Bangle.js Development Guide

Discover and develop Bangle.js applications for context-aware physical spaces using Espruino and Bluetooth Low Energy.

Prerequisites

A Bangle.js and, optionally, a Pareto Anywhere instance creating a context-aware space

• 

• Buy a Bangle.js 2 from the Espruino Shop

  Support the ongoing development of Espruino open source software and devices!

• 

• [OPTIONAL] Run Pareto Anywhere on a PC

  Install and run Pareto Anywhere on a personal computer to make any physical space context-aware.

• 

• [OPTIONAL] Run Pareto Anywhere on a Raspberry Pi

  Install and run Pareto Anywhere on a Pi to make any physical space context-aware.

Prerequisites

A web browser which supports Web Bluetooth

Many—but not all—modern browsers such as Chrome support Web Bluetooth by default. MDN maintains this list of browser compatibility should your preferred web browser fail to support Web Bluetooth by default.

Browse to the Espruino IDE Part 1

Point a web browser to espruino.com/ide/ and observe the integrated development environment (IDE) as in the screenshot below.

Connect with Web Bluetooth Part 2

Click on the Connect/Disconnect icon at top left, and then select Web Bluetooth from the popup.

Pair with the Bangle.js Part 3

Identify and select Bangle.js from the list of scanned devices, then click Pair.

If the desired Bangle.js does not appear, check the following:

• is it powered on?
• is it within a few metres of the computer?
• is the Bangle.js connectable in its Settings menu?

If pairing is successful, the Connect/Disconnect icon at top left will turn green.

The Bangle.js can now be programmed wirelessly from the browser using Web Bluetooth, which is the subject of the next step.

From the Espruino IDE connected to the Bangle.js:

Enter the "Hello World!" program Part 1

Copy Ctrl+C and paste Ctrl+V the following lines of code into the code editor window of the Espruino IDE:

// Display Hello World!
g.clear();
g.setFont('Vector', 30);
g.drawString("Hello World!");

// Transmit Bluetooth Low Energy advertising packets
NRF.setAdvertising({}, {
    showName: false,
    manufacturer: 0x0590,
    manufacturerData: JSON.stringify({ name: "Bangle.js 2" })
});

Upload to RAM Part 2

Click on the Send to Espruino button in the centre toolbar, ensuring that the default option to write to RAM is selected.

A progress bar will appear in the bottom right corner followed by SENT in the bottom left corner of the IDE once the program upload completes.

The program will automatically execute and any console output, including error messages, may be observed in the area highlighted in the screenshot below.

Observe the "Hello World!" output Part 3

The Bangle.js will immediately display Hello World!

The Bangle.js will not, however, transmit Bluetooth Low Energy advertising packets while it is connected. Click on the Connect/Disconnect icon at top left to disconnect from the Bangle.js.

If an instance of Pareto Anywhere is running, the Bangle.js should be discoverable by its Bluetooth Low Energy advertising packets which use the company code 0x0590 registered to Pur3 Ltd, the company which develops the Espruino open source firmware running on the Bangle.js as well as the web IDE we used to upload our "Hello World!" program.

Program execution can be stopped by a short button press followed by a long button press.

More programs

See our Espruino Apps repository on GitHub for the latest available programs. More content to come!

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Where to next?

Continue exploring our open architecture and all its applications.

• 

• Puck.js Development Guide

  Discover and develop Puck.js applications for context-aware physical spaces using Espruino and Bluetooth Low Energy.

• 

• Directory of Devices

  Browse all device configuration tutorials and development guides.

• 

• reelyActive Developers

  Browse all developer documentation and tutorials.

• 

• reelyActive

  Let's put things in context, one space at a time.