Espruino
JavaScript for microcontrollers — run JS on hardware.
Open the official app on www.espruino.com
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Use it free
Open the official tool or demo — no account needed.
Self-host it
Run the open-source version on your own infrastructure.
What is Espruino?
Espruino is an open-source JavaScript microcontroller platform designed for embedded systems development. It enables developers to program microcontrollers using JavaScript, targeting applications in IoT, wearables, and wireless peripherals. The platform supports a range of hardware boards, including Bangle.js smartwatches, Puck.js sensors, and Jolt.js control modules, allowing users to create interactive devices without soldering. Espruino addresses the challenge of rapid prototyping by providing a web-based development environment that eliminates the need for traditional IDEs or desktop software. It is particularly useful for hobbyists, educators, and professionals seeking to build low-cost, wireless-connected hardware projects with minimal setup.
How it works
Espruino is a JavaScript-based microcontroller platform that runs on devices like Bangle.js, Puck.js, and Jolt.js. It allows developers to write code directly in JavaScript, enabling real-time interaction with hardware components such as sensors, LEDs, and Bluetooth modules. The platform is ideal for creating IoT devices, smart wearables, and wireless peripherals. Its primary purpose is to simplify hardware programming by leveraging JavaScript's ease of use and web technologies, reducing the learning curve for embedded development. Espruino supports Web Bluetooth for wireless programming, allowing users to debug and control devices via a browser without additional software. It also includes a built-in JavaScript interpreter, enabling immediate execution of code on connected hardware.
How to use it
- 1Connect the Espruino board to a computer via USB or Bluetooth. 2. Access the web-based IDE or use a browser to interact with the device via Web Bluetooth. 3. Write JavaScript code to control hardware components, such as reading sensor data or toggling LEDs. 4. Upload the code to the board, which executes it in real time. Practical tips include using the Espruino Web IDE for quick prototyping, leveraging pre-built libraries for common tasks, and testing Bluetooth connectivity before deployment to ensure stable communication.
What it can do
- javascript microcontroller
Use cases
Assumptions and limitations
Assumptions
- source: https://www.espruino.com/
- license: MPL-2.0 — free to use
- privacy: Self-hosted — you control your data
Limitations
- Limited processing power compared to traditional microcontrollers like Arduino
- Dependence on Bluetooth connectivity for programming and debugging
- Smaller memory capacity restricting complex applications
- Lack of native OS-level features compared to full-fledged embedded systems
- Limited community support compared to more established platforms
Understanding the result
JavaScript for microcontrollers — run JS on hardware.
Tool details
- Clearly flagged when a network request is needed.
- No account, no sign-up, and no tracking of your content.
- Powered by (MPL-2.0).
- Built with
- (https://www.espruino.com/)
- License
- MPL-2.0
- Runs locally
- No — requires a network request
- Verification
- Not yet verified
- Input
- Query
- Output
- Text
Built with https://www.espruino.com/. OpenToolVault provides the discovery and browser interface while crediting the original project maintainers.
- Built with
- License
- MPL-2.0
Open-source project
OpenToolVault is an independent directory. We are not affiliated with or endorsed by this project.
References
- / — GitHub Repository
Upstream project · GitHub
- MPL-2.0 License
Upstream project
Frequently asked
How does Espruino differ from traditional microcontroller platforms like Arduino?
Espruino uses JavaScript instead of C/C++ for programming, enabling rapid prototyping through web-based IDEs and Web Bluetooth. Unlike Arduino, it requires no desktop software for basic operations, though it lacks the extensive library ecosystem and performance optimizations of Arduino-compatible boards.
How does Espruino execute JavaScript on microcontrollers?
Espruino embeds a lightweight JavaScript interpreter optimized for resource-constrained devices. This interpreter processes code in real time, allowing direct control of hardware peripherals like GPIO pins, sensors, and Bluetooth modules without requiring a separate compilation step.
How do I program an Espruino board using Web Bluetooth?
After connecting, use the `print()` function to view debug output and adjust code dynamically. For example, `print('Connected')` confirms successful communication.
How does Espruino compare to Arduino in terms of development workflow?
Espruino eliminates the need for a desktop IDE and USB drivers, allowing web-based programming via Web Bluetooth. However, Arduino offers a larger ecosystem of libraries and shields for complex projects. Espruino is better suited for quick experiments and wireless prototyping, while Arduino is preferred for resource-intensive applications.
What should I do if my Espruino board isn't connecting via Bluetooth?
Check that the board is in pairing mode (usually indicated by a blinking LED). Ensure Bluetooth is enabled on your device and that no other devices are interfering. Reset the board by holding the reset button. If issues persist, try updating the firmware or using a different browser for the Web IDE.