Pendulum Balance Robot

Hi everyone, unfortuantely I'm still having no luck, the PID output it still remaining constant. I have tried normalising the position data between 0-1, however that has not given a response. Changing the P value has no effect on the output, neither does changing the position. Has anyone got any thoughts on what might not be working?

Is the PID on?

//turn the PID on
myPID.SetMode(AUTOMATIC);

http://playground.arduino.cc//Code/PIDLibaryBasicExample

tobo bolta hai - "sab galat hai ye BC"

Is it even feasible to control an inverse pendulum using a PID regulator reliably? I mean, it depends on the length of the said pendulum, but from what I recall, it's usually better to use a state feeback with observer. Hmmmmm although Maybe a lead regulator or a PD one would suffice. This being said, you'd probably need a really fast feedback loop, so I would treat the loop code as speed critical.