GPS on Option's GlobeTrotter modules
How to enable and use the GPS functionality on your GTM378 module?
13/07/2009
On some Option Globetrotter modules it is possible to enable the GPS interface, so you will be able to use the second antenna connector of the module to retrieve GPS information from over the air and to forward the GPS signals to third party software like Googlemaps for example
Getting started : check hardware and interface configuration
To verify whether it is technically possible to retrieve any GPS signals from over-the-air, you should verify whether your module has the secondary antenna fysically available. Normally you have two connectors on the module, some modules only have one connector available, hence it is impossible to use this module for retrieving any GPS signals. The connector where you can find the character 'A' can be used to connect the GPS antenna. The other connector is the main antenna for your 3G signal.
Now that you verified the availibility of the GPS antenna connector, you should check whether you have the GPS interfaces enabled on your module.
Please check device manager whether the GPS interface is available.
How to activate the GPS interface?
The GPS interface can be turned ON and OFF through AT commands issued on the application interface.
To activate the GPS interface, the AT_OIFC command is required.
This command also enables or disables other interface settings. To enable the GPS interface only, it is required to first call the currently loaded configuration.
This is done by issuing:
AT_OIFC?This AT command will return an unsolicited response: “_OIFC : w,x,y,z” (where w, x, y and z are numbers representing the currently loaded interface states.)
To enable the GPS interface, only the last number needs to be set. All other numbers must be repeated unchanged!
Issue the following AT command:
- AT_OIFC=w,x,y,0 to turn the GPS interface OFF
- AT_OIFC=w,x,y,2 to turn the GPS interface ON
The Globetrotter module needs to be rebooted for the GPS port to become available.
Unplug the power supply from the evaluation board.
After applying power back to the evaluation board, the GPS interface will become available in the Windows Device Manager.