Quote Originally Posted by pupqt View Post
The downloaded source is "qextserialport-1.1.tar.gz" from "http://qextserialport.sourceforge.net/qextserialport-1.0.x/" website.
qextserialport is no longer hosted on sourceforge - please go to http://code.google.com/p/qextserialport like littletux suggested. Plus, you should follow the suggestion by high_flyer and install Qt4 (if possible).

qextserialport has been discussed many times in this forum. It is a library and it comes with examples. If you study and understand how the examples use the library then you are well on your way.