Pi-Rex: Have your dog open the door with a bark

Our homes are built for people, not pets. With the Pi-Rex you can make your home a lot more dog-friendly.

Self-service door

Dog owners know the problem: their four-legged friend wants to go through a doorway, but can’t because the handle is built for humans, not dogs. Very annoying, if you are just sleeping and you are awakened by loud dog barking. David Hunt, the owner of the dog Rex, who is also handy with electronics, came up with the solution: the Pi-Rex. This is a fun DIY project that you can build for a few bucks.

Warning: don’t do this at an outside door, unless you live alone on an island far from civilization or have created a very accurate profile of your best friend’s bark using machine learning, for example. Then you could also make it work on the voice of yourself or another person.

How does the Pi-Rex work?

In fact, this is a fairly simple device that opens the door as soon as it hears a sound. The sound sensor is connected to a Raspberry Pi, which drives a motor (linear actuator to be precise) that opens the door.

As soon as the sound sensor detects a sound above a certain threshold, for example a loud bark, it triggers the program in the Raspberry Pi that makes the linear actuator unlock the door. The Pi-Rex’s linear actuator can only move back and forth, so this sounds more complicated than it is. At the same time, the door swings open with the help of a pulley and a weight.

Build the Pi-Rex yourself

Do you want to recreate this project? Then read here on the page of the creator of all this beauty, exactly what you need and how you can ease the dog life of your four-legged friend. As mentioned, this Pi-Rex project lends itself well to expansion. Before you know it, your whole house will be running smoothly.