Joystick Control of a Servo
The hardware setup is very simple, and is described in detail in the serial-servo article. The JR Sport ST47 standard servo is wired directly to Arduino’s 5V power and ground, and the servo’s control wire is connected to Digital pin #2. The Arduino module is connected to a PC (running Linux in our case) with a USB cable, and a standard USB joystick is also connected.
   Joystick Control of a Servo
Check out Joystick Control of a Servo website
principialabs.com