Running Robots From Your Browser With Cylon.js

by Javier Cervantes and Andrew Stewart

Ever thought about controlling robots directly from your browser? With the latest release of Cylon.js, we make it easy to control robots and connected devices from your own browser-based and mobile applications.

For now, in-browser support is limited to a few modules, due to browser sandboxing. JS running in a normal browser can't, for instance, talk directly to Bluetooth or a serial port. You CAN however do this if you are running Cylon.js in a Chrome application.

However, if a Cylon.js browser communicates with hardware over the network, it will work from within any browser without a hitch. For example, the cylon-ardrone, cylon-spark, cylon-leapmotion, cylon-hue and more are supported already.

In this example, we're going to blink the LED on a Spark Core from Cylon.js running in a regular browser.


In a new folder, use NPM to install cylon-spark:

$ npm install cylon cylon-spark

Once that's installed copy this Cylon.js program to script.js. Add your Spark Core's accessToken and deviceId.

You can get both of these from Spark's Build tool:

  • accessToken: In the Build tool, click on the Settings cog in the bottom-left corner to find your access token.
  • deviceId: After you have your Spark Core registered to your account through the Tinker app, click on the Cores section (just above the Settings cog) on the Build tool. Then, click on the arrow next to your core's name to get its device ID.

Make sure to add these to the script, or it won't work.

var Cylon = require('cylon');

  connections: {
    spark: {
      adaptor: 'spark',
      accessToken: '[YOUR_ACCESS_TOKEN]',
      deviceId: '[YOUR_DEVICE_ID]'

  devices: {
    led: { driver: 'led', pin: 'D7' }

  work: function(my) {
    every((1).second(), function() {

Code in place, let's write a small HTML file (index.html) that'll host the script:

<!doctype html>
<html lang="en">

    <script src="browser_script.js"></script>

And that's it.


Now with the pieces in place, let's compile the Cylon.js program for browser use with the Browserify tool.

If you don't have it already, install it through NPM:

$ npm install -g browserify

Then, use it to compile the script:

$ browserify script.js -r cylon-gpio -r cylon-spark -o browser_script.js


Now, just open index.html in your browser and your Spark's LED should start blinking.

Want more?

From here, the sky's the limit. If you want to get started on a more complex Cylon.js robot for use in the browser, we've created an example project on GitHub to get you started.

If that's not enough for you, you can also package Cylon.js scripts into Chrome Apps. We've created another example project repo to get you started on that front.

Cylon.js PhoneGap Spark

You can even include Cylon.js in your PhoneGap mobile app. Look for an upcoming blog post focusing on this, but for now here is an example of PhoneGap + Cylon.js

Check out our Browser Support guide for more information.

For more updates, be sure to follow us on Twitter at @CylonJS.