Espruino is an open source effort by Gordon Williams to create a microcontroller that runs JavaScript right on the board. There are currently two models available: the Espruino, which is the size of a credit card, and the Pico, which is nearly stamp-sized. Both interact via a USB connection.

Note that the Espruino doesn't use Node; it uses its own version of JavaScript that is in some places heavily modified. However, to most JavaScript developers, it will feel remarkably familiar.

The Espruino uses a Chrome app to code and flash the board, and has a good amount of documentation. As the entire effort is open-source, users are welcome to contribute. You can find out more about the Espruino at www.espruino.com, and the boards are available for purchase on Adafruit.

The Tessel project is another fully open sourced platform that has two versions. Tessel 1 ran a Node-like environment using a LUA interpreter under the hood, and Tessel 2 runs Linux with Node on top. Note that the Johnny-Five wrapper tessel-io only works for Tessel 2! However, both of these boards are very interesting and fairly easy to use without Johnny-Five, and are well-supported and documented by the Tessel steering committee.

Tessel 2 was ready to be shipped soon at the time of writing this book, and you can check out its progress or pre-order/buy one at tessel.io.

Cylon.js is a library much like Johnny-Five, which also supports many platforms. Its focus is also slightly broader. While Johnny-Five sticks to making sure that microcontroller support is the main focus, Cylon supports other serial peripherals. You can find out more about this open-source project at cylonjs.com.

JerryScript is a brand new open-source project from Samsung to get a JavaScript engine running in a small enough amount of memory so that it can run on a microcontroller without Linux running underneath. While this is a very new and ambitious project, if it succeeds, it can usher in a whole new era of JavaScript robotics. You can learn more at https://samsung.github.io/jerryscript/.

While this is less of a concerted effort and more of a category of devices, there are new, smaller, faster Linux machines coming out every few months. From Raspberry Pi to Onion Omega, these machines that carry their own GPIO are definitely an interesting segment of devices to explore. Many have their own GPIO Node modules outside of Johnny-Five. BeagleBone Black has BoneScript, for instance. Keep an eye out in the future for more of these tiny computers, and definitely consider them for your standalone NodeBots projects.

Many IoT microcontrollers also come with JS libraries to use. For instance, Particle has released an npm module to work with their Core and Photon platforms over their cloud service using the Spark package. (Note that, because of their company name change, this package name may change when this book is published). Many vendors are moving to support Node on their own terms, so definitely look for an npm package when looking at new hardware platforms.