Difference between revisions of "GPS"

Revision as of 22:29, 8 December 2007

This page will summarizes informations to connect GPS modules to your Armadeus board

Introduction

GPS stands for Global Positioning System and is intended to allow one to knows its localization on Earth quite accuratly. See Wikipedia Article for more informations.

Tested hardware

GPS receiver are generally driven through a low speed RS232 bus. Currenlty JulienB is experimenting the GPS receiver of the Aurore/Sequanux association. This autonomous receiver uses a standard NMEA GPS module that can be connected to the 3,3V RS232 port of your APF9328. All you need to do is to get the GND and TX signals out of this module and connect is to your GND and RX signals of your APF: File:GPS Aurore front.png
File:GPS Aurore back.png

Usage

• Configure Serial port 1 of your APF (4800 bauds 8N1):

# stty -F /dev/ttySMX1 4800

• Power on your GPS module
• Test it: you'll get NMEA frames:

# cat /dev/ttySMX1
$GPGGA,000026.032,,,,,0,00,,,M,0.0,M,,0000*53

$GPGSA,A,1,,,,,,,,,,,,,,,*1E

$GPRMC,000026.032,V,,,,,,,160406,,*2F

$GPGGA,000027.032,,,,,0,00,,,M,0.0,M,,0000*52

There is a small tool (under development) in target/demos/gps/ that can help you to parse some NMEA frames.

NMEA Frames signification

• $GPGGA: Global Positioning System Fix Data
• $GPGLL: Geographic Position, Latitude/Longitude
• $GPGSA: GPS DOP and Active Satellites
• $GPGSV: GPS Satellites in View
• $GPRMB: Recommended Minimum Navigation Information
• $GPRMC: Recommended Minimum Specific GPS/TRANSIT Data

Links

• http://en.wikipedia.org/wiki/Global_Positioning_System
• http://vancouver-webpages.com/peter/nmeafaq.txt
• http://www.futuraelettronica.net/pdf_ita/8160-ET312.pdf
• Documentation sur le module GPS du projet Aurore