Cook Intermediate Robot Building

2. ed
ISBN: 978-1-4302-2755-7
Verlag: Apress
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 480 Seiten

For readers of Robot Building for Beginner (Apress, 2002 and 2009), welcome to the next level. Intermediate Robot Building, Second Edition offers you the kind of real-world knowledge that only renowned author David Cook can offer. In this book, you'll learn the value of a robot heartbeat and the purpose of the wavy lines in photocells. You'll find out what electronic part you should sand. You'll discover how a well-placed switch can help a robot avoid obstacles better than a pair of feelers. And you'll avoid mistakes that can cause a capacitor to explode. Want a robot that can explore rooms, follow lines, or battle opponents in mini-sumo? This book presents step-by-step instructions and circuit and part descriptions so that you can build the robot featured in the book or apply the modules to your own robot designs. Finally, you'll find the complete schematics for Roundabout, a room explorer that requires no programming and uses only off-the-shelf electronics. With Roundabout, you'll use many of the same techniques used by professional robotics engineers, and you'll experience many of the same challenges and joys they feel when a robot 'comes to life.'

David Cook is an engineering manager at Motorola. He has 20 years of experience as a software developer, creating everything from award-winning computer games to mobile background-check applications for police. Self-taught in electronics and basic mechanics, David explains his years of robot experiences to the average backyard scientist in a comfortable and helpful manner, without scholarly intimidation. David hosts the popular robot site RobotRoom.com.

Autoren/Hrsg.

Cook, David

Inhaltsverzeichnis

1;Title Page;1
2;Copyright Page;2
3;Table of Contents;3
4;About the Author;24
5;About the Technical Reviewer;25
6;Acknowledgments;26
6.1;Appreciating Technical Editors;26
6.2;Getting Support at Work;26
6.3;Getting Support from the Field;26
6.4;Support at Home;27
7;Introduction;28
7.1;Intended Audience;28
7.1.1;Prerequisites;28
7.1.1.1;Required Electronics and Machine Shop Experience;28
7.1.1.2;Required Software Development Experience;29
7.1.1.3;Preferred Robot Building Experience;30
7.1.2;Would LEGO MindStorms Be Better For You?;30
7.1.3;Would BEAM Robots Be Better For You?;30
7.1.4;No Remote-Controlled Armageddon;30
7.2;Volatile Parts;31
7.3;Safety Rules;31
7.4;Preferring the Metric System;32
7.5;Getting Updates and Seeing What’s New;32
8;CHAPTER 1 Assembling a Modular Robot;33
8.1;Building Modules;33
8.1.1;Assembling Roundabout, or Not;34
8.1.2;Arranging Chapters;34
8.2;Getting Comfortable with Machining;35
8.2.1;Stocking Your Machine Shop;35
8.2.2;Looking at a Miniature Milling Machine;37
8.2.2.1;Using a Milling Machine;37
8.2.2.2;Precisely Positioning the Workpiece with Handwheels;38
8.2.2.3;Correcting Circuit Board Errors;39
8.2.3;Admitting a Bias Toward Milling;39
8.3;Putting It All Together;39
8.3.1;Grouping Machining Parts;40
8.3.2;Grouping Stand-Alone Electronic Modules;40
8.3.3;Assembling and Testing a Robot;40
8.4;Applying Parts and Techniques to Other Robots;41
9;CHAPTER 2 Comparing Two Types of Homemade Motor Couplers and Common Errors to Avoid;43
9.1;Comparing Two Homemade Coupler Technologies;44
9.1.1;Examining Telescoping-Tube Couplers;44
9.1.2;Comparing with Solid-Rod Couplers;45
9.2;Identifying Desired Results in Coupler Drill Holes, Along with Common Errors and Their Effects;46
9.2.1;Connecting the Setscrew Hole to the Motor Shaft Hole;47
9.2.2;Aligning the Hole Angles and Hole Centers;48
9.2.2.1;Accepting Parallel Offset Between the Holes and the Coupler Body;48
9.2.2.2;Avoiding Parallel Offset Between the Holes Themselves;50
9.2.2.3;Avoiding Angular Offset Between the Holes Themselves;51
9.2.2.4;Reiterating the Advantages of Telescoping Tubing;53
9.3;Getting Ready to Make a Solid-Rod Coupler;53
10;CHAPTER 3 Making a Fixture and Drilling Solid Rods for a Coupler;54
10.1;Gathering Tools and Parts;54
10.2;Preparing Lengths of Solid Rod for the Couplers;55
10.2.1;Measuring the Motor and Axle;55
10.2.2;Selecting a Solid Rod for the Coupler Body;56
10.2.2.1;Calculating the Coupler Length;56
10.2.2.2;Calculating the Coupler Diameter;56
10.2.2.3;Selecting the Coupler Material;56
10.2.3;Cutting the Solid Rod into Coupler-Size Pieces;57
10.2.4;Smoothing the Ends of the Coupler Body Pieces;58
10.2.5;Setting Aside the Lengths of Rod;61
10.3;Making a Coupler Fixture;61
10.3.1;Cutting the Coupler Fixture Block;62
10.3.2;Drilling the Coupler Fixture Setscrew Hole;64
10.3.3;Tapping the Coupler Fixture Setscrew Hole;66
10.3.4;Drilling the Coupler Rod Hole in the Coupler Fixture;66
10.3.4.1;Selecting Drills;67
10.3.4.2;Fixing the Depth;68
10.3.4.3;Drilling;71
10.4;Getting the Money Shot;72
10.4.1;Enlarging Tight Fits;73
10.4.2;Adding a Setscrew to the Coupler Fixture;73
10.4.3;Repositioning the Coupler Fixture;74
10.5;Drilling the Motor-Shaft and LEGO Axle Coupler Holes;74
10.5.1;Swapping Drills, Not Coupler Rods;77
10.5.2;Add the Finishing Touch: Squaring the Ends;77
10.6;Examining the Coupler So Far;77
11;CHAPTER 4 Finishing the Solid-RodMotor Coupler;79
11.1;Installing the Coupler Setscrew;79
11.1.1;Determining the Location for the Coupler Setscrew;79
11.1.2;Drilling the Coupler Setscrew Hole;80
11.1.3;Tapping the Coupler Setscrew Hole;81
11.1.3.1;Selecting a Bottom-Style Tap;81
11.1.3.2;Comparing to a Taper-Style Tap;82
11.1.3.3;Tapping Tips;83
11.1.4;Selecting a Setscrew;83
11.2;Adding the LEGO Axle;85
11.3;Summary;87
12;CHAPTER 5 Blding a Motor Inside a Wheel;88
12.1;Encountering Danger: Bent Shafts Ahead;89
12.1.1;Driving Properly with Bearings;89
12.1.1.1;Protecting Against Bumps and Falls;89
12.1.1.2;Shifting Against the Coupler, Laterally;90
12.1.1.3;Bending Without Support;90
12.2;Making a Hub-Adapter Coupler;90
12.2.1;Adapting the Motor Shaft’s Outer Diameter to the LEGO Wheel’s Inner Diameter;91
12.2.2;Starting Simply with the Coupler Rod;92
12.2.3;Making the Inner and Outer Hub-Adapter Discs;94
12.2.3.1;Choosing a Shape;94
12.2.3.2;Determining the Size;94
12.2.3.3;Choosing the Raw Material;95
12.2.3.4;Cutting the Raw Sheet Down to Size;95
12.2.3.5;Drilling the 14-Inch in Diameter Center Hole;96
12.2.3.6;Again, Why Measure Oversize?;98
12.2.3.7;Milling Circles with a Rotary Table;98
12.2.3.7.1;Adapting the Rotary Table for Small Pieces;99
12.2.3.7.2;Placing the Square Rough-Cut Stock in a Stack on the Rotary Table with the Candlestick in the Billiard Room;99
12.2.3.7.3;Rotating, Cutting, and Approaching the Center;101
12.2.3.8;Drilling Screw Holes in the Discs;102
12.2.3.8.1;Accurately Positioning More Than One Screw Hole;103
12.2.3.8.2;Making Cool Wheels Instead of Hub Adapters;104
12.2.3.9;Finishing the Inner and Outer Hub-Adapter Discs;105
12.2.3.9.1;Enlarging the Holes on the Outer Discs;105
12.2.3.9.2;Making a Setscrew Notch in the Outer Discs;107
12.2.3.9.3;Reducing the Diameter of the Inner Discs;107
12.2.3.9.4;Sanding the Discs;107
12.2.3.9.5;All Done?;107
12.3;Coring the LEGO Hubs;107
12.3.1;Securing the Hub During Machining;108
12.3.2;Selecting a Silver & Deming Drill;109
12.3.3;Drilling Out the Center of the Hub;109
12.3.4;Sanding Away the Remains of the Center of the Hub;110
12.4;Fitting and Gluing the Parts Together;111
12.4.1;Fitting and Gluing the Outer Disc into the Hub;111
12.4.2;Fitting and Gluing the Inner Disc onto the Rod;111
12.4.2.1;Making a Fixture for Gluing;112
12.4.2.2;Gluing the Inner Disc to the Rod;112
12.4.3;Waiting for Glue to Dry;113
12.5;Summary;113
13;CHAPTER 6 Understanding the Standards and Setup for Electronic Experiments;114
13.1;Reading Schematics;114
13.1.1;Connecting Wires;115
13.1.2;Designating Parts;116
13.1.2.1;Lettering Designations;116
13.1.2.2;Numbering Designations;117
13.1.3;Labeling Parts;117
13.1.3.1;Labeling Resistors;118
13.1.3.1.1;Coloring Resistors;118
13.1.3.1.2;Selecting Resistor Construction, Tolerance, and Wattage;119
13.1.3.1.3;Substituting Lower-Wattage Resistors;119
13.1.3.1.4;Including Other Parts As Resistors;120
13.1.3.2;Labeling Capacitors;120
13.1.3.2.1;Indicating Capacitor Values;120
13.1.3.2.2;Selecting Capacitor Construction;121
13.1.3.2.3;Selecting Capacitor Working Voltage and Temperature;121
13.1.3.3;Labeling LEDs and IEDs;122
13.1.3.4;Labeling Other Parts;123
13.1.4;Specifying Power Supply;123
13.1.4.1;Simplifying the Positive Voltage Supply Label;123
13.1.4.2;Symbolizing Ground and Simplifying Wiring;123
13.2;Using Solderless Breadboards;124
13.2.1;Selecting a Solderless Breadboard;125
13.2.2;Setting Up a Solderless Breadboard to Match the Photographs;126
13.2.2.1;Powering a Solderless Breadboard;127
13.2.2.2;Selecting an AC Power Adapter;127
13.2.2.2.1;Choosing a Professional Power Supply;128
13.2.2.2.2;Reusing a Consumer Appliance AC Power Adapter;128
13.2.2.2.3;Risking Electrocution;128
13.2.2.3;Adding a Few Amenities;129
13.3;Understanding Oscilloscope Traces;130
13.4;Riding the Bandwagon of Modern Electronics;131
13.4.1;Getting Past the Learning Curve Barrier;131
13.4.2;Avoiding Obsolete Technology;131
13.4.3;Using Surface-Mount Components;131
13.4.3.1;Sizing Down Surface-Mount;132
13.4.3.2;Saying “Good-Bye” to Through-Hole;133
13.4.3.3;Working with Surface-Mount Components;133
13.4.3.4;Converting Surface-Mount Components to Through-Hole;133
13.4.3.5;Mixing and Matching Package Technologies;135
13.4.3.6;Shrinking Below Hand-Labor Level;135
13.5;Summary;135
14;CHAPTER 7 Creating a Linear Voltage-Regulated Power Supply;136
14.1;Understanding Voltage Regulators;136
14.2;Understanding Linear Voltage-Regulated Power Supplies;137
14.2.1;The 7805 Linear Voltage Regulator;137
14.2.1.1;Introducing a 7805-Based 5 V Power Supply;138
14.2.1.1.1;Assisting the Batteries and Voltage Regulator;139
14.2.1.1.2;Protecting the Voltage Regulator Against Reverse Flows;139
14.2.1.2;Building the 7805-Based Power Supply;140
14.2.1.3;Tracing the Power Flow of the 7805-Based Power Supply Circuit;141
14.2.1.4;Obtaining Capacitors for the 7805-Based Power Supply Circuit;142
14.2.1.5;Obtaining the Power Switch;142
14.2.2;Improving the Power Supply by Reducing the Minimum Required Unregulated Voltage;142
14.2.2.1;Substituting an LM2940, MCP1702, or LP2954 for the 7805;143
14.2.2.2;Substituting a Power MOSFET for the 1N5817;144
14.2.2.2.1;Switching On and Off the Robot Based on the Battery Connection;145
14.2.2.2.2;Powering a Full Circuit Requires a Power MOSFET;145
14.2.2.2.3;Saving Voltage Drop Through Low Resistance;145
14.2.2.3;Increasing Resistance at Lower Voltages;146
14.2.2.4;Selecting a Low-Resistance P-Channel Power MOSFET;146
14.2.2.5;Analyzing the Minimum Input Voltage of Various Linear Regulator Circuits;147
14.2.2.5.1;Defining the Test Apparatus;148
14.2.2.5.2;Introducing the LM1117 Adjustable Voltage Regulator;148
14.2.2.5.3;Setting Up the LM1117;149
14.2.2.6;Presenting the Input/Output Voltage Results of Three 5 V Linear Voltage Regulators;151
14.2.2.6.1;Current Loads Affecting the Minimum Required Voltage;153
14.2.2.6.2;Low-Dropout Voltage Regulators Make a Difference;153
14.2.2.6.3;Dropping Suddenly vs. Dropping Steadily;153
14.2.3;Considering Various Factors in Linear Voltage Regulators;153
14.2.3.1;Protecting Against a Reverse Battery;153
14.2.3.2;Protecting Against Short Circuits;153
14.2.3.3;Protecting Against Thermal Overload;154
14.2.3.4;Simplicity and Low Cost of a Complete Circuit;155
14.2.3.5;Consuming Quiescent Current;155
14.2.3.6;Isolating Power and Noise;155
14.2.3.6.1;Avoiding Connecting Motors to Regulated Voltage;156
14.2.3.6.2;Producing Maximum Physical Power by Connecting Motors to Unregulated Electrical Power;156
14.2.3.6.3;Avoiding Burdening a Voltage Regulator with Motor Loads;156
14.2.3.7;Selecting a Linear Voltage Regulator for Your Robot;157
14.2.3.7.1;The 9 V Battery in a Moderately Active Robot;157
14.2.3.7.2;The 9 V Battery in a Low-Draw Longevity Robot;157
14.2.3.7.3;The Alkaline Four-Pack;158
14.2.3.7.4;The 12 V Winter Robot;158
14.2.4;Changing Marketplace Is Limiting 5 V Linear Regulator Selection;158
14.3;Heading into Optimizations;159
15;CHAPTER 8 Making Robot Power Supply Improvements;160
15.1;Bulking Up the Input and Output Capacitors;160
15.1.1;Increasing Battery Lifetime with Bulk Capacitors;162
15.1.2;Delayed Power-Off Because of Bulk Capacitors;162
15.1.3;Using a DPDT Power Switch to Reduce Turn-Off Time;164
15.1.4;Selecting Bulk Capacitors;165
15.1.5;Implementing Higher Margins of Safety for Tantalum Capacitors;165
15.2;Adding Voodoo Capacitors;166
15.3;Sprinkling with Bypass/Decoupling Capacitors;167
15.3.1;Bypassing the Long Path to the Power Supply;168
15.3.2;Decoupling Noise at Each Source;169
15.3.3;Selecting Bypass/Decoupling Capacitors;169
15.4;Preventing Damage from Short Circuits or Overcurrent;170
15.4.1;Deciding If Overcurrent Protection Is Required;170
15.4.2;Protecting with a Fuse;170
15.4.3;Protecting with a Manually Reset Circuit Breaker;171
15.4.4;Protecting Robots from Short Circuits and Overcurrents with a Solid-State Auto-Resetting PPTC Device;171
15.4.4.1;Greatly Increasing Resistance to Greatly Reduce Current;171
15.4.4.2;Installing PPTC Overcurrent-Protection Devices;172
15.4.4.3;Selecting PPTC Overcurrent-Protection Devices;174
15.4.4.3.1;Choosing a Rough Current Limit;174
15.4.4.3.2;Accepting Some Voltage Loss in Exchange for Protection;174
15.4.4.3.3;Purchasing PPTC Overcurrent-Protection Devices;175
15.5;Preventing Damage from Overvoltage in a Regulated Circuit;175
15.5.1;Introducing the Zener Diode;175
15.5.2;Using a Zener Diode to Short Circuit Power Upon Overvoltage;176
15.5.2.1;Tripping Overcurrent Protection with the Overvoltage Short Circuit;177
15.5.2.2;Taking One for the Team: The Sacrificial Death of Mr. Zener;178
15.5.3;Choosing an Appropriate Breakdown Voltage;178
15.5.4;Purchasing Zener Diodes;178
15.6;Putting It All Together for a Robust Robot Power Supply;179
16;CHAPTER 9 Driving Miss Motor;181
16.1;Why a Motor Driver?;181
16.1.1;Running Motors at Higher Voltages Than Logic Chips Can Provide;182
16.1.2;Supplying More Current to Motors Than Logic Chips Can Provide;182
16.1.3;Causing Logic Errors with Motor Noise;182
16.1.4;Supplying Motor Power from Unregulated vs. Regulated Power;182
16.2;Demonstrating the Four Modes of a Motor;183
16.2.1;Rotating Clockwise;184
16.2.2;Rotating Counterclockwise;185
16.2.3;Rotating Freely/Coasting (Slow Decay);185
16.2.4;Braking/Stopping (Fast Decay);185
16.2.4.1;Using Up More Energy;185
16.2.4.2;Braking by Fast Decay;186
16.3;Driving Simply with a Single Transistor;186
16.3.1;Introducing the NPN Bipolar Single-Transistor Motor-Driver Circuit;188
16.3.1.1;Switching with a Transistor;189
16.3.1.2;Using Transistors As Off/On Switches, Not Amplifiers, in Motor-Driver Circuits;189
16.3.1.3;Limiting Base Current with a Resistor;189
16.3.1.4;Protecting the Transistor with a Diode;190
16.3.2;Implementing the NPN Bipolar Single-Transistor Motor-Driver Circuit;190
16.3.3;Introducing the PNP Bipolar Single-Transistor Motor-Driver Circuit;192
16.3.4;Implementing the PNP Bipolar Single-Transistor Motor-Driver Circuit;193
16.4;Putting the NPN and PNP Motor Drivers Together;194
16.4.1;Implementing the Combination NPN and PNP Motor-Driver Circuit;194
16.4.2;Avoiding a Short Circuit;195
16.5;The Classic Bipolar H-Bridge;196
16.5.1;Spinning Clockwise with an H-Bridge;197
16.5.2;Spinning Counterclockwise with an H-Bridge;198
16.5.3;Slowing Down with an H-Bridge Electronic Brake;199
16.5.4;Braking High;199
16.5.5;Coasting with an H-Bridge;200
16.5.6;Enumerating the Other H-Bridge Combinations;201
16.5.7;Implementing the Classic Bipolar H-Bridge;202
16.6;Interfacing with the High Side;203
16.6.1;Avoiding an Interface by Not Regulating the Logic Chips;203
16.6.2;Avoiding an Interface by Regulating the H-Bridge;203
16.6.3;Interfacing a PNP via an NPN;203
16.6.3.1;Flipping the Switch;204
16.6.3.2;Selecting a Resistor Value for R5;204
16.6.3.3;Specifying the Voltage Range for the Bipolar Motor-Driver Circuits;205
16.6.3.4;Implementing a PNP Single-Transistor Bipolar Motor Driverwith an NPN Interface;205
16.6.3.5;Finishing the Bipolar H-Bridge;206
16.6.4;Using an Interface Chip;207
16.6.4.1;Choosing the 4427;207
16.6.4.2;Interfacing the 4427 to the H-Bridge;208
16.6.4.3;Selecting the 4427 or a Close Family Member;209
16.7;Mastering Motor Control;210
17;CHAPTER 10 Driving Mister Motor;211
17.1;Driving Motors with MOSFETs;211
17.1.1;Introducing the N-Channel Power MOSFET Single-Transistor Motor-Driver Circuit;211
17.1.1.1;Controlling the Transistor Switch with Voltage, Not Current;212
17.1.1.2;Always Connecting the Gate of a MOSFET;212
17.1.1.3;Implementing the N-Channel Power MOSFET Single-Transistor Motor-Driver Circuit;213
17.1.2;Providing a Default Input Value with a Resistor;215
17.1.2.1;Setting the Input High by Default with a Pull-Up Resistor;215
17.1.2.2;Setting the Input Low by Default with a Pull-Down Resistor;216
17.1.2.3;Choosing a Value for a Pull-Up or Pull-Down Resistor;216
17.1.2.4;Choosing Between No Resistor, a Pull-Up Resistor, or a Pull-Down Resistor;218
17.1.2.4.1;Stabilizing Motors at Power-Up;218
17.1.2.4.2;Safeguarding Subcircuits, Cables, Connectors, and Daughter Boards;218
17.1.2.4.3;Reducing Noise and Power Consumption on Unused Inputs;218
17.1.3;Revising the N-Channel Power MOSFET Single-Transistor Motor-Driver Circuit to Include a Pull-Down Resistor;219
17.1.4;Implementing the N-Channel Power MOSFET Single-Transistor Motor-Driver Circuit with a Pull-Down Resistor;220
17.1.5;Introducing the P-Channel Power MOSFET Single-Transistor Motor-Driver Circuit;220
17.1.6;Implementing the P-Channel Power MOSFET Single-Transistor Motor-Driver Circuit;221
17.1.7;Introducing the Power MOSFET H-Bridge;222
17.1.7.1;Adding Schottky Diodes Is Optional but Recommended;223
17.1.7.2;Implementing the Power MOSFET H-Bridge;223
17.1.7.3;Interfacing to a Power MOSFET H-Bridge;224
17.1.7.4;Adding Capacitors to Support Rapid Charging and Dischargingof the Power MOSFETs Gates;225
17.1.7.5;Exposing a Flaw: Shoot-Through;225
17.1.7.6;Implementing the Power MOSFET H-Bridge with a Single 4427 Interface;225
17.1.7.7;Using Two Interface Chips Eliminates Shoot-Through and Adds Complete Motor Control;226
17.1.7.8;Controlling Speed with One and a Half Interface Chips;227
17.1.8;Selecting Power MOSFETs;228
17.1.8.1;Reducing Switch Resistance Is Desirable;229
17.1.8.2;Recognizing That MOSFETs Have Resistance;230
17.1.8.3;Heating Up Increases a MOSFET’s Resistance;230
17.1.8.4;Paralleling MOSFETs Decreases Resistance;230
17.1.8.5;Contrasting Parallel MOSFET Transistors with Parallel Bipolar Transistors;232
17.2;Driving Motors with Chips;233
17.2.1;Dreaming of the Ideal;233
17.2.2;Using the 4427-Family As a Stand-Alone Motor Driver;234
17.2.3;Getting the Classic Bipolar H-Bridge on a Chip;237
17.2.4;Introducing the MC33887: A Feature-Rich MOSFET H-Bridge Motor Driver;239
17.2.4.1;Understanding the Pins;241
17.2.4.1.1;Disconnecting Inputs Results in Protective Reaction;242
17.2.4.1.2;Controlling the Motor Modes;242
17.2.4.2;Implementing the MC33887 H-Bridge Motor Driver;243
17.2.4.3;Sensing Motor Current;244
17.2.4.3.1;Sensing Obstacles or Dangerous Conditions Through Motor Current Sensing;244
17.2.4.3.2;Sensing Motor Disconnection, Potential Falls, Being Turned Over, or Being Picked Up;245
17.2.4.3.3;Converting Motor Current to a Voltage in the Motor Driver;245
17.3;Evaluating Motor Drivers;246
17.3.1;Evaluating Motor-Driver Power Delivery;247
17.3.1.1;Evaluating Motor-Driver Voltage Output with a Very Light Load;247
17.3.1.2;Evaluating Motor-Driver Voltage Output with a Moderate Load;248
17.3.2;Evaluating Motor-Driver Efficiency;249
17.3.2.1;Evaluating Motor-Driver Efficiency with a Very Light Load;249
17.3.2.2;Evaluating Motor-Driver Efficiency with a Moderate Load;250
17.4;Summary;251
18;CHAPTER 11 Creating an Infrared Modulated Obstacle, Opponent, and Wall Detector;252
18.1;Detecting Modulated Infrared with a Popular Module, or, Another Reason to Hog the Remote Control;253
18.1.1;Introducing the Panasonic PNA4602M Photo IC;254
18.1.2;Hooking Up the PNA4602M Photo IC;254
18.1.3;Testing the PNA4602M Photo IC;255
18.1.3.1;Looking Closely at the Modulated Signal;256
18.1.3.2;Looking Even More Closely to See the Detection Delay;256
18.2;Expanding the Detection Circuit to Include an LED Indicator;257
18.2.1;Adding a 74AC14 Inverter Chip to Drive the LED;257
18.2.2;Examining the Indicator Circuit;258
18.2.2.1;Cleaning the Power Supply with Local Capacitors;258
18.2.2.2;Powering the LED with an Advanced CMOS Logic Chip;258
18.2.2.3;Showing Both Detect and No-Detect States with a Bicolor LED;258
18.2.2.3.1;Illustrating LED and Logic Chip Current Flow When Nothing Is Detected;259
18.2.2.3.2;Illustrating LED and Logic Chip Current Flow When Something Is Detected;260
18.3;Completing the Reflector Detector Circuit;261
18.3.1;Examining the Complete Reflector Detector Schematic;261
18.3.1.1;Generating the 38 kHz Wave;262
18.3.1.2;Emitting the 38 kHz Wave;262
18.3.2;Implementing the 38 kHz Reflector Detector on a Solderless Breadboard;263
18.3.2.1;Selecting an Infrared LED for the PNA4602M;263
18.3.2.2;Purchasing an Appropriate Infrared LED;265
18.3.2.3;Selecting Trimpots for R7 and R6;265
18.3.2.3.1;Purchasing Trimpots;266
18.3.2.3.2;Adding Trimpots to the Circuit;266
18.3.2.4;Selecting Capacitors;267
18.3.2.5;Reducing Cross Talk with a Tantalum Capacitor;267
18.3.2.5.1;Selecting the Correct Capacitor to Reduce False Detections;268
18.3.2.5.2;Inserting Polarized Capacitors in the Correct Orientation;268
18.3.2.6;Selecting a Timing Capacitor;269
18.4;Making It Work;270
19;CHAPTER 12 Fine-Tuning the Reflector Detector;271
19.1;Tuning In 38 kHz;271
19.1.1;Selecting Halfway Between the Start of Detection and End of Detection;271
19.1.1.1;Never Indicating Detection Suggests Something Is Wrong with the Emitters;272
19.1.1.2;Always Indicating Detection Suggests Signal Leakage;272
19.1.1.2.1;Checking for Circuit Noise Signal Leakage;272
19.1.1.2.2;Shooting the Messenger;273
19.1.1.2.3;Checking for Infrared LEDs Being Too “Bright”;273
19.1.1.2.4;Leaking Signal from the Sides of the Infrared LEDs;273
19.1.2;Using a Multimeter with Frequency Detection;275
19.1.3;Using an Oscilloscope;275
19.1.4;Revealing the Purpose of a Schmitt-Trigger Inverter;276
19.1.5;Diagnosing Problems Encountered in Circuit Tuning;277
19.1.5.1;Targeting Reasonable Frequency Accuracy;277
19.1.5.2;Stretching for Unreasonable Frequency Accuracy;278
19.1.5.3;Accepting the Limited Accuracy and Stability of the Oscillator Circuit;278
19.2;Limitations of the Reflector Detector;279
19.2.1;Failing to Work Outdoors or Under Bright Lights;279
19.2.2;Failing to Detect Certain Kinds of Objects;279
19.2.3;Failing to Detect Objects Far Away or Really, Really Close;280
19.2.3.1;Comparing Your Distances to Mine;281
19.2.3.2;Analyzing the Distance Results;281
19.2.4;Failing to Provide a Range Value;283
19.3;Getting Ready for a Practical Robot Application;284
20;CHAPTER 13 Roundabout Robot!;285
20.1;Examining Roundabout;286
20.2;Viewing Roundabout from the Sides;286
20.3;Viewing Roundabout from Above and Beneath;287
20.4;Roundabout’s Circuitry;288
20.4.1;Supplying Power;289
20.4.2;Controlling Direction with Simple Logic;289
20.4.3;Turning Left and Turning Right;290
20.4.4;Gradually Heading Left and Gradually Heading Right;291
20.4.5;Avoiding Infrared Leaks;292
20.5;Building Roundabout’s Body;293
20.6;Declaring Caveats Because of Gearmotor Availability;293
20.6.1;Using Precision Escap Gearmotors in Roundabout;294
20.7;Leaning Toward Particular Attributes;295
20.8;Designing a Robot Body;296
20.8.1;Creating a Template;296
20.8.2;Printing a Template;297
20.8.3;Attaching a Template;298
20.8.4;Squaring the Template with the Workpiece;298
20.8.5;Punching Holes for Better Centering;299
20.8.6;Removing Tape Before Machining Sides;300
20.9;Constructing the Center Platform of Roundabout;301
20.9.1;Milling or Purchasing a Disc;301
20.9.2;Placing and Tapping Screw Holes in Roundabout’s Center Platform;302
20.10;Examining Roundabout’s Motor Mechanism;302
20.10.1;Using Matching Rectangular Motor Mounts;303
20.10.2;Choosing Between Friction-Fit Motors and Using Mounting Screws;304
20.10.3;Mounting Motors with Screws;304
20.10.4;Connecting to LEGO Gears and Wheels;305
20.11;Selecting LEGO Gears;305
20.11.1;Centering Wheels with Idler Gears;305
20.11.2;Slowing Down the Speed and Increasing the Torque;306
20.11.3;Increasing Speed in Exchange for Torque;307
20.11.4;Altering Speed and Torque with Pulleys Instead of Gears;307
20.12;Reaching the Physical Limits of LEGO Moving Parts;308
20.13;Making Roundabout’s Motor Mounts;309
20.13.1;Defining Motor-Mount Dimensions;309
20.13.2;Preparing the Raw Material;310
20.13.3;Selecting Ready-Made Material Instead of Milling;310
20.13.4;Drilling All of the Motor Mounts at the Same Time;310
20.13.4.1;Placing the Stack in the Vise, with Room to Spare;311
20.13.4.2;Positioning the Drill;312
20.13.4.3;Drilling Three Holes;312
20.13.4.4;Preparing to Drill Larger Motor Holes;313
20.13.4.5;Positioning the Wider Diameter Drill;314
20.13.4.6;Drilling the Motor Holes;315
20.13.5;Making Holes to Secure the Motor Mounts to the Center Platform;315
20.13.5.1;Selecting Partially Drilled Motor-Mount Screw Holes with Threads;315
20.13.5.2;Selecting Fully Drilled, Unthreaded, Motor-Mount Screw Holes;316
20.13.5.3;Gliding Along;317
20.13.5.4;Drilling the Motor-Mount Screw Holes;318
20.13.5.5;Tapping Partially Drilled Motor-Mount Holes;319
20.13.6;Revealing the Finished Motor Mounts;319
20.14;Summarizing Roundabout;320
21;CHAPTER 14 Test Driving Roundabout;321
21.1;Preparing for the Test Drive;321
21.1.1;Setting All Controls to Safe or Moderate Positions;321
21.1.2;Testing One Module at a Time;322
21.1.3;Measuring the Resistance of the Complete Circuit;322
21.1.3.1;Draining Power;322
21.1.3.2;Measuring Resistance;324
21.1.3.3;Getting Too Low of a Resistance;324
21.1.3.4;Getting Too High of a Resistance;324
21.1.4;Placing the Robot on Blocks;325
21.1.5;Checking Battery Voltage and Polarity;325
21.1.6;Watching Current Usage During Power-Up;325
21.2;Preparing the Robot and Correcting Minor Glitches;326
21.2.1;Fine-Tuning the Infrared Reflector Detector;326
21.2.2;Flipping Bicolor LEDs;327
21.2.3;Testing the Sensors;327
21.2.4;Mixing Up Motor Connections;328
21.3;Evaluating Roundabout’s Performance;328
21.3.1;Encountering Problems with the Test Drive;328
21.3.1.1;Encountering a Reversing Robot;328
21.3.1.2;Encountering a Stalling Robot;329
21.3.1.3;Encountering a Slow-Motion Robot;329
21.3.1.4;Encountering a Speeding Robot;330
21.3.1.5;Encountering a Rotating Robot;330
21.3.2;Exercising All of the Robot’s Maneuvers;331
21.3.3;Challenging Roundabout;332
21.3.3.1;Avoiding Toilet Paper Alley;332
21.3.3.2;Switching to Blocks of Wood;333
21.3.3.3;Ringing Around the Robot;334
21.4;Getting Stuck;335
21.4.1;Evaluating a Drunkard’s Walk;335
21.4.2;Evaluating Roundabout’s Walk;336
21.4.3;Reducing Detection Ambiguity;337
21.4.3.1;Attempting to Use a Resistor-Capacitor Circuit;337
21.4.3.2;Attempting to Use High-Beam Hysteresis;339
21.4.3.2.1;Analyzing the High-Beam Circuit;340
21.4.3.2.2;Implementing the High-Beam Circuit;340
21.4.3.2.2.1;Measuring Current with Two-Pin Male Square Headers and Shorting Jumpers;341
21.4.3.3;Rerouting Signals and Controls with a Multipin Header;342
21.4.3.3.1;Looking for Improved Performance;342
21.4.3.4;Running Out of Simple Ideas;342
22;CHAPTER 15 If I Only Had a Brain;344
22.1;Considering the Atmel ATtiny84 Microcontroller As an Example;344
22.2;Comparing a Microcontroller to a Logic Chip;345
22.2.1;Choosing a Logic Chip Over a Microcontroller;345
22.2.2;Choosing a Microcontroller Over a Logic Chip;346
22.3;Programming a Microcontroller;347
22.3.1;Storing Programs;347
22.3.2;Sizing Up Program Storage;348
22.3.3;Writing Programs;348
22.3.4;Working Without a .NET;349
22.3.5;Compiling and Downloading the Program;349
22.3.6;Debugging the Program;349
22.3.6.1;Lighting Up an LED;350
22.3.6.2;Changing a Pin;352
22.3.6.3;Creating a Heartbeat;352
22.3.6.4;Driving a Display;353
22.4;Exploring Common Microcontroller Features;355
22.4.1;Microcontroller Packages;355
22.4.2;Microcontroller Pins;356
22.4.2.1;Input Pins;356
22.4.2.1.1;Analog-to-Digital Input Pins;356
22.4.2.1.2;Interrupt Input Pins;356
22.4.2.1.3;Reset Pin;357
22.4.2.1.4;Reusing the Reset Pin;357
22.4.2.1.5;Configurable Pull-Up and Pull-Down Resistors on Input Pins;357
22.4.2.2;Output Pins;358
22.4.2.2.1;Avoiding Glitches When Configuring an Output Pin;358
22.4.2.2.2;Higher-Current Output Pins;358
22.4.2.2.3;Pulse-Width Output;359
22.4.2.2.3.1;Using Only One Infrared Detector by Using Two PWM Output Pins;359
22.4.2.2.3.2;Using a PWM for Other Purposes;360
22.4.2.2.3.3;Software-Generated PWMs;360
22.4.2.2.4;Combinations of Input and Output Pins: Serial Ports;361
22.4.3;Microcontroller Memory;361
22.4.3.1;Nonvolatile Memory;362
22.4.3.2;Supplementing with External Nonvolatile Memory;362
22.4.3.3;Volatile Memory;363
22.4.4;Microcontroller Instruction Size;364
22.4.5;Microcontroller Instruction Complexity;364
22.4.6;Microcontroller Speed;364
22.4.6.1;Comparing Clock Speed;365
22.4.6.2;Generating a Clock Signal;365
22.4.6.3;Using the Clock As a Timer;367
22.4.7;Special Watchdogs;368
22.4.8;Low-Voltage Watchdog;368
22.5;Choosing a Microcontroller;369
22.5.1;Running Out Of . . .;369
22.5.2;Recommending Atmel AVR 8-bit Microcontrollers;370
22.5.3;Recommending the Parallax BASIC St370
22.5.4;Asking Around;372
22.6;Graduating Your Robot;372
23;CHAPTER 16 Building Roundabout’sDaughterboard;373
23.1;Converting to a Two-Story Configuration;374
23.1.1;Connecting to the DIP Socket;375
23.1.1.1;Using Machine-Pin Sockets and Headers;378
23.1.1.1.1;Dividing Headers and Sockets;378
23.1.1.2;Securing the Daughterboard to the Motherboard;379
23.1.1.2.1;Experimenting with Anodized Aluminum Socket Head Cap Screws;379
23.1.1.3;Soldering the Headers;381
23.1.1.3.1;Soldering While Bolted;382
23.1.1.3.2;Trimming the Solder Joints;383
23.1.1.3.3;Reheating the Solder Joints;383
23.1.1.4;Soldering the New DIP Socket;384
23.1.2;Difficulty Accessing the Motherboard;386
23.1.2.1;Relocating the Power Switch;386
23.1.2.2;Perilously Stacking Sockets;386
23.1.3;Shading the Infrared Reflector Detectors;387
23.2;Intercepting Signals: Meeting the New Boss;388
23.2.1;Retaining Valuable Functions;389
23.2.2;Rerouting the Infrared Detection Signals;389
23.2.3;Catching and Disrupting the Stalled State;390
23.2.4;Rerouting the Motor and Bipolar Controls;390
23.2.5;Producing (Almost) Complete Control;390
23.3;Expanding Functionality;391
23.3.1;Examining the Microcontroller Pins;391
23.3.2;Powering the Microcontroller;391
23.3.3;Detecting Walls and Obstacles;392
23.3.4;Controlling the Motors and Bipolar LEDs;392
23.3.5;Controlling the Bipolar LEDs;392
23.3.6;Reading the Push Button;393
23.3.6.1;Debouncing an Input;393
23.3.6.2;Adding the Push Button to the Daughterboard;394
23.3.7;Providing Options with a DIP Switch;394
23.3.7.1;Debouncing Through Software;396
23.3.7.2;Avoiding Intermittent Switch Changes;396
23.3.8;Making Music;397
23.3.9;Remaining Pins Available for Expansion;397
23.3.9.1;Communicating with Other Modules or a Computer;398
23.4;Upgrading a Robot;398
24;CHAPTER 17 Adding the Floor Sensor Module;399
24.1;Sensing Brightness with Photoresistors;399
24.1.1;Converting Varying Resistance into Varying Voltage Through a Voltage Divider;401
24.1.1.1;Selecting a Voltage for the Voltage Divider;402
24.1.1.2;Selecting a Resistor for the Voltage Divider;402
24.1.1.3;Staying Below the Maximum Power Dissipation Rating of the Photoresistor;403
24.1.2;Photoresistor Response Is Nonlinear;403
24.1.2.1;Graphing the Response of a Specific Photoresistor;405
24.1.2.2;Calculating Sensitivity;405
24.1.2.3;Calculating Any Resistance for a Given Illuminance;405
24.1.3;Recognizing Inconsistency Between Photoresistors;406
24.1.3.1;Testing Variance;406
24.1.4;Rising and Falling Resistance Speeds;407
24.1.5;Reusing the Balanced Brightness-Sensing Circuit;408
24.2;Sensing Brightness with a Photodiode IC;408
24.2.1;Presenting the Floor Reflectivity Circuit;409
24.2.2;Implementing the Floor Reflectivity Circuit;410
24.2.2.1;Cutting Out a Semicircular Breadboard;411
24.2.2.2;Baffling the Board;412
24.2.2.3;Putting on a Black Skirt;413
24.2.2.4;Gutting a LEGO Brick;414
24.2.2.5;Tuning and Testing the Floor Reflectivity Circuit;415
24.2.2.6;Tuning Just Below 5 V on a Maximally Reflective Surface;416
24.2.2.7;Testing on a Minimally Reflective Surface;416
24.3;Following a Line;417
24.3.1;Autodetection of Line Brightness;417
24.3.2;Reading Floor Sensor Values;418
24.3.3;Inverting Sensor Values;418
24.3.4;Following the Dark Line;419
24.3.5;Centering Over the Dark Line;419
24.3.6;Improving the Line-Following Algorithm;419
24.4;Competing in Robot Sumo;420
24.4.1;Entering Roundabout in Robot Sumo;420
24.4.2;Strategizing with DIP Switch Settings;421
24.5;Expanding Possibilities;421
25;CHAPTER 18 Cooking Up Some Robot Stew;422
25.1;Making Music;422
25.1.1;Presenting the Audio Circuit;422
25.1.2;Implementing the Audio Circuit;423
25.1.3;Turning the Volume;423
25.1.3.1;Listening to Binary;423
25.1.3.2;Boosting Loudness;424
25.1.4;Driving a Speaker;424
25.1.4.1;Selecting a Speaker;424
25.1.4.2;Choosing an Audio Amplifier Chip Instead of a Simple Transistor;425
25.1.5;Seeing Sound;425
25.1.6;Playing a Note;426
25.1.7;Playing a Tune;426
25.1.7.1;Playing Tunes Simultaneous to Robot Action;427
25.2;Scaling Up;428
25.2.1;Creating a Double Platform;428
25.2.2;Sliding Around;429
25.2.3;Providing Greater Headroom with Homemade Spacers;429
25.2.4;Wheel Slots;430
25.2.5;Supporting Both Ends of the Axle;431
25.3;Mounting Motors;432
25.3.1;Mounting with Angle Stock;432
25.3.1.1;Purchasing Aluminum Angle Stock;433
25.3.1.2;Preparing the Proper Lengths;434
25.3.1.3;Drilling Holes with a Template;434
25.3.1.4;Purposely Incorporating Wiggle Room by Drilling Unthreaded Oversized Holes;435
25.3.2;Saving Space with Right Angle Gearing;436
25.3.2.1;Notching and Grooving;436
25.3.2.2;Inserting Wheel Axles;437
25.3.2.3;Reducing Friction;437
25.3.2.4;Placing the Drive Train into the Robot’s Body;437
25.3.3;Adapting a Small-Diameter Motor Shaft and Integrated Mount for LEGO Compatibility;438
25.3.3.1;Altering the Gearmotor Shaft;439
25.3.3.2;Grinding the Shaft;440
25.3.3.3;Adding Tubing;440
25.3.3.4;Attaching the Motor with a Peg-Based Mount;441
25.4;Roaming the Solar Terrain;442
25.4.1;Selecting Wheels for a Smooth Ride;443
25.4.2;Detecting Obstacles;444
25.4.2.1;Looking for Light and Sensing Shadows;444
25.4.2.2;Feeling Around with Whisker Sensors;445
25.4.2.3;Using Spring Tubing;445
25.4.2.4;Lever Switches;446
25.4.2.4.1;Mounting the Lever Switch Sensors;447
25.4.2.4.2;Detecting Lift Off;447
25.5;Standing in a Robot’s Shoes for a While;448
25.5.1;Adding a Wireless Video Camera to Any Existing Robot;448
25.5.2;Exploring with Wireless Video;449
25.5.3;Exploring Yourself with Wireless Video;449
25.6;Thank You;450
26;APPENDIX Internet References;451
27;Index;455