Integrating Kidde Smoke / CO Sensors into SmartThings Properly

[ritchierich (Michael)]

You will find in the sm120x instructions that it has a 9V DC wire as well. Like you I was hoping to hardwire the contact sensor. Unfortunately that 9v doesn’t supply 9v at load and drops to 2v which isn’t enough to power the contact sensor. So I ended up following what I had done with several other sensors which I documented here:

Make a battery powered sensor run on USB

I have a few sensors in locations near a receptacle but yet I continue to change batteries. Well no more! After reviewing several YouTube videos and doing a little research I found a small device a little smaller than a CR2 battery that converts 4-12V DC down to 3.3V DC which is the equivalent to 1 CR2 or 2 AAA batteries. I converted my first sensor today and thought I would share. Here is a good video tutorial. I ended up getting a slightly different power module than the one mentioned in the video since this one has a higher range of input voltage. Plus it is smaller in size too. This power supply module to down-convert the power: https://www.amazon.com/gp/product/B01CONBSV0/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1 First I hooked up a few wires to the power module that I ho…

This is much cheaper than your battery eliminators which I had looked into.