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🤔 What is this?

A single-page web tool for receiving photos from the Game Boy Printer Emulator. No installation, no build step, no serial monitor — just open the page, plug in your Arduino, and print.

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✨ Features

• 🚀 Zero install — runs entirely in the browser, single HTML file
• 🔌 Web Serial — direct USB communication, no drivers needed
• 📦 Offline-first — load once, works without internet
• 🖼️ Native PNG export — single photos or batch ZIP (1× / 2× / 4× / 8×)
• 🎨 22 palettes — emulators, hardware-accurate, GBC modes, community favorites, and classics
• 🖌️ Custom palette — paste any palletizer string (#aaa #bbb #ccc #ddd palletizer Name)
• 🔲 Dithering — Bayer 4×4 ordered dither for smoother gradients
• 📐 Gamma correction — γ=2.2 curve to simulate the real DMG screen response
• 🕹️ DMG-themed UI — grey plastic shell, purple DOT MATRIX stripe, magenta buttons

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🚀 Quick Start

What you need

• 🌐 A Chromium browser (Chrome, Edge, Brave, Opera, Arc…)
• 🤖 An Arduino Nano or Uno with the GBP Emulator firmware flashed
• 🎮 A Game Boy + Link Cable wired to the Arduino
• 📷 A Game Boy Camera (or any printable GB game)

Step-by-step

┌─────────────────────────────────────────────────────────┐
│  1. 🔌 Plug the Arduino into USB                         │
│  2. 🎮 Connect the Game Boy via Link Cable               │
│  3. 🌐 Open the app → click Connect                      │
│  4. 🖨️  Print from the Game Boy                          │
│  5. 🖼️  Save photos as PNG or download all as ZIP        │
└─────────────────────────────────────────────────────────┘

💡 Need to flash the firmware? Grab the .hex from mofosyne/arduino-gameboy-printer-emulator and use the Arduino IDE or avrdude.

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🎨 Palettes

22 palettes organised in 5 groups:

Group	Palettes
Emulators	BGB, DMG, SameBoy, Gambatte
Hardware accurate	Accurate (DMG-01 sampled), NSO, Pocket, GB Light
GBC color modes	GBC Green, GBC Red, GBC Blue, GBC Gray
Community	Kirokaze, Mist, Wishes, Hollow, 2-Bit
Classic	B&W, Sepia, Noir, Ice, Burn

You can also paste any palletizer string directly in the sidebar to create a custom palette:

#dbf4b4 #abc396 #7b9278 #4c625a palletizer My Custom Palette

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📁 Project structure

GBP-Downloader/
├── gbp_downloader.html    ← the app (v1.5)
├── index.html             ← redirect to downloader
├── README.md
├── LICENSE                ← GPL-3.0
└── .gitignore

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🙏 Credits

This project stands on the shoulders of an amazing open-source community:

• 🔧 mofosyne/arduino-gameboy-printer-emulator — the Arduino firmware that makes it all possible
• 🖼️ HerrZatacke, BjornB2, virtuaCode — pioneering work on JS-based Game Boy Printer decoding
• 🎨 Raphaël Boichot — protocol research and compression support
• 🗺️ West McGowan — wiring documentation

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📜 License

Released under the GNU General Public License v3.0 — same as the upstream firmware, keeping the whole ecosystem fully open and free.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

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