Acceleration based on position

[umangv620]

I tried implementing Mark's example and my encoder into the code, and got this: http://img687.imageshack.us/img687/4504/photodtz.jpg (sorry for the bad screenshot).

There is a (-x) on Joystick 2 axis 2 because going forward gives -1 for some reason, and we have no clue how to calibrate the logitech attack 3 joysticks. It shouldn't change anything in the code, right?

When I deployed this and clicked enable on DS, the elevator suddenly started moving up, and about halfway, it started jerking down and up. By then I rushed to click disable, but no one was moving the joystick during the deployment. Why did the elevator start moving on its own? Since the joystick wasn't moving, its value was 0, and the encoder reset its value to 0 when I clicked enable, so it shouldnt move, right?

Or did I miss something while coding the PID? (Wasn't really sure what the 3,0,0 for PID meant in mark's code, so I just tried using 1 and keeping it simple).