Bluetooth LE-powered wearable delivers wireless smartphone control for active people

The ArcX smart ring employs Nordic’s nRF52832 SoC to enable remote control of music and phone calls for people on the move

Nordic Semiconductor today announces that London, U.K.-based sports tech start-up, ArcX Technology, has selected Nordic’s nRF52832 Bluetooth® Low Energy (Bluetooth LE) multiprotocol System-on-Chip (SoC) to provide the wireless connectivity for its ‘ArcX’ smart ring. The ring is designed to be worn on the index finger, and via its thumb-controlled micro-joystick allows users engaged in sporting activities to remotely control a range of smartphone functions—for example shuffling music playlists, taking split times, or accepting incoming calls—without the need to stop exercising.

Low latency connectivity

The IP67-rated waterproof and shockproof device is supplied in a range of ring sizes, as well as a watch-strap form factor, enabling it to be worn either on the person, or attached to a handlebar, paddle, or other piece of sports equipment. Once paired with a Bluetooth 4.0 (and later) smartphone hosting the iOS or Android ‘ArcX’ app, the wearer can use the nRF52832 SoC’s low latency Bluetooth LE wireless connectivity to remotely-control smartphone functionality. For example, an aerobics instructor can change class workout music on a wireless speaker without recourse to their smartphone, and without requiring any disruption to the activity.

The software architecture of Nordic’s ‘stack’ is far superior to the competition

Kumar Bala, ArcX

Powered by a customized, rechargeable Li-Poly battery, ArcX provides a minimum of five days usage or 20 days standby between charges thanks in part to the ultra-low power characteristics of the Nordic SoC. The nRF52832 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 per cent compared with Nordic’s nRF51 Series SoCs.

Nordic’s nRF52832 multiprotocol SoC combines a 64MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU), with a 2.4GHz multiprotocol radio (supporting Bluetooth 5.2, ANT™, and proprietary 2.4GHz RF protocol software) featuring -96dB 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.

SoftDevice superiority

“Taking one hand off an indoor rowing machine or a bicycle handlebar to control a phone is frustrating,” says Kumar Bala, CTO and Co-founder of ArcX. “The new ArcX ring is designed to remove those barriers and to easily manage personal music while exercising.

“The nRF52832 SoC was ideal for our application because of its size, power consumption, and SoftDevice benefits. The software architecture of Nordic’s ‘stack’ is far superior to the competition, and the SDK [Software Development Kit] reduced our engineering time dramatically.”

ArcX was one of five solutions shortlisted for the CES 2021 ‘Last Gadget Standing’ competition. The annual award champions the best new tech products displayed at CES, the world’s largest consumer electronic technology event.