MDAIII phone status on COM port

[Anonymous]

Hi to all hardware developers!

I am trying connect my MDAIII to car audio aux input as simple handsfree device (to hear voice or navigation commands in loudspeakers). For this I need simple logical information is phone in talk mode or not. I cannot find this signal in connector when is serial and usb port , +5V power supply and mic/audio output. In serial port is also no activity when phone is in active state, when talking.
When I can find technical information on COM port in Windows mobile 2003 system?

How can I do that? Thanks in advance for any answer.

Andreas

[Anonymous]

Hi,
in http://forum.xda-developers.com/viewtopic.php?t=16096
s93ncer wrote:
What pin is that that gives +5V when in a call on the XDAII?
Pin 12 on an XDA II goes to a positive voltage when in a call.

I am trying control voltage in my MDA3 on pin 12 but is always low 0,1V.
And also in COM port I can't see any activity during calls.
Is there a solution to check phone when in use?
Andreas