Let your Pet get Fresh Air

Introduction

This project was born from the desire to save some electricity and money, obviously, making an automatic fan for my sister's dog, Toby. She lives in an apartment in Barranquilla, that city is hot, and the apartment doesn't have much ventilation, and the dog stays under the table next to the window.

Recently, she has been turning on the fan when she goes to her job, and she returns home at 5 pm, which means the fan has been on for around 10 hours. I can imagine that Toby doesn't use the fan all the day - he walks, barks, "goes to the bathroom", and moves around the apartment.

At this point, you get the idea of this project.

So, let's do it.

The materials you'll see in the guide, but the main ones are published up here.

Step 1

The box I used was a CoolCold Box (a fan for the laptop) to create an enclosure. It is not artistic, but it works.

I painted the PIR rectangle and the two holes of the HC-SR04; they will sense when the dog is present or in front the fan.

Step 2

Then we need to power up the box. I've got a cable and a AC connector, and made a knot inside the box to prevent take off the components if I pull the cable.

Let's mount the power supply 120V AC to 5V; at this point, I need to make a parallel connection to connect the relay's contact switch for turning on/off the fan.

Step 3

Now, I need to make a PCB to mount the NodeMCU and the pin for every sensor and actuator.

Now, I'll make the connections of every sensor and the relay and power.