Raspberry Pi A, Raspberry Pi B User Manual
Raspberry Pi®
User Guide
2nd Edition
Raspberry Pi®
User Guide
2nd Edition
Eben Upton and Gareth Halfacree
is edition rst published 2014
© 2014 Eben Upton and Gareth Halfacree
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Publisher’s Acknowledgements
Some of the people who helped bring this book to market include the following:
For Liz, who made it all possible.
—Eben
For my father, the enthusiastic past,
and my daughter, the exciting future.
—Gareth
About the Authors
Eben Upton is a founder and trustee of the Raspberry Pi Foundation, and serves as its
Executive Director. He is responsible for the overall software and hardware architecture of
the Raspberry Pi, and for the Foundation’s relationships with its key suppliers and customers. In an earlier life, he founded two successful mobile games and middleware companies,
Ideaworks 3d Ltd. and Podfun Ltd., and held the post of Director of Studies for Computer
Science at St John’s College, Cambridge. He holds a BA, a PhD and an MBA from the
University of Cambridge.
In his day job, Eben works for Broadcom as an ASIC architect and general troublemaker.
Gareth Halfacree is a freelance technology journalist and the co-author of the Raspberry Pi
User Guide alongside project co-founder Eben Upton. Formerly a system administrator working
in the education sector, Gareth’s passion for open source projects has followed him from one
career to another, and he can often be seen reviewing, documenting or even contributing to
projects including GNU/Linux, LibreOce, Fritzing and Arduino. He is also the creator of
the Sleepduino and Burnduino open hardware projects, which extend the capabilities of the
Arduino electronics prototyping system. A summary of his current work can be found at
http://freelance.halfacree.co.uk.
Table of Contents
Introduction ......................................... 1
Programming Is Fun! .........................................................1
A Bit of History ..............................................................3
So What Can You Do with the Raspberry Pi? .....................................8
Part I: Connecting the Board
CHAPTER 1
Meet the Raspberry Pi ................................. 13
A Trip Around the Board .....................................................14
Model A ...................................................................16
Model B ...................................................................17
A History of Model B PCB Revisions ...........................................18
Revision 1 ...............................................................18
Revision 2 ...............................................................18
A Bit of Background .........................................................18
ARM versus x86 ..........................................................19
Windows versus Linux ....................................................20
CHAPTER 2
Getting Started with the Raspberry Pi ...................... 21
Connecting a Display ........................................................22
Composite Video .........................................................22
HDMI Video .............................................................23
DSI Video ...............................................................24
Connecting Audio ...........................................................24
Connecting a Keyboard and Mouse ............................................25
Installing NOOBS on an SD Card ..............................................27
Connecting External Storage ..................................................28
Connecting the Network .....................................................29
Wired Networking ........................................................30
Wireless Networking ......................................................31
Connecting Power ........................................................32
Installing the Operating System ...............................................33
Installing Using NOOBS ...................................................33
Installing Manually .......................................................35
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RASPBERRY PI USER GUIDE, 2ND EDITION
CHAPTER 3
Linux System Administration ............................ 41
Linux: An Overview .........................................................42
Linux Basics ................................................................44
Introducing Raspbian ........................................................45
About Raspbian’s Parent, Debian ...........................................49
Alternatives to Raspbian. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Using External Storage Devices ...............................................50
Creating a New User Account .................................................51
File System Layout ..........................................................52
Logical Layout ...........................................................53
Physical Layout ..........................................................54
Installing and Uninstalling Software ...........................................55
Obtaining Software from the Pi Store .......................................55
Obtaining Software from Elsewhere .........................................57
Finding the Software You Want ............................................58
Installing Software ........................................................59
Uninstalling Software .....................................................61
Upgrading Software .......................................................61
Shutting the Pi Down Safely ..................................................62
CHAPTER 4
Troubleshooting..................................... 63
Keyboard and Mouse Diagnostics .............................................64
Power Diagnostics ...........................................................65
Display Diagnostics .........................................................67
Boot Diagnostics ............................................................68
Network Diagnostics ........................................................68
e Emergency Kernel .......................................................71
CHAPTER 5
Network Conguration ................................. 73
Wired Networking ..........................................................74
Wireless Networking ........................................................77
Installing Firmware .......................................................78
Connecting to a Wireless Network via wpa_gui ...............................82
Connecting to a Wireless Network via the Terminal ...........................85
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TABLE OF CONTENTS
CHAPTER 6
The Raspberry Pi Software Conguration Tool ................ 93
Running the Tool ...........................................................94
e Setup Options Screen ....................................................95
1 Expand Filesystem ......................................................95
2 Change User Password. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
3 Enable Boot to Desktop ..................................................96
4 Internationalisation Options .............................................97
5 Enable Camera .........................................................99
6 Add to Rastrack .........................................................99
7 Overclock .............................................................100
8 Advanced Options .....................................................101
9 About raspi-cong .....................................................105
CHAPTER 7
Advanced Raspberry Pi Conguration..................... 107
Editing Conguration Files via NOOBS .......................................108
Hardware Settings—cong.txt ...............................................110
Modifying the Display ....................................................111
Boot Options ...........................................................114
Overclocking the Raspberry Pi .............................................114
Disabling L2 Cache .........................................................118
Enabling Test Mode .....................................................119
Memory Partitioning .......................................................119
Software Settings—cmdline.txt ..............................................120
Part II: Building a Media Centre, Productivity Machine
or Web Server
CHAPTER 8
The Pi as a Home Theatre PC ........................... 125
Playing Music at the Console ................................................126
Dedicated HTPC with Raspbmc ..............................................128
Streaming Internet Media ................................................129
Streaming Local Network Media ...........................................131
Conguring Raspbmc ....................................................133
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RASPBERRY PI USER GUIDE, 2ND EDITION
CHAPTER 9
The Pi as a Productivity Machine ........................ 135
Using Cloud-Based Apps ....................................................136
Using LibreOce ..........................................................139
Image Editing with e Gimp ................................................141
CHAPTER 10
The Pi as a Web Server............................... 145
Installing a LAMP Stack .....................................................146
Installing WordPress .......................................................150
Part III: Programming with the Raspberry Pi
CHAPTER 11
An Introduction to Scratch ............................. 157
Introducing Scratch ........................................................158
Example 1: Hello World .....................................................159
Example 2: Animation and Sound ............................................162
Example 3: A Simple Game ..................................................165
Robotics and Sensors .......................................................171
Sensing with the PicoBoard ...............................................171
Robotics with LEGO .....................................................171
Further Reading ...........................................................172
CHAPTER 12
An Introduction to Python............................. 173
Introducing Python ........................................................174
Example 1: Hello World .....................................................174
Example 2: Comments, Inputs, Variables and Loops ............................180
Example 3: Gaming with pygame .............................................184
Example 4: Python and Networking ..........................................193
Further Reading ...........................................................199
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TABLE OF CONTENTS
Part IV: Hardware Hacking
CHAPTER 13
Learning to Hack Hardware ............................ 203
Electronic Equipment .......................................................204
Reading Resistor Colour Codes ...............................................206
Sourcing Components ......................................................208
Online Sources ..........................................................208
Oine Sources ..........................................................209
Hobby Specialists ........................................................209
Moving Up From the Breadboard .............................................210
A Brief Guide to Soldering ...................................................213
CHAPTER 14
The GPIO Port ..................................... 219
Identifying Your Board Revision ..............................................220
GPIO Pinout Diagrams ......................................................220
GPIO Features .............................................................222
UART Serial Bus .........................................................222
I2C Bus .................................................................223
SPI Bus ................................................................223
Using the GPIO Port in Python ..............................................223
GPIO Output: Flashing an LED ............................................224
GPIO Input: Reading a Button .............................................228
CHAPTER 15
The Raspberry Pi Camera Module ........................ 233
Why Use the Camera Module? ...............................................234
Installing the Camera Module ................................................235
Enabling Camera Mode .....................................................238
Capturing Stills ............................................................239
Recording Video ...........................................................242
Command-Line Time-Lapse Photography .....................................243
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RASPBERRY PI USER GUIDE, 2ND EDITION
CHAPTER 16
Add-on Boards..................................... 249
Ciseco Slice of Pi ...........................................................250
Adafruit Prototyping Pi Plate ................................................254
Fen Logic Gertboard ........................................................257
Part V: Appendixes
APPENDIX A
Python Recipes ..................................... 265
Raspberry Snake (Chapter 12, Example 3) .....................................266
IRC User List (Chapter 12, Example 4) ........................................268
GPIO Input and Output (Chapter 14) .........................................270
APPENDIX B
Camera Module Quick Reference ........................ 271
Shared Options ............................................................272
Raspistill Options ..........................................................275
Raspivid Options ...........................................................276
Raspiyuv Options ..........................................................276
APPENDIX C
HDMI Display Modes ................................. 277
Index............................................ 283
Introduction
“CHILDREN TODAY ARE digital natives”, said a man I got talking to at a reworks party
last year. “I don’t understand why you’re making this thing. My kids know more about setting up our PC than I do.”
I asked him if they could program, to which he replied: “Why would they want to? e computers do all the stu they need for them already, don’t they? Isn’t that the point?”
As it happens, plenty of kids today aren’t digital natives. We have yet to meet any of these
imagined wild digital children, swinging from ropes of twisted-pair cable and chanting war
songs in nicely parsed Python. In the Raspberry Pi Foundation’s educational outreach work, we
do meet a lot of kids whose entire interaction with technology is limited to closed platforms
with graphical user interfaces (GUIs) that they use to play movies, do a spot of word-processed
homework and play games. ey can browse the web, upload pictures and video, and even
design web pages. (ey’re often better at setting the satellite TV box than Mum or Dad, too.)
It’s a useful toolset, but it’s shockingly incomplete, and in a country where 20 percent of households still don’t have a computer in the home, even this toolset is not available to all children.
Despite the most fervent wishes of my new acquaintance at the reworks party, computers
don’t program themselves. We need an industry full of skilled engineers to keep technology
moving forward, and we need young people to be taking those jobs to ll the pipeline as older
engineers retire and leave the industry. But there’s much more to teaching a skill like programmatic thinking than breeding a new generation of coders and hardware hackers. Being
able to structure your creative thoughts and tasks in complex, non-linear ways is a learned
talent, and one that has huge benets for everyone who acquires it, from historians to
designers, lawyers and chemists.
Programming Is Fun!
It’s enormous, rewarding, creative fun. You can create gorgeous intricacies, as well as (much
more gorgeous, in my opinion) clever, devastatingly quick and deceptively simple-looking
routes through, under and over obstacles. You can make stu that’ll have other people looking
on jealously, and that’ll make you feel wonderfully smug all afternoon. In my day job, where I
design the sort of silicon chips that we use in the Raspberry Pi as a processor and work on the
low-level software that runs on them, I basically get paid to sit around all day playing. What
could be better than equipping people to be able to spend a lifetime doing that?
RASPBERRY PI USER GUIDE, SECOND EDITION
2
It’s not even as if we’re coming from a position where children don’t want to get involved in
the computer industry. A big kick up the backside came a few years ago, when we were moving quite slowly on the Raspberry Pi project. All the development work on Raspberry Pi was
done in the spare evenings and weekends of the Foundation’s trustees and volunteers—
we’re a charity, so the trustees aren’t paid by the Foundation, and we all have full-time jobs
to pay the bills. is meant that occasionally, motivation was hard to come by when all I
wanted to do in the evening was slump in front of the Arrested Development boxed set with a
glass of wine. One evening, when not slumping, I was talking to a neighbour’s nephew about
the subjects he was taking for his General Certicate of Secondary Education (GCSE, the
British system of public examinations taken in various subjects from the age of about 16),
and I asked him what he wanted to do for a living later on.
“I want to write computer games”, he said.
“Awesome. What sort of computer do you have at home? I’ve got some programming books
you might be interested in.”
“A Wii and an Xbox.”
On talking with him a bit more, it became clear that this perfectly smart kid had never done
any real programming at all; that there wasn’t any machine that he could program in the
house; and that his information and communication technology (ICT) classes—where he
shared a computer and was taught about web page design, using spreadsheets and word processing—hadn’t really equipped him to use a computer even in the barest sense. But computer games were a passion for him (and there’s nothing peculiar about wanting to work on
something you’re passionate about). So that was what he was hoping the GCSE subjects he’d
chosen would enable him to do. He certainly had the artistic skills that the games industry
looks for, and his maths and science marks weren’t bad. But his schooling had skirted around
any programming—there were no Computing options on his syllabus, just more of the same
ICT classes, with its emphasis on end users rather than programming. And his home interactions with computing meant that he stood a vanishingly small chance of acquiring the skills
he needed in order to do what he really wanted to do with his life.
is is the sort of situation I want to see the back of, where potential and enthusiasm is
squandered to no purpose. Now, obviously, I’m not monomaniacal enough to imagine that
simply making the Raspberry Pi is enough to eect all the changes that are needed. But I do
believe that it can act as a catalyst. We’re already seeing big changes in the UK schools’ curriculum, where Computing is arriving on the syllabus and ICT is being reshaped, and we’ve
seen a massive change in awareness of a gap in our educational and cultural provision for
kids just in the short time since the Raspberry Pi was launched.
INTRODUCTION
3
Too many of the computing devices a child will interact with daily are so locked down that they
can’t be used creatively as a tool—even though computing is a creative subject. Try using your
iPhone to act as the brains of a robot, or getting your PS3 to play a game you’ve written. Sure,
you can program the home PC, but there are signicant barriers in doing that which a lot of
children don’t overcome: the need to download special software, and having the sort of parents
who aren’t worried about you breaking something that they don’t know how to x. And plenty
of kids aren’t even aware that doing such a thing as programming the home PC is possible. ey
think of the PC as a machine with nice clicky icons that give you an easy way to do the things
you need to do so you don’t need to think much. It comes in a sealed box, which Mum and Dad
use to do the banking and which will cost lots of money to replace if something goes wrong!
e Raspberry Pi is cheap enough to buy with a few weeks’ pocket money, and you probably
have all the equipment you need to make it work: a TV, an SD card that can come from an old
camera, a mobile phone charger, a keyboard and a mouse. It’s not shared with the family; it
belongs to the kid; and it’s small enough to put in a pocket and take to a friend’s house. If
something goes wrong, it’s no big deal—you just swap out a new SD card and your Raspberry
Pi is factory-new again. And all the tools, environments and learning materials that you need
to get started on the long, smooth curve to learning how to program your Raspberry Pi are
right there, waiting for you as soon as you turn it on.
A Bit of History
I started work on a tiny, aordable, bare-bones computer about seven years ago, when I was
a Director of Studies in Computer Science at Cambridge University. I’d received a degree at
the University Computer Lab as well as studying for a PhD while teaching there, and over
that period, I’d noticed a distinct decline in the skillset of the young people who were applying to read Computer Science at the Lab. From a position in the mid-1990s, when 17-yearolds wanting to read Computer Science had come to the University with a grounding in
several computer languages, knew a bit about hardware hacking, and often even worked in
assembly language, we gradually found ourselves in a position where, by 2005, those kids
were arriving having done some HTML—with a bit of PHP and Cascading Style Sheets if you
were lucky. ey were still fearsomely clever kids with lots of potential, but their experience
with computers was entirely dierent from what we’d been seeing before.
e Computer Science course at Cambridge includes about 60 weeks of lecture and seminar
time over three years. If you’re using the whole rst year to bring students up to speed, it’s
harder to get them to a position where they can start a PhD or go into industry over the next
two years. e best undergraduates—the ones who performed the best at the end of their
three-year course—were the ones who weren’t just programming when they’d been told to
for their weekly assignment or for a class project. ey were the ones who were programming
RASPBERRY PI USER GUIDE, SECOND EDITION
4
in their spare time. So the initial idea behind the Raspberry Pi was a very parochial one with
a very tight (and pretty unambitious) focus: I wanted to make a tool to get the small number
of applicants to this small university course a kick start. My colleagues and I imagined we’d
hand out these devices to schoolkids at open days, and if they came to Cambridge for an
interview a few months later, we’d ask what they’d done with the free computer we’d given
them. ose who had done something interesting would be the ones that we’d be interested
in having in the program. We thought maybe we’d make a few hundred of these devices, or
best case, a lifetime production run of a few thousand.
Of course, once work was seriously underway on the project, it became obvious that there was
a lot more we could address with a cheap little computer like this. What we started with is a
long way indeed from the Raspberry Pi you see today. I began by soldering up the longest piece
of breadboard you can buy at Maplin with an Atmel chip at our kitchen table, and the rst
crude prototypes used cheap microcontroller chips to drive a standard-denition TV set
directly. With only 512 K of RAM, and a few MIPS of processing power, these prototypes were
very similar in performance to the original 8-bit microcomputers. It was hard to imagine these
machines capturing the imaginations of kids used to modern games consoles and iPads.
ere had been discussions at the University Computer Lab about the general state of computer education, and when I left the Lab for a non-academic job in the industry, I noticed
that I was seeing the same issues in young job applicants as I’d been seeing at the University.
So I got together with my colleagues Dr Rob Mullins and Professor Alan Mycroft (two colleagues from the Computer Lab), Jack Lang (who lectures in entrepreneurship at the
University), Pete Lomas (a hardware guru) and David Braben (a Cambridge games industry
leading light with an invaluable address book), and over beers (and, in Jack’s case, cheese and
wine), we set up the Raspberry Pi Foundation—a little charity with big ideas.
Why “Raspberry Pi”?
We get asked a lot where the name “Raspberry Pi” came from. Bits of the name came from
different trustees. It’s one of the very few successful bits of design by committee I’ve seen, and
to be honest, I hated it at rst. (I have since come to love the name, because it works really
well—but it took a bit of getting used to since I’d been calling the project the “ABC Micro” in my
head for years.) It’s “Raspberry” because there’s a long tradition of fruit names in computer
companies (besides the obvious, there are the old Tangerine and Apricot computers—and we
like to think of the Acorn as a fruit as well). “Pi” is a mangling of “Python”, which we thought
early on in development would be the only programming language available on a much less
powerful platform than the Raspberry Pi we ended up with. As it happens, we still recommend
Python as our favourite language for learning and development, but there is a world of other
language options you can explore on the Raspberry Pi too.
INTRODUCTION
5
In my new role as a chip architect at Broadcom, a big semiconductor company, I had access to
inexpensive but high-performing hardware produced by the company with the intention of
being used in very high-end mobile phones—the sort with the HD video and the 14-megapixel cameras. I was amazed by the dierence between the chips you could buy for $10 as a
small developer, and what you could buy as a cell-phone manufacturer for roughly the same
amount of money: general purpose processing, 3D graphics, video and memory bundled into
a single BGA package the size of a ngernail. ese microchips consume very little power,
and have big capabilities. ey are especially good at multimedia, and were already being
used by set-top box companies to play high-denition video. A chip like this seemed the
obvious next step for the shape the Raspberry Pi was taking, so I worked on taping out a lowcost variant that had an ARM microprocessor on board and could handle the processing
grunt we needed.
We felt it was important to have a way to get kids enthusiastic about using a Raspberry Pi
even if they didn’t feel very enthusiastic about programming. In the 1980s, if you wanted to
play a computer game, you had to boot up a box that went “bing” and fed you a command
prompt. It required typing a little bit of code just to get started, and most users didn’t ever go
beyond that—but some did, and got beguiled into learning how to program by that little bit
of interaction. We realised that the Raspberry Pi could work as a very capable, very tiny, very
cheap modern media centre, so we emphasised that capability to suck in the unwary—with
the hope that they’d pick up some programming while they’re at it.
After about ve years’ hard grind, we had created a very cute prototype board, about the size
of a thumb drive. We included a permanent camera module on top of the board to demonstrate the sort of peripherals that can easily be added (there was no camera when we launched
because it brought the price up too much, but we’ve now made a separate, cheap camera
module available for photography projects), and brought it along to a number of meetings
with the BBC’s R&D department. ose of us who grew up in the UK in the 1980s had
learned a lot about 8-bit computing from the BBC Microcomputer and the ecosystem that
had grown up around it—with BBC-produced books, magazines and TV programmes—so I’d
hoped that they might be interested in developing the Raspberry Pi further. But as it turned
out, something has changed since we were kids: various competition laws in the UK and the
EU meant that “the Beeb” couldn’t become involved in the way we’d hoped. In a last-ditch
attempt to get something organised with them, we ditched the R&D department idea and
David (he of the giant address book) organised a meeting with Rory Cellan-Jones, a senior
tech journalist, in May 2011. Rory didn’t hold out much hope for partnership with the BBC,
but he did ask if he could take a video of the little prototype board with his phone, to put on
his blog.
RASPBERRY PI USER GUIDE, SECOND EDITION
6
e next morning, Rory’s video had gone viral, and I realised that we had accidentally promised the world that we’d make everybody a $25 computer.
While Rory went o to write another blog post on exactly what it is that makes a video go
viral, we went o to put our thinking caps on. at original, thumb-drive-sized prototype
didn’t t the bill: with the camera included as standard, it was way too expensive to meet the
cost model we’d suggested (the $25 gure came from my statement to the BBC that the
Raspberry Pi should cost around the same as a text book, and is a splendid demonstration of
the fact that I had no idea how much text books cost these days), and the tiny prototype
model didn’t have enough room around its periphery for all the ports we needed to make it
as useable as we wanted it to be. So we spent a year working on engineering the board to
lower cost as much as possible while retaining all the features we wanted (engineering cost
down is a harder job than you might think), and to get the Raspberry Pi as useable as possible
for people who might not be able to aord much in the way of peripherals.
We knew we wanted the Raspberry Pi to be used with TVs at home, just like the ZX Spectrum
in the 1980s, saving the user the cost of a monitor. But not everybody has access to an
HDMI television, so we added a composite port to make the Raspberry Pi work with an old
cathode-ray television instead since SD cards are cheap and easy to nd. We decided against
microSD as the storage medium, because the little ngernail-sized cards are so imsy in the
hands of children and so easy to lose. And we went through several iterations of power supply, ending up with a micro USB cable. Recently, micro USB became the standard charger
cable for mobile telephones across the EU (and it’s becoming the standard everywhere),
which means the cables are becoming more and more ubiquitous, and in many cases, people
already have them at home.
By the end of 2011, with a projected February release date, it was becoming obvious to us
that things were moving faster, and demand was higher, than we were ever going to be able
to cope with. e initial launch was always aimed at developers, with the educational launch
planned for later in 2012. We had a small number of very dedicated volunteers, but we
needed the wider Linux community to help us prepare a software stack and iron out any
early-life niggles with the board before releasing into the educational market. We had enough
capital in the Foundation to buy the parts for and build 10,000 Raspberry Pis over a period
of a month or so, and we thought that the people in the community who would be interested
in an early board would come to around that number. Fortunately and unfortunately, we’d
been really successful in building a big online community around the device, and interest
wasn’t limited to the UK, or to the educational market. Ten thousand was looking less and
less realistic.
INTRODUCTION
7
We blog something interesting about the device at www.raspberrypi.org at least once
every day. Come and join in the conversation!
ere were 100,000 people on our mailing list wanting a Raspberry Pi—and they all put an
order in on day one! Not surprisingly, this brought up a few issues.
First o, there are the inevitable paper cuts you’re going to get boxing up 100,000 little computers and mailing them out—and the fact was that we had absolutely no money to hire
people to do this for us. We didn’t have a warehouse—we had Jack’s garage. ere was no
way we could raise the money to build 100,000 units at once—we’d envisaged making them
in batches of 2,000 every couple of weeks, which, with this level of interest, was going to take
so long that the thing would be obsolete before we managed to full all the orders. Clearly,
manufacturing and distribution were something we were going to have to give up on and
Our Community
The Raspberry Pi community is one of the things we’re proudest of. We started with a very
bare-bones blog at www.raspberrypi.org just after Rory’s May 2011 video, and put up a
forum on the same website shortly after that. That forum now has more than 60,000 members—between them they’ve contributed nearly 400,000 posts of wit and wisdom about
the Raspberry Pi. If there’s any question, no matter how abstruse, that you want to ask
about the Raspberry Pi or about programming in general, someone there will have the
answer (if it’s not in this book, you’ll nd it in the forums).
Part of my job at Raspberry Pi involves giving talks to hacker groups, computing conferences, teachers, programming collectives and the like, and there’s always someone in the
audience who has talked to me or to my wife Liz (who runs the community) on the Raspberry
Pi website—and some of these people have become good friends of ours. The Raspberry
Pi website gets more than one request every single second of the day.
There are now hundreds of fan sites out there. There’s also a fan magazine called The
MagPi (a free download from www.themagpi.com), which is produced monthly by com-
munity members, with type-in listings, lots of articles, project guides, tutorials and more.
Type-in games in magazines and books provided an easy route into programming for me—
my earliest programming experience with the BBC Micro was of modifying a type-in helicopter game to add enemies and pick-ups.
RASPBERRY PI USER GUIDE, SECOND EDITION
8
hand over to somebody else who already had the infrastructure and capital to do that, so we
got in touch with element14 and RS Components, both UK microelectronics suppliers with
worldwide businesses, and contracted with them to do the actual manufacture and distribution side of things worldwide so we could concentrate on development and the Raspberry Pi
Foundation’s charitable goals.
Demand on the rst day was still so large that RS and element14’s websites both crashed for
most of the day—at one point in the day, element14 were getting seven orders a second, and
for a couple of hours on February 29, Google showed more searches were made worldwide
for “Raspberry Pi” than were made for “Lady Gaga”. We made and sold more than a million
Raspberry Pis in the rst year of business, making Raspberry Pi the fastest-growing computer company in the world, ever. ings aren’t slowing down: we sell more than 100,000 Pis
every month. If we’d stuck with our original plans, we’d have made 100 or so of these devices
for University open days, and that would have been it.
NOTE
The rst production Pis were made in Chinese factories, but in the last year we have managed
to repatriate all of the production to the UK. Your Raspberry Pi is now made in South Wales,
in an area of the country with a proud manufacturing heritage, but few remaining factories.
Amazingly, it costs us the same to manufacture in Wales as it did in China, and we’re able to
do that manufacture without a language or cultural barrier, and with the ability to jump in the
car and be on the factory oor in a few hours if necessary.
ere is nothing that aects the blood pressure quite like accidentally ending up running a
large computer company!
So What Can You Do with the Raspberry Pi?
is book explores a number of things you can do with your Raspberry Pi, from controlling
hardware with Python, to using it as a media centre, setting up camera projects, or building
games in Scratch. e beauty of the Raspberry Pi is that it’s just a very tiny general-purpose
computer (which may be a little slower than you’re used to for some desktop applications,
but much better at some other stu than a regular PC), so you can do anything you could do
on a regular computer with it. In addition, the Raspberry Pi has powerful multimedia and 3D
graphics capabilities, so it has the potential to be used as a games platform, and we very
much hope to see more people starting to write games for it.
INTRODUCTION
9
We think physical computing—building systems using sensors, motors, lights and microcontrollers—is something that gets overlooked in favour of pure software projects in a lot of
instances, and it’s a shame, because physical computing is massive fun. To the extent that
there was any children’s computing movement when we began this project, it was a physical
computing movement. e LOGO turtles that represented physical computing when we
were kids are now ghting robots, quadcopters or parent-sensing bedroom doors, and we
love it. However, the lack of General Purpose Input/Output (GPIO) on home PCs is a real
handicap for many people getting started with robotics projects. e Raspberry Pi exposes
GPIO so you can get to work straight away.
I keep being surprised by ideas the community comes up with which wouldn’t have crossed
my mind in a thousand years: the Australian school meteor-tracking project; the Boreatton
Scouts in the UK and their robot, which is controlled via an electroencephalography headset
(the world’s rst robot controlled by Scouting brain waves); the family who are building a
robot vacuum cleaner; Manuel, the talking Christmas moose. And I’m a real space cadet, so
reading about the people sending Raspberry Pis into near-earth orbit on rockets and balloons
gives me goosebumps.
In the rst edition of this book, I said that success for us would be another 1,000 people
every year taking up Computer Science at the university level in the UK. at would not only
be benecial for the country, the software and hardware industries, and the economy; but it
would be even more benecial for every one of those 1,000 people, who, I hope, discover that
there’s a whole world of possibilities and a great deal of fun to be had out there. We’ve gotten
greedy now: I’d like to see that sort of statistic replicated in many more countries across the
developed world, and to see something similar starting to happen in the developing world.
We’ve been immensely proud to see Raspberry Pi labs spring up in the most unlikely places,
like a village lab in a part of Cameroon with no electricity network where the Pis run o solar
power, generators and batteries, or a school high in the mountains in Bhutan.
Building a robot when you’re a kid can take you to places you never imagined—I know
because it happened to me!
—Eben Upton
RASPBERRY PI USER GUIDE, SECOND EDITION
10
Part I
Connecting the
Board
Chapter 1 Meet the Raspberry Pi
Chapter 2 Getting Started with Raspberry Pi
Chapter 3 Linux System Administration
Chapter 4 Troubleshooting
Chapter 5 Network Conguration
Chapter 6 e Raspberry Pi Software Conguration Tool
Chapter 7 Advanced Raspberry Pi Conguration
Chapter 1
Meet the Raspberry Pi
PAR T I CONNECTING THE BOARD
14
YOUR RASPBERRY PI board is a miniature marvel, packing considerable computing power
into a footprint no larger than a credit card. It’s capable of some amazing feats, but there are
a few things you need to know before you plunge head-rst into the bramble patch.
TIP
If you’re eager to get started, skip to the next chapter to nd out how to connect your
Raspberry Pi to a display, keyboard and mouse, install an operating system, and jump straight
in to using the Pi.
A Trip Around the Board
e Raspberry Pi is currently available as two dierent models, known as the Model A and
the Model B. While there are dierences, with the Model A sacricing some functionality in
order to reduce its cost and power requirements, both share plenty of similarities that you’ll
learn about in this chapter. Figure 1-1 shows a Raspberry Pi Model B.
Figure 1-1:
e Raspberry Pi
board
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