Book Image

Internet of Things Programming with JavaScript

Book Image

Internet of Things Programming with JavaScript

Overview of this book

The Internet of Things is taking the tech world by storm, and JavaScript is at its helm. This book will get you to grips with this exciting new technology. Where do Node.js, HTML5 and Windows 10 IoT Core come in with JavaScript and IoT? Why Raspberry Pi Zero rather than Arduino? How do you configure and build an IoT network from scratch? All your IoT JavaScript questions are answered in this book.
Table of Contents (15 chapters)
Internet of Things Programming with JavaScript
Credits
About the Author
www.packtpub.com
Customer Feedback
Preface

Measuring the concentration of gas


It's important to have in our system a sensor that detects gas so we can apply it in our home in order to detect a gas leak. Now we´re going to describe how to connect to an Arduino board and read the concentration of gas.

In this section, we will use a gas sensor and Methane CH4. In this case, we will use an MQ-4 sensor that can detect concentrations from 200 to 10000 ppm.

This sensor has an analog resistance in its output and can connect to an ADC; it needs a coil energize of 5 volts. The image for the sensor can be seen as follows:

We can find information for the MQ-4 sensor at https://www.sparkfun.com/products/9404.

Connections with the sensor and Arduino board

According to the preceding diagram, we will now see the connections made in the following image:

Open the Arduino IDE, and copy the following sketch:

void setup(){ 
  Serial.begin(9600); 
} 
 
void loop() 
{ 
  float vol; 
  int sensorValue = analogRead(A0); 
...