ER-332
Specifications are subject to be changed without notice.
Page 6 of 14
Version 1.3.1
* PBRES (Push button reset):
This pin provides an active-low reset input to the engine board. It causes
the engine board to reset and start searching for satellites.
* SELECT:
Do not connect (do not use)
* TXA:
This is the main transmits channel for outputting navigation and measurement data to user’s
navigation software or user written software.
* RXA:
This is the main receive channel for receiving software commands to the engine board from
SiRFdemo software or from user written software. Normally this pin must be kept in high, and if you don’t
use this pin please connect a resistor to pull high. (
NOTE
:
When not in use this pin must be kept “
HIGH
” for
operation. From Vcc connect a 470 Ohm resistor in series with a 3.2v Zener diode to Ground. Then,
connect the Rx input to Zener’s cathode to pull the input “
HIGH
”.)
* Time mark:
This pin provides one pulse-per-second output from the engine board that is synchronized
to GPS time.
* GND:
GND provides the ground for the engine board. Connect all grounds.
3. Software Commands
NMEA Output Command
GGA-Global Positioning System Fixed Data
Table B-2 contains the values for the following example:
$GPGGA,161229.487,3723.2475,N,12158.3416,W,1,07,1.0,9.0,M,,,,0000*18
Table B-2 GGA Data Format
Name
Example
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 Table B-3
Satellites Used
07
Range 0 to 12
HDOP
1.0
Horizontal Dilution of Precision
MSL Altitude
1
9.0
meters
Units
M
meters
Geoid Separation
1
meters
Units
M
meters
