What are Beacons?

Bluetooth beacons are primarily used to allow other Bluetooth devices such as smartphones or Bluetooth-WiFi gateways to determine their location and associated sensor information. In terms of working distances, beacons fit between NFC and GPS and provide a solution to the problem of GPS not working indoors. Bluetooth beacons also use much lower receiving device battery power than GPS. 

Some beacons have sensors that can provide extra information such as temperature, movement, light level, humidity, magnetic detection, barometric pressure, water leak, smoke, gas and generic switch on/off detection.

View the introductory video on the left (34 secs - best viewed full screen).

Beacons use Bluetooth Low Energy (LE) to repeatedly transmit a unique id or web address without having to pair devices as was the case with previous versions of Bluetooth. The range is typically 50m but can reach up to 100m outdoors for some beacons. We also stock some specialist beacons that can reach up to 4000m.

Physically, beacons are small computers typically packaged in a small plastic box, usually powered by one or more coin batteries. Some models can be powered by USB or packaged as a USB dongle.

Beacon with coin battery
Beacon with coin battery

The small chip on the circuit board is a System on a Chip (SoC) provided by one of four manufacturers : Dialog, Nordic, Texas Instruments and NXP. The use of these SoC devices simplifies circuit designs and ensures beacons transmit standard Bluetooth radio signals that, in turn, ensures compatibility with receiving devices such as iOS/Android phones and Bluetooth WiFi gateways.

The id in the beacon advertising data can be formatted as either an Apple iBeacon id (UUID, major and minor), Google’s Eddystone-UID or for tracker-type beacons the MAC address (that's turned into a peripheral id on iOS) is used. The supported advertising format, iBeacon and/or Eddystone, depends on the manufacturer implementation.

Here's a screenshot from the Android iBeaconDetector app showing advertising data from both Eddystone-UID and iBeacon:

Beacon Advertising

The Eddystone data has a Namespace and an Instance. The namespace is intended to uniquely identify your company and the instance identifies the beacon within your company. See the Eddystone specification and our article for more details. The UUID, major and minor can be seen in the iBeacon advertising data.

The ids and other configurable data such as power and the transmit period are usually set up via a free manufacturer-supplied Android and/or iOS app. Unlike the usual passive detection of beacons ids where the beacon doesn't know or care who is seeing the advertised data, setup of configurable data in the beacon requires that the app connect to the beacon, via Bluetooth Generic Attributes (GATT), to change values. This setup is usually password protected.

View a demonstration showing iBeacon and accelerometer sensor beacons, manufacturer setting apps and the raw Bluetooth advertising data in the Nordic nRF Connect app. Nordic is the manufacturer of the main chip in most beacons.

See a Bluetooth-WiFi gateway, it's setup and sending of advertising data to a server.

Best viewed full screen.

The main differences when comparing beacons are:

  • Whether it's an iBeacon, Eddystone, Sensor or Tracker Bluetooth beacon. Some support multiple transmission types simultaneously.
  • The power and corresponding maximum range.
  • The battery size and hence life.
  • Physical aspects such as waterproofing, the size and colour of the box and how it will be mounted.
  • Whether it's standalone or needs a platform subscription. All the beacons we supply are standalone. Read more about generic beacons.

Most beacons allow battery health to be read via the connected settings mode and a few offer this via advertising data. Google Eddystone has an Eddystone-TLM broadcast that can transmit data about the beacon.

As previously mentioned, some beacons also have additional sensors such as temperature, humidity and acceleration. The acceleration is sometimes linked to other beacon features, for example, the initiation of connectable mode to change settings or, on a few beacons, motion-triggered broadcasting. Temperature and acceleration is also, in some beacons, visible in the advertising data so that it can be easily read without connecting. Fitness devices are essentially Bluetooth sensor beacons in a wristband form factor. A few beacons have buzzers and/or switches to provide additional interaction possibilities.

Mesh beacons have the added capability of being able to listen as well as advertise so as to relay information. This allows Bluetooth capable devices at the edge of the mesh network to send and receive data to/from all the beacons. Beacons that listen and advertise are also the basis for social distancing wearables that warn users via vibration, sound or flashing, when beacons of the same type come too close together.

Read about Ways to Use Beacons

View beacons

Tags: ibeacon, eddystone