This project connects the MQ135 sensor board to an Arduino-based controller to calibrate your specific board outdoors and then monitor inside air quality, primarily CO2, using one or any combination ...

An Arduino UNO-based system using the MQ135 sensor to detect harmful gases. Alerts are given via LED and buzzer, with real-time data shown on an LCD and sent to a mobile app via Bluetooth for ...

Abstract: Emission checking is essential to reducing air pollution in urban areas. Conventional systems, such as Pollution Under Control (PUC) registration in India, rely on manual inspections without ...