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(DIY) C64iSTANBUL

TURKEY
- 749
- 825
1

Components

	MQ135 air quality sensor module	x 1
	0.96 Inch Oled Display Module	x 1
	Arduino Nano	x 1

Description

Air quality sensor

MQ-135 Air quality sensor, Arduino nano, SSD1306 OLED

Code

Arduino

#include "MQ135.h"
//OLED Display libraries
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#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("MQ 135"); // Print text
display.display();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0,20);
display.println("Sensore");
display.display();
display.setTextSize(1);
display.setTextColor(WHITE);
display.setCursor(0,35);
display.println(" Air quality");
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
else if( 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
else if (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);
}
}

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Jul 29,2025

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Air quality sensor

524

Published: Jul 29,2025

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BOM(Bill of materials)

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File Last Updated: 2025/07/30 (GMT+8)

File update record

2025-07-3006:48:50

Parts List (BOM) is updated.

2025-07-3005:01:53

Gerber file is updated.

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