I do not have a PC and am currently running Gran Turismo 6 on Playstation 3. I know that this is not supported, but I figured I would get the rig built and worry about PC/software later. I was going to write my own arduino software and take the data from the pedals for pitch and from the on-screen Gforce display for roll. So I don't know if the software here will be of any use to me.
Can X-sim accept raw analogue data inputs straight from potentiometers connected to pedals/LDR's clipped on to screen?