[stack-teapot]

Description

This PR adds a new example demonstrating how to use the Pico SDK with libjoybus to simulate a GameCube controller over USB serial. The example allows button presses to be sent from a USB serial terminal to the Raspberry Pi Pico, which then acts as a GameCube controller on RP2XXX devices.

Changes Included

• examples/pico-sdk/gcn-controller-target/usb_serial/main.c — USB serial GameCube controller implementation.
• examples/pico-sdk/gcn-controller-target/usb_serial/CMakeLists.txt — Build configuration for Pico SDK and libjoybus.
• examples/pico-sdk/gcn-controller-target/usb_serial/.gitignore — Ignores the build directory.
• examples/pico-sdk/gcn-controller-target/usb_serial/README.txt — Documentation including build, flash, and usage instructions.

Notes

• Builds using standard Pico SDK and libjoybus setup.
• Supports all main GameCube buttons via simple USB serial input.
• Build output (build/) is ignored; users must have Pico SDK and libjoybus checked out locally.

Usage

1. Build the example with:

cmake -B build -DPICO_ENABLE_STDIO_USB=1 -DPICO_ENABLE_STDIO_UART=0 -DPICO_BOARD=pico2 -DPICO_PLATFORM=rp2350 . 
cmake --build build

[stack-teapot]

Hi! I just wanted to say thank you for this project it really helped me with a remote GameCube playing project I’m working on. I appreciate all the work you’ve put into this!

[loopj]

Thanks for this, and sorry it sat for so long! The library API changed quite a bit since you opened it, so I've rebased your commit onto main and built on top of it in #66. Your commit is kept as-is, so you're credited in the history.

The main change is that the computer now sends the full controller state (buttons, both sticks and triggers) as a line of hex, rather than one character per button. This makes holds, combos and analog input possible. Closing this in favor of #66. Thanks again!