Adding a contact sensor to a doorbell

Oh so you don’t actually use the doorbell wiring?

Nope (10 char)

Does it matter if the reed is normally open or normally closed? Also do I use this style

Or this style

The second. Doesn’t matter if NC or NO.

In that first screenshot, you see the small white box above the doorbell ringer? That’s the Multisensor. When the doorbell rings, that spring in your doorbell enclosure hits the metal plate which triggers the accelerator in the sensor sitting right on top of the metal plate. It’s the easiest integration.

Then you can write a Piston in webCoRE or a Notify me when rule when vibration is sensed to either send messages or perform another function and turn something on or off. You can even write a custom rule in SHM for when Vibration is sensed on your doorbell sensor.

So I’d recorded a video of how the doorbell operates to get a better understanding and now see that there’s the little rod that moves up and down to make the noise - place the reed switch next to that rod right?

In taking a closer look inside my doorbell I’m not sure I’ve got enough space to be able to place a multisensor inside the housing.

Here’s how much space you need:

The sensor is 1.9" long (you insert sideways), by 1.04 inches wide and the part that would be most important for you is that it is .6 inches thick (official specs). however, just measured officially on mine and it is .5 (1/2 inch) thick exactly). See if you have that much space in between the ding plate and the upper portion. Mine is super snug but it fits nicely:

you place it next to the motor that moves the rod.

If it’s snug though does that affect the operation or sound of the doorbell?

For me, I don’t want the loud ding of the metal doorbell plate ringing, so I shoved it in real tight so when it smacks the ding plate, it is a dull noise. I then receive voice notifications on my phone, on a Bose speaker and on a tablet in the hallway letting me know someone is at the door, so whether I am home or not, I hear the announcement, no ding ding needed.

However, if I push it in above the ding plate further to the right or left, not directly over the spring mechanism, the doorbell will still go ding ding like normal, but my preference is dulling that noise out.

As for operation, when the spring smacks the doorbell plate (that’s what I call it - not technical term), that’s enough to cause vibration in the Sensor.

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I’ve probably got about 1/4” of from so sadly that’s not going to work.

Looking at the screenshot you provided, visually that gap looks a lot more than a 1/4 inch from the top of the ding plate to the top of the unit. Hmmmm.

You can’t really see in the picture because it’s black against black, but there’s a tab that’s in be way over the rod on the left side.

So to the right of of the arrow / black tab there is 1/2 inch of clearance? Doesn’t need to be sitting right over the spring. It just needs to be able to rest on the metal bar there. When the spring shoots up and hits that metal bar, as long as the sensor is sitting on that bar, the sensor is going to detect the vibration

Going to try this after work… I have a few ST multisensors in a box not being used. Hopefully it fits!

I finally got around to this, I just placed ST multisensor on top of case! (It didn’t fit inside)
Then I added two ST smartapp automations:

  1. (HSM, custom): send alert when door bell rings (vibration)
  2. (Smartlighting): turn on porch light for 1 min. when doorbell rings (vibration).

Easy!! Just used what I already had, no need for all those extra parts & software.

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