Tiny Bluetooth low energy proximity key fob runs for a year on a coin cell

June 13, 2012 // By Jean-Pierre Joosting
Nordic Semiconductor ASA has announced that Hong Kong-headquartered Dayton Industrial Co. Ltd., a leading OEM/ODM of wireless products has launched a Bluetooth® low energy proximity key fob based on Nordic's µBlue™ nRF8002 System-on-Chip (SoC) that is less than half the size of a credit card.

The nRF8002's class-leading ULP performance and size will enable the Dayton Bluetooth low energy proximity key fob to run for around a year from a regular 3-V CR2025 lithium coin cell battery under typical (daily) usage conditions while featuring an extremely slim (0.5-cm-thick) and compact (4.9- x 3.2-cm) plastic sensor housing that features a single push button and two submerged LED status lights (one red to signal alerts, and one green to signal pairing status) within a product that weighs less than 40-g. There are also additional micro-vibrator and buzzer alert options.

The Dayton production-ready product platform will allow OEMs and developers to develop a whole range of both standard (Bluetooth v4.0 profile-based) and non-standard (uniquely developed) proximity, property location and security applications ('apps') for use with devices that employ Bluetooth v4.0 wireless technology such as the latest iPad and the iPhone 4S.

The nRF8002’s ULP design features peak currents as low as 13 mA and does not require an external 32 kHz crystal. Depending on the duty cycle of the application, battery life from a single coin cell-powered wireless device can extend to months or even years.

Within the latest Bluetooth v4.0 specification there are currently two profiles applicable to proximity-based property location and security. The first, the Find Me profile targets smartphone applications and allows users to pair small — but commonly misplaced — everyday objects with their smartphone in order to locate them via, for example, a Bluetooth low energy proximity key fob that could be used to find a misplaced phone (by pushing a button on the fob to make the phone sound an audible alert), or a misplaced key fob (by pushing a button within a smartphone app to make the key fob sound an alert).

The second, the Bluetooth low energy Proximity profile targets smartphones and other portable devices such as computer laptops and tablets, and further extends the functionality of the Find Me