Build Configuration

Network Configuration

Determine App Sending Port

By default, the gamepad App broadcasts data to port 12121. The port passed during SDK construction must match:

RetroidGamepad rc(12121);  ///< Port must match App configuration

Determine Development Host IP

The mobile App needs to know the development host’s IP address to send UDP data:

• Ensure the phone and development host are on the same local network (connected to the same WiFi)
• Check the IP address on the development host:

ip addr show   # Linux
ipconfig       # Windows

• Configure the development host’s IP address in the gamepad App

Firewall Configuration

Ensure the development host’s firewall allows inbound connections on UDP port 12121:

# Linux (Ubuntu)
sudo ufw allow 12121/udp

# Windows
# Add UDP 12121 inbound rule in Windows Defender Firewall

Environment Requirements

Item	Requirement
Operating System	Linux (Ubuntu recommended) or Windows (WSL)
CMake	≥ 3.10
Compiler	C++17 compiler
Git	For pulling the fmt submodule

Build Steps

Pull Submodules

The example programs depend on the fmt library (managed via git submodule). Initialize before first build:

cd gamepad
git submodule update --init --recursive

Build SDK and Examples

Enter the project directory, create a build folder and compile:

cd gamepad
mkdir build && cd build
cmake ..
make -j

Build artifacts:

Artifact	Description
libgamepad_receiver.a	Static library for upper-layer application linking
example/example_retroid	Retroid gamepad example executable
example/example_skydroid	Skydroid gamepad example executable

Build Static Library Only (No Examples)

cmake .. -DBUILD_EXAMPLE=OFF
make -j

ARM Cross-Compilation

To run on an ARM platform (e.g., Lite3 onboard host), uncomment the cross-compiler settings in CMakeLists.txt:

SET(CMAKE_C_COMPILER "aarch64-linux-gnu-gcc")
SET(CMAKE_CXX_COMPILER "aarch64-linux-gnu-g++")

Then compile:

cmake ..
make -j

CMake Configuration

CMakeLists.txt main configuration options:

Parameter	Default	Description
BUILD_EXAMPLE	ON	Whether to build example programs

Linked dependency libraries:

target_link_libraries(gamepad_receiver PRIVATE -lpthread -lm -lrt -ldl -lstdc++)

Mobile App

App Installation

The controlapp.apk is provided in the project root directory. Install it on an Android phone to use.

App Configuration

Configure the following in the gamepad App:

• Target IP: Development host’s IP address (ensure phone and host are on the same local network)
• Target Port: Default 12121, must match SDK construction parameters
• Gamepad Type: Select Retroid or Skydroid

Usage Steps

1. Ensure the phone and development host are connected to the same WiFi
2. Open the App and configure the target IP and port
3. Run the example program or custom program on the development host
4. Operate the gamepad and observe whether the terminal output updates in real time