Application Circuit
Pin Assignment
Pin No. Title
1
Vin
I/O
Note
P
Voltage input 3.3~5V DC +/-10%
Description
Main DC supply for a 3.3V~5V +/-5% DC power module
board
Ground
Provides ground for the engine board. Connect all grounds
Serial port 1(leave open if not used)
Mainly transmits channel for outputting navigation and
measurement data to user’s navigation software or user written
software. Output 0v~2.8v.
Serial port 1(leave open if not used)
Main receive channel for receiving software commands to the
engine board from MiniGPS or GPS Locator Utility software
or from user written software. Input 0v~2.8v.
Reserve
Leave it open.
Serial port 2(leave open if not used)
Mainly used to receive signals for differential purpose. Input
0v~2.8v.
Time pulse (leave open if not used)
For special function. (ex, on/off LED). Output 0v~2.8v.
Backup input voltage 2~5V DC +/-10% Battery backup input; provides power when main power is
removed. Battery voltage should be between 2.0v and 5v.
2
3
GND
TX1
G
O
4
RX1
I
5
6
TX2
RX2
O
I
7
8
1PPS
BAT
O
I
NMEA Protocol (standard messages)
Those messages are output at TX1 at rate of 4800bps. When more than 4 messaged are chosen, a higher baud rate is required.
1) GGA (GPS Fix Data): Gives position, time, number of satellites in use, latitude, latitude sector, longitude, longitude sector,
GPS quality indicator, altitude above mean sea level, etc.
2) GLL (Geographic Position) : Gives latitude, latitude sector, longitude, longitude sector, time as position is fixed, mode
indicator and status for position fix.
3) GSA (Active satellites): Gives selection mode, mode for position fix, number of satellites used, etc.
4) GSV (Satellites in View): Gives total number of messages, messages number, total number of satellites in view, elevation
degrees.
5) RMC (Recommended Minimum Specific Data): Gives time as position is fixed, status of position fix, latitude, latitude sector,
longitude, longitude sector, speed over ground, date, mode indicator.
6) VTG (Over Ground and Ground Speed): Gives speed over ground, unit of speed, mode indicator.
7) ZDA (Time & Date): Gives time, day, month, year, local zone hours, local zone minuets.