A BBC micro:bit being used as an Eddystone beacon and a smartphone app making use of the web site URL being broadcast.

Bluetooth beacons are used to indicate proximity to a place or object of interest. Beacons use Bluetooth advertising to broadcast a small amount of data, which can be received and acted upon by anyone in range with a suitable device and software, typically a smartphone and application.

There are various beacon message formats, which define the way Bluetooth advertising packets are used as containers for beacon data. iBeacon is Apple’s beacon message format. Eddystone comes from Google.

The Eddystone specification defines four frame types at the time of writing. UID (unique ID), URL (Uniform Resource Locator), TLM (telemetry) and EID (Ephemeral ID).

UID – this is simply an identifier which is mapped by an application receiving it, to something meaningful like a location

URL – this is exactly what you’d expect. A URL, typically in compressed form, which points to something like a web site

TLM – this frame type contains data about the beacon’s operation such as its battery level or temperature.

EID – this is the newest frame type and provides a way of using IDs which is secure such that only the operator of the beacons can make use of the encrypted, temporary IDs in these beacon messages.

The micro:bit beacon in this application uses the URL frame type.


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