xAC v2 alternative garage door button control

In this video we talk about how you can use the xAC v2 access controller with a certain type of garage door control button, specifically one that simply requires the lead wires to be shorted together in order to signal the lift mechanism.

Well not all garage door systems work this way. Some have internal control buttons that signal the lift mechanism using everything from specific line resistance to digital data communication with the lift controller. But fret not! The actual physical pushbutton used in the internal door control interface still works by shorting two very tiny conductors together on the PCB. We’re going to show how you can still use the xEM Access Controller v2 to interface with these types of garage door “buttons”.

First you can see the screen from the video where I show the through-hole posts (pins) coming from the microswitch button on the PCB;

When the physical button is pressed, these two pins are shorted;

In fact, there are two pins per “side” of the pushbutton, and on this PCB it is clear which two pins are electrically the same;

In this case it is obvious from the traces on the PCB which pins are which, but you can also easily test which pins are connected together and which are shorted when the button is pressed using a continuity meter. Disconnect the entire garage door interface from the lead wires, and with the button unpressed (in it’s normal state), measure the pins that have continuity. The pins that have no continuity with the button resting normally should have continuity when the button is pressed. Mark which pins are which.

So in this scenario, if my control board for the internal garage door lift button required me to connect directly to the physical microswitch button, I would solder my wires like this;

That way when the relay closes, it is electrically identical to someone physically pushing the button. The control board PCB will think that the microswitch button has been pressed and communicate that to the lift controller mounted to the ceiling in whatever manner it needs to.