AS CELLULAR PHONES became affordable and available for everyone, many noted that the traditional wristwatch was either discarded or simply became a fashion accessory. With a phone in hand, no one needed a watch to check the time. Yet watches may see a resurgence as some of them integrate wireless-communications capabilities. For example, Casio's G-SHOCK has become the first publicly announced Bluetooth low-energy watch product for consumers (see photo).

By employing Nordic Semiconductor's Nordic Blue nRF8001 single-chip integrated circuit (IC), this watch is able to wirelessly link to Bluetooth v4.0-equipped smartphones. The Casio G-SHOCK Bluetooth Low Energy Watch, which will be available later this year, includes time correction from smartphone to watch, thereby ensuring that the watch always displays the correct time anywhere in the world. The watch also provides incoming call, e-mail, and SMS-alert notifications from smartphone to watch. It can even stop smartphone ring alerts from the watch. In addition, a finder function enables users to locate a misplaced phone by activating the smartphone's alarm and vibration functions from a button-press on the watch.

Thanks to the low-power performance of the Nordic nRF8001, the G-SHOCK Bluetooth Low Energy Watch promises to offer a battery life that is similar to that of a conventional Casio wristwatch. It will be able to run from a single, conventional CR2032 coin-cell watch battery for as long as two years. The watch will provide up to 12 hours per day of continuous wireless communication with Bluetooth v4.0-equipped smartphones and other devices. The Casio G-SHOCK Bluetooth Low Energy Watch will have similar weight (65 g) as a conventional Casio G-SHOCK watch. It also has a similarly small casing size of 53.2 x 50.0 x 18.3 mm.