Published December 8, 2019 © GPL3+

IoT Based Simple Air Pollution Monitoring System

We are using some simple cost effective materials to make an IoT based air pollution monitoring system.

BeginnerFull instructions provided14,274

IoT Based Simple Air Pollution Monitoring System

Things used in this project

Hardware components

Seeed Studio Grove - Gas Sensor(MQ2)

IMPORTANT:please use mq135 gas sensor...

Arduino UNO

Buzzer

Breadboard (generic)

Resistor 221 ohm

5 mm LED: Red

5 mm LED: Green

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Soldering iron (generic)

Not needed if you are using proper jumper wires

Story

This page is about how to make an air pollution monitoring system using an Arduino UNO, buzzer, LEDs and MQ135 gas sensor.

Working principle:

When we keep some fuels which have harmful gases like CO2, NO2 etc(when we keep an inscence stick close to this sensor), the RED LED will glow and the buzzer starts ringing else if it is good quality air around, then green LED will glow.

Code is as given below:

code for this project

Connection diagram is as given below:

Connection diagram

The video tutorial is here:

Code

Arduino code for this program

int redLed = 12;
int greenLed = 8;
int buzzer = 10;
int smokeA0 = A0;
// Your threshold value
int sensorThres = 150;

void setup() {
  pinMode(redLed, OUTPUT);
  pinMode(greenLed, OUTPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(smokeA0, INPUT);
  Serial.begin(9600);
}
void loop() {
  int analogSensor = analogRead(smokeA0);
  Serial.print("Pin A0: ");
  Serial.println(analogSensor);
  // Checks if it has reached the threshold value
  if (analogSensor > sensorThres)
  {
    digitalWrite(redLed, HIGH);
    digitalWrite(greenLed, LOW);
    tone(buzzer, 3000, 300);
  }
  else
  {
    digitalWrite(redLed, LOW);
    digitalWrite(greenLed, HIGH);
    noTone(buzzer);
  }
  delay(100);
}