FlyByWire A32NX API
This section is aimed at sim pilots who intend to use external hardware or software to connect to the FlyByWire A32NX to read values and control the aircraft.
General
Many sim pilots wish to use dedicated hardware or specific software to control their aircraft, which goes beyond just the normal flight stick and maybe a controller for thrust.
However, hardware alone is not sufficient to control an aircraft in Microsoft Flight Simulator (or any sim). Software is required to tell the sim what the different levers (axis) and buttons shall actually do.
Most hardware (or software) vendors ship their products with a driver for their hardware which translates hardware input into software commands which are then sent to the simulator.
The problem with this approach is that all aircraft need to actually use the same software commands (API) for this to work on. For Microsoft Flight Simulator, this has been achieved by most default aircraft delivered when MSFS launched. Unfortunately, the API used (SimConnect, MSFS API) is not able to handle more complex aircraft and in addition, there are other limitations that would go beyond this guide to explain.
To make it possible for 3rd party aircraft developers to go beyond these limitations, Microsoft Flight Simulator enables aircraft developers to create their own API, most commonly in the form of so called sim-vars and sim-events.
All the major custom aircraft on the market use this possibility. So, not only does the FlyByWire A32NX do this but e.g., the Aerosoft CRJ, PMDG DC-6, Working Title's CJ4 mod, Justflight PA-28 Arrow, etc.
What these advanced aircraft have in common is that any standard drivers for hardware (or software) controllers can not use the additional aircraft APIs (variables and events).
Therefore, much to the frustration of users, many hardware controllers do not correctly work with these aircraft with their default drivers.
But there is a solution to this problem.
Solutions
To solve the issue described above, there are several software solutions which basically replace any default hardware drivers. These solutions take the hardware inputs and translate them into the correct software commands for the current aircraft and send them to the simulator.
The main feature of these solutions is that the hardware/software mapping is highly configurable and programmable, and in some cases even with a nice and user-friendly interface.
Example:
So, for example, the standard software command for the landing lights is the SimConnect event "LANDING_LIGHTS_ON".
But the Aerosoft CRJ aircraft requires these variables:
- set ASCRJ_OVHD_LDG_LEFT -> 1
- set ASCRJ_OVHD_LDG_NOSE -> 1
- set ASCRJ_OVHD_LDG_RIGHT -> 1
The mentioned software solutions would then enable the user to map a hardware landing light button to these three aircraft specific variables instead of using the default SimConnect event.
The FlyByWire A32NX also requires specific variables to control its advanced features. The documentation for these variables and events can be found here:
Flight-Deck Documentation: Flight-Deck API
Developer Documentation: A32NX API Documentation
The most common software solutions are: