AxisAndOhs is an external application that replaces the controller (=yokes, joysticks, etc) logic in

• FSX Acceleration, FSX:SteamEdition
• P3D V2 - 3 - 4 - 5
• Microsoft Flight Simulator (2020)

The app supports native Windows USB Game Controller devices and MIDI devices.

Key features:

• Assign axis movement and simulator events to joystick axis or MIDI rotary encoders
• Assign any simulator event to joystick or MIDI buttons
• Access simulator internal LVARs
• Utilize the new MSFS HTML variables to control for example the buttons on the G1000 units. 
• RPN scripting: by creating your own scripts, it is possible to trigger more complex functionality with a single button than is normally possible with native simulator events.
• Mouse controlled yoke, rudder, throttle or spoilers axis, with trim (in MSFS too)
• AxisAndOhs will also handle Saitek Multi, Radio, Switch and Backlit Information panels. Up to 3 Saitek Flight Instrument Panels ("FIP") can be used as well.
• The app includes a set of virtual flight instruments that you can drag anywhere on your desktop (for example to another screen) or view them using a web browser on any device (for example phone or tablet) that is connected to your LAN or WiFi.
• API based on standard web technology (XMLHttpRequests and JSONP). It supports sending button events, triggering of simulator event IDs, reading and writing of simulator variables.

More virtual flight instruments, like the Airbus type PFD, and an Elgato StreamDeck plugin utilizing the WebAPI are available as separate free downloads on the AxisAndOhs product website.

PLEASE TRY THE DEMO VERSION FIRST, TO MAKE SURE THAT YOUR HARDWARE IS SUPPORTED! 
There will be no refunds, and there won't be any support for non-functional hardware. 
The DEMO version is available on the Lorby-SI website.