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In-depth instruction and practical techniques for building with the BeagleBone embedded Linux platform

Exploring BeagleBone is a hands-on guide to bringing gadgets, gizmos, and robots to life using the popular BeagleBone embedded Linux platform. Comprehensive content and deep detail provide more than just a BeagleBone instruction manual-you'll also learn the underlying engineering techniques that will allow you to create your own projects. The book begins with a foundational primer on essential skills, and then gradually moves into communication, control, and advanced applications using C/C++, allowing you to learn at your own pace. In addition, the book's companion website features instructional videos, source code, discussion forums, and more, to ensure that you have everything you need.

The BeagleBone's small size, high performance, low cost, and extreme adaptability have made it a favorite development platform, and the Linux software base allows for complex yet flexible functionality. The BeagleBone has applications in smart buildings, robot control, environmental sensing, to name a few; and, expansion boards and peripherals dramatically increase the possibilities. Exploring BeagleBone provides a reader-friendly guide to the device, including a crash course in computer engineering. While following step by step, you can:

Get up to speed on embedded Linux, electronics, and programming
Master interfacing electronic circuits, buses and modules, with practical examples
Explore the Internet-connected BeagleBone and the BeagleBone with a display
Apply the BeagleBone to sensing applications, including video and sound
Explore the BeagleBone's Programmable Real-Time Controllers
Hands-on learning helps ensure that your new skills stay with you, allowing you to design with electronics, modules, or peripherals even beyond the BeagleBone. Insightful guidance and online peer support help you transition from beginner to expert as you master the techniques presented in Exploring BeagleBone, the practical handbook for the popular computing platform.



Table of Contents
Introduction xxv
Part I BeagleBone Basics 1

Chapter 1 The BeagleBone Hardware 3

Introduction to the Platform 3

Who Should Use the BeagleBone 5

When to Use the BeagleBone 6

When You Should Not Use the BeagleBone 6

BeagleBone Documentation 7

The BeagleBone Hardware 8

BeagleBone Versions 9

The BeagleBone Black Hardware 11

BeagleBone Accessories 14

Highly Recommended Accessories 14

Micro?]SD Card (for Flashing the BBB) 14

External 5V Power Supply (for Flashing and Peripherals) 15

Ethernet Cable (for Network Connection) 15

HDMI Cable (for Connection to Monitors/Televisions) 15

USB to Serial UART TTL 3.3 V (for Finding Problems) 16

Optional Accessories 17

USB Hub (to Connect Several USB Devices to a USB Host) 17

Micro-HDMI to VGA adapters (for VGA Video and Sound) 17

Wi-Fi Adapters (for Wireless Networking) 18

USB Webcam (for Capturing Images and Streaming Video) 18

USB Keyboard and Mouse (for General-Purpose Computing) 18

Capes 19

How to Destroy Your BeagleBone! 20

Summary 22

Support 22

Chapter 2 The BeagleBone Black Software 23

Linux on the BeagleBone 24

Linux Distributions 24

Communicating with the BBB 25

Installing Drivers 26

Network Connections 26

Internet?]over?]USB 26

Regular Ethernet 29

Ethernet Crossover Cable 30

Communicating with the BBB 31

Serial Connection over USB 31

Serial Connection with the USB?]to?]TTL 3.3 V Cable 33

Connecting through Secure Shell (SSH) 33

Secure Shell Connections using PuTTY 34

Chrome Apps: Secure Shell Client 34

Transferring Files Using PuTTY/psftp over SSH 35

Controlling the BeagleBone 37

Basic Linux Commands 37

First Steps 37

Basic File System Commands 38

Environment Variables 40

Basic File Editing 41

What Time Is It? 42

Package Management 44

Interacting with the BBB On?]board LEDs 45

Shutdown 47

Node.js, Cloud9, and BoneScript 48

Introduction to Node.js 48

Introduction to the Cloud9 IDE 50

Introduction to BoneScript 51

Summary 52

Further Reading 53

Chapter 3 Exploring Embedded Linux Systems 55

Embedded Linux Basics 55

What Embedded Linux Offers 57

Is Linux Open Source and Free? 57

Booting the BeagleBone 58

The BeagleBone Bootloaders 58

Kernel Space and User Space 62

System V init (SysVinit) 63

Managing Linux Systems 67

The Super User 67

System Administration 68

The Linux File System 68

Linking to Files and Directories 69

Users and Groups 71

File System Permissions 74

Exploring the File System 75

Commands for File Systems 75

find and whereis 81

more or less 82

Linux Commands 82

Standard Input and Output Redirection (>, >>, and <) 82

Pipes ( and tee) 83

Filter Commands (from sort to xargs) 84

echo and cat 86

diff 87

tar 88

md5sum 88

Linux Processes 89

Controlling Linux Processes 89

Foreground and Background Processes 90

The BusyBox Multi?]call Binary 92

Other Linux Topics 93

Git 93

Getting Started with Git 94

Cloning a Repository (git clone) 95

Getting the Status (git status) 96

Adding to the Staging Area (git add) 96

Committing to the Local Repository (git commit) 97

Pushing to the Remote Repository (git push) 97

Advanced Git 98

Creating a Branch (git branch) 98

Merging the Branch (git merge) 100

Deleting a Branch (git branch ?]d) 100

Conclusions on Git 101

Desktop Virtualization 102

Code for This Book 103

Summary 104

Further Reading 104

Chapter 4 Interfacing Electronics 105

Recommended Equipment 105

Digital Multimeter 106

Oscilloscopes 106

Basic Circuit Principles 108

Voltage, Current, Resistance, and Ohm's Law 109

Voltage Division 110

Current Division 112

Implementing Circuits on a Breadboard 113

Digital Multimeters (DMMs) and Breadboards 114

Example Circuit: Voltage Regulation 115

Discrete Components 117

Diodes 117

Light?]Emitting Diodes (LEDs) 118

Smoothing and Decoupling Capacitors 121

Transistors 123

Transistors as Switches 124

Field Effect Transistors (FETs) as Switches 127

Optocouplers/Opto?]isolators 128

Switches and Buttons 130

Hysteresis 132

Logic Gates 133

Floating Inputs 137

Pull?]Up and Pull?]Down Resistors 138

Open?]Collector and Open?]Drain Outputs 139

Interconnecting Gates 140

Analog?]to?]Digital Conversion 141

Sampling Rate 142

Quantization 142

Operational Amplifiers 143

Ideal Operational Amplifiers 143

Negative Feedback and Voltage Follower 146

Positive Feedback 146

Concluding Advice 147

Summary 147

Further Reading 148

Chapter 5 Practical BeagleBone Programming 149

Introduction 149

Performance of Different Languages 150

Setting the BBB CPU Frequency 153

Scripting Languages 153

Scripting Language Optio