this – – using a dead battery is very likely to lead to problems long-term as there are still chemicals inside that battery which will eventually leak. Better to go with something that is inert.


Use a wooden dowel, cut to length.


I posted about this as well. I include a few pictures and a link to a useful YouTube video:

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