This repository contains an X-Plane plugin that enables Hardware in the Loop (HIL) testing of a flight controller.

It has been tested on X-Plane's default plane (Cessna Skyhawk), but it should work fine on any single-engine airplane with "standard" control surfaces.

The plugin will override user control of the aircraft while enabled. If manual control of the aircraft is required, the plugin can be enabled and disabled mid-flight via the menu under Plugins->Plugin Admin->Enable/Disable.

The parking brake can be controlled by the user even when the plugin is enabled. It's usually under the 'B' key.

Communication is done via USB-UART (FTDI), so you will need to make sure the serial port has the right permissions set. Also you may need to hardcode the serial port used if it is not /dev/ttyUSB0 or COM5—ideally this would be configurable via the X-Plane GUI instead.

The plugin will print debug information if launched from the command line with ./X-Plane-x86 |grep FFSim or similar. It will print a message when the serial connection is established or lost.

Windows has a few prerequisites. The following worked for an RSCS Windows 10 Education machine, YMMV:

1. Install Cygwin. Make sure the standard development packages are installed—in particular a 64-bit GNU linker is essential.
2. Install Rust via the EXE. When prompted, enter your host triple as x86_64-pc-windows-gnu.
3. Install LLVM via the latest 64-bit prebuilt Windows binary available from the LLVM releases page.

You must use a 64-bit compiler

cargo build
cp target/debug/libffsim.so $XPLANE_DIR/Resources/plugins/ffsim.xpl

The name of the DLL (libffsim.so) will differ slightly on Windows and macOS. The destination file should still have the extension .xpl.

cargo build --release
cp target/release/libffsim.so $XPLANE_DIR/Resources/plugins/ffsim.xpl