OpenBlink VSCode Extension

Edit Ruby, save, and your device changes instantly — wireless embedded development in < 0.1 seconds, with no restart required.

OpenBlink VSCode Extension brings OpenBlink's "Build & Blink" experience to VS Code and Windsurf. Write Ruby code, hit save, and watch it compile and transfer to your microcontroller over Bluetooth LE — all within your editor.

What is OpenBlink?

OpenBlink is an open-source project that enables "Thinking Speed Prototyping" for embedded systems.

Key ideas:

• Instant rewriting — Ruby code changes are reflected on the real device in < 0.1 sec, without microcontroller restart
• Fully wireless — All program transfer and debug console output run over Bluetooth LE — no cables needed
• Ruby for embedded — Use mruby/c, a lightweight Ruby VM, to develop for microcontrollers with high productivity and readability
• For everyone — Not just for embedded engineers. Designed for system designers, mechanical engineers, hobbyists, students, and end users who want to customize their own devices ("DIY-able value")

Features

• Build & Blink — Save any .rb file to instantly compile and transfer via BLE to your device
• BLE Device Management — Dedicated Devices view with scan/stop buttons, real-time device discovery, connection animations, saved-device persistence, and auto-reconnect
• mrbc WASM Compiler — Cross-platform mruby bytecode compilation powered by Emscripten (no native toolchain needed)
• Device Console — Real-time output from your device in the Output Channel
• Board Configurations — Built-in support for Generic (mruby/c standard library), M5 Stamp S3, and XIAO nRF54L15
• Slot Selection — Choose program slot 1 or 2
• Metrics — Compile time, transfer time, and program size with min/avg/max statistics in the TreeView
• Multi-language UI — English, やさしい日本語, 简体中文, 繁體中文
• AI-friendly — Structured [COMPILE]/[TRANSFER]/[DEVICE]/[BLE] output for Windsurf Cascade integration
• MCP Integration — Built-in Model Context Protocol server exposes Build & Blink, device info, console output, metrics, and board reference as AI agent tools (Windsurf, VS Code Copilot, Cursor, Cline), with a dedicated MCP Status sidebar view showing connection activity and build results

Supported Platforms

Installation

1. Open the Extensions view in VS Code / Windsurf (Ctrl+Shift+X)
2. Search for OpenBlink
3. Click Install

Requires VS Code 1.96.0 or later.

Quick Start

1. Click the OpenBlink icon in the Activity Bar
2. In the Devices view, click the Scan (🔍) button to discover nearby OpenBlink devices
3. Click a discovered device to connect — it is automatically saved for future use
4. Open any .rb file and press Ctrl+S / Cmd+S — the file is saved, compiled, and transferred to the device

The currently active .rb file in the editor is always the one that gets compiled and transferred. Previously connected devices appear in the Saved Devices section and can be reconnected with a single click or removed via the trash icon.

Documentation

• Architecture — System overview with Mermaid diagrams
• BLE Protocol — OpenBlink BLE protocol specification
• Build System — Emscripten / mrbc WASM build instructions
• Compiler — mrbc WASM compiler internals
• Board Configuration — How to add new board definitions
• MCP Integration — AI agent setup for Windsurf, VS Code Copilot, Cursor, and Cline
• Internationalization — Multi-language support guide
• Contributing — Development setup, code guidelines, and release process
• Security — Security policy and dependency audit

License

BSD-3-Clause — see LICENSE for details.