Introduction#

Beginning with Bluetooth SDK v3.1, Silicon Labs’ Bluetooth stack supports CTE transmitting and receiving features and can take phase measurements on the incoming signal as specified by the Bluetooth standard. Note, however, that the determination of the angle of incidence from the phase measurements is outside of the scope of the standard and must be implemented in the application. To reduce the Time to Market for its customers, Silicon Labs also offers a reference implementation of a Bluetooth-based Real Time Locating System (RTLS), which provides both an out-of-box experience to evaluate the solution and a flexible framework that makes it possible for everyone to create their own RTLS. To get started with the reference implementation, refer to Application Development with Silicon Labs’ RTL Library. The implementation described in this application note requires you to configure and build both individual locators and a locator host application in order to test the system. While the SDK examples provide the openness to customize and add new features to your direction finding project using RTL library APIs directly, the manual configuration of the locators and their topologies may not be a trivial task. It is simpler to configure a single locator and multi-locator setup through interactive graphical interfaces available through the Direction Finding Tools Suite.

AoA Analyzer can:

  • Create a locator configuration file without the need to manually edit the .json file, to ease the configurations process.

  • Apply the configuration for a single locator board and run the RTL library to estimate angles from the incoming data (without the need to build and run any host sample application).

AoA Analyzer is available through Simplicity Studio’s Tools menu, as described next.

While it is easy to configure a single locator and get angle information of asset tags, configuring and running a multi-locator setup to get position information can be rather complicated. To calculate position, the RTL needs to know the coordinates and orientation of the locator so that it can translate the angle feeds from each one of them with respect to the coordinate system of a given topology. Simplicity Studio provides the Positioning tool, which makes the configuration and testing of a multi-locator setup easy and quick.

Positioning Tool can:

  • Create a multi-locator topology without the need to manually edit the configuration .json file.

  • Add locators to the topology and configure their positioning RTL parameters (such coordinates and orientation) easily.

  • Apply the configuration and locate asset tags in 3D.

  • Import/Export a topology from/to a configuration .json file.

Positioning Tool is available through Simplicity Studio’s Tools menu as described next.