IBM G-Mouse GPS Receiver G-Mouse MR Appendix A Software Protocol

G-Mouse GPS Receiver User Manual
Page 11
Appendix A Software Protocol
The protocol of G-MR is designed base on NMEA(National Marine Electronics Association) 0183
ASCII format. The full protocol is defined in “NMEA 0183, Version 3.01”.
A.1 NMEA Transmitted Message
G-MR GPS receiver use MediaTek as the core, and output NMEA-0183 standard format message.
The default communication parameters for NMEA output are 9600 baud, 8 data bits, stop bit, and no
parity. Table A-1 NMEA-0183 Output Messages
NMEA Sentence Description
GPGGA Global positioning system fixed data
GPGLL Geographic position latitude \ longitude
GPGSA GNSS DOP and active satellites
GPGSV GNSS satellites in view
GPRMC Recommended minimum specific GNSS data
GPVTG Course over ground and ground speed
GPZDA Data and Time
A.1.1 Global Positioning System Fix Data (GGA)
Samples:
$GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M, , , ,0000*18
Table A-2 GGA Data Format
Name Description Units Description
Message ID $GPGGA GGA protocol header
UTC Time 161229.487 Hhmmss.sss
Latitude 3723.2475 ddmm.mmmm
N/S Indicator N N = north or S = south
Longitude 12158.3416 dddmm.mmmm
E/W Indicator W E = east or W = west
Position Fix Indicator 1 See Table4-3
Satellites Used 07 Range 0 to 12
HDOP 1.0 Horizontal Dilution of Precision
MSL Altitude 9.0 Meters
Units M Meters
Geoid Separation Meters
Units M Meters
Age of Diff. Corr.
Second
Null fields when DGPS is not used
Diff. Ref. Station ID 0000
Checksum *18
Table A-3 Position Fix Indicator
Value Description
0 0 Fix not available or invalid
1 GPS SPS Mode fix valid
2 Differential GPS, SPS Mode fix valid