A system determines a position of a rotating object in a device and controls the device according to the determined position of the rotating object. The system includes a reflecting region on the rotating object and a light source located in the device. Emitted light is emitted by the light source onto the reflecting region and reflected light is reflected off the rotating object. The reflected light has an intensity. The system also includes a detector that detects the reflected light and measures the intensity of the reflected light. The reflecting region has a feature configured to effect a change in the intensity of the reflected light as the rotating object rotates. The change in the intensity of the reflected light corresponds to a change in a signal associated with a determined position of the rotating object. The device is controlled according to the determined position of the rotating object.

A system determines a position of a rotating object in a device and controls the device according to the determined position of the rotating object. The system includes a reflecting region on the rotating object and a light source located in the device. Emitted light is emitted by the light source onto the reflecting region and reflected light is reflected off the rotating object. The reflected light has an intensity. The system also includes a detector that detects the reflected light and measures the intensity of the reflected light. The reflecting region has a feature configured to effect a change in the intensity of the reflected light as the rotating object rotates. The change in the intensity of the reflected light corresponds to a change in a signal associated with a determined position of the rotating object. The device is controlled according to the determined position of the rotating object.

An apparatus, a system and a method for detecting position of a movable object in a device and using the same for controlling the device. A distance and/or an intensity of emitted light may be measured by using a sensor to emit light and detect light to determine the location of the movable object. The movable element absorbs emitted light from the sensor. The sensor determines and/or measures an intensity of the emitted light from the sensor which is not absorbed by the movable object. The intensity of emitted light is related to the position of the movable object in the device. A microprocessor may determine the position of the movable object based on the intensity of emitted light detected by the sensor. The position of a rotating object on a crankshaft in an engine may be detected.