The 22 pin connector that fits into the iPaq 3900 series uses the following
pins for a connection to a NMEA serial port:
pins 1,2,3,4 = 5Volt
pins 10,15,22 = common
pin 7 = RD (input to iPaq)
pin 8 = TD (output from iPaq)

When using a DB9 male connector for the serial port connection use the
following pins on this connector:
pin 2 = data in (to iPaq)
pin 3 = data out (from iPaq, but normally not used)
pin 5 = common
pin 8 = +5Volt

Good luck,

Karel, NL

"Michael" schreef in bericht
om...
There are commercial solutions availabe, ready to use.
But I would like to know which pins are used on the
IPAQ 3900 side for a two wire communication with the GPS
and which pins are used for the +5V power supply.

The IPAQ connector has some 22 pins and I guess that for
power pins 19 gets +5V and pin 21 gets ground.

A standard serial cable may connect pins 6,7,8,9,10,11,12,13,14,
whereas the USB cable connects to what? Is it pin 17 and 22 or
some of the serial pins?

Can someone explain the pin usage for a 4 wire power/com cable
on the IPAq side?

Thanks a lot
Michael