[mikets]

The way the PID controller in WPI lib works is that you inherit the PIDOutput class and provide a PIDWrite callback function. The PID controller will call the PIDOutput:: PIDWrite function to run your motors. In essence, do something similar to this:

class MyRobot: public SimpleRobot, public PIDOutput
{
 
public:
    void PIDWrite(float output)
    {
        //program your motors accordingly with the output value.
    }
 
    MyRobot()
    {
        //Create the PID controller object.
    }
}