Near Future Laboratory has put some information on their analog version of a PS2 controller for the PSX project online recently.
This is the one that slows the analog part of the controller down over time, so that when you play a title like Katamari Damacy the Prince will get tired. A lot more details are available linked above.
To quote in part: So, this is my analog version of a playful Playstation 2 controller for the PSX project -- the one that slows the analog part of the controller down over time so, you know.. when I'm playing Katamari Damacy it's a bit more realistic that the Prince gets tired or during GTA, my guy actually gets tired from running away from liquor store heists and stuff.
I'm looking at two approaches. The first is digital -- basically intercepting and modifying the communication between the console and the controller. (I've described the protocol, and there's lots of great, hard-gained information out and about describing how it works.)
This second, is a more expeditious design. Basically, I tap right into the PSX controller, putting a microcontroller in between the analog control joysticks and the little FPGA or whatever it is that senses the analog control joysticks.
So, my microcontroller determines where the control sticks are and, depending on how long the game's been played, "dampens" the value, constraining its range.
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