Programming stuff

Sorry, i know this site is about security and all but i need some programming help.
I've been asked to write a program for the palm (WinCE) that can talk to a sensor my science teacher has. Anyway, I can't get it to respond to anything and was wondering how to find out exactly what is being sent by another program. I have something on the palm that listens and catches info sent but it comes up as characters, I've succesfully found the numerical values of all of them but when I send them it still doesn't do anything. This is essentially the same thing as writing a device driver for a binary device on a serial (RS-232) connection and I have no idea what i'm doing.

Oops my mistake, I've been playing around with stuff for awhile and what I think I need to know is how to send command values over the connection. Like the null value, etc.. all the commands with binary values of 0-30 that can't be sent as text.

check www.programmersheaven.com . Very useful info there on all types of programming.

If you working w/a palm you might want to visit
http://palm.com/developers/