XInput to vJoy RC Flight Mixer

A C++ application that bridges standard XInput gamepads (like Xbox controllers) to radio-control (RC) flight simulators. It reads raw gamepad inputs, applies deadzones and aviation-specific control mixing (such as differential ailerons), and translates the signals into standard RC PWM pulse widths (1000–2000µs) before feeding them into a vJoy virtual device.

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Tech Stack

• Language: C++
• APIs: Windows API, Microsoft XInput API
• Driver Integration: vJoy SDK (Dynamic DLL injection)

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Key Features

• Aviation Control Mixing: Implements programmable differential ailerons (currently configured to 40%) to counteract adverse yaw, accurately mapping a single roll axis input to dual independent servo outputs.
• RC Pulse Translation: Converts normalized floating-point gamepad inputs into standard Radio Control PWM pulse widths (1000µs – 2000µs) expected by flight simulators.
• Dynamic Driver Hooking: Safely loads vJoyInterface.dll and resolves memory addresses for core functions at runtime, preventing hard crashes if the virtual driver is missing.
• Signal Processing: Implements custom deadzones and linear magnitude scaling for thumbsticks and analog triggers to guarantee precise control resolution.
• Low-Latency Polling: Operates at a stable 50Hz (20ms) polling rate, perfectly matching standard RC receiver hardware output frequencies.

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Hardware Requirements

• Windows PC
• XInput-compatible controller (e.g., Xbox One / Series X Controller)
• vJoy (Virtual Joystick) installed and configured with at least 5 axes.

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Installation & Setup

1. Prerequisites

Ensure you have installed the vJoy device driver and configured a virtual controller. You will also need a C++ compiler (like MinGW or MSVC) installed on your system.

2. Clone the Repository

git clone [https://github.com/sonnyrising/controller-to-rc-util.git](https://github.com/sonnyrising/controller-to-rc-util.git)
cd controller-to-rc-util

3. Compile the Code

If you are using GCC/MinGW, compile the project and link the XInput library:

g++ main.cpp -o rc_mixer.exe -lxinput

Note: Ensure vJoyInterface.dll is present in the same directory as the executable, or added to your system PATH.

4. Run the Application

./rc_mixer.exe

Once running, the terminal will output the live PWM telemetry data (1000-2000) for Left Aileron, Right Aileron, Elevator, Rudder, and Throttle.

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Project Architecture

• main.cpp — The monolithic core of the application. It contains the 50Hz polling loop, the mathematical normalization functions, the RC mixing logic (differentialAilerons), and the Windows API hooks for both XInput and the vJoy DLL.