Citizen Watch Co. solar-powered Bluetooth LE watch offers customized functionality to suit user’s lifestyle and interests

Citizen Watch

‘Eco-Drive Riiiver’ employs Nordic’s nRF52810 SoC enabling user to wirelessly create personalized functions from smartphone app via Bluetooth LE

Nordic Semiconductor today announces that Tokyo, Japan-based Citizen Watch Co., one of the world’s leading watch manufacturers, has selected Nordic’s nRF52810 Bluetooth® Low Energy (Bluetooth LE) System-on-Chip (SoC) to provide the wireless connectivity for its ‘Eco-Drive Riiiver’, a fully customizable solar-powered watch. 

Unlike conventional watches that have prefixed button functions, Eco-Drive Riiiver allows users to not only customize the buttons to suit their own preferences, but also create up to three mini-programs—known as ‘iiideas’—that can be actioned from, or displayed on, the smartwatch to suit the user’s own lifestyle and interests. For example, from the iOS- and Android-compatible ‘Eco-Drive Riiiver’ app the user can select a ‘trigger’ (the press of a specific button on the smartwatch) to deliver a ‘service’, and an ‘action’. For example, a specific button could trigger the smartwatch to update the user on the score in a sporting event and display the score via the hands of the smartwatch. Alternatively, a press of a button could trigger the smartwatch to send the user’s current location to nominated contacts with a pre-set message, for example “I’ve arrived”. Wireless connectivity between the smartwatch and the user’s Bluetooth 4.0 (and later) smartphone is provided by the Nordic SoC.

Another advantage was Nordic’s SDK which has everything, it’s excellent, so we could save time in development without worrying about the Bluetooth LE part
Daisuke Matsuoh, Citizen Watch Co.
Despite its processor-intensive applications, the Eco-Drive Riiiver watch is solar-powered, thanks in part to the ultra low power characteristics of the Nordic SoC. The nRF52810 has been engineered to minimize power consumption with features such as the 2.4GHz radio’s 4.6mA 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. In addition, the nRF52810 SoC’s high link budget 2.4GHz radio offers a maximum receive (RX) sensitivity of -96-dBm and a maximum transmit (TX) output of +4-dBm for a total link budget of >100dBm. This high link budget ensures robust wireless connectivity for the stainless steel smartwatch.
Nordic’s nRF52810 multiprotocol SoC combines a 64MHz, 32-bit Arm® Cortex® M4 processor, with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT™, and proprietary 2.4GHz RF protocol software) featuring reduced radio energy consumption, with 192kB Flash memory and 24kB RAM.  The nRF52810 SoC is supplied with the latest version of Nordic’s S112 SoftDevice, Bluetooth 5-compliant RF protocol software. 
“We selected Nordic’s nRF52810 SoC for Eco-Drive Riiiver due to its low power consumption and radio sensitivity, which is essential because the watch is a full metal device,” says Daisuke Matsuoh, Engineer and System Architect at Citizen Watch Co. “Another advantage was Nordic’s SDK [Software Development Kit] which has everything, it’s excellent, so we could save time in development without worrying about the Bluetooth LE part. If we were in any doubt we just asked Nordic’s DevZone which immediately provided expert advice.”