A got an idea on how to make support for USB devices (not only garmin)
Seeking for USB Serial driver for wince, I read a lot of topics, where
people saying how they use usb GPS (and some other) devices with their
PDAs. By default there are only HID and MSD drivers installed on WM2003
(can't tell about WM5, since I don't have any device with it).
E.g. this topic:
The idea is: USB Serial driver creates virtual COMx port. All
communication with device is done thru that port. Even in apps, that can
work with serial ports only.
So, to add USB garmin support, we have to add some new option, to force
garmin code to use USB protocol over serial port. This also may be
useful in other builds - garmin device might be connected thru USB-COM
From: Robert Lipe <robertlipe@us...> - 2006-06-04 21:14:34
> So, to add USB garmin support, we have to add some new option, to force
> garmin code to use USB protocol over serial port. This also may be
> useful in other builds - garmin device might be connected thru USB-COM
Garmin serial protocol and Garmin USB protocol are similar but
different. They are similar at the upper layers, but every packet and
every response is different.
There are X kinds of USB GPSes.
1) Garmin USB protocol devices.
2) GPSes that have the equivalent of a USB/Serial adapter (such as the
prolific or ftdi chips) built into them. These are typically the
"hockey puck" class of products. This works well for low-cost devices
that stream position info.
3) GPSes that show up as a mass storage device - you communicate with
these by copying files of a special format to or from them. Nuvi and
C500 do GPX files. Explorist and Meridian use files that look like
What you're describing works reasonably well for only the second class.