Three Companies Outline How to Build Bluetooth-based Tracking System

July 05, 2023 by Darshil Patel

Onsemi, in partnership with Unikie and CoreHW, has released an application note on an end-to-end positioning system for precise, low-power asset tracking.

Bluetooth asset tracking systems have become invaluable in various industries because of their accuracy and low power consumption. These systems can track assets in real time within a specific area, allowing businesses to gain instant insights into the product's location, status, and condition. Bluetooth tags can also be seamlessly integrated into existing infrastructure and enterprise software systems. Their flexibility and efficiency allow industries to optimize their operations, increase productivity, and minimize asset-related risks.


A typical location-finding system setup

A typical location-finding system setup. Image courtesy of Onsemi


In partnership with Unikie and CoreHW, Onsemi recently launched a new end-to-end positioning system for more accurate and power-efficient asset tracking.


Onsemi's Asset Tracking Solutions

The three companies built a new end-to-end solution to simplify and accelerate the development time for more accurate, cost, and power-efficient asset tracking devices. The system is based on Onsemi's RSL15 MCU, with software algorithms and components (like antennas) provided by Unikie and CoreHW, respectively. The system can track objects with sub-meter accuracy in closed environments like warehouses, stores, or other buildings. The company claims it is also scalable for large volumes of assets without affecting performance.


Block diagram of the RSL15 MCU

Block diagram of the RSL15 MCU. Image courtesy of Onsemi

RSL15 is at the heart of this new solution. It is an ultra-low power Arm Cortex-M33 processor-based Bluetooth Low Energy (BLE) 5.2 wireless microcontroller. It supports long-range, higher data transmissions and localization through Angle of Arrival (AoA) and Angle of Departure (AoD) as defined by the BLE standards. The processor can go into a deep sleep while still monitoring sensor interfaces, thanks to Onsemi's smart sensing feature. 

The RSL15 incorporates Arm TrustZone and Arm CryptoCell-312 technology to form the hardware's root of trust and protect code and data authenticity with software encryption. It also includes tag firmware to enable application development.


Unikie BLE Localization Engine

Unikie developed the software algorithms and components to calculate the real-time positions of BLE tags, integrated as the Unikie Localization Engine. It is co-developed and tested with CoreHW and supports CoreHW Gen2 and Gen3 antennas. The engine is also optimized for RSL15 BLE tags. 


Heat map data of a store

Heat map data of a store. Image courtesy of Unikie

The Unikie Localization Engine consists of two components: an angle calculation and a positioning module. The angle calculation module is optimized for low footprint and high performance on edge servers. The position calculation module can be integrated with the angle calculation on edge servers or deployed separately in the cloud. It also produces easy-to-use APIs for subscribing to external enterprise systems.


CoreHW Antenna Arrays

CoreHW designs antennas with position accuracy down to the cm-level. Onsemi's end-to-end solution uses one of CoreHW's CHW1010 antenna series, which consists of SP16T Bluetooth AoA and AoD antenna switches for antenna selection and RF and control signal connectors for easy BLE board interfacing.


CHW1010−ANT1−1.0 antenna module

CHW1010−ANT1−1.0 antenna module. Image courtesy of CoreHW

Onsemi's solution includes three of CoreHW's antennas:

  • CHW1010-ANT1-1.0: Dual-polarized antenna array with eight patch antenna elements with accuracy down to sub-40-cm level
  • CHW1010-ANT2-1.0: 16 patch antenna elements with up to 10-cm-level accuracy
  • CHW1010-ANT3-1.0: Four patch antenna elements with position accuracy down to 50-cm level

To extend the benefits of this location-finding system to the public, Onsemi released an application note outlining how designers might set up a similar Bluetooth wireless-based asset-tracking system. This project, which will require Bluetooth-enabled tags, a localization engine, and locators, is outlined in more detail here