Arduino Air Quality Monitoring System

The Arduino Air Quality Monitoring System continuously measures environmental conditions using a combination of sensors wired to an Arduino Uno board. At the heart of the setup, the DHT11 sensor uses a capacitive humidity sensor and a thermistor to measure the surrounding air's relative humidity and temperature, sending digital signals back to the Arduino. Meanwhile, the MQ135 gas sensor detects various harmful gases and pollutants in the air by changing its internal electrical resistance when exposed to target gases; the Arduino reads this analog change through its built-in analog-to-digital converter. To make this data easy to read, the system uses an I2C communication protocol to connect an OLED display (128x64 pixels) to the Arduino Uno. The required software libraries process the raw data from both sensors, format the numbers and text, and send them to the screen. Everything is wired together neatly on a breadboard using jumper wires, creating a self-contained desktop unit that updates its environmental readings in real time.