• You should have a powerful PC running a Linux distribution, preferably Ubuntu 18.04 LTS.
• You can use a laptop or desktop with a graphics card, and RAM of at least 4 to 8 GB is preferred. This is actually for running high-end simulations in Gazebo, as well as for processing point clouds and computer vision.

• You should have the sensors, actuators, and I/O boards mentioned in the book and should be able to connect them all to your PC. You also need Git installed to clone the package files.
• If you are a Windows user, it will be good to download VirtualBox and set up Ubuntu on it. However, do note that you may have issues while you try to interface real hardware to ROS when working with VirtualBox.

You can download the example code files for this book from your account at www.packt.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.packt.com.
2. Select the Support tab.
3. Click on Code Downloads.
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/ROS-Robotics-Projects-SecondEdition. 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!

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it here: http://www.packtpub.com/sites/default/files/downloads/9781838649326_ColorImages.pdf.

Visit the following link to check out videos of the code being run:
http://bit.ly/34p6hL0

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: "Remove the CMakelists.txt file."

A block of code is set as follows:

def talker_main():
   rospy.init_node('ros1_talker_node')    
    pub = rospy.Publisher('/chatter', String)
    msg = String()
    i = 0

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

$ sudo apt-get update 
$ sudo rosdep init 

Bold: Indicates a new term, an important word, or words that you see on screen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "Click on Software & Updates and enable all of the Ubuntu repositories."