Israel-based APS has selected Nordic Semiconductor’s nRF52840 Bluetooth 5/Bluetooth Low Energy (Bluetooth LE) advanced multiprotocol System-on-Chip (SoC), and its nRF52832 and nRF51822 Bluetooth LE SoCs to provide the wireless connectivity for its employee and asset tracking system.
Designed for construction sites where Ethernet or Wi-Fi is impractical, the Bluetooth 5/Bluetooth LE solution comprises wearable tags, mesh controllers, and a gateway, enabling management to keep track of employees or assets in ‘real-time’ as they move about the site. To provide low latency Bluetooth mesh connectivity throughout the system, Nordic’s nRF52840 and nRF52832 SoCs are integrated in the ‘APS DETECTOR’ controllers, while Nordic’s nRF51822 SoC is deployed in the ‘APS tags’. The APS tags each employ a CR2032 coin cell battery, providing 12 months average battery life between replacement, thanks in part to ultra-low power performance of the Nordic SoC, says Nordic Semi.
In operation, the tracking system monitors tagged employees or assets by broadcasting their location to the mesh-networked controllers. Multiple controllers can be placed through a construction site enabling them to receive the data from the Bluetooth LE APS tags and transmit it together with the Received Signal Strength Indication (RSSI) data to a central gateway via the Nordic nRF52840 SoC-enabled Bluetooth mesh network. RSSI is used to estimate the distance of the employee or the asset from the controller. The nRF52840 SoC provides full Bluetooth 5 support including Long Range, enabling the mesh network controllers to communicate with each other, and the gateway, over distances up to 250 meters. The gateway in turn sends the location of the employees or the assets to a Cloud-based server, allowing site management to remotely monitor staff and asset movement via an Internet-based dashboard.
The nRF52840 multiprotocol SoC is Nordic’s most advanced ultra-low power wireless solution. The SoC is Bluetooth 5-, Thread 1.1-, and Zigbee PRO (R21) and Green Power proxy specification-certified. The SoC combines a 64MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU), with a 2.4GHz multiprotocol radio with 1MB Flash memory and 256kB RAM. A new radio architecture with on-chip PA provides features -95dBm RX sensitivity (at 1Mbps Bluetooth LE), a maximum output power of 8dBm, and a total link budget of 103dBm. The SoC is supplied with Nordic’s S140 SoftDevice, a Bluetooth 5-certified software protocol stack for building long range and high data Bluetooth LE applications. The S140 SoftDevice offers concurrent Central, Peripheral, Broadcaster, and Observer Bluetooth LE roles, and supports high throughput and Long Range modes as well as advertising extensions.
Nordic’s nRF52832 multiprotocol SoC combines a 64MHz, 32-bit Arm Cortex M4 processor with FPU, with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT, and proprietary 2.4GHz RF protocol software) featuring -96dB RX sensitivity, with 512KB Flash memory and 64kB RAM. The nRF51822 is built around a 32-bit Arm Cortex M0 processor, 2.4GHz multiprotocol radio, and 256kB/128kB flash and 32KB/16KB RAM, and is ideally suited for Bluetooth LE and 2.4GHz ultra low power wireless applications.
APS Products’ tracking system is currently deployed for employee tracking inside several stations under construction as part of the new Tel Aviv Light Rail system in Israel. The APS DETECTOR mesh network controllers are located in designated areas covering the entrances to each floor, as well as coverage of the working areas and the tunnels, enabling continuous monitoring of the entire station area.
Nordic Semiconductor | www.nordicsemi.com