Is there a reliable method to determine serial pin layout?

[wesley96]

I'm currently using a Samsung MITs-M400 PDA-phone which runs the Korean edition of Pocket PC 2002 Phone Edition. From the 19-pin connector on the bottom of the unit, the battery charge and USB connecton pins have been determined after cracking open the cradle and some 3rd-party data cables for this device, but the serial port pins are still elusive. Samsung does not intend to release any specifications relating to the port (but then again they don't even release SDK for the internal camcorder and TV on the device, so we're used to that), so I'll have to try finding out the hard way. Trouble is, there is hardly any device on the market that uses this port. Is there still a way to determine which pins are assigned to serial connection? I'd appreciate any help.

[Peter Poelman]

Use a program that opens the port (after killing ActiveSync) and try to figure out which pins are high impedance by hooking a 10k resistor to ground from the tip of your multimeter. Anything that measures 5v under these conditions is an output that is driven high. Now hook the end of the resistor to 5v instead of ground, and repeat measurements. Any pin that is now 0v is an output that is driven low. Remaining pins are either inputs or non-connected pins. Experiment from there and you will find it.

[wesley96]

Alright, thanks for your input. :)