The project is pretty forward. The "RUN" buttons are wired to pins 3 (LEFT) and 4 (RIGHT) of the controller port and the "JUMP/THROW" button is wired to pin 6 (FIRE). All buttons return to pin 8 (GROUND).
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Few components are required: Three buttons, one cable and one box.
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The buttons used on this project have low profile
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The low profile buttons allowed to use a low profile box.
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The buttons were disposed like the original track and field controller
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The unused wires are isolated using heat shrink tubing
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And here's the finished controller.
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Do you by any chance have the Link/files for the Plastic case/box?
Also how are you finding those buttons? If they are great, can you please share their part number as well so I can get something which you have tested.