Bluetooth 5.1 AoA explorer kits enable location services applications 

Nordic Semiconductor today announces that u-blox, a global provider of leading positioning and wireless communication technologies and services, has specified Nordic’s nRF52833 Bluetooth® 5.2/Bluetooth Low Energy (Bluetooth LE) general-purpose multiprotocol System-on-Chip (SoC) to provide the core processing power, wireless connectivity, and Bluetooth Direction Finding capability for its ‘XPLR-AOA explorer kits’. The kits are designed to help OEMs evaluate and develop location services applications using direction finding and indoor positioning, in turn enabling a wide array of IoT applications across logistics, smart building, healthcare, retail, and manufacturing.  

Bluetooth Direction Finding 

The ‘XPLR-AOA-1’ and ‘XPLR-AOA-2’ explorer kits allow users to evaluate and experiment with Bluetooth Direction Finding technology. XPLR‑AOA‑1 provides everything needed to start evaluating Angle-of-Arrival (AoA) technology, including a ‘C211 antenna board’ equipped with u‑blox’s ‘NINA‑B411’ Bluetooth LE module based on Nordic’s nRF52833 SoC, and the ‘C209 tag’ based on the company’s ‘NINA‑B406’ Bluetooth LE module (also based on the nRF52833). The XPLR‑AOA‑2 kit meanwhile comprises a full indoor positioning Proof-of-Concept including four antenna boards, four tags, and the positioning engine software required to track the tags in real-time as they move. In both kits, the ‘u-connectLocate’ software leverages the nRF52833 SoC’s processing power to run the algorithms that calculate AoA on top of the Bluetooth ‘stack’, requiring no additional processing. The angle is delivered to the host system directly from the antenna board. 

In operation, one or more C211 antenna boards (anchor units) containing an antenna array connected to a Bluetooth receiver can detect the angle of a signal received from moving tags transmitting Bluetooth 5.1 advertisement packets. On receipt of the advertisements, the anchor units perform an angle calculation algorithm and use it to deduce the direction to the tags relative to the anchor position. The angle is calculated by u-blox’s u-connectLocate software, running on the embedded Arm Cortex-M4 processor in the Nordic SoC-based NINA-B411.  

The XPLR-AOA-1 kit is suitable for applications such as detecting if an object is approaching a door, keeping track of assets passing through a gate, or avoiding collisions, for example. The XPLR-AOA-2 kit’s four anchor units enable more precise positioning than direction alone, and are designed for indoor positioning, asset and people tracking, as well as indoor location applications. XPLR-AOA-2 also works in conjunction with a Cloud-based enterprise asset tracking platform for visualization and planning by u-blox partner, Traxmate. 

IQ component sampling support 

Nordic’s nRF52833 SoC supports the in-phase and quadrature (IQ) component sampling required for the explorer kits’ direction finding algorithm. This allows use cases requiring low latency direction finding to be met. The nRF52833’s 2.4GHz multiprotocol radio is capable of all Bluetooth Direction Finding features enabling AoA/Angle-of-Departure (AoD) positioning applications that rely on signal direction. The Bluetooth LE radio supports 2.4GHz RF protocol software in addition to Bluetooth 5.2, Bluetooth mesh, Bluetooth Direction Finding, 2Mbps throughput, and Long Range plus Thread, Zigbee and IEEE 802.15.4 software. The nRF52833 SoC’s radio architecture with on-chip PA provides -95dBm RX sensitivity (at 1Mbps in Bluetooth LE mode), a maximum output power of 8dBm, and a total link budget of 103dBm.  

Nordic’s nRF52833 SoC is supplied with S113 or S140 SoftDevices, Nordic’s Bluetooth RF protocol stacks. The S140 is a qualified Bluetooth 5.1 stack and includes support for 2 Mbps throughput, Long Range, and improved coexistence through CSA #2. 

“We selected Nordic’s nRF52833 SoC for our XPLR-AOA explorer kits as it supports Bluetooth Direction Finding and can run our advanced u-connectLocate software,” says Håkan Svegerud, Senior Director, Product Strategy Short Range Radio at ublox. “We believe Bluetooth Direction Finding can enable low cost, low power consumption, highly accurate indoor positioning systems. 

“In addition, Nordic and u-blox share a close, long-standing business relationship, and the company provides good technical support.” 

• About u-blox 
• About nRF52833
• About Nordic Semiconductor