Courtesy of Nordic Semiconductor : Bluetooth Low Energy wearable monitors heart rate, sleep, and activity data while supporting mesh network control
‘Lifesense Band 5’ employs Nordic’s nRF52840 SoC to act as the device’s central processor, managing sleep and motion sensor algorithm implementation, and enabling Bluetooth mesh networking
Nordic Semiconductor today announces that Zhongshan, China-based smart healthcare device developer, Guangdong Transtek Medical Electronics Co., Ltd. (Lifesense), has specified Nordic’s nRF52840 Bluetooth 5/Bluetooth® Low Energy (Bluetooth LE) advanced multiprotocol System-on-Chip (SoC) to provide the wireless connectivity and meet the intensive processing demands of its ‘Lifesense Band 5’.
Developed for the public health market, the Lifesense Band 5 wearable features a TFT LCD color display and integrates a Nordic SoC-supervised 3D accelerometer and heart rate sensor to track and record the user’s health and exercise data. It functions as a 24-hour dynamic heart rate monitor, sleep monitor, and activity tracker for steps taken, distance covered, calories burned, and activity duration. The nRF52840 SoC’s 64MHz, 32-bit Arm® Cortex® M4F processor acts as the device’s CPU, managing the sensor’s sleep and motion algorithm implementation and data storage management, as well as acting as the display driver, and providing Bluetooth mesh functionality, enabling the wearable to connect to, and control, mesh networked smart-home devices. The Lifesense Band 5 also supports offline payment by Alipay, a China-based mobile payment platform developed by e-commerce giant Alibaba.
Using Bluetooth LE low latency wireless connectivity provided by the Nordic SoC, health, exercise, and sleep data is synced to the user’s Bluetooth 4.0 (and later) smartphone or tablet, where the information can be reviewed via the Lifesense app. The app integrates sports training, weight management, and sleep monitoring, and is available in both iOS and Android versions.
The Lifesense Band 5 employs an 80mAh rechargeable lithium battery offering extended battery life, thanks in part, to the ultra low power operating characteristics of the Nordic nRF52840 SoC. The nRF52840 SoC has been engineered to minimize power consumption with a fully-automatic power management system that reduces power consumption by up to 80 percent compared with the nRF51 Series.
Nordic’s nRF52840 multiprotocol SoC is Nordic’s most advanced ultra low power wireless solution. The SoC supports complex Bluetooth 5/Bluetooth LE and other low-power wireless protocol applications that were previously not possible with a single-chip solution. The SoC combines the Arm processor with a 2.4GHz multiprotocol radio with 1MB Flash memory and 256kB RAM. A new radio architecture with on-chip PA provides features -96-dBm RX sensitivity, a maximum output power of 8dBm, and a total link budget of >110dBm. The chip supports all the features of Bluetooth 5 (including 4x the range or 2x the raw data bandwidth (2Mbps)) compared with Bluetooth 4.2.
The Nordic SoC’s S140 SoftDevice—a Bluetooth 5-certified software protocol stack for building long range and high data throughput Bluetooth LE applications—offers concurrent Central, Peripheral, Broadcaster, and Observer Bluetooth LE roles and supports up to 20 connections with variable bandwidth.
“Battery life is a key factor for wristbands and bracelets, and along with the processor capability, memory capacity, Bluetooth mesh functionality, and support for multiprotocol implementation was the most important reason behind selecting the nRF52840 SoC,” says Shirley Xu, Project Manager, Lifesense.
“We are a long term partner of Nordic, and its application engineers always provide a fast response and excellent support helping us to solve problems quickly.”