To work with the content of this book, you will need the following hardware:

• Raspberry Pi 3
• DHT11 temperature and humidity sensor
• Three jumper cables
• One breadboard

For the software, we need a Raspberry Pi 3 with Raspbian OS installed and Wi-Fi or Ethernet configured. We will be installing Node.js as we work through the book.

You will also need another machine that supports the installation of Node.js. We will be installing Node.js as we work through the book.

You can download the example code files for this book from your account at www.packtpub.com. If you purchased this book elsewhere, you can visit www.packtpub.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packtpub.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Enterprise-Internet-of-Things-Handbook. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Now, we will construct the GET URL that we will use to send the data: https://api.thingspeak.com/update?api_key=R9XY4AXEG52DJHIT&field1=25&field2=30."

A block of code is set as follows:

[default]
var Protocol = require('azure-iot-device-mqtt').Mqtt;
var Client = require('azure-iot-device').Client;
var Message = require('azure-iot-device').Message;
var async = require('async');

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

[default]
var Protocol = require('azure-iot-device-mqtt').Mqtt;
var Client = require('azure-iot-device').Client;
var Message = require('azure-iot-device').Message;
var async = require('async');

Any command-line input or output is written as follows:

$ curl -sL https://deb.nodesource.com/setup_7.x | sudo -E bash -
$ sudo apt install nodejs 

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Update the previous URL with your Write API Key."