Air Quality Monitoring System Using NodeMCU or ESP8266, DHT21, Dust Sensor, MQ2, MQ4, MQ9, MQ135

The increasing air pollution levels have become a major concern for environmentalists and health experts. It's vital to monitor air quality to protect our health and reduce pollution levels. One of the most effective ways to monitor air quality is by using an air quality monitoring system. In this blog, we will discuss how to create an air quality monitoring system using NodeMCU or ESP8266, DHT21, Dust Sensor, MQ2, MQ4, MQ9, and MQ135 sensors.

What is NodeMCU or ESP8266?

NodeMCU or ESP8266 is a low-cost, Wi-Fi enabled microcontroller board that can be programmed with Arduino IDE. It's easy to use and can be integrated into various Internet of Things (IoT) projects. With the help of NodeMCU or ESP8266, you can build a Wi-Fi enabled air quality monitoring system that can send data to your smartphone or cloud.

What is DHT21?

DHT21 is a digital temperature and humidity sensor that can be used to measure the surrounding temperature and humidity. It's easy to use and can be connected to NodeMCU or ESP8266 through a digital pin.

What is Dust Sensor?

Dust Sensor is a sensor that can be used to measure the level of dust particles in the air. It works on the principle of light scattering and can detect dust particles as small as 0.5 microns. It can be connected to NodeMCU or ESP8266 through an analog pin.

What are MQ2, MQ4, MQ9, and MQ135 sensors?

MQ2, MQ4, MQ9, and MQ135 are gas sensors that can detect various types of gases such as smoke, carbon monoxide, methane, and nitrogen dioxide. They work on the principle of detecting the resistance changes in the sensor when the gas is present. They can be connected to NodeMCU or ESP8266 through an analog pin.

How to create an air quality monitoring system using NodeMCU or ESP8266, DHT21, Dust Sensor, MQ2, MQ4, MQ9, and MQ135?

Step 1: Set up the NodeMCU or ESP8266 board and install the required libraries.

Step 2: Connect the DHT21 sensor to NodeMCU or ESP8266 through a digital pin.

Step 3: Connect the Dust Sensor to NodeMCU or ESP8266 through an analog pin.

Step 4: Connect MQ2, MQ4, MQ9, and MQ135 sensors to NodeMCU or ESP8266 through analog pins.

Step 5: Write a code in Arduino IDE to read the data from all the sensors and send it to the cloud or your smartphone.

Step 6: Deploy the system and start monitoring the air quality.