Arduino controlled light switch


Qty Description Link
1 Decora Light switch Home Depot
1 9g servo (preferably with metal gears) Amazon | EBay
a few inches 14 guage wire Scrap romex


Needle nose pilers
Hot glue gun
Thin blade flat head screwdriver

Step 1

Gently pry the lightswitch paddle off.

Careful not to loose this little piece of metal

Final Result

Step 2

Measure out some wire

And give it a bend

And another bend

Strip the tip of the short side up to the plastic block

Drill a small hole through the plastic block to allow the stripped wire to pass through

Make sure the wire fits snugly inside of the paddle

Dremel out a valley on the opposite side of your drill hole

After and before

Notch out a valley on the outer part of the plastic clip big enough for a stripped bit of wire to fit into

Cut the long side of the wire about an inch past the paddle’s length

And strip back until the middle of the paddle

Fit the wire into the valley you notched out

And bend it upwards so that it is flush to the outside.

Here is another view of the prior step.

Hot glue down your handywork

Step 3

Remove the tab on the opposite side of the screw terminals

Before and after

Drill a 1/4in hole down the middle of the tab you just removed

Snap it together, and make sure it toggles with ease

Step 4

Position the servo so that it is flush to the switch body

Make sure not to cover this hole

Or this one

Hot glue down your handywork

Final product

Step 5

Chop two legs off of a X servo horn

Like so

It should look like this once it is attached

Shape the wire so that it can easily be toggled by the servo.
Yet does not protude out to far past the lightswitch body

The mechanical portion is complete!

Stay tuned for the circuit and firmware!
coming soon.

8 thoughts on “Arduino controlled light switch”

  1. It would be great if you could post your code example. Thanks for this, it’s going to make my setup much more resilient considering human input and digital can be combined to eliminate the need for neutral wires got switching remotely.

  2. This seemed like a great idea so I got the parts and put one together on the bench, worked great except I have my doubts about using hot glue to hold the server on. I had knocked it off twice so used superglue instead. Anyway, when it came to putting the switch into an actual wall box that’s where its downfall became apparent. There just isn’t the room to be able to fit the switch with the servo into the box with the wires. Maybe a single switch in a double gang box would be ok but that wouldn’t work for me.
    Maybe if it was an open backed box, or if more of the wires could be shoved into the wall cavity maybe it would work but I had to call it quits.
    So, for others reading this site, I’d suggest checking out your wall boxes first, see if there’s enough space in there.
    Thanks for the post though, an interesting idea that might work in some homes.

    1. Super glue is probably a much better bet, and I ran into the same issue with depth. The biggest hangup that I ran into is that it is almost impossible to get a 120v ac to 5v dc module that will also fit back there aswell. Only reason I posted it was I had never seen anyone do it, hoped it could inspire someone to make something better.

        1. That was the plan, but there is really not a ton of space in these outlets :/ also there is some US Electrical code that says no to high and low voltage in the same enclosure

Leave a Reply