Adventures In Raspberry Pi

258 Pages·2014·34.12 MB·english

by  Carrie Anne Philbin

Adventures in
Raspberry Pi®
Carrie Anne Philbin
This edition first published 2014
© 2014 Carrie Anne Philbin
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About the Author
CARRIE ANNE PHILBIN is a high school-level Computing and Google Certified Teacher
and a member of the DfE Computing expert panel reviewing the new Computing
School Curriculum in the UK. She is also the founder and presenter of the award win-
ning Gurl Geek Diaries (www.geekgurldiaries.co.uk) and vice chair of the
#include Computing At Schools initiative (http://casinclude.org.uk) to get
more girls and minority groups into computing. Currently, Carrie Anne is working
with the Raspberry Pi Foundation to improve the teaching of Computing in schools.
Acknowledgments
I would like to express my deep gratitude to the Raspberry Pi Foundation for allowing
me to set my creativity free on their marvellous invention. In particular I’d like to
thank Alex Bradbury and Dr Sam Aaron for their enthusiastic encouragement and
patient guidance. Their willingness to give their time so generously is very much appre-
ciated. I would also like to thank David Whale and the Raspberry Pi Community for
their useful critiques of this work. Thanks to Jennifer Mayberry for her design work
and Sarah Wright for much of the art.
Special thanks should also be given to the staff of Pimoroni for providing necessary
equipment in order to complete elements of this book, as well as members of CAS
#include and the Rainham Library Book Club, for keeping my progress on schedule
with their kind words of encouragement.
My special thanks are also extended to my good friends: Emma, Sian, Helen, Viv, Lizi
and Kylie who are a constant source of inspiration in my life.
Finally, I wish to thank my parents, brother and sister-in-law for their patience, sup-
port and encouragement throughout.
Contents
About the Author v
Acknowledgments vi
Introduction 1
1
Adventure
You Have a Raspberry Pi. Now What? . . . . . . 9
What Hardware Do You Need? ...........................................10
What Other Equipment Is Helpful? .......................................11
Setting Up the Raspberry Pi .............................................13
Downloading and Copying the Raspbian Operating System ...............13
Preparing an SD Card to Store Your Software .........................14
Making It Easy with NOOBS .......................................16
Plugging in the Hardware .............................................17
Installing and Configuring the Software ................................18
Logging in to Your Raspberry Pi ..........................................21
Exploring the Desktop in Raspbian .......................................22
Shutting Down your Raspberry Pi ........................................24
Backing up an SD Card Image ............................................24
2
Adventure
Taking Command of Your Raspberry Pi . . . . 27
Exploring the Terminal .................................................29
Commands for Navigating Through Your File System .......................31
Understanding sudo ....................................................35
Launching Programs from the Command Line .............................35
Managing Files and Directories ..........................................36
Installing and Updating Applications .....................................37
Downloading and Installing Applications ...............................37
Learning More About an Application ...................................38
Upgrading Your Apps ................................................39
Editing Files ...........................................................39
Using Shutdown and Restart Commands ..................................41
Continuing Your Text Adventure .........................................41
TABLE OF CONTENTS vii
3
Adventure
Creating Stories and Games with Scratch . . .45
Getting Started with Scratch .............................................46
The Scratch Interface ................................................47
A Quick Hello from Scratch Cat ........................................48
Setting the Stage .......................................................50
Creating Costumes and Original Sprites ...................................52
Using the Scratch Sprite Image Library .................................52
Editing an Existing Sprite .............................................52
Creating Your Own Original Sprites ....................................53
Animating a Crazy Monkey .............................................53
Creating an Adventure Role-Playing Game ................................59
Creating Your Sprite and Stage ........................................59
Setting the Start Position of the Adventurer Sprite .......................60
Creating Variables: Including Health Points for the Adventurer Sprite ......61
Controlling the Direction and Movement of the Adventurer Sprite .........63
Entering a Cave and Switching Backgrounds ............................64
Adding a Script to Make the Adventurer Sprite Move
Between Backgrounds ..........................................64
Adding a Script to Switch the Stage ..................................66
Creating an Enchanted Key to Exit the Cave and Giving Extra
Health Points ..................................................67
Using “if” Statements to Show and Hide Sprites .......................69
Creating Health-Point-Stealing Sprites .................................70
Improving the Movement of the Adventurer Sprite Using “if” Blocks .......71
Creating a Game Over Screen .........................................72
Ideas for Improvements to Your Game .................................73
4
Adventure
Programming Shapes with Turtle Graphics ...77
Scratch Turtle Graphics .................................................78
Using Pen Down and Pen Up ..........................................79
Drawing Simple Shapes ..............................................80
Using “clear” and Setting a Start Point ..................................82
Using Variables Instead of Values ......................................82
Changing the Size and Colour of the Pen ................................83
Creating Spiral Patterns ..............................................84
Using User Input to Determine the Number of Sides .....................86
viii ADVENTURES IN RASPBERRY PI