Getting GPS information
Retreiving GPS coordinates
22/05/2009
The GPS interface is a serial port to the module.
The GPS interface is a serial port to the module., this allows you to connect with a terminal program.
In our example to retreive GPS data, we can connect toCOM31.
The terminal cannot be used forentering commands, but the GPS output will appear on it.
GPS position determination is started usingthe AT_OGPS command. Here is the syntax:
| Command | Possible Response(s) |
| _OGPS=<mode> | OK ERROR |
| _OGPS? | _OGPS: <mode> |
| _OGPS=? | _OGPS: (0-2) |
Description
Changes the mode of the GPS engine: on, offor tracking.
Defined values
<mode>:
0: disable GPS Position Determination
1: enable GPS Position Determination
It will turn off upon error or positionfix.
2: enable GPS Tracking
This will automatically re-start thePosition Determination when it ends.
Example:
When there is a sufficiently strong GPSsignal, an NMEA data stream will appear on the GPS interface. Initially, the module will continuouslyreceive satellite data. The position data will be empty at this time. After a while, the module will get a positionfix and display it in the $GPGGA value.
For more information about the NMEA codes,see the NMEA specifications.
Option develops the following AT commands forusing GPS function.
AT_OGPS // Start or stop a GPS determination
AT_OGPSP // Set parameters for a GPSdetermination
AT_OGPSLS //Set parameters for using withSUPL A-GPS
AT_OGPSCONT //Set Context information whichGPS will use to contact the SUPL server
AT_OMOLR // Start a Mobile OriginatedLocation Request(MOLR) and set Transfer to Third Party information to be used
AT_OMTLR // Set automatic response, show alocation verify indication and allow the user to send a response
Beware, for different modules, theinstructions of these AT commands might be slightly different. Please contactOption for the latest instructions.