Joypad OS

Universal controller firmware for adapters, controllers, and input systems.

Joypad OS translates any input device into any output protocol. Connect USB, Bluetooth, or WiFi controllers to retro consoles, or bridge native retro controllers to USB. It runs on RP2040, ESP32-S3, and nRF52840 microcontrollers.

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Understand the System

• Architecture

  The 4-layer model: inputs, core, outputs, and apps

• Data Flow

  How controller input travels from device to console

• Glossary

  Key terms: input_event_t, router, profiles, PIO, and more

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Browse by Layer

• Input Interfaces

  USB HID, XInput, Bluetooth, WiFi, SNES, N64, GameCube, NES, Neo Geo, LodgeNet, and more

• Output Interfaces

  GameCube, PCEngine, Dreamcast, Nuon, 3DO, N64, Loopy, USB Device, BLE, UART

• Joypad Core

  Router, profiles, players, storage, LEDs, hotkeys, and other shared services

• Apps

  30+ firmware configurations: usb2gc, bt2usb, snes2usb, n642dc, and more

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Getting Started

• Installation Guide

  Flash firmware to your adapter in minutes

• Build Guide

  Set up a development environment and compile from source

• Supported Boards

  RP2040, ESP32-S3, and nRF52840 boards

• Supported Controllers

  USB, Bluetooth, keyboards, mice, and hubs

• Web Config

  Configure your adapter from the browser -- no install required

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Console Adapters

Console	App	Highlights
PCEngine / TurboGrafx-16	usb2pce	Multitap (5 players), mouse, 2/3/6-button
GameCube / Wii	usb2gc	Profiles, rumble, keyboard mode
Sega Dreamcast	usb2dc	Rumble, analog triggers, 4 players
Nuon	usb2nuon	Controller, Tempest 3000 spinner, IGR
3DO	usb23do	8-player support, mouse, extension passthrough
Neo Geo / SuperGun	usb2neogeo	7 profiles, 1L6B arcade layouts
Casio Loopy	usb2loopy	4-player (experimental)
N64 (wireless)	bt2n64	BT controllers, rumble, profiles

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Native Input Adapters

Convert retro controllers to USB or bridge them to other consoles:

• SNES to USB -- SNES/NES controller to USB gamepad
• N64 to USB -- N64 controller to USB gamepad
• GameCube to USB -- GameCube controller to USB gamepad
• NES to USB -- NES controller to USB gamepad
• Neo Geo to USB -- Arcade stick to USB gamepad
• LodgeNet to USB -- LodgeNet hotel controllers (N64/GC/SNES) to USB
• LodgeNet to N64 -- LodgeNet hotel controllers to N64 console
• LodgeNet to GameCube -- LodgeNet hotel controllers to GameCube console
• N64 to Dreamcast, SNES to 3DO, N64 to Nuon -- Cross-console bridges

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Platforms

Platform	Apps	Documentation
RP2040	All adapters	Build Guide
ESP32-S3	bt2usb (BLE)	ESP32-S3 Docs
nRF52840	bt2usb, usb2usb (BLE)	nRF52840 Docs

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For Developers

• Development Guide -- How to add inputs, outputs, apps, and drivers
• Architecture -- The 4-layer model and dual-core execution
• Data Flow -- Input-to-output pipeline walkthrough
• Router -- Routing modes, merge, transforms

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Protocol Reference

Dive into the low-level console protocols that Joypad OS implements:

• 3DO PBus
• GameCube Joybus
• Nuon Polyface
• PC Engine
• LodgeNet
• SInput HID

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Community & Support

• Discord: community.joypad.ai -- Community chat
• Issues: GitHub Issues -- Bug reports
• Source: GitHub -- Contributions welcome

Joypad OS is licensed under the Apache-2.0 License.