In the above project, we are going to utilize an MQ-135 sensor with Arduino to estimate CO2 concentration.

Summary

In the above project, we are going to utilize an MQ-135 sensor with Arduino to estimate CO2 concentration

About Project

0.96’ OLED Display Module

0.96''OLED display.jpg

OLED is basically a self light-emitting technology, designed by putting a series of organic thin films between two conductors. When an electric current is applied to these films, a bright light is generated.

OLED Specifications:

  • Driver IC: SSD1306
  • Resolution: 128 x 64
  • Input Voltage: 3.3V ~ 6V
  • Operating temperature: -30°C ~ 70°C

MQ-135 Gas Sensor is a sensor for recognizing a broad range of gases, involving NH3, benzene, smoke and CO2. It can be bought as a module or just as a sensor alone.

MQ 135 sensor.jpg

IoT Training will help you to learn more about IoT Solutions.

        // The load resistance on the board
#define RLOAD 22.0
#include "MQ135.h"
#include <SPI.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
// Declaration for SSD1306 display connected using software SPI (default case):
#define OLED_MOSI   9
#define OLED_CLK   10
#define OLED_DC    11
#define OLED_CS    12
#define OLED_RESET 13
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT,
  OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);
MQ135 gasSensor = MQ135(A0);
int val;
int sensorPin = A0;
int sensorValue = 0;
void setup() {
  Serial.begin(9600);
  pinMode(sensorPin, INPUT);
  display.begin(SSD1306_SWITCHCAPVCC);
  display.clearDisplay();
  display.display();
}
void loop() {
  val = analogRead(A0);
  Serial.print ("raw = ");
  Serial.println (val);
 // float zero = gasSensor.getRZero();
 // Serial.print ("rzero: ");
  //Serial.println (zero);
  float ppm = gasSensor.getPPM();
  Serial.print ("ppm: ");
  Serial.println (ppm);
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(18,43);
  display.println("CO2");
  display.setCursor(63,43);
  display.println("(PPM)");
  display.setTextSize(2);
  display.setCursor(28,5);
  display.println(ppm);
  display.display();
  display.clearDisplay();
  delay(2000);
}
    
rasika Joshi
hIoTron offers an End-to-End IoT Training with live use cases using IoT hardware kit.