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 




  • @Vishai, Can you remove the wall switch from the wall and take pictures showing how the wires from the door openers pins 1&2 are connected to the switch. Does it look like the multifunction wall switch I provided pictures of in earlier posts. Can you find any type of model number on the wall switch? -Greg
  • Here you go.
  • @Vishai, Try this. Disconnect the two wires from the NO relay to pins 1&2 on the door opener. Leave the wall switch wires connected to pins 1&2 on the door opener. Then remove both the red and white wires from the back of the wall switch. Next monetarily touch the red and white wires together. Verify if the door opener starts.
  • @Greg. Will try that during daytime tomorrow. For now I can tell you that the wall switch is not getting any power and that seems to be the problem. Without NodeMCU, the wall button's light is on but with it nothing. Is your suggestion about proving something towards this?
  • @Vishal, The reason I'm having you perform the test is to determine if the wall switch is a simple momentary switch. Touching the wires momentarily will either make the door opener work as it would with a simple momentary switch. If nothing happens then the wall switch must contain some special logic that communicates with the door opener and activated it. If that's the case then connecting the NO relay to the same pins 1&2 is interfering with that communication and disabling its function.
  • @Greg. Back with more pictures and observations. Attached are the 2 pictures of wall button board from each side. I did what you asked (sort of). I powered off the NodeMCU board and thus relay and joined 2 wires of the wall button shortly and the garage door opened which means it's a momentary switch. I also noticed that as soon as I powered off NodeMCU, the wall button light came on. Also, when I powered back the NodeMCU and (I believe) as soon as it acquired wifi connection, the wall button stopped receiving power. It didn't happen as soon as I powered on NodeMCU but rather took a few seconds which I guess was the time to acquire wifi connection. Hope this helps you in helping me. :-)

  • Vishal, I just had another thought on your configuration after completing my last message. Let try a different approach. Let's use the relay in a NC (normally closed) configuration. Remove the the wires from pin 2 on the door opener. Then connect the wall switch wire just removed from pin 2 to one of the terminals on the NC relay. Then connect the other terminal of the NC relay back to pin 2 on the door opener. With the relay in the NC configuration the circuit from the wall switch will be completed when the relay is inactive. When either the wall switch or NodeMCU relay are activated it opens the circuit and may activate the door opener. -Greg
  • Greg. Follow up questions to make sure I am doing the right thing and not blowing up anything. Here is a depiction of what I already have. Please ignore the artistic look of my picture. :-D It's nowhere close to how you showed your setup.


    So if you look here, NodeMCU config is simple. Connecting D1 to Relay and providing power as well. It's currently a NO relay which means NO port is connected to pin 1 on garage door opener (or pin 2.. don't remember right now while sitting in office) and COM is connected to 2 (or 1). Wall switch is also connected to pins 1 & 2 on garage door opener.

    What you're suggesting is:

    1. Remove Relay'S NO wire from it and attach it to NC

    2. Remove both wall switch and Relay wires from pin 2 

    3. Connect wall switch wire removed from pin 2 and attach it to NC on same relay where another wire is already connected as mentioned in step 1 above

    4. Attach relay's previously removed wire from step 2 above to pin 2 again

    This should keep the circuit closed/completed for wall switch thus providing it power (light will be ON on the wall switch then). Now, whenever either wall switch or NodeMCU is activated, it should open the circuit and garage door should operate.



    2. Is my understanding above correct? Especially the part where Relay's NC will have 2 wires: one coming from wall switch and other going out to garage door.


    Please (don't) ignore the blow up question asked twice. I recently spent around $1000 when garage door spring broke and some other part in the motor. Don't want to spend more money on that. TIA for your patience and time.

  • @Vishal, 

    I would suggest using a proven configuration which I have confidence in given its the method I used for my own garage door opener which has been in service without issues for a year. 

    To ensure this method works for your garage door opener I would suggest running a quick test. 

    1.) Disconnect the NO relay wires to Pins 1 & 2 on the door opener. 

    2.) Verify the wall switch wires are attached to Pins 1 & 2 on the door opener and the back of the wall switch

    3.) With the wall switch NOT mounted to the wall take a small jumper wire and momentarily touch across the switch pins which are diagonal from each other on the back of the switch. See attached diagram to identify the switch pins. 

    4.) Verify the door opener activates when you momentarily jumper across the switch pins in step 3. 

    5.) If the door opener activates then proceed to configure system as shown in the attached diagram. 

    6.) Happy Home Automation!


    This will require some soldering on the back of your existing wall switch and to relocate the NodeMCU (ESP8266) and Relay closer to the wall switch. It may also require you to relocate the NodeMCU and NO Relay closer to the wall switch. 


  • Greg, thanks for detailed steps with diagram. I can try what you're saying but moving NodeMCU and relay closer to wall switch isn't that easy. There is no power near the wall switch and they are 15 ft apart. I can then run the wire from wall switch to Relay. It's doable but then 15 ft of wire running in the garage. It won't look that good. Not sure how I can pass it thru the wall like the existing wall switch wire. Will see if I can do that but I will atleast run the test to be sure and let you know.

  • Vishal, 

    Just to ensure you understand the soldering points on the wall switch I modified an identical switch I had to show your the location of where to solder the two wires coming from the NO relay module. 


  • Greg, I did the test by touching mentioned wires momentarily and the garage door activated. However, running the wires from wall switch to relay is a problem. I couldn't fish the wire. I even went in attic to see and could see the wire but fishing from wall till attic and attic to opener is a problem right now. Will see if I can achieve it otherwise will have to look for other options. Thank you so much for all the help.
  • Vishal, Thank you for the response. Well at least you have one known potential solution. Just out of curiosity, it might be interesting to determine if when the relay and NodeMCU are connected to the two pins on the back of the wall switch if the wall switch light remains lit. Another test would be to disconnect the two wires from the NO relay but leave the other ends connected to pins 1&2. Momentarily touch the two wires together and see if the door activates. If yes, this mimics what the NO relay does when momentarily activated by the NodeMCU. If this test activates the door opener then there has to be some type of negative influence the relay has when connected into the system. Can you provide the model of the NO relay and a picture of it connected into the system. I'm very interested in the details of the wires from pins 1&2 into the relay. -Greg
  • Hi Greg. Apologies for the late reply. I kind of overlooked the email and noticed today what you were asking. Here are a few answers for the questions you asked: * The wall switch light comes on as soon as I remove the Konnected setup * I removed wires from relay and momentarily touched those. Garage door activated. * This is the relay I am using DAOKI 5 PCS 5v Relay Module for Arduino ARM PIC AVR MCU 5V Indicator Light LED 1 Channel Relay Module Works with Official Arduino Boards For now I have bought an extra remote and attached it on wall which serves the purpose.
  • I also have same problem as Vishal. In my case i have Liftmaster garage door opener. If i connect nodemcu without relay directly to garage opener it triggers open close but the physical wall remote goes offline. The down side is everytime node restarts it triggers open close in my case. I dont have base for node mcu. If i add 5v relay to setup, it doesn't trigger open close. its frustrating. I think the nodemcu is eating up voltage or making an open circuit which gets no power to wall switch. My node mcu is latest and it has only 3v power. I think the relay needs minimum 5v to trigger. Its frustrating.
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