I had an old PSOne controller lying around that I thought would be perfect for this project. I used precision screwdrivers, a hammer and a larger flathead screwdriver to disassemble [and mangle] the controller:
Here is what the controller looked like before I started taking it apart.
As you can see, the controller is held together with seven screws. The middle screw was being stubborn, but was put into its place using a handheld electric drill.
This is the controller opened up:
The back case came off cleanly, taking the L2 and R2 buttons with it. The majority of the electronics within the controller were left attached to the front of the controller.
The shoulder buttons were held on a plastic cradle. The cradle straddled a rubber mat with raised dimples that mapped onto two buttons on a printed circuit board. All of the printed circuit boards [PCB] on the controller were stamped with the numbers S003 94HB. From my research, 94HB corresponds to the part number for an LED, one of which was used for the on/off indicator for the analog sticks in the controller. I couldn’t find anything for S003.
Below, you can see the PCB that mapped to the directional pad, analog, start and select buttons, as well as the triangle, square, cross and circle buttons on the controller. These were connected to the PCB that housed the analog sticks with a Sumitomo G91 AWM 2896 80C 16pin ribbon cable.
Once the PCBs were removed, the dimpled rubber pads for the buttons were visible. The analog button was different from the rest in that it mapped to the PCB using a rigid plastic piece that also housed the stubborn screw that I mentioned earlier.
I thought that the button design for the triangle, square, cross and circle buttons on the controller was pretty awesome. Each button is keyed uniquely so that it sits flush with the housing only when it’s inserted in the correct position with the correct orientation.
The analog stick covers were easily removed to show the following set-up. I tried to pry these off of the PCB that housed them but only succeeded in snapping the PCB in two. I tried to hammer/lever these open, but these things are very sturdily built. They are probably really strongly welded together? Makes sense, and is an example of the thoughtful design that went into the design of these controllers, as they receive a ton of punishment from hardcore gamers.
From HowStuffWorks.com, the analog stick system consists of two potentiometers at right angles to one another. Current flows through each one, but the amount is determined by the resistance of the set-up [my research indicates that the controller receives 5V from the system]. The position of the joysticks impacts the amount of resistance in the system, which can then be used to map the precise location of the joystick, enabling user control.
The rumble functionality looks to be powered by two simple DC motors, each attached to two unbalanced weights.
The PCB that housed the analog sticks had this CXD8771Q T5V17 9949HAL 754327 chip on it. I tried to google it, but found nothing.
The controller’s cable head [where it inserts into the system] also proved difficult to open up. It houses 9 pins, each of which can be used to send data between the controller and the system. Here is the mapping, again from HowStuffWorks.com:
- DATA – This pin carries the signal that the controller sends to the PSX each time a button is pressed. It is an 8-bit serial transmission.
- COMMAND – This pin is used by the PSX to send information to the controller. Such information might trigger the motors in a Dual Shock controller at the proper moment. It also uses an 8-bit serial transmission.
- Not used
- POWER – This pin supplies 5 volts to the controller from the PSX.
- SELECT – This pin is used by the PSX to notify the controller of incoming data.
- CLOCK – This pin carries a synchronizing signal sent from the PSX to the controller.
- Not used
- ACKNOWLEDGE – This pin sends a signal to the PSX from the controller after each command that is received on Pin 2.
I was not able to find out what the metal [non-ferrous] collar around the controller cable did. My guess is that it regulates voltage/current somehow.
Finally, the fully deconstructed/exploded view of the controller. The controller’s plastic casings and buttons were injection molded, as were the rubber stoppers that sat between the buttons and the circuit board: