Interfacing MQ5 Gas Sensor Module

What is a MQ5 sensor?

The Grove – Gas Sensor (MQ5) module is useful for gas leakage detection (in home and industry). It is suitable for detecting H2, LPG, CH4, CO, Alcohol. Due to its high sensitivity and fast response time, measurements can be taken as soon as possible.

And, how does it work?

The MQ series of gas sensors use a small heater inside with an electro-chemical sensor. They are sensitive for a range of gasses and are used indoors at room temperature.

They can be calibrated more or less (see the section about “Load-resistor” and “Burn-in”) but a known concentration of the measured gas or gasses is needed for that.

So, Here we are just going to interface the sensor and observe that the output is always 1 till a gas leak occurs upon which it becomes 0.

Components Required

Arduino Uno 

MQ-5 Gas sensor module

Jumper Wires

USB cable 

Circuit Diagram

Schematic:

Wire up and upload the given code below, open the serial monitor once done to observe how this sensor works! (You can use a normal Cigar or a deodorant to fake a gas leak)

int sensor=7;

int gas_value;

void setup()

{

pinMode(sensor,INPUT);

Serial.begin(9600);

}

void loop()

{

gas_value=digitalRead(sensor);

Serial.println(gas_value);

}

Arduino IoT Tutorial 1 – Digital Input/Output

Components Required:

1. Arduino Uno – Buy2. Linux PC/Windows PC (Tested with Windows 10, Ubuntu 14.04 LTS)3. USB cable A to B –  Buy4. Breadboard5. 5 mm LED – Buy6. 220 Ohms Resistor (color code – Red, Red, Brown)7. Momentary button or Switch8. 10K Ohms Resistor (color code – Brown, Black, Orange)9. Jumper Wires

Procedure:

1. Connect Arduino Uno to PC via the USB cable.

2. Write the following sketches in the Arduino IDE, and upload them one by one.

LEDControl.ino

// the setup function runs once when you press reset or power the board

void setup() {

  // initialize digital pin 13 as an output.

  pinMode(13, OUTPUT);

}

// the loop function runs over and over again forever

void loop() {

  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)

  delay(3000);              // wait for a second

  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW

  delay(2000);              // wait for a second

}

ButtonLEDControl.ino

const int buttonPin = 2;     // the number of the pushbutton pin

const int ledPin =  13;      // the number of the LED pin

// variables will change:

int buttonState = 0;         // variable for reading the pushbutton status

void setup() {

  // initialize the LED pin as an output:

  pinMode(ledPin, OUTPUT);

  // initialize the pushbutton pin as an input:

  pinMode(buttonPin, INPUT);

}

void loop() {

  // read the state of the pushbutton value:

  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.

  // if it is, the buttonState is HIGH:

  if (buttonState == HIGH) {

    // turn LED on:

    digitalWrite(ledPin, HIGH);

  } else {

    // turn LED off:

    digitalWrite(ledPin, LOW);

  }

}

Hardware Connections:

1. LED to Arduino Uno

2. Button to Arduino Uno

Arduino IoT Tutorial 2 – Analog Input/Output

Components Required:

1. Arduino Uno 

2. Linux PC/Windows PC (Tested with Windows 10, Ubuntu 14.04 LTS)

3. USB cable A to B 

4. Breadboard

5. 5 mm LED 

6. 220 Ohms Resistor (colour code – Red, Red, Brown)

7. Potentiometer – 10K Ohm

8. Light Dependent Resistor (LDR)

9. Jumper Wires

Way to go ->

1. Connect Arduino Uno to PC via the USB cable.

2. Write the following sketches in the Arduino IDE, and upload them one by one.

LEDFade.ino

// These constants won't change.  They're used to give names

// to the pins used:

const int analogInPin = A0;  // Analog input pin that the potentiometer is attached to

const int analogOutPin = 9; // Analog output pin that the LED is attached to

int sensorValue = 0;        // value read from the pot

int outputValue = 0;        // value output to the PWM (analog out)

void setup() {

  // initialize serial communications at 9600 bps:

  Serial.begin(9600);

}

void loop() {

  // read the analog in value:

  sensorValue = analogRead(analogInPin);

  // map it to the range of the analog out:

  outputValue = map(sensorValue, 0, 1023, 0, 255);

  // change the analog out value:

  analogWrite(analogOutPin, outputValue);

  // print the results to the serial monitor:

  Serial.print("sensor = ");

  Serial.print(sensorValue);

  Serial.print("\t output = ");

  Serial.println(outputValue);

  // wait 2 milliseconds before the next loop

  // for the analog-to-digital converter to settle

  // after the last reading:  delay(2);

}

LDRBlink.ino

int sensorPin = A0;    // select the input pin for the potentiometer
int ledPin = 13;      // select the pin for the LED
int sensorValue = 0;  // variable to store the value coming from the sensor

void setup() {
  // declare the ledPin as an OUTPUT:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // read the value from the sensor:
  sensorValue = analogRead(sensorPin);
  // turn the ledPin on
  digitalWrite(ledPin, HIGH);
  // stop the program for <sensorValue> milliseconds:
  delay(sensorValue);
  // turn the ledPin off:
  digitalWrite(ledPin, LOW);
  // stop the program for for <sensorValue> milliseconds:
  delay(sensorValue);

}

Hardware Connections ->

1. LED and Potentiometer to Arduino Uno

2. LED and LDR to Arduino Uno

Arduino IoT Tutorial 3 – Serial Communication

Components Required:

1. Arduino Uno 

2. Linux PC/Windows PC (Tested with Windows 10, Ubuntu 14.04 LTS)

3. USB cable A to B 

4. Breadboard 

5. 5 mm LED (your favourite colour)

6. 220 Ohms Resistor (colour code – Red, Red, Brown)

7. Jumper Wires

Way to go ->

1. Connect Arduino Uno to PC via the USB cable.

2. Write the ArduinoReceive.ino sketch in the Arduino IDE, and upload it.

ArduinoReceive.ino

char val; // Data received from the serial port

int ledPin = 13; // Set the pin to digital I/O 13

void setup() {

   pinMode(ledPin, OUTPUT); // Set pin as OUTPUT

   Serial.begin(9600); // Start serial communication at 9600 bps

}

void loop() {

   if (Serial.available()) 

   { // If data is available to read,

     val = Serial.read(); // read it and store it in val

   }

   if (val == '1') 

   { // If 1 was received

     digitalWrite(ledPin, HIGH); // turn the LED on

   } else {

     digitalWrite(ledPin, LOW); // otherwise turn it off

   }

   delay(10); // Wait 10 milliseconds for next reading

}

3. Write the button.pde in the Processing IDE and run it.

button.pde

import processing.serial.*;

Serial myPort;

boolean button = true;

int x = 25;

int y = 25;

int w = 100;

int h = 75;

int r = 10;

void setup() {

  size(150, 125);  // width, height

  String portName = Serial.list()[0]; //change the 0 to a 1 or 2 etc. to match your port

  myPort = new Serial(this, portName, 9600);

  smooth();

}

void draw() {

  if (button) {

    background(0, 255, 0);

    stroke(255, 255, 0);

    myPort.write('1');         

    println("1"); 

  } 

  else {

    background(255, 0, 0);

    stroke(255, 255, 0);

    myPort.write('0');

    println("0");

  }

  

  fill(0, 0, 255);

  rect(x, y, w, h, r);

}

// When the mouse is pressed, the state of the button is toggled.   

// Try moving this code to draw() like in the rollover example.  What goes wrong?

void mousePressed() {

  if (mouseX > x && mouseX < x+w && mouseY > y && mouseY < y+h) {

    button = !button;

  }  

}

Button -> OFF

Button -> ON

Hardware Connections ->

1. LED to Arduino Uno