This application report presents the concept of beacons by using Bluetooth low energy technology. The important parameters when designing beacon solutions are elaborated on a detailed level throughout the document. With the use of the TI Bluetooth low energy-Stack, beacons can be done in a simple and intuitive way.
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A beacon in wireless technology is the concept of broadcasting small pieces of information. The information may be anything, ranging from ambient data (temperature, air pressure, humidity, and so forth) to micro-location data (asset tracking, retail, and so forth) or orientation data (acceleration, rotation, and so forth).
The transmitted data is typically static but can also be dynamic and change over time. With the use of Bluetooth low energy, beacons can be designed to run for years on a single coin cell battery. This application report introduces the concept of beacons and how to get started with implementing a beacon solution. Naming conventions throughout this document can be summarized as Beacons that broadcast information by using advertisements with Bluetooth low energy technology that could be branded as Bluetooth low energy.
A Bluetooth low energy device can operate in four different device roles. Depending on the role, the devices behave differently. The first two roles are connection-based:
This means that the device roles used for established connections are the Peripheral and the Central roles. The other two device roles are used for one-directional communication:
The two obvious device roles for beacon applications are Peripheral and Broadcaster. Both of them send the same type of advertisements with the exception of one specific flag that indicates if it is connectable or non-connectable. A Peripheral device that implements a GATT Server (GATT is an architecture for how data is stored and exchanged between two or more devices) can be branded as a Bluetooth low energy device. So a Bluetooth low energy branding indicates that the device is a connectable Peripheral device that has data, which could be interacted with.
A Bluetooth low energy solution is ideal for beacons because it is low power and the eco-system is already deployed in the majority of smartphones or other Bluetooth low energy enabled devices on the market. The low-power consumption is achieved by keeping the transmission time as short as possible and allowing the device to go into sleep mode between the transmissions.
The non-connectable beacon is a Bluetooth low energy device in broadcasting mode. It simply transmits information that is stored internally. Because the non-connectable broadcasting does not activate any receiving capabilities, it achieves the lowest possible power consumption by simply waking up, transmit data and going back to sleep. This comes with the drawback of dynamic data being restricted to what is only known to the device, or data being available through external input from example serial protocols (universal asynchronous receiver/transmitter (UART), serial peripheral interface (SPI), universal serial bus (USB), and so forth).
The connectable beacon is a Bluetooth low energy device in peripheral mode, which means that it can not only transmit, but receive as well. This allows a central device (for example, a smartphone) to connect and interact with services implemented on the beacon device. Services provide one or more characteristics that could be modified by a peer device. One example of these characteristics could be a string of data that represents the broadcasted information. This way, it is possible to have a configurable Beacon that is easily updated over the air.