Hello, my name is Henri Van Oost and I am a student at Howest Kortrijk. I have made this IOT-project in my first year of Mulitimedia and Communication Technology.

I came up with the idea because I have a cat and a dog at home and it wanted to make feeding them way more easier (or lazy ;) ). So I've build PetFret: a smart pet feeder.

Below you can read all the necessary steps that I've had to go through in order to bring the project to a succesfull outcome.

Step 1: Components and Materials

For my project I used a lot of different components to be able to bring everything to a good end. The components

that I used are listed below. The total cost for this project was around €256.

Components :

Raspberry Pi 4 model B
Raspberry Pi power supply
Raspberry Pi T-cobbler
16GB micro SD-card
Breadboard
Temperature Sensor ~ DS18B20
Non-Contact Watersensor ~ XKC-Y25-NPN
3 weight sensors ~ HX711
4.7K Resistor
LCD 16x2
Servo motor ~ MG996R
Female to Female jumper wires
Male to Male jumper wires
Female to Male jumper wires
Waterpump
12V Supply
Relais
PIR Sensor

Materials:

Wood
Plexiglass
2 food bowls

Tools:

Industrial wood saw
Electric saw
Electric screwdriver
Soldering Iron Drill
Knife

In the pdf file below you can see the complete price list of all my materials.

BOM_bill-of-materials-HVO-2.pdf
Download

Step 2: Database

After i figured out every component, I started to create a entity relationship diagram.

With my database you are able to see:

The current value of the supplies and bowls
The temperature of the water
History of measurements
List of sensors
Opportunity for accounts
Food details

I hosted my database on my RPI using MariaDB

Step 3: Fritzing Scheme

After everything was figured out, it was time to put my hardware together. I've made first a Fritzing Scheme so I could not do anything wrong which could cause a short circuit. For creating this scheme i used the program Fritzing.

Step 4: Assembling the Hardware

Once my fritzing scheme was finished and I was satisfied with it, I started putting my hardware together. I started with my temperature, PIR-sensor and non-contact watersensor. I did that because the sensors looked the easiest to me. The weight sensors were the last thing I did of the sensors because I had some troubles to program it.

After the sensors were done, I did my LCD.

The last step was to connect my actuators. The first actuator I connected was my servo. Once I succeeded I switched to the last actuator: my waterpump.

You can find my code on github: https://github.com/henrivanoost1/PetFret

Step 5: Mobile First Website

In order to be able to display all the data measured by my sensors I decided to make a webapplication. First I've made adesign in Adobe XD. When my design was ready, I've made it in HTML, CSS and Javascript. You can also feed your pet by using my site.

Step 6: Building the Case

Then it was time to make my enclosure. For my materials I went to Brico and bought wood an plexiglass. I made the outside of my box from wood that I cut by myself.I put plexiglass so you can easily see the supplies.