Hacking GPS

Hacking GPS

Kathie Kingsley-Hughes

Hacking GPS

Published by

Wiley Publishing, Inc.

10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com

Copyright © 2005 by Wiley Publishing, Inc., Indianapolis, Indiana

Published by Wiley Publishing, Inc., Indianapolis, Indiana

Published simultaneously in Canada

ISBN: 0-7645-8424-3

Manufactured in the United States of America

10 9 8 7 6 5 4 3 2 1

1B/QR/QT/QV/IN

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About the Author

Kathie Kingsley-Hughes has written numerous books in the PC and programming fields and is comfortable explaining hi-tech concepts in an easy-to-follow way. Several of the titles that she has authored or co-authored are set books used in many U.S. and international colleges and universities. Writing in the technical arena has given her many opportunities to use hundreds of different gadgets and gizmos; and because she has a love of the outdoors, it was inevitable that she would become involved in GPS and digital mapping.

Kathie has been using GPS since its early days when the accuracy and quality of the receivers were poor. Even back then, however, she realized the potential of such devices and predicted that they would be a huge hit in the consumer arena.

Credits

	Acquisitions Editor	Executive Editorial Director
	Katie Mohr	Mary Bednarek
	Development Editor	Project Coordinator
	Brian MacDonald	Erin Smith
	Project Editor	Graphics and Production Specialists
	Pamela Hanley	Jonelle Burns
	Technical Editor	Lauren Goddard
		Denny Hager
	Joel McNamara	Heather Ryan
	Copy Editor	Erin Zeltner
		Quality Control Technicians
	Luann Rouff
	Editorial Manager	Leeann Harney
		Carl Pierce
	Mary Beth Wakefield	Brian Walls
	Vice President & Executive Group	Proofreading and Indexing
	Publisher	TECHBOOKS Production Services
	Richard Swadley
	Vice President and Publisher
	Joseph B. Wikert

To my husband, Adrian—my inspiration

Acknowledgments

Extra special thanks to Katie Mohr for believing in this project and guiding it along from concept to completion. It’s been a pleasure working with you on this project.

Thanks too to Chris Webb for all his feedback and help in molding the book into a workable project.

I also want to extend a sincere “thank-you” to the rest of the publishing team, both those I’ve dealt with directly and those who have worked hard behind the scenes.

Contents at a Glance

Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix

Part I: Hardware Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Chapter 1: GPS Secrets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Chapter 2: Building GPS Data Cables and Power Cords . . . . . . . . . . . . . . . . . . 13 Chapter 3: Power Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Chapter 4: Antenna Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Chapter 5: Protecting Your GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

Part II: Software Hacks . . . . . . . . . . .	. . . . . . . . . . . . . . . . 123
Chapter 6: Hacking the Firmware . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 125
Chapter 7: Making Connections . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 147
Part III: Data Hacking . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
Chapter 8: GPS Data . . . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 165
Chapter 9: Examining the Data. . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 195
Chapter 10: More Data Tricks . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 223
Part IV: Playtime . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Chapter 11: Hacking Geocaching . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 255
Chapter 12: GPS Games . . . . . . . . . . . . . . .	. . . . . . . . . . . . . . . . . . . 289

Appendix A: GPS Primer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Appendix B: Websites/Internet Resources . . . . . . . . . . . . . . . . . . . . . . . . . 313 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

321

Contents

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix

Part I: Hardware Hacks

1

Chapter 1: GPS Secrets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Hidden Secrets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Garmin Secret Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Hard Resets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Soft Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Warm Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Full GPS Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Diagnostic Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Autolocating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Magellan Secret Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Magellan Meridian Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 After a Hard or Soft Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Chapter 2: Building GPS Data Cables and Power Cords . . . . . . . . . . 13

Cables Demystified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
The Data Cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	14
Power Cords. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	16
Combo Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	17
Combining Cable Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
Multi-GPS Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
Multi-Data Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
Multi-Data/Power Cables . . . . . . . . . . . . . . . . . . . . . . . . . . .	18
Multi-Data/Power/GPS Cables . . . . . . . . . . . . . . . . . . . . . . . .	19
Making Your Own Data Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . .	19
Materials You Will Need . . . . . . . . . . . . . . . . . . . . . . . . . . . .	19
Don’t Want to Buy a Connector? . . . . . . . . . . . . . . . . . . . . . . . .	28
Making Power Cords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	30
Power Cord Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	31
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	31
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	32

xiv Contents

GPS/iPAQ Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Cradle Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Testing the Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Making Combo Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Making Multi Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Chapter 3: Power Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

GPS Power Needs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Alkaline Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Lithium Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Rechargeable (NiMH) Batteries . . . . . . . . . . . . . . . . . . . . . . . . 43 Battery Do’s and Don’ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Power Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Carrying Your Own 12-Volt Power Supply . . . . . . . . . . . . . . . . . . . 47 Battery Packs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 A Different Kind of Battery Pack. . . . . . . . . . . . . . . . . . . . . . . . 52

Alternative Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Chapter 4: Antenna Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . 61

The GPS Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	61
Quad-Helix Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . . .	63
Patch Antenna Orientation . . . . . . . . . . . . . . . . . . . . . . . . . . .	64
Best Performance Summary . . . . . . . . . . . . . . . . . . . . . . . . . .	65
External Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	66
Antenna Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	70
Other Things to Avoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	72
Reradiating Antennas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	72
Personal Reradiating Antenna . . . . . . . . . . . . . . . . . . . . . . . . .	73
Communal Reradiating Antenna . . . . . . . . . . . . . . . . . . . . . . . .	74
Reradiating Antenna Considerations . . . . . . . . . . . . . . . . . . . . . .	74
Setting Up a Reradiating Antenna in a Car . . . . . . . . . . . . . . . . . . . . . .	75
Testing the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	76
Making the System Permanent . . . . . . . . . . . . . . . . . . . . . . . . .	76
Carrying a GPS Signal via Cable . . . . . . . . . . . . . . . . . . . . . . . . . . .	77
How Much Signal Do You Need? . . . . . . . . . . . . . . . . . . . . . . .	77
Cable Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	77
Connector Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	78
Using a Signal Repeater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	79
Building Your Own Mega GPS Antenna . . . . . . . . . . . . . . . . . . . . . . .	79
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	79
Building the Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	80
Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	85

Contents xv

Chapter 5: Protecting Your GPS . . . . . . . . . . . . . . . . . . . . . . . 87

Screen Damage . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . 87
Screen Protectors . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . 88
More Screen Armoring . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . 93
Commercial Protection for GPS and PDAs . . . . . . . . .	. . . . . . . . . 99
Mounting GPS . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . 108
Car Mounting . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . 108
Mounting a GPS for Biking, Hiking, and Skiing . . . . . . .	. . . . . . . . 111
Making a Personalized Case . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . 113
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . 122
Part II: Software Hacks	123
Chapter 6: Hacking the Firmware . . . . . . . . . . . . . .	. . . . . . . 125

Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Updating Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Updating the Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 Hacking GPS Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Bypassing the Garmin eTrex Vista Startup Screen . . . . . . . . . . . . . . 130 Bypassing the Garmin eTrex Legend Startup Screen . . . . . . . . . . . . . 133 Bypassing the Garmin eTrex Venture Startup Screen . . . . . . . . . . . . . 133 MeMap Personalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Manual Firmware Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 Magellan GPS Firmware Modifications . . . . . . . . . . . . . . . . . . . 143 Recovering from a Failed Firmware Load . . . . . . . . . . . . . . . . . . . . . . 144 Garmin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Magellan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Chapter 7: Making Connections . . . . . . . . . . . . . . . . . . . . . . 147

The PC — GPS Relationship . . . . . . . . . . . . . . . . . . . . . . . . . . . .	147
Connection Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	150
Which Connection Is Best? . . . . . . . . . . . . . . . . . . . . . . . . . .	155
Troubleshooting Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	155
PC Connection Trouble . . . . . . . . . . . . . . . . . . . . . . . . . . . .	155
General PDA Connection Trouble . . . . . . . . . . . . . . . . . . . . . .	157
General Bluetooth Connection Trouble . . . . . . . . . . . . . . . . . . . .	158
Software-Specific Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	159
Erratic Mouse Pointer after Connecting a GPS. . . . . . . . . . . . . . . .	159
Windows XP Problem: Microsoft Ball Point . . . . . . . . . . . . . . . . .	159
Microsoft MapPoint Troubleshooting . . . . . . . . . . . . . . . . . . . . .	160
USB-to-Serial Converters . . . . . . . . . . . . . . . . . . . . . . . . . . .	162
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	162

xvi Contents

Part III: Data Hacking	163
Chapter 8: GPS Data . . . . .	. . . . . . . . . . . . . . . . . . . . . . . 165

GPS Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Position, Velocity, Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Working with the Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 EasyGPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 G7toWin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Creative Uses of GPS Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Sharing Waypoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Adding GPS Information to Digital Photos . . . . . . . . . . . . . . . . . 191 Lightning Detector and Plotter . . . . . . . . . . . . . . . . . . . . . . . . 192 Wardriving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 GPS in Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

Chapter 9: Examining the Data . . . . . . . . . . . . . . . . . . . . . . . 195

NMEA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	195
NMEA Sentences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	196
NMEA Sentence Structure . . . . . . . . . . . . . . . . . . . . . . . . . .	196
A Closer Look at NMEA Sentences . . . . . . . . . . . . . . . . . . . . .	197
Examining NMEA Sentences . . . . . . . . . . . . . . . . . . . . . . . . .	199
NMEA Checksum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	205
SiRF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	206
Using NMEA Sentences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	206
GPS NMEA LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	207
GPS Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	209
RECSIM III . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	211
Using NMEA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	213
GpsGate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	213
Recording Actual NMEA Sentences with GpsGate . . . . . . . . . . . . .	216
Recording Simulated NMEA Using GpsGate . . . . . . . . . . . . . . . .	219
Data Playback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	220
Why Bother with NMEA?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	220
Ensuring That Your GPS Works . . . . . . . . . . . . . . . . . . . . . . .	221
Avoiding Data Corruption . . . . . . . . . . . . . . . . . . . . . . . . . .	221
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	222

Chapter 10: More Data Tricks. . . . . . . . . . . . . . . . . . . . . . . . 223

Screenshots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 G7toWin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 G7toCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229