Pico NES HDMI Dual Controller

Open-source RP2040 project for building a NES-style emulator console with HDMI video output and two custom push-button controllers.

About

This repository provides a complete starter architecture for:

• Raspberry Pi Pico / RP2040 based NES emulator host
• HDMI/DVI output pipeline abstraction (PicoDVI-ready)
• Two-player custom controller input using direct push buttons
• Modular emulator core adapter layer (nes_core) so you can plug in an NES core implementation

Features

• RP2040 C/C++ firmware structure using Pico SDK
• Dual-controller input scanning with software debounce
• NES-style button mapping (A, B, Select, Start, Up, Down, Left, Right)
• Input sanitation (Up+Down and Left+Right conflict handling)
• Frame timing loop targeting 60 FPS
• Stub renderer and emulator adapter for bring-up testing
• HDMI reference circuit diagram and wiring notes
• Controller reference circuit diagram and wiring notes
• Build, hardware, and roadmap documentation

Repository Layout

.
|-- CMakeLists.txt
|-- pico_sdk_import.cmake
|-- include/
|   |-- project_config.h
|   |-- controller.h
|   |-- hdmi_video.h
|   `-- nes_core.h
|-- src/
|   |-- CMakeLists.txt
|   |-- main.c
|   |-- controller.c
|   |-- hdmi_video.c
|   `-- nes_core_stub.c
|-- docs/
|   |-- build.md
|   |-- hardware.md
|   `-- roadmap.md
|-- hardware/
|   |-- controllers/
|   |   |-- wiring.md
|   |   `-- controller_circuit_diagram.svg
|   `-- hdmi/
|       |-- README.md
|       `-- hdmi_circuit_diagram.svg
`-- scripts/
    `-- fetch_dependencies.ps1

Hardware Overview

• Board: Raspberry Pi Pico (RP2040)
• Video output: HDMI/DVI via external RP2040-compatible DVI hardware (PicoDVI style)
• Controllers: two custom wired remotes, each with 8 push buttons + common GND
• HDMI reference diagram: hardware/hdmi/hdmi_circuit_diagram.svg
• Controller reference diagram: hardware/controllers/controller_circuit_diagram.svg

Quick Start

1. Install Pico SDK toolchain.
2. Set PICO_SDK_PATH environment variable.
3. (Optional for HDMI) Fetch PicoDVI library: powershell -ExecutionPolicy Bypass -File scripts/fetch_dependencies.ps1
4. Configure and build:

   cmake -S . -B build -DPICO_BOARD=pico
   cmake --build build

5. Flash generated .uf2 to Pico.

Emulator Core Integration

Current repository ships with a bring-up/test stub renderer.

To enable real NES emulation:

1. Add your emulator core source into lib/ (for example a port of nofrendo/fceumm).
2. Implement adapter functions declared in include/nes_core.h.
3. Update src/CMakeLists.txt to compile and link the selected core.

Controller Mapping

• A
• B
• Select
• Start
• Up
• Down
• Left
• Right

Pin assignment defaults are in include/project_config.h.

License

MIT License (see LICENSE).