You question is a bit too vague and general to answer properly. You mention PID and Qt, which implies you are working in C++. You mention a specific sensor.
Which part(s) are you having difficulty with:
a) Understanding the PID control algorithm,
b) Writing an implementation of PID in C/C++,
c) Creating a user interface with Qt,
d) Using C++,
e) Reading the sensors
The PID control algorithm is very simple and described all around the internet. For example: https://en.wikipedia.org/wiki/PID_controller
. Actually using it properly can be rather application dependent and difficult to tune the parameters. Usually requires a good deal of experimentation before getting satisfactory results.
Actually writing a PID algorithm is also very simple in any language. It's only a handful of lines of code and some simple arithmetic. If you are lazy you can find source codes for PID all over the net as well. For example: https://gist.github.com/bradley219/5373998
and https://github.com/tekdemo/MiniPID/blob ... iniPID.cpp
Creating a user interface in Qt is to big a topic for a forum thread. Again there are articles and blogs about using Qt all over the net.
Programming in C++ is too big a topic for a forum thread. Again, see internet.
I know nothing about the sensors you have there.