MAE 5483 ADVANCED MECHATRONICS DESIGN

TERM PROJECT - SPRING 2012 REPORT

GPS Receiver Interfacing With Microcontroller And Displaying

Data On LCD And PC

SHUVRA BANIK 5/1/2012

SCHOOL OF MECHANICAL AND AEROSPACE ENGINEERING OKLAHOMA STATE UNIVERSITY

1

The Global Positioning System (GPS) is a navigation system which provides location and time

information using satellites orbiting the earth. A GPS receiver can locate satellites and their distances

from its position and based on those distances, it uses a simple mathematical calculation called

Trilateration by which can provide location information very accurately. GPS receivers are getting very

popular nowadays for their simplicity to use. In this project a basic GPS receiver unit has been interfaced

with a microcontroller and the data found have been shown in both LCD and PC.

2

Page Number

Introduction 4

Components 5

Hardware 5

Working Principles 7

How To Locate 7

Circuit Diagram 8

GPS Receiver (Garmin GPS 18 LVC, 5m)

8

LCD Module (4*20 Serial LCD Module (BPP-420) v4.0)

8

Project Setup 9

NMEA 0183 Protocol 10

Initial Programming Strategy 11

RDA Interrupts 11

External Interrupts 12

Direct Data Read 13

Final Programming Outline 15

Changes Made After Final Presentation

15

Explanation OF Final Code 17

Main Function 17

Option, Display Related Functions

17

GPS Parsing Functions 18

Other Supportive Functions

18

3

LCD Functions 19

All Functions Summary 20

Final Output 21

LCD Display 21

PC Display 24

Conclusion 27

References 28

Appendix 29

Final Code 29

4

A GPS system is a space-based satellite navigation system developed by U.S. Department of Defense in

1973 which became fully operational in 1994 constellation of 27 satellites (24 are active

at a time and 3 are standby). Each of these satellites makes two complete rotations every day around

the Earth in some predefined orbits and the orbits are arranged in such a way that at anytime, anywhere

on Earth, there are at least four satellites visible in the sky. Low Power Radio Signal at 1575.42 MHz in

the UHF band is used to send signal from satellites to GPS receiver. In this project a Garmin GPS 18 LVC,

5m GPS receiver has been interfaced with a CCS PIC18F4520 Development Kit. Sentences have been

sent to GPS receiver to control which output sentences it should transmit. Sentences from the GPS

receiver have been parsed with different string manipulations and resulting data have been showed in

both LCD and PC.

5

Hardware

Breadboard

A 3.25X2.125 400PNT breadboard has been used to place the electronic circuits.

Figure 1: Breadboard

Wires

Wires have been used to connect electronic devices on the breadboard.

Figure 2: Wires

GPS Receiver

A Garmin GPS 18 LVC, 5m has been used as GPS receiver.

Figure 3: Garmin GPS 18 LVC, 5m

6

LCD Module

A 4*20 Serial LCD Module (BPP-420) v4.0 has been used.

Figure 4: 4*20 Serial LCD Module (BPP-420) v4.0

Development Kit

One CCS PIC18F4520 Development Kit has been used.

Figure 5: Development Kit