Tip of the Month (June 2007)

Troubleshooting GPS Connections

When people first start using Global Position System (GPS) devices with Visual CE, they sometimes have problems getting them to work. Here is how to resolve these problems.

When you installed Visual CE, we installed a sample form (GPS.VCE) that reads and displays a GPS signal. It is most probably in C:\Program Files\Windows CE Services\SYWARE Visual CE\GPS.VCE. Open that form in the form designer (FILE | OPEN), download it to the handheld (FILE | DOWNLOAD FORM), and then try it on the handheld (START | PROGRAMS | GPS). If that for works, use it as a model for your form.

If GPS.VCE does not work, look at the manual that came with your GPS (or contact your GPS manufacturer) and find out these connection settings for your particular GPS:

COM port: COM1:, COM2:, COM3:, COM4:, COM5:, COM6:, COM7:, or COM8:
Baud rate: 300, 1200, 2400, 4800, 9600, 14400, 19200, 38400, 57600, or 115200
Data bits: 4, 5, 6, 7, or 8
Parity: none, even, odd, mark, or space
Stop bits: 1,1.5, or 2
Flow contol: none, RTS/CTS, or XON/XOFF

In the form designer, open C:\Program Files\Windows CE Services\SYWARE Visual CE\GPS.VCE (FILE | OPEN), select EDIT | MACROS/EVENTS, and make sure the connection settings are correct in the COMMUNICATE | OPEN step.

Also click on the COMMUNICATE | GPS step and make sure the correct COM port is specified. Also, click on the COMUNICATE | CLOSE step and make sure the correct COM port is specified.

Download the form to the handheld (FILE | DOWNLOAD FORM), and then try it on the handheld (START | PROGRAMS | GPS).

If that does not fix the problem, it could be that your GPS device needs a delay between the time the COM port is opened and the time the GPS information is available. You may have to put in a small delay. To do this:

1. In the form designer, open C:\Program Files\Windows CE Services\SYWARE Visual CE\GPS.VCE (FILE | OPEN).
2. Select EDIT | MACRO/EVENTS. Insert a new step between the COMMUNICATE | OPEN and COMMUNICATE | GPS steps. Change the action from "Move to when pressed" to "Sleep", and set the seconds to 15 (or maybe even 30). Click CLOSE to close the macro editor.
3. Download the form to the handheld (FILE | DOWNLOAD FORM), and then try it on the handheld (START | PROGRAMS | GPS).

If this does not work, make sure that your GPS is functioning properly by using the GPS software that came with yor GPS device.