Build a CO2 Monitor with Arduino Uno & MH-Z19: OLED Display & Ventilation Alert

Every part needed, pre-tested for compatibility, with an AI build companion trained on this exact project. Shipped from Bengaluru in 3-5 days.

Indoor air quality directly impacts focus, health, and learning-especially in crowded classrooms, labs, and homes across India. This kit puts a professional-grade MH-Z19B NDIR CO? sensor into your hands, letting you build a portable monitor that displays live ppm readings on an OLED screen, switches a traffic-light LED from green to red as levels rise, and screams a buzzer warning the moment CO? crosses 1000ppm. It is the same science behind commercial air quality monitors, now on your breadboard.

What You'll Build

You'll assemble a compact, battery-powered device that reads CO? concentration every second using the MH-Z19B's non-dispersive infrared sensor. The Arduino Uno processes the data and drives a 0.96-inch OLED showing exact ppm. When CO? is below 800ppm, a green LED glows; 800-1000ppm lights a red LED; above 1000ppm, the buzzer pulses to demand ventilation. The result is a desktop sentinel for dorm rooms, maker spaces, or any enclosed area where stuffiness signals it's time to open a window.

What You'll Learn

• Interfacing a digital NDIR gas sensor via UART with Arduino Uno
• Reading and calibrating real-time ppm data from the MH-Z19B
• Programming multi-level threshold logic to control LEDs and a buzzer
• Outputting dynamic sensor data on an I2C OLED display

Kit Contents

Why Buy This Kit Instead of Sourcing Parts Separately

Who This Kit Is For

Designed for CBSE Class 11-12 students building investigatory projects, B.Tech ECE/EEE first-years exploring sensor integration, ATL Tinkering Lab mentors seeking a reliable air-quality module, and Smart India Hackathon participants needing rapid prototyping. If you've tinkered with Arduino before and want to move beyond blinking LEDs into real-world environmental sensing, this kit matches your skill level and delivers a permanent learning tool.

Built and Backed by Compoden

Every Compoden kit ships with an AI build companion trained on this exact project - accessible via a QR code on the box, with WhatsApp and email backup. We've spent 10 years building projects for makers, schools, and institutions across India. If a part fails because of a manufacturing defect, replace it free within 7 days.