DIY steering wheel questions

Hi,
This is my first post so I may have gone in the wrong section.
Let's come to my problem, I am building a steering wheel for my PC using the UnoJoy software on a Arduino Mega 2560, everything works fine but I wanted to make a LED visualizer to see the right moment to shift (F1 style) and I can't find any clue on how to get the data from games like Project: CARS to the controller, anyone knows how I could do? Thanks in advance.

I can’t find any clue on how to get the data from games like Project: CARS to the controller, anyone knows how I could do?

To start with “using the Unojoy software” doesn’t really cut it. You have some code running on the Arduino that you got from somewhere. You should at least tell us where.

The last time I used a steering wheel (my motorcycles do not have steering wheels, and that’s all I usually use), it was an input device. I used it to tell the wheels where to point. It has controls on it to tell the heater to get warmer or cooler, to tell the fan to spin faster or slower, to turn on or off the cruise control, etc. But, it has no way to output anything.

It is not used for shifting, either.

So, the fact that you want some additional data from some application running on another computer, for some other purpose has nothing to do with building a steering wheel, does it?

Unless the code you currently have has a way to send requests for data to the application on the PC, and the application on the PC has a way to respond to those requests, the simple answer is “You can’t”.

But, without knowing anything about the code on the Arduino, or any details about the application(s) on the PC, we really can’t help you.