Teach Yourself VISUALLY Raspberry Pi

322 Pages·2014·83.474 MB·English

by  Richard Wentk

Are you a visual learner? Do you prefer instructions You’ll learn to:
that show you how to do something — and skip the
• Set up your Raspberry Pi®
long-winded explanations? If so, then this book is for
®
• Select and install your OS Raspberry Pi
you. Open it up and you’ll find clear, step-by-step screen
shots that show you how to tackle more than 140 • Understand advanced commands
Raspberry Pi tasks. Each task-based spread covers a
• Use Scratch, Python, and Pygame
single technique, sure to help you get up and running
• Add custom hardware
on Raspberry Pi in no time.
Wiley. R
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Cover Design: asp
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Front ry

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• Two-page lessons break big topics into bite-sized modules ®
ISBN:978-1-118-76819-8
• Succinct explanations walk you through step by step 52999
• Full-color screen shots demonstrate each task
• Helpful sidebars offer practical tips and tricks
9 781118768198
Computers/ W
System Architecture/General e Richard Wentk
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www.wiley.com/go/tyvraspberrypi $29.99 USA • $35.99 CAN • £21.99 UK tk

Raspberry Pi
®
Richard Wentk
Teach Yourself VISUALLY™ Raspberry Pi® LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND
THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT
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Wiley publishes in a variety of print and electronic formats and by print- FOR PURPOSES OF ILLUSTRATING THE CONCEPTS AND TECHNIQUES
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ISBN: 978-1-118-76819-8
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tact our Customer Care Department within the U.S. at 877-762-2974,
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Sales | Contact Wiley at [phone] or fax [phone].
Credits
Acquisitions Editor Director, Content Development
Aaron Black & Assembly
Robyn Siesky
Sr. Project Editor
Sarah Hellert Vice President and Executive
Group Publisher
Technical Editor
Richard Swadley
Paul Hallett
Copy Editor
Kim Heusel
About the Author
Richard Wentk has been building, working with, and writing about
technology since the 1980s. He has had a lot of fun installing Raspberry Pi
boards around his home for music storage, remote heating control and
efficiency, and security. He is also an app developer and the author of a
number of books for developers and Mac users. For the latest news and
information, visit his site at www.zettaboom.com.
Author’s Acknowledgments
All books are a collaboration, and this one is no exception. I’d like to
thank Aaron Black for giving the green light to this project, Paul Hallet for
checking code and facts, and Sarah Hellert for making the transition from
copy to print as smooth as possible.
Extra special thanks are due to Annette Saunders for cake.
How to Use This Book
Who This Book Is For 3 Icons and Buttons
This book is for the reader who has never used this Icons and buttons show you exactly what you need to
particular technology or software application. It is click to perform a step.
also for readers who want to expand their knowledge.
4 Tips
The Conventions in This Book Tips offer additional information, including warnings
and shortcuts.
1 Steps
5 Bold
This book uses a step-by-step format to guide you
Bold type shows command names, options, and text
easily through each task. Numbered steps are actions
or numbers you must type.
you must do; bulleted steps clarify a point, step, or
optional feature; and indented steps give you the 6 Italics
result. Italic type introduces and defines a new term.
2 Notes
Notes give additional information — special
conditions that may occur during an operation, a
situation that you want to avoid, or a cross reference
to a related area of the book.
CHAPTER
14
Control an LED with a Button Adding Custom Hardware
You can breadboard a simple circuit around the Pi to control an LED with a button or switch. 7 Place the switch into the breadboard
Both components connect to the Pi’s GPIO (general-purpose input output) pins. To light an LED, so that the two switch connectors are
connect a GPIO pin to the LED, to a small resistor (220R to 470R) next, and finally to GND. over the break in the board.
To use a switch, connect one end directly to GND. Connect the other end to a GPIO pin. You must 8 Connect pin 13 to the top of the switch.
6add a pull-up resistor that “pulls” the pin to 3V3 — that is, logic one, when it is not connected to 9 Connect pin 13 to the 3V3 power line
anything. Use a medium (4k7 to 10k) resistor. via a 4k7 resistor.
Note: You can use any resistor from 4k7
Control an LED with a Button to 10k.
Note: You can find the code used in this 10 Connect the other end of the switch
section on this book’s website, www. directly to 0V.
wiley.com/go/tyvraspberrypi. Note: Use a male-to-male jumper lead.
Note: These steps assume you have a If you do not have one, cut the leg off a
breadboard with power lines on at least resistor and use that.
foenme aslied eju, manpde ra l ecaodllse.ction of male-to- 11 Launch the desktop and IDLE.
Note: On a breadboard, the holes are 12 Tay fiplee tchael lecodd LeE Dsh.poyw.n, and save it to
joined horizontally, except for the power
ljioniense do nv eerittihcaelrl yo.r both sides, which are 13 LOpEeDn. LpXyT,e ramnidn aplr,e tsysp e sud.o pyth3on
1 1 Caot nthnee cfta rp ilnef 1t —(3V t3o) o—ne tphoew loerw leirn ep.in Tswheit cLhE.D lights when you push the
2 Cfroonmn etchte pleinft 6 o (nG tNhDe) t—op trhoew t—hir dto p in Nsuotdeo: .Y Yoouu m cuanstn orutn r utnh ei tc fordoem a IsD rLoEo.t with
another line. Note: Press , type C exit(), and
2 Note: Use the diagram at www.modmypi. press to quit Python.
com/blog/raspberry-pi-gpio-cheat-sheet
as a reference.
3 Cborenandebcota prdin. 11 to a line on the TIPS
4 Plug the long leg of the LED into the Can I use any LED? My circuit does not work. What did I do wrong? 5
same line. There are hundreds of LEDs in every color. High- A common mistake is using the wrong GPIO pins.
5 Ploluwge rt hlien es.hort leg of the LED into a blirgihgth.t nAe sstsa LnEdDasrd a LreE D“ twunilel dw”o trok ,p broudt uitc em baryi gnhotte rb e as Dafotuebr lset-ecph e2c.k N uesxitn,g c thheec ko nthliante tdhiea gLrEaDm i sm tehnet icoonreredc t 4
bright. For more light, use a smaller resistor. Keep it way around. Finally, check that you connected the
6 Join that line to the GND power line bigger than 220R to avoid burning out the LED or LED to GND and not 3V3, and that the order of
through a 330R resistor. your Pi. components is Pin, LED, Resistor, and GND.
278 279
Table of Contents
Chapter 1 Getting Started with Raspberry Pi
Introducing Raspberry Pi ...........................................4
Take a Tour of Raspberry Pi .......................................5
Choose Accessories ..................................................6
Choose and Use a Case .............................................8
Connect a Monitor ................................................. 10
Connect USB Accessories ......................................... 12
Connect Power and Boot ......................................... 14
Chapter 2 Selecting an Operating System
Understanding OS Options ....................................... 18
Prepare an SD Card ................................................. 20
Copy NOOBS to an SD card ....................................... 22
Select and Install Raspbian Wheezy .......................... 24
Back Up an SD Card ................................................ 26
Get Started with BerryBoot ...................................... 28
Chapter 3 Setting Up Raspbian
Set a Password ...................................................... 32
Select a Keyboard Layout ........................................ 34
Select a Time Zone ................................................. 36
Manage Memory and SD Card Options ........................ 38
Set Up Overclocking ............................................... 40
Connect to the Internet .......................................... 42
Revise the Configuration ......................................... 43
Update the Operating System .................................. 44
Launch the Desktop ............................................... 46
Shut Down the Pi ................................................... 47
Chapter 4 Working with Applications
Introducing Raspberry Pi Apps ................................. 50
Set Up Wi-Fi .......................................................... 52
View Web Pages ..................................................... 54
Work with Files in File Manager ................................ 56
Edit Text with Leafpad ............................................ 58
Configure the Desktop ............................................ 60
Configure the Launch Panel ..................................... 62
Table of Contents
Chapter 5 Working with the Command Line
Introducing Linux .................................................. 66
Using the Command Line ........................................ 68
Become the Superuser ............................................ 69
Understanding the File System ................................. 70
Navigate and List Directories ................................... 72
Create a Directory .................................................. 74
Delete Files and Directories ..................................... 75
View a File ............................................................ 76
Find a File or Command .......................................... 77
Copy, Move, and Rename Files ................................. 78
Work with File Permissions ...................................... 80
Using the Command Line History .............................. 82
Chapter 6 Understanding Advanced Commands
Understanding Advanced Linux ................................ 86
Using the Nano Editor ............................................ 88
Set Up Autologin ................................................... 90
Download and Install Applications ........................... 92
Configure an Application ......................................... 94
Redirect Screen Output to a File ............................... 96
Combine Commands with a Pipe ............................... 97
Process Text with grep and sed ................................ 98
Create a Simple Script ...........................................100
Run a Command at Set Times ..................................102