Air Quality and Control

This project started as a hobby project during Summer 2024 with the goal of helping my cat with breathing issues. It continued in the Autumn as a project for the IoT Experimental Project course lead by Heikki Hietala.

Furthermore this project is made up of 4 parts which you can find in their respective repositories:

• ESP32 Air Quality Monitor (You are here)
• ESP32 AC Control Unit
• Express + Node Server
• React Client

Table of Contents

• Air Quality Monitor
• AC Control Unit
• Server
• Client

Air Quality Monitor

Components

• ESP32
• DHT11 temperature and humidity Sensor
• 10 KΩ resistor
• SGP30 CO2 and VOC sensor
• TFT Display

Features

• Monitors the temperature, humidity, CO2 (ppm), and VOC (ppb) of my apartment
• Displays data and a sprite GIF of my cat on the screen
• Sends the air quality data to the server

Challenges

• Converting the GIF to a C header file. All credit for that goes to Maduinos for making a great tool
• Getting everything to fit on the device as some of the libraries and the gif header file are quite large

AC Control Unit

Components

• ESP32
• IR LED
• NPN Transistor
• 220 Ω resistor

Features

• Takes commands sent by the client through the server
• Sends the appropriate command to the AC unit via the IR emitter

Challenges

• Decoding IR signals as my AC unit's remote uses a somewhat uncommon protocol
• Config and device IP registration with server

Server

Features

• Express + Node Server
• Hosted on Heroku
• Routes:
  • Connect Device
  • Register local ESP32 IP address
  • Send sensor data; handled as a single object that is overwritten (I do not need to store the data)
  • Fetch sensor data
  • Generic /:command route to handle all commands to the AC Control Unit device

Challenges

• Not really a challenge, more of a brainfart on my part, but route specificity. I was troubleshooting an issue for a while caused by my generic /:command route being before my post/get sensor-data routes 🤦‍♂️

Client

Features

• React + TS Client
• Google 0Auth (Access restricted to the members of the household)
• Fun sprite GIF of my cat. It's happy when the air is good and cries when certain air quality thresholds are exceeded
• Displays data sent to the sever by the air quality monitor to allow me to remotely monitor my apartment's air quality
• Has buttons that allow me to remotely control my AC unit to pull in fresh air, cool, or heat the apartment as needed. This is done by sending a request to the server that gets forwarded to the air control device via port forwarding. The device then sends an IR signal to my AC unit.

Challenges

• No real challenges to note for the client.