Have an operational PID system

The PID of the power converter in voltage mode is an important milestone for the project. It allows the control of voltage in both input and output. Ultimately, the PID needs to be:

Stable
Callibrated (Kp, Ki and Kd)
Generic

The criteria to reach this milestone are:

A PID code that is tested for its stability with different disturbances
A PID code that has a expected behavior in terms of response time and overshoot
A PID that can be easily created, called for and manipulated by users without the need to go into much detail of its implementation