Transcription: In the Microsoft Joystick, two infrared light-emitting diodes attached to the joystick handle project beams of light that are detected by a stationary camera in the base of the joystick. Signals from the camera not only tell the software which way you're moving the joystick, but they tell the processor how the motors are moving the joystick, information the processor uses in a local control loop to constantly correct the joystick's motion.
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