Thank Mike for explaining since i was not aware of that type of sensors but this is the kind of tech one have to experiment to see if it could be a good solution because like i mention in another post the cursor need to be immobilize and not be moving while he have his foot on the pedal or else aiming will be very problematic and that's the reason i went for a very basic wasd or keyboard arrows buttons.
And the right foot control the inverted mouse and with the correct dpi value only slight movement of the foot should give him the precision require to play fps or any other type of games. I have already test the inverted mouse and after 2 hours i was able to move the cursor very precisely at 2400 dpi value and this is where the dpi button came in handy since if he want to play as a sniper he can then lower the dpi to something like 800 dpi and have more precision.