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Title: Garage Door Opener Hack
Date: 2021-12-26
Category: Creations
Summary: Hacking my garage door opener to work over Wifi.
2023-10-19 19:22:22 +00:00
Image: garage3.jpg
Short: 5
In the quest to automate as much of my house as possible, I thought it would be useful to be able to remotely control my garage door from my home automation system. If I suspected that I forgot to close it while leaving, I could check in my security cameras and then close it from anywhere. It's nice having this peace of mind, even if it almost never happens.
2023-10-19 11:48:03 +00:00
Instead of reverse engineering the wireless protocol, cracking the encryption, and sending my own commands, I figured it would be much easier to hack the hardware. I pried open a spare remote to find that it contained a basic PCB with simple tactile switches.
![[garage1.jpg | the six parts of the spare remote on my desk: metal clip, plastic buttons, battery, PCB, and two halves of the case]]
My plan was to solder an Arduino controlled relay in parallel with the button that toggled the garage door. I would also power the remote from the 3 V pin. I soldered four wires on to the appropriate pins.
![[garage2.jpg | a closeup of the green PCB with two wires soldered to the battery terminals and two to the button pins]]
I drilled a hole in the plastic case and routed the wires through it while reassembling the remote. It's connected to an Adafruit ESP8266 Arduino with a relay module shield.
The Arduino joins my isolated home automation Wifi network and connects over MQTT, a simple messaging protocol, to my automation server. When it receives a command over MQTT it toggles the relay on for a quarter of a second and then off, simulating a button press.
![[garage3.jpg | the completed system: an arduino with a white relay and wires leading to the reassembled garage door remote]]
Update: this system has been flawless for two months now. It's worked every time I've tried to toggle the door and has never opened by mistake.