Turning a Travel Router into a Distributed Desktop

A distributed embedded system built around the TL-MR3020.

Architecture • The Protocols • Build Guide

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📖 Overview

The 3020 Project transforms a limited consumer travel router (TP-Link TL-MR3020) into a functional computer with a display, keyboard, and physical I/O.

Since the router lacks the hardware to do this natively, we built a Distributed System. The router acts as the central orchestrator, offloading specialized tasks to expansion modules over network and serial links.

• The Brain: TL-MR3020 (OpenWrt Linux) — Orchestration & Logic.
• The GPU: ESP32 via TCP/IP — VGA Graphics.
• The I/O: Arduino Nano via Serial — Sensors & Actuators.
• The Input: USB Keyboard via a custom kernel driver.

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🏗️ System Architecture

This repository acts as the System Integrator. It contains the OS configuration, the input driver, and links to the firmware submodules for the expansion devices.

📂 Repository Structure

Directory	Type	Description
openwrt/	Core	OpenWrt build configs & overlay files. Note: Highly stripped to fit HID drivers.
keyboard/	Driver	The "Software Glue." Reads /dev/input/event0, splits output to TCP (Display) and Serial (Nano).
esp-vga/	Submodule	Firmware for the ESP32 VGA adapter. View Repo
nano/	Submodule	Firmware for the Arduino I/O bridge. View Repo
docs/	Docs	Wiring diagrams and architectural notes (In Progress).

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📡 The Protocols

The system relies on human-readable text protocols to communicate between the Router, ESP32, and Nano.

1. Graphics Protocol (TCP/IP)

The ESP32 listens on Port 1337. It accepts newline-terminated text commands to draw text, change colors, or clear the screen.

👉 Full Command Reference: Read the ESP-VGA-Displayer Documentation

2. I/O Protocol (Serial)

The Arduino Nano listens on the router's internal serial port (/dev/ttyATH0) at 9600 baud. It interprets text strings to control GPIO pins and I2C peripherals.

👉 Full Command Reference: Read the 3020-NANO Documentation

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⚡ Build & Setup

1. Clone Recursively

⚠️ Important: This repo uses submodules. You must clone recursively to pull the ESP and Nano firmware.

git clone --recursive [https://github.com/WNH-Organization/The-3020-Project.git](https://github.com/WNH-Organization/The-3020-Project.git)

2. The Router (OpenWrt)

Navigate to the openwrt/ directory. Due to the strict 4MB Flash limit of the TL-MR3020 v1, we had to aggressively strip the OS to the bone.

• Removed: LuCI (Web UI) and all non-essential modules.
• Added: USB HID support (kmod-usb-hid, kmod-input-core, kmod-input-evdev) was prioritized to enable the keyboard.

Flash the generated .bin file to your router.

3. The Expansion Modules

• ESP32: Open esp-vga/ in PlatformIO and flash.

• Config: Ensure it connects to the same Wi-Fi SSID as the router.

• Nano: Open nano/ in PlatformIO or Arduino IDE and flash.

• Wiring: Connect Nano RX/TX to Router UART.

• ⚠️ Warning: You need a voltage divider or level shifter on the RX/TX lines to avoid damaging components. The Router operates at 3.3V and the Nano at 5V.

4. The Keyboard Driver

Compile the keyboard/ program for the MIPS architecture (using the OpenWrt SDK).

# On the router
./3020_keyboard <ESP_IP> <ESP_PORT>

Note: The port is configurable (default is 1337).

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🔌 Hardware LIST

• Router: TP-Link TL-MR3020 v1.
• Microcontrollers: ESP32 (WROOM-32), Arduino Nano (ATmega328P).
• Display: Standard VGA Monitor + VGA Breakout.
• Input: Standard USB Keyboard.

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🤝 Contributing

This project is part of the WNH Initiative.

• Hardware Issues? Check the wiring in docs/ (Coming soon).
• Software Bugs? Open an issue in the relevant submodule.

Maintainer: Taha Ed-dafili (@0rayn)

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_{Built with ☕, Solder fumes, and stripped drivers in Morocco.}