Exploring Arduino: Tools and Techniques for Engineering Wizardry – Jeremy Blum

Introduction xix
Part I Arduino Engineering Basics 1
Chapter 1 Getting Up and Blinking with the Arduino 3
Exploring the Arduino Ecosystem 4
Arduino Functionality 4
Atmel Microcontroller 6
Programming Interfaces 6
General I/O and ADCs 7
Power Supplies 7
Arduino Boards 8
Creating Your First Program 13
Downloading and Installing the Arduino IDE 13
Running the IDE and Connecting to the Arduino 14
Breaking Down Your First Program 16
Summary 18
Chapter 2 Digital Inputs, Outputs, and Pulse-Width Modulation 19
Digital Outputs 20
Wiring Up an LED and Using Breadboards 20
Working with Breadboards 21
Wiring LEDs 22
Programming Digital Outputs 24
Using For Loops 25
Pulse-Width Modulation with analogWrite() 27
Reading Digital Inputs 29
Reading Digital Inputs with Pulldown Resistors 29
Working with “Bouncy” Buttons 32
Building a Controllable RGB LED Nightlight 35
Summary 39
Chapter 3 Reading Analog Sensors 41
Understanding Analog and Digital Signals 42
Comparing Analog and Digital Signals 43
Converting an Analog Signal to a Digital One 44
Reading Analog Sensors with the Arduino: analogRead() 45
Reading a Potentiometer 45
Using Analog Sensors 50
Working with Analog Sensors to Sense Temperature 52
Using Variable Resistors to Make Your Own Analog Sensors 54
Using Resistive Voltage Dividers 55
Using Analog Inputs to Control Analog Outputs 56
Summary 59
Part II Controlling Your Environment 61
Chapter 4 Using Transistors and Driving Motors 63
Driving DC Motors 65
Handling High-Current Inductive Loads 65
Using Transistors as Switches 66
Using Protection Diodes 67
Using a Secondary Power Source 68
Wiring the Motor 68
Controlling Motor Speed with PWM 70
Using an H-Bridge to Control DC Motor Direction 72
Building an H-bridge Circuit 73
Operating an H-bridge Circuit 76
Driving Servo Motors 80
Understanding the Difference Between Continuous Rotation
and Standard Servos 80
Understanding Servo Control 80
Controlling a Servo 85
Building a Sweeping Distance Sensor 86
Summary 90
Chapter 5 Making Sounds 91
Understanding How Speakers Work 92
The Properties of Sound 92
How a Speaker Produces Sound 94
Using tone() to Make Sounds 95
Including a Definition File 95
Wiring the Speaker 96
Making Sound Sequences 99
Using Arrays 99
Making Note and Duration Arrays 100
Completing the Program 101
Understanding the Limitations of the tone() Function 102
Building a Micro Piano 102
Summary 105
Chapter 6 USB and Serial Communication 107
Understanding the Arduino’s Serial Communication
Capabilities 108
Arduino Boards with an Internal or External FTDI
USB-to-Serial Converter 110
Arduino Boards with a Secondary USB-Capable
ATMega MCU Emulating a Serial Converter 112
Arduino Boards with a Single USB-Capable MCU 114
Arduino Boards with USB-Host Capabilities 114
Listening to the Arduino 115
Using print Statements 115
Using Special Characters 117
Changing Data Type Representations 119
Talking to the Arduino 119
Reading Information from a Computer or Other Serial Device 120
Telling the Arduino to Echo Incoming Data 120
Understanding the Differences Between Chars and Ints 121
Sending Single Characters to Control an LED 122
Sending Lists of Values to Control an RGB LED 125
Talking to a Desktop App 127
Talking to Processing 127
Installing Processing 128
Controlling a Processing Sketch from Your Arduino 129
Sending Data from Processing to Your Arduino 132
Learning Special Tricks with the Arduino Leonardo
(and Other 32U4-Based Arduinos) 134
Emulating a Keyboard 135
Typing Data into the Computer 135
Commanding Your Computer to Do Your Bidding 139
Emulating a Mouse 140
Summary 144
Chapter 7 Shift Registers 145
Understanding Shift Registers 146
Sending Parallel and Serial Data 147
Working with the 74HC595 Shift Register 148
Understanding the Shift Register Pin Functions 148
Understanding How the Shift Register Works 149
Shifting Serial Data from the Arduino 151
Converting Between Binary and Decimal Formats 154
Controlling Light Animations with a Shift Register 154
Building a “Light Rider” 154
Responding to Inputs with an LED Bar Graph 157
Summary 160
Part III Communication Interfaces 161
Chapter 8 The I2C Bus 163
History of the I2
C Bus 164
I2
C Hardware Design 164
Communication Scheme and ID Numbers 165
Hardware Requirements and Pull-Up Resistors 167
Communicating with an I2
C Temperature Probe 167
Setting Up the Hardware 168
Referencing the Datasheet 169
Writing the Software 171
Combining Shift Registers, Serial Communication,
and I2
C Communications 173
Building the Hardware for a Temperature Monitoring System 173
Modifying the Embedded Program 174
Writing the Processing Sketch 177
Summary 180
Chapter 9 The SPI Bus 181
Overview of the SPI Bus 182
SPI Hardware and Communication Design 183
Hardware Configuration 184
Communication Scheme 184
Comparing SPI to I2
C 185
Communicating with an SPI Digital Potentiometer 185
Gathering Information from the Datasheet 186
Setting Up the Hardware 189
Writing the Software 190
Creating an Audiovisual Display Using
SPI Digital Potentiometers 193
Setting Up the Hardware 194
Modifying the Software 195
Summary 197
Chapter 10 Interfacing with Liquid Crystal Displays 199
Setting Up the LCD 200
Using the LiquidCrystal Library to Write to the LCD 203
Adding Text to the Display 204
Creating Special Characters and Animations 206
Building a Personal Thermostat 209
Setting Up the Hardware 210
Displaying Data on the LCD 211
Adjusting the Set Point with a Button 213
Adding an Audible Warning and a Fan 214
Bringing It All Together: The Complete Program 215
Taking This Project to the Next Level 219
Summary 219
Chapter 11 Wireless Communication with XBee Radios 221
Understanding XBee Wireless Communication 222
XBee Radios 223
The XBee Radio Shield and Serial Connections 224
3.3V Regulator 226
Logic Level Shifting 226
Associate LED and RSSI LED 226
UART Selection Jumper or Switch 226
Hardware vs. Software Serial UART Connection Option 227
Configuring Your XBees 228
Configuring via a Shield or a USB Adapter 228
Programming Option 1: Using the Uno as a Programmer
(Not Recommended) 229
Programming Option 2: Using the SparkFun USB Explorer
(Recommended) 230
Choosing Your XBee Settings and Connecting Your XBee
to Your Host Computer 230
Configuring Your XBee with X-CTU 231
Configuring Your XBee with a Serial Terminal 235
Talking with Your Computer Wirelessly 236
Powering Your Remote Arduino 236
USB with a Computer or a 5V Wall Adapter 237
Batteries 237
Wall Power Adapters 239
Revisiting the Serial Examples: Controlling Processing
with a Potentiometer 239
Revisiting the Serial Examples: Controlling an RGB LED 243
Talking with Another Arduino: Building a Wireless Doorbell 246
System Design 246
Transmitter Hardware 247
Receiver Hardware 248
Transmitter Software 249
Receiver Software 250
Summary 252
Part IV Advanced Topics and Projects 255
Chapter 12 Hardware and Timer Interrupts 257
Using Hardware Interrupts 258
Knowing the Tradeoffs Between Polling and Interrupting 259
Ease of Implementation (Software) 260
Ease of Implementation (Hardware) 260
Multitasking 260
Acquisition Accuracy 261
Understanding the Arduino’s Hardware
Interrupt Capabilities 261
Building and Testing a Hardware-Debounced
Button Interrupt Circuit 262
Creating a Hardware-Debouncing Circuit 262
Assembling the Complete Test Circuit 267
Writing the Software 267
Using Timer Interrupts 270
Understanding Timer Interrupts 270
Getting the Library 270
Executing Two Tasks Simultaneously(ish) 271
Building an Interrupt-Driven Sound Machine 272
Sound Machine Hardware 272
Sound Machine Software 273
Summary 275
Chapter 13 Data Logging with SD Cards 277
Getting Ready for Data Logging 278
Formatting Data with CSV Files 279
Preparing an SD Card for Data Logging 279
Interfacing the Arduino with an SD Card 284
SD Card Shields 284
SD Card SPI Interface 288
Writing to an SD Card 289
Reading from an SD Card 293
Using a Real-Time Clock 297
Understanding Real-Time Clocks 298
Using the DS1307 Real-Time Clock 298
Using the RTC Arduino Third-Party Library 299
Using the Real-Time Clock 300
Installing the RTC and SD Card Modules 300
Updating the Software 301
Building an Entrance Logger 305
Logger Hardware 306
Logger Software 307
Data Analysis 311
Summary 312
Chapter 14 Connecting Your Arduino to the Internet 313
The Web, the Arduino, and You 314
Networking Lingo 314
IP Address 314
Network Address Translation 315
MAC Address 316
HTML 316
HTTP 316
GET/POST 316
DHCP 316
DNS 317
Clients and Servers 317
Networking Your Arduino 317
Controlling Your Arduino from the Web 318
Setting Up the I/O Control Hardware 318
Designing a Simple Web Page 318
Writing an Arduino Server Sketch 320
Connecting to the Network and Retrieving an IP via DHCP 321
Replying to a Client Response 321
Putting It Together: Web Server Sketch 322
Controlling Your Arduino via the Network 326
Controlling Your Arduino over the Local Network 326
Using Port Forwarding to Control your Arduino
from Anywhere 327
Sending Live Data to a Graphing Service 329
Building a Live Data Feed on Xively 330
Creating a Xively Account 330
Creating a Data Feed 330
Installing the Xively and HttpClient Libraries 331
Wiring Up Your Arduino 332
Configuring the Xively Sketch and Running the Code 332
Displaying Data on the Web 335
Adding Feed Components 336
Adding an Analog Temperature Sensor 336
Adding Additional Sensor Readings to the Datastream 336
Summary 339
Appendix Deciphering the ATMega Datasheet
and Arduino Schematics 341
Reading Datasheets 341
Breaking Down a Datasheet 341
Understanding Component Pin-outs 344
Understanding the Arduino Schematic 345
Index 349