Handheld Wireless GPS Tracking Device

Senior DesignEEL 4914C : UWF, Fall 2006

Team

Doug Cumbie Developed GPS Module and Wireless Transceiver

Module. Assisted in development of LCD software interface.

Jonathon Bean Developed User-Interface Module, Power Supply

Module, and assisted with LCD software/hardware interface. PCB Design and assembly.

Faculty Mentor: Dr. Thomas Gilbar

Abstract

The enhanced awareness that Global Positioning Systems (GPS) provide has revolutionized the way we interact with our surroundings. Many industries today, primarily in aviation, depend upon the latitude, longitude, and altitude information that GPS provides. Commercially, GPS has become increasing popular for use in vehicles and handheld units. An enhancement to a GPS device would allow for the ability to not only track your own position, but the position of other remote devices. By utilizing wireless communication technology, the position information obtained from a GPS may be relayed to other devices for tracking and increased awareness of other remote units.

Introduction

Main Goal: Develop a GPS Device with the added feature of remote position tracking/sharing.Intended Users: Various user groups

Hikers Military Disaster Relief – Rescue workers

Limitations GPS requirement for outdoor, sky-visible condition Limited range of wireless transceiver

Design Requirements

Main Design Objectives Provide geographical present position information Provide ability to transmit present position information to a

remote unit either automatically or on-command Provide ability to receive a remote unit’s position

information Present a graphical presentation of remote unit’s position

relative to self position Provide a predefined-message sending capability Present all information on a graphical liquid crystal display

(LCD) Provide a minimal user-interface for simple use Package components in a compact case

Design Requirements cont…

Constraints Time Product Selection and Cost

Standards NMEA 0183 Interface Standard for GPS Data

Retrieval UART for Module Communications FCC Approved Radio Transmission

End Product DescriptionThe Handheld Wireless GPS Tracking Device is a product that provides the user with the ability to obtain one’s geographical position in the form of latitude, longitude, and altitude and wirelessly share this data with another similar device. The battery-powered device is packaged in a compact case for easy operation and portable use. The user interface consists of a graphical display and four buttons used for paging through various informative screens. The graphic LCD provides information to the user that consists of current present position, numeric position of the remote unit, graphical position of the remote unit, and a message sending/receiving capability. The device utilizes a wireless transceiver that is capable of transmitting the user’s position information up to 14 miles line-of-sight. The Handheld Wireless GPS Tracking Device is useful for many scenarios that require knowledge of another person or group’s location.

Technical ApproachModularized Design

Microprocessor Module GPS Receiver Module Wireless Transceiver Module User Interface Module

LCD and Pushbuttons Interface Power Supply Module

System Software Modules Main GPS Radio LCD

Component Parts Breakdown

Microprocessor ModuleRuns Main LoopInitializes all ModulesUART ParsingButton HandlingLCD RefreshLCD Screen TransitionsUser Message Sending

GPS Receiver Module

Initializes GPS ReceiverNMEA ParserUpdates Present Position Structure (Latitude, Longitude, Altitude, Heading, and Speed)Slant Range and Bearing to Remote Device CalculationsFormats Position Message for Sending

Radio Software ModuleInitializes Wireless TransceiverSends Message DataReceives Message Data Parses Received Position or User Messages Stores Parsed Position Data in Remote

Position StructureMessage Structure Format: Comma-Delimited ASCII Packets

User Interface ModulePushbutton Interface Power Switch: Double-Pole Double-Throw Four User Pushbuttons

User Interface Module cont…LCD Interface

Initializes MOD5213 Queued Serial Peripheral Interface (QSPI)

Initializes LCD Device Provides Software API for Character Writing and Graphical

Drawing to the Display Format 48x84 pixel display into 6 row x 14 column

character map

User Interface Module cont…

User Interface Module cont…Graphical Tracking

“X” represents remote unit position relative to self

User’s heading is referenced toward top of screen, remote unit is referenced from user’s heading.

2 Miles Wide by 0.878 Miles High Maximum Distance (1 mile = 20.5 pixels)

Range (miles) and Bearing (degrees)

Power Supply ModuleTwo DC Voltage Supplies 3.3VDC Regulated for MOD5213 and LCD 5.0VDC Regulated for GPS and Radio Modem

Double-Pole Double-Throw used for Power SwitchTransient Suppression Circuits for ProtectionBattery Life (max calculated): 20.697 hrs for 3.3V Supply 9.69 hrs for 5.0V Supply Approximately 9 hour overall battery lifetime

Full System Schematic

Power Supply Schematic

Printed Circuit Board Design

Printed Circuit Board Assembly

Testing Approach

Validate each individual module independently for proper operationFull System Tests Validate all modules operate as expected Radio transmission between units GPS Position Fix LCD Updates Pushbutton Events

Budget

Final Product Results -Handheld Wireless GPS Tracking Device

Compact Case Design with Simple User InterfaceGPS Position InformationRemote Device Position TrackingPredefined Message Sending/Receiving