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RSA-1500L User Manual

2 Software Interface

2.1 NMEA V3.0 Protocol

Its output signal level is TTL: 4800 bps (default), 8 bit data, 1 stop bit and no parity. It supports
the following NMEA-0183
Messages: GGA, GLL, GSA, GSV, RMC and VTG.
NMEA Output Messages: the Engine board outputs the following messages as shown in Table
2-1:
Table 2-1 NMEA-0183 Output Messages
NMEA Record Description
GGA Global positioning system fixed data
GLL Geographic position – latitude / longitude
GSA GNSS DOP and active satellites
GSV GNSS satellites in view
RMC Recommended minimum specific GNSS data
VTG Course over ground and ground speed

2.1.1 GGA-Global Positioning System Fixed Data
Table 2-2 contains the values of the following example:
$GPGGA, 161229.487, 3723.2475, N, 12158.3416, W, 1, 07, 1.0, 9.0, M, , , ,0000*18

Table 2-2 GGA Data Format
Name Example
Units Description
Message ID $GPGGA
GGA protocol header
UTC Position 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 Table 2-1
Satellites Used 07 Range 0 to 12
HDOP 1.0 Horizontal Dilution of Precision
MSL Altitude 9.0 meters
Units M meters