update README with new features being tested

Author: jmriego

README.md

@@ -9,6 +9,9 @@ There are two different ways you can use this sketch:
 1. You can use it as some sort of virtual vJoy device. This is what the sketch is doing at the moment. It will receive messages through the COM port and update the current position of the joystick. It can also send the current forces through the COM port. I'm using this in [BrunnerDX](https://github.com/jmriego/brunnerdx) repo to make the Brunner base appear as a DirectX joystick
 2. You can create your own Arduino based joystick using this library as a base. Instead of sending the position/forces through the COM port you can add potentiometers/motors directly.
 
+## In testing
+
+There is currently experimental support for driving wheels on the [wheel](https://github.com/jmriego/Fino/tree/wheel) branch and for using an Arduino DUE on the [due](https://github.com/jmriego/Fino/tree/due) branch. I don't own any of these two devices so if you want to donate them or if testing them yourself please let me know how it's working for you.
 
 ## Ref