wiring servo with PID?

Hi,

My projects goal is to build an autonomous gps car that goes through a set of way points. Since the gps module is not very accurate, I am trying to use PID to get rid of the deviation between points.

In the PID v1 library there is a PID tuning example, that demonstrates tuning using input and output.

My question is how I would wire the servo to analog input pin and an analog output pin on the arduino uno? There are only 3 wires on the servo, two which are also for ground and voltage.

So how would I wire it up?

Servo's are driven by the Servo library, they are output only devices - you get no
feedback. Your PID will need some other input to tell it the deviation.

MarkT:
Servo's are driven by the Servo library, they are output only devices - you get no
feedback. Your PID will need some other input to tell it the deviation.

Although, adafruit do sell servoes with feedback.