This project is a basic IoT-based air quality monitoring system using:
- ESP8266 (NodeMCU)
- DHT11 Temperature & Humidity Sensor
- MQ135 Gas Sensor
The system reads environmental parameters and displays them on the Serial Monitor.
- ESP8266 NodeMCU
- DHT11 Sensor
- MQ135 Gas Sensor
- Breadboard & Jumper Wires
| Component | ESP8266 Pin |
|---|---|
| DHT11 Data | D4 |
| DHT11 VCC | 3.3V |
| DHT11 GND | GND |
| MQ135 AOUT | A0 |
| MQ135 VCC | 5V |
| MQ135 GND | GND |
- Temperature (°C)
- Humidity (%)
- Estimated CO₂ concentration (ppm)
- Estimated NH₃ concentration (ppm)
⚠️ Note: Gas concentration values are approximate and intended for academic/demo purposes only.
The ESP8266 connects to a WiFi network (currently used only for connectivity testing).
Future enhancements may include cloud integration.
- Real MQ135 calibration
- Cloud dashboard (ThingSpeak / Firebase / Blynk)
- Alert system using buzzer or notifications
- OLED/LCD display
Mohith R