Garage Door Opener & Alert Project

Inspired by one of Nate's Konnected video's  ( I was inspired to integrate a Konnected DIY board to Chamberlain garage door control. While many of garage door openers use a momentary switch to activate the garage door my Chamberlain system didn't. So the initial challenge was to discover how to implement a simple momentary contact to activate the door on my system.

So I disassembled the Chamberlain Wall Mounted Mutifunction Control Panel to gain access to the PCB. Knowing the activation was a button push I located the only monetary switch on the PCB labeled (SW1). Then using my multi-meter I checked for continuity on the four (4) SW1 pins (see pic) when the switch was activated and found that the pins located diagonally across from each other closed with the switch activated. So I soldered a wire leads from a pair of pins opposite of each other and extended them outside of the door opener case.

Not knowing if the voltage or noise levels that maybe present on these leads I choose to isolate them with a normally open relay and not directly connect them to the DIY PCB. Next I used the Konnected smart app to configure the DIY PCB board pins GND, D8 as a momentary switch to activate the relay.

With hardware in hand, I strapped together the system for an initial test (see pic) and it was a success! Of course when I showed the wife she wasn't impressed. Her only meaningful comment was it looked horrible and dangerous taped to the wall. So the next step was to package it in a wife approved container. In fact, she mentioned that a travel soap container looked like it would work. So, I let my fingers do the shopping and ordered a couple of black plastic clam shell travel soap containers from Amazon. I have to say after a few mods to the container to allow for a 12VDC power plug and wiring leads from the door PCB things were looking good (see pic).

Since I intended to automate the door opening and closing with a presence sensor I wanted to add an audible alert anytime the door was activated to ensure anyone in the area was aware of the movement. So I used a Smartthing Multipurpose sensor configured as a garage door sensor and mounted on the garage door. This sensor provides the open/closed status on the door and also has accelerometer feedback. So with a couple of smart apps I now have a complete system which detects a presence sensor to activate the doors, monitors the accelerometers and activates the piezo buzzer to produce an audible alert when the door moments is detected. (see pic). 

Garage Door Control PCB






Mounted with Piezo Buzzer


Wife Approved Installation 




  • Hi Maxime, Great job identifying the issue with the relay. From the view it does appear the markings for the NO and NC are reversed. The convention typically shows the state of the relay contacts when the relay in NOT energized. 

    A couple of thoughts. When you were testing the continuity was the relay powered? If yes remove any power source and test again and see if the results change. Also, is there any type of jumper on pins on the front side of the board. If so it may be used to reverse the logic of the board. If it appears to be marked that way remove and retest. Also a jumper might also me used to select the input power lever as either +5VDC or +3VDC. If you can identify the manufacture and model of the relay we can look for the technical data sheet which should document all the features and functions. Just goes to show you can't always make assumptions. 

    Here is a relay that follows that convention that I'm using in my garage door Konnected project. It follows the convention of marking the state of the relay and contacts in the de-energized state. 


    (1.21 MB)
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