Bluetooth Low Energy connected ski boot integrates motion sensors

Bluetooth Low Energy connected ski boot integrates multiple force and motion sensors to help skiers improve balance, control, and technique

Courtesy of Nordic Semiconductor : Bluetooth Low Energy connected ski boot integrates multiple force and motion sensors to help skiers improve balance, control, and technique

Atomic’s Hawx Connected ski boot employs Nordic nRF52832 WL-CSP SoC to run complex sensor algorithms and wirelessly report skiing performance metrics via smartphone app

Nordic Semiconductor today announces that Altenmarkt, Austria-based ski equipment manufacturer, Atomic, has released its ‘Hawx Connected’ ski boot, employing Nordic’s nRF52832 System-on-Chip (SoC). The tiny Wafer Level Chip Scale Package (WL-CSP) SoC functions as the main microcontroller for the ski boot, as well as providing it with Bluetooth® Low Energy (Bluetooth LE) wireless connectivity.

Based on sister company Suunto’s ‘Movesense’ platform—an open environment for developers of wireless motion sensing solutions incorporating a nine-axis Inertial Measurement Unit (IMU)—the Hawx Connected ski boot provides the user with direct sensory feedback while skiing. Eight force sensors measure pressure at key contact points in the boot liner, while the IMU’s accelerometer and gyroscope detect the orientation of the boot to detect turns and edging angles. Once paired with the user’s Bluetooth 4.0 (and later) smartphone using Bluetooth LE wireless connectivity provided by the Nordic SoC, a skier can from the ‘Atomic CTD’ app get in-depth performance analysis such as balance and edging, turn count, and G-force, to help them refine their balance, pressure control, and edging technique. The app also enables users to set goals, challenge friends, and compare their performance data against professional athletes.

The nRF52832 SoC’s powerful 64MHz, 32-bit Arm® Cortex® M4F processor acts as the main controller for the Hawx Connected ski boot, providing ample computational capacity to run the complex sensor algorithms as well as provide low latency Bluetooth LE wireless connectivity.

The availability of the nRF52832 SoC in a WL-CSP was hugely important for us due to the size constraints we were facing – Jussi Kaasinen, Suunto

The Hawx Connected ski boot employs a Li-Poly battery that provides up to 4.5 days of operation in typical usage between recharge, thanks in part to the ultra low power consumption of the nRF52832 SoC. The nRF52832 SoC has been engineered to minimize power consumption with features such as the 2.4GHz radio’s 5.5mA peak RX/TX currents and a fully-automatic power management system that reduces power consumption by up to 80 percent compared with Nordic’s nRF51 Series SoCs. The result is a Bluetooth LE solution which offers 58 CoreMark/mA, up to twice as power efficient as competing devices.

The nRF52832 WL-CSP SoC measures just 3.0 by 3.2mm while offering all the features of the conventionally-packaged chip. Nordic’s nRF52832 multiprotocol SoC combines the Arm processor with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT™, and proprietary 2.4GHz RF protocol software) featuring -96-dB RX sensitivity, with 512kB Flash memory and 64kB RAM. The SoC is supplied with Nordic’s S132 SoftDevice, a Bluetooth 5-certifed RF software protocol stack for building advanced Bluetooth LE applications. The S132 SoftDevice features Central, Peripheral, Broadcaster and Observer Bluetooth LE roles, supports up to twenty connections, and enables concurrent role operation. Nordic’s software architecture includes a clear separation between the RF protocol software and the application code, delivering flexibility and reliability to application software development.

“The availability of the nRF52832 SoC in a WL-CSP was hugely important for us due to the size constraints we were facing,” says Jussi Kaasinen, General Manager/Emerging Businesses Unit, Suunto. “On the other hand, the Arm M4F processor was essential for running our cutting edge signal processing algorithms.”

“We also have a long and excellent working relationship with Nordic. Fast turnaround time on our technical questions meant we knew we would always have first-hand expertise available to us if needed.”