Datasheet

ZEUS Embedded Linux Development Kit Quickstart AEL Embedded Linux
© 2007 Eurotech Ltd Issue C 27
Terminating the PPP connection
To end the PPP connection, use the poff command:
# poff gprs (alternatively use: killall –TERM pppd)
To power off the modem use:
# zeus-modem-off.sh
Using GPS under AEL Embedded Linux
For the Embedded Linux configuration, the GPS module is attached to COM7
(/dev/ttyS6). The following details show how to set up a GPS connection under AEL
Embedded Linux. The specific operation may vary with other types of GPS receiver.
Initiating a connection
When the board is switched on, the GPS module is enabled by default, so you do not
need to explicitly turn it on.
Set up the serial port to the correct baud rate to suit the GPS receiver. The following
command line will set the correct baud rate for the supplied GPS module.:
# stty -F /dev/ttyS6 speed 4800
Running the above command will report back 9600 on completion but it does
set 4800. If you run it a second time it will report 4800
If the GPS module can locate at least three satellites it starts to provide position data.
Some modules take longer than others to acquire their initial position. You can dump the
raw NMEA data from the GPS module to your console by using a simple cat command:
# cat /dev/ttyS6
Here is an example of what you should see when you are receiving valid NMEA data:
$GPRMC,170446.000,A,5211.3763,N,00008.3102,E,0.11,294.58,041006,,,A*61
$GPGGA,170447.000,5211.3763,N,00008.3101,E,1,08,1.0,17.6,M,47.0,M,,0000*6A
$GPGSA,A,3,25,10,21,06,16,30,23,07,,,,,1.5,1.0,1.2*35
(The exact data returned from the GPS module will vary depending on your location.)
Instead of using cat, you can use minicom on the port if you prefer.
The NMEA data returned from the GPS module can be fed directly into applications
such as VisualGPS and Google Earth back on an external host to gain a visual
representation of the GPS data.
Terminating the GPS connection
Press Ctrl-C to stop the cat command dumping data from the GPS receiver to your
console.