声優視覚文化研究会

This is the first of a series of posts documenting the efforts to reverse engineer the Playstation Move Controller’s mysterious EXT port.

Nobody seems to know how this works…

At the time of this writing, the EXT port is only used by the Sharp Shooter attachement.

The Move itself already received a lot of attention and there is now an API [4] that lets you use the controller in your programs, including button presses, sensor fusion and tracking. However, it has never been used with accessories.

So how does it work when you plug the move into the Sharp Shooter?

First, the buttons on the move still seem to behave as usual: presses get caught by the API. Same for the start and select buttons that are aligned to the real buttons and mechanically transmit the presses.

The “pump action” also directly presses on the trigger.

That’s actually where things get complicated.

The trigger on the Sharp Shooter is just a push button with a spring. When fully pressed, it sends the maximum value of the analog trigger (255). That input is still catched by the API. So the question is: how does the Playstation distinguishes between the Sharp Shooter trigger being pressed and a very nervous pump action going suddenly from 0 to 255?

The “square” and “triangle” buttons are identical on both sides of the gun. They seem to work as they would on the controller itself. Same goes for the “move” button under the trigger.

The “Lock” button mechanically prevents accidentally pressing on the “move” button. The 3 positions switch on top is more problematic. It doesn’t seem to be mapped to any of the buttons on the move and doesn’t get read by the API.

Same for the “reload” button on the bottom.

In the second part, we will tear down the Sharp Shooter and the move and try to eavesdrop on their communications. 

This project is carried on by Raphaël de Courville and Hauke Altmann of Graffiti Research Lab Germany.

Sources: 

Move teardown (video): http://youtu.be/BN2tnTOXzHc

Ifixit move teardown: http://www.ifixit.com/Teardown/PlayStation+Move+Teardown/3594

Sharp Shooter promo video: http://youtu.be/rXNrlAFjq88