Garage Door Smartphone BLE Control

Bill at Taste The Code has a rather standard garage door opener with a 433 MHz remote. As this remote is “quite bulky and in the way” he doesn’t always carry it with him, and sometimes had to go inside and manually trigger it with the wall switch. Rather than put up with this first world annoyance, he instead came up with a way to trigger the garage door using a smartphone or other device, with no modification to the unit itself.

Conveniently, Bill’s garage door opener features a rather hackable method of manual opening, as it connects two terminals together via an external button. To emulate a button press, he used a relay module, which is connected to a NodeMCU dev board for control. The NodeMCU, in turn, connects to a smartphone or other device via a Reyax BLE module, which communicates with the NodeMCU via serial.

For an easy user interface interface, Bill set up an app in MIT App Inventor, with the BLE module’s address hard-coded. The system can link to multiple devices, and is put in pairing mode via a button connected to the NodeMCU. This is an essential security feature, as otherwise one could theoretically walk by, pair with the garage door opener, and get access to the garage with a fairly trivial bit of hacking.

Code for the build is found on GitHub and given the NodeMCU’s WiFi capabilities, it would be possible to expand this project to other control and/or home automation integrations. This type of simple on/off button control is fairly typical for garage door openers, so a similar Bluetooth hack would be applicable in a variety of situations.