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This section explains how to feed TomTom Navigator with your own GPS information (position, speed,
direction).
9.1. About External GPS Drivers
You can provide your own GPS positional information to TomTom Navigator. Whilst the GPS support
application for TomTom Navigator allows you to connect to a GPS feed through the built−in COM ports,
certain applications require a feed which is delivered through a different source, such as a TCP/IP
connection. The mechanism described here also allows multi−plexed GPS/GSM/Telemetry data delivered
over a built−in COM port to be demulti−plexed by you − the GPS feed can then be passed on to TomTom
Navigator. Many blackboxes apply this mechanism.
When providing your own GPS feed, you may supply NMEA 0183 V2 or SiRF binary data formats.
You must at least supply UTC, Longitude, Latitude, Direction, Speed and HDOP (horizontal dilution of
precision).
For NMEA 0183 V2 the RMC, GLL, GGA, GSA, GSV and VTG verbs are recognised.
Caveats: The feed works in one direction only − you will never receive any commands (such as GPS reset)
from TomTom Navigator. The "Reset GPS for this location" feature in TomTom Navigator will have no
effect, and you will need to implement such features yourself.
9.2. Providing GPS information
9.2.1. Configuring TomTom Navigator
In TomTom Navigator, go to the GPS information screen and select the "GPS" tab. Choose either the
"NMEA 0183v2 Driver" or the "SiRF Driver" as your GPS device. The usual COM port drop down list will
only allow you to select "Ext Driver".
The driver may be selected programmatically by setting the following registry keys (TomTom
Navigator and the GPS support application should not be running on the device):
For an NMEA 0183 V2 feed:
[HKEY_LOCAL_MACHINE\SOFTWARE\TomTom\GPS Engine]
"Enabled"=dword:00000001
"Device"="NMEA 0183v2 Driver"
"Option"="Ext Driver"
For a SiRF Binary feed:
[HKEY_LOCAL_MACHINE\SOFTWARE\TomTom\GPS Engine]
"Enabled"=dword:00000001
"Device"="SiRF Driver"
"Option"="Ext Driver"
Caveats: Changing any other registry keys may render TomTom Navigator unusable.
9.2.2. Providing your own feed
TomTom Navigator installs a Control Panel applet in the \Windows folder on the Pocket PC. It will
show up in the System tab of the Settings option on the main Start menu and pops up the GPS support
application.
9. External GPS Drivers
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