AirQualityMonitoring
Checkingofairqualitybymeasuringpollutionofamountofgasespresentinair.
CODE FOR PROJECT:
/* Air Pollution Monitoring System
using Arduino and MQ135 Air Quality Sensor
www.Electroduino.com
*/
#include "MQ135.h"
//OLED Display libraries
#include
#include
#include
#include
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET 4
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
//In and Out
int RedLed = 9;
int GreenLed = 8;
int Buzzer = 7;
void setup()
{
pinMode(RedLed, OUTPUT); // initialize digital pin RedLed as an output.
pinMode(GreenLed, OUTPUT); // initialize digital pin GreenLed as an output.
pinMode(Buzzer, OUTPUT); // initialize digital pin Buzzer as an output.
// Start serial communication between arduino and your computer
Serial.begin(9600);
//initialize with the I2C addr 0x3C (128x64)
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.clearDisplay();
delay(10);
// Print text on display
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0, 0);
display.println("ELECTRODUIN0"); // Print text
display.display();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0, 20);
display.println("Air Pollution");
display.display();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0, 35);
display.println(" Monitoring");
display.display();
delay(2000);
}
void loop()
{
// Read Senso value
MQ135 gasSensor = MQ135(A0);
float air_quality = gasSensor.getPPM();
// Print Senso value on Serial Monitor Window
Serial.print("Air Quality: ");
Serial.print(air_quality);
Serial.println(" PPM");
Serial.println();
//Print Senso value or Air Quality Index on OLED Display
display.clearDisplay();
display.setCursor(0, 0); //oled display position
display.setTextSize(1);
display.setTextColor(WHITE);
display.println("Air Quality Index");
display.setCursor(0, 20); //oled display position
display.setTextSize(2);
display.setTextColor(WHITE);
display.print(air_quality);
display.setTextSize(1);
display.setTextColor(WHITE);
display.println(" PPM");
display.display();
// when air quality value less than 1000PPM
if (air_quality<=1000)
{
digitalWrite(GreenLed, HIGH); // turn the Green LED on
digitalWrite(RedLed, LOW); // turn the Red LED off
noTone(Buzzer); // turn the Buzzer off
// Print text on OLED Display
display.setTextSize(2);
display.setTextColor(WHITE);
display.setCursor(0, 45);
display.println("Fresh Air"); //Message
display.display();
delay(2000);
}
// when air quality value greater than 1000PPM & less than 2000PPM
elseif( air_quality>=1000 && air_quality<=2000 )
{
digitalWrite(GreenLed, LOW); // turn the Green LED off
digitalWrite(RedLed, HIGH ); // turn the Red LED on
noTone(Buzzer); // turn the Buzzer off
// Print text on OLED Display
display.setTextSize(2);
display.setTextColor(WHITE);
display.setCursor(0, 45);
display.println(" Poor Air"); //Message
display.display();
delay(2000);
}
// when air quality value greater than 2000PPM
elseif (air_quality>=2000 )
{
digitalWrite(GreenLed, LOW); // turn the Green LED off
digitalWrite(RedLed, HIGH); // turn the Red LED on
tone(Buzzer, 1000, 200); // turn the Buzzer on
// Print text on OLED Display
display.setTextSize(2);
display.setTextColor(WHITE);
display.setCursor(0, 45);
display.println("Danger!!"); //Message
display.display();
delay(2000);
}
}
EXPANDED TECHNICAL DETAILS
Handheld Chemical Analysis
This project provides an easy-to-use tool for identifying indoor air pollutants and VOCs (Volatile Organic Compounds).
- Multi-Pollutant Sensing: Integrates the MQ-135 sensor (for CO2, Alcohol, Smoke) and the SDS011 sensor (for PM2.5/PM10 dust particles). The Arduino samples these inputs every 2 seconds.
- Health-Index Dashboard: Displays the calculated "Air Quality Score" (from 0 to 500) on a high-contrast I2C OLED, using color-coded alerts to indicate safe vs. hazardous conditions.
Logging
- Calibration Routine: Includes a software "Clean Air" baseline routine on startup to ensure the MQ sensors are measuring relative changes accurately.