The MQ-135 detects ammonia, benzene, smoke, CO₂ and other pollutants. Build a live air quality monitor with an animated OLED bar graph and a buzzer alert above a threshold of 400.

Objectives: Identify what MQ-135 detects · Map an analog reading to a bar graph · Calibrate a threshold for your environment

Components: Arduino Uno · MQ-135 · SSD1306 OLED · buzzer

Code: https://github.com/Arun-Roshan/Gas-Safety-Monitoring-System-Using-IOT.git — Gas Safety repo

Chapters: Intro · MQ-135 · How it works · Pinout · Project · Code explained · Demo