The PlayStation Move functions by using a combination of accelerometers, gyrometers, and magnetometers. Sony determined that the sensors alone are not enough to accurately track movement. As a result, the lit bulb on top of the controller works in conjunction with the PlayStation Eye to help do so.
The colors of the bulbs are activated by a combination of LEDs and are fully customizable by game developers. The colors can also change shade to help the PS Eye better track movement in case a particular room environment has similar color schemes.
Data processing for the PlayStation Move controller is handled by the PlayStation 3′s Cell processor. A single SPU handles data from the controller’s sensors and images from the PS Eye. Up to four controllers can be tracked at one time. Furthermore, Sony indicated that the Cell is rather adept at image processing and does so with little memory overhead and minimal impact to overall performance.
The PS Eye’s camera system generates images at 60 frames per second, with a resolution of 640×480. When combined with the PlayStation Move controller and the Cell processor, the setup can accurately measure millimeter differences in movement and is accurate enough to detect one-degree shifts in angle.
Calibration of the controllers will likely take place when a gaming session begins, and according to Sony’s researchers, it shouldn’t take more than half a second to accomplish. Should conditions change sufficiently (for instance, if someone turns on the lights or the sun sets), in order for the setup to accurately determine movement, gameplay will automatically stop, and the player will be prompted to recalibrate the controller.