Inside a PS3 Controller

A PlayStation 3 SIXAXIS controller looks a lot like a PlayStation DualShock controller on the outside. But inside, a SIXAXIS controller is different. Unlike a DualShock controller or an Xbox 360 controller, it doesn’t vibrate. It’s missing the motors and spinning weights you’ll find in vibrating controllers. Instead, it has a piezoresistive acceleration sensor, which is made up of silicon crystals. This sensor lets it detect movement. In some games, you can play by moving the whole controller around. 
 

The buttons and sticks are still part of the controller, though. They communicate with the controller’s microprocessor through a printed circuit board (PCB). The processor, which acts like the controller’s brain, monitors changes to the controller’s circuitry. The buttons and thumb sticks cause these changes.
The analog sticks use variable resistors to change the flow of electricity. These resistors are a lot like dimmer switches used to make lights brighter or darker. The farther you move the sticks, the more the resistance changes. In a flying game, for example, this could let you descend quickly or slowly, depending on how far you move the sticks. 




The controller sends all this information to the console using a Bluetooth transmitter or a USB cable. You can also use the USB cable to recharge the lithium-ion battery that provides electricity for the controller.
Light-emitting diodes (LEDs) on the PCB let you know whether the controller is on and which port on the console it’s connected to. Clear pieces of plastic allow the light from the LEDs to travel to the surface of the controller where you can see it.

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When you move the controller, the crystals inside the piezoresistive acceleration sensor change shape, causing the amount of electrical resistance in the sensor to change. By analyzing how and where the crystals change shape (how and where the resistance changes) the chip can detect movement. When you tilt the controller, it barely moves in the middle. The edges, on the other hand, move most. For this reason, the acceleration sensor is on the corner of the PCB.