Unity does not currently provide a way to create a custom input device. I've added a feature request in the Wishlist/Feedback, but it doesn't have very many votes. I think this feature is a huge weak spot that reduces Unity's candidacy as a development platform in markets that don't exactly fit into the same mold as commercial video games.
Here's a link to the Wishlist. Please upvote!
[Expose Input system for custom devices][1] Hardware that the OS does not see as a game input device (joystick/gamepad), a keyboard, or a mouse will not be "seen" by the Unity Input Manager and will require a plugin. My suggestion would be to create an event system that will send out input changes from all relevant devices and have your object subscribe to that event. Or, you could wrap all valid input devices with a single class which would do its own polling, and then have your object poll that class. Depending on how much time you have for development, a custom driver could probably be created to make your input device look like a game controller at the OS level. Unity would then likely treat it as any other joystick device. [1]: http://feedback.unity3d.com/forums/15792-unity/suggestions/1121947-expose-input-system-for-custom-devices?ref=title
[Expose Input system for custom devices][1] Hardware that the OS does not see as a game input device (joystick/gamepad), a keyboard, or a mouse will not be "seen" by the Unity Input Manager and will require a plugin. My suggestion would be to create an event system that will send out input changes from all relevant devices and have your object subscribe to that event. Or, you could wrap all valid input devices with a single class which would do its own polling, and then have your object poll that class. Depending on how much time you have for development, a custom driver could probably be created to make your input device look like a game controller at the OS level. Unity would then likely treat it as any other joystick device. [1]: http://feedback.unity3d.com/forums/15792-unity/suggestions/1121947-expose-input-system-for-custom-devices?ref=title
