GPS Logger

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GPS Logger
ECE 345 Project 27 Jim Kohout Derek Starr TA
Jon Wheeler
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Introduction

• Goals
• Utilize differential GPS to log the performance
  of a vehicle on the road.
• Create an easy-to-use user interface to
  facilitate data storage, simulation, and analysis

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ObjectivesUser Interface

• Graphical analysis of velocity and acceleration
• Visually identifiable position indicator
• Something other than just longitude and latitude
  coordinates
• GPS Status indicator
• Ease of control of all program functionality

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ObjectivesData Acquisition

• Acquire positional, time, altitude, and velocity
  data from serial port
• Calculate road slope and acceleration
• Record incoming data to .txt file
• Sequentially load data from a .txt file for
  simulation purposes

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ObjectivesCommunication

• Identical software on both ends of communication
• Data Transmission over serial port
• Indistinguishable from data sent by GPS

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ObjectivesHardware

• Wireless serial link
• At least 600 Bytes/sec

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Parts

• Garmin GPS 12XL 200
• Garmin GBR 23 200
• Mount for GBR 23 23.50
• Linx Transmitter 433 MHz / 315 MHz 6.90
• Linx Receiver 433 MHz/ 315 MHz 13.79
• 330 Ohm Resistor 0.05
• Total 444.24

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Total Cost

• Labor Total- 40/hour 2.5 150 hours
  15,000/person
• Parts Total 444.24
• Total Cost 30,444.24

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Block Diagram
Computer 1
Computer 2
GPS 12 XL
Satellites
GBR 23
Coast GuardBeacon
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Project Construction and TestingMotionless GPS
Serial Input

• Construction
• Program function to receive data from the GPS
• Program basic displays to assist in debugging
• Testing
• Can we extract position, velocity, etc. from the
  GPS data stream while in the lab?

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Project Construction and TestingRecording Data

• Construction
• Program functions to record incoming data to .txt
  file
• Testing
• After simulating the ILLINI 22 bus route, has the
  .txt file been created correctly?

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Project Construction and TestingSimulating Data

• Construction
• Program functions to read .txt file, and to
  sequentially read and display the data
• Testing
• Is the data being read in the correct order and
  at the correct speed? Is any data being missed,
  etc.?

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Project Construction and TestingSerial
Communication

• Construction
• Program function to transmit data over serial
  link
• Testing
• Can the receiving application distinguish the
  signal from a GPS sent signal?

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Project Construction and TestingWireless Link

• Construction
• Build Linx transmitter and receiver circuits
• Testing
• Using an oscilloscope and function generator, are
  the circuits operating correctly?
• At what maximum distance will this link still
  operate reliably (SNR at different distances)?
• Can the wireless link transmit the serial data
  transparently?

These tests werent performed due to a failure
of the circuit in previous tests
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Project Construction and TestingAdditional
Functionality

• Construction
• Program functions to calculate road slope and
  acceleration
• Program functions to graph velocity and
  acceleration data
• Program function to plot position on a map
• Testing
• Do the velocity and acceleration graphs
  accurately reflect what is occurring?
• Is the position being plotted correctly on the
  map?

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Problems and Challenges

• Receiving the Garmin GBR 23
• Parsing the data from the GPS
• Getting the LINX chips to transmit and receive
• Burning out original LINX chips

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Successes

• Reading in the data through the serial port and
  being able to parse it
• Writing data to files
• Sending data from one computer and having another
  computer receive and log the data

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Recommendations

• Order parts as early as possible AND continually
  check on the parts status
• Using the GBR 23
• Future project idea
• How to increase the range beyond several miles,
  i.e. using a pager system to transmit data.