ArduinoNano-CO2-Visualization

ArduinoNano real-time CO2 monitoring from MH-Z19B to Browser

Arduino Nano CO2 Visualization

ArduinoNano real-time CO2 monitoring from MH-Z19B to Browser

Description

This project demonstrates a real-time CO2 monitoring system using ..

• an Arduino Nano
• a Python Flask web server

The Arduino Nano reads CO2 levels from a MH-Z19B sensor and sends the data to a connected computer via a serial port. A Python Flask application reads this data, processes it, and serves it to a web page using Flask-SocketIO and Chart.js for real-time visualization. Users can view live updates of CO2 levels directly in their web browser.

Tooling

Hardware:

• Notebook
• USB-connector to your Arduino Nano
• Arduino Nano
• 4 Jumper cables (Female to female)
• MH-Z19B CO2-sensor

Software Tools:

• Tools

  • Arduino IDE
  • Visual Studio Code

• Languages / Scripts

  • Python3
  • HTML
  • JavaScript

Hardware setup

On the Arduino Nano the PINs are used to be connected to the CO2-sensor as follows:

Arduino Nano	MH-Z19B
D3	Tx
D2	Rx
GND	GND
5V	VIN

Be aware that TX and Rx are swapped (Python-Code vs. Hardware-Connectors)

Installation

After connecting the hardware, push the co2Sense.ino onto your Arduino Nano using the Arduino IDE.

Arduino IDE

You will have to install the following libraries via Library Editor:

• MH-Z19 by Jonathan Dempsey
• ArduinoJson by Benoit Blanchon

You can check the Arduino Nano working properly by opening the serial monitor. Sample output:

{'millis': 1564189, 'ABCEnabled': True, 'Range': 5000, 'BackgroundCO2': 557, 'Temperature': 17, 'CO2': 550}
{'millis': 1566189, 'ABCEnabled': True, 'Range': 5000, 'BackgroundCO2': 553, 'Temperature': 17, 'CO2': 553}
{'millis': 1570189, 'ABCEnabled': True, 'Range': 5000, 'BackgroundCO2': 551, 'Temperature': 17, 'CO2': 557}

Close the Arduino IDE serial monitor to release the serial port.

Python environment setup

Assumption:

• Python3
• pip3

Create virtual environment:

python3 -m venv tempvenv
source tempvenv/bin/activate

Within the tempvenv:

pip3 install pyserial
pip3 install flask
pip3 install flask_socketio

Now, all dependencies shall be available.

Check the serial port

You may have to install packages via python pip!

Check the used serial port:

ls /dev/tty.*

Choose the right port as input for your python script. Start with checkPort.py to find your desired 'not in use' serial port.

Adjust main.py

Use the gained knowledge to fill in the serial port in main.py

    ser = serial.Serial('/dev/tty.usbserial-10', 9600)  # Adjust to your serial port

Now the main.py is supposed to consume the data from the serial port.

View in browser

The data are now displayed on the given website.

Sample output