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HayBox supports multiple communication backends that determine how your controller communicates with consoles or PCs. Each backend implements a different protocol, and some can even be used simultaneously.

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Available Backends

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XInput (Default for Pico USB)

XInput is the default USB backend for Pico/RP2040 devices and provides the best PC gaming experience.
Platform: Pico/RP2040 only Use cases:
  • Modern PC games with native controller support
  • Steam games
  • Windows gaming in general
Advantages:
  • Plug-and-play compatibility with most PC games
  • No driver installation required on Windows
  • Full analog stick and trigger support
  • Native rumble support (if implemented)
Selection:
  • Automatically selected on USB connection (Pico)
  • Cannot be manually forced on Arduino

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DInput

Platform: All devices (Pico and Arduino) Use cases:
  • Legacy PC games that don’t support XInput
  • Dolphin Emulator on Arduino devices
  • Games that explicitly require DInput
  • Required for keyboard modes
Selection:
  • Pico: Hold RF3 (Z) on plugin
  • Arduino: Automatic when USB is detected
DInput is the only backend that supports keyboard modes. To use any keyboard mode, you must be in DInput mode.
Keyboard Mode Support: 
// Keyboard modes only work with DInput
if (backend->BackendId() != COMMS_BACKEND_DINPUT) {
    return; // Keyboard mode activation fails
}

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GameCube Console

Platform: All devices Use cases:
  • GameCube console
  • GameCube controller adapters (Mayflash, official, etc.)
  • Dolphin with native GCC support
Automatic Detection:
  • Pico devices automatically detect GameCube console connection
  • Arduino devices default to GameCube when no USB detected
Manual Selection (Arduino only):
  • Hold RT1 (A) on plugin for GameCube mode with polling rate fix disabled (required for most adapters)
Polling Rate: 
// Arduino example - 125Hz polling for console
GamecubeBackend *backend = new GamecubeBackend(
    inputs, input_sources, input_source_count, 
    pinout.joybus_data, 
    125 // Polling rate in Hz
);
Arduino-based controllers without a boost circuit require 5V power. For Mayflash adapter, both USB cables must be plugged in. On console, the rumble line must be intact.

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Nintendo 64 Console

Platform: All devices Use cases:
  • Nintendo 64 console
  • N64 emulators with native controller support
Selection:
  • Pico: Automatically detected when connected to N64 console
  • Arduino: Hold RT3 (C-Left) on plugin
Polling Rate:
  • N64 runs at 60Hz polling rate
  • Can be configured similarly to GameCube backend on Arduino

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Nintendo Switch USB

Platform: Pico/RP2040 only Use cases:
  • Nintendo Switch console via USB
  • Super Smash Bros. Ultimate
Selection:
  • Hold RF2 (X) on plugin
  • Automatically sets initial game mode to Ultimate mode
Features:
  • Emulates Pro Controller
  • Full support for all Switch buttons and sticks
  • Optimized for Smash Ultimate

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B0XX Input Viewer

Platform: All devices Use cases:
  • Streaming and content creation
  • Practice and input analysis
  • Visualizing inputs in real-time
Automatic Activation:
  • Automatically enabled as secondary backend when using DInput or XInput
  • Runs simultaneously with the primary backend
Implementation: 
switch (backend_id) {
    case COMMS_BACKEND_DINPUT:
    case COMMS_BACKEND_XINPUT:
        backend_count = 2;
        backends = new CommunicationBackend *[backend_count] {
            primary_backend, 
            new B0XXInputViewer(inputs, input_sources, input_source_count)
        };
        break;
}

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Backend Detection and Selection

1

Check Button Holds

On plugin, HayBox first checks for button hold combinations to see if a specific backend is requested.
2

Auto-detect Console

If no button hold matches, HayBox attempts to detect if connected to a console:
  • GameCube console (via data line detection)
  • N64 console (via data line detection)
3

Default to USB Backend

If no console detected, uses the default USB backend:
  • Pico: XInput (configurable)
  • Arduino: DInput

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Platform-Specific Differences

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Advantages

  • Automatic console detection
  • XInput support for better PC compatibility
  • No polling rate configuration needed
  • Can switch between backends by unplugging and replugging
  • More backends available (Switch, XInput)

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Default USB Backend

XInput (best for PC gaming)

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Available Backends

  • XInput
  • DInput
  • GameCube
  • N64
  • Nintendo Switch
  • NES (experimental)
  • SNES (experimental)
  • Configurator (web-based config)

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Multiple Backends Simultaneously

HayBox supports running multiple communication backends at the same time: 
// Primary backend + Input viewer
backends = new CommunicationBackend *[2] {
    primary_backend,
    new B0XXInputViewer(inputs, input_sources, input_source_count)
};

// Both backends receive reports each iteration
for (size_t i = 0; i < backend_count; i++) {
    backends[i]->SendReport();
}
This allows you to, for example:
  • Play on PC while streaming with input viewer
  • Send inputs to multiple outputs simultaneously
  • Debug input behavior while playing

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Troubleshooting

If using an official adapter with Arduino, hold A (RT1) on plugin to disable polling rate optimization.For Mayflash adapters:
  • Arduino: Requires both USB cables plugged in for 5V power
  • Pico: Works with single USB cable (3.3V native)
The backend is selected on plugin. To change backends:
  1. Unplug the controller
  2. Hold the appropriate button combination (see above)
  3. Plug in the controller while holding the button(s)
Keyboard modes only work with the DInput backend. If using Pico:
  1. Hold RF3 (Z) on plugin to force DInput mode
  2. Then activate keyboard mode using the mode selection combination
XInput is only available on Pico/RP2040 devices. Arduino/AVR devices are limited to DInput for USB communication due to hardware constraints.

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