Leopard Gecko MCU used in Wearable Fitness Tracker

The Misfit Shine is tapping into the burgeoning market for wearable computing devices. Sports and fitness monitors, running and cycling computers, and other physical activity trackers are expected to reach 56.2 million unit shipments globally in 2017, according to IMS Research. Up from 43.8 million units in 2013, IMS predicts that a total of 252 million units will ship over the next five years. In a related survey, 62.3% of smartphone owners who exercise regularly expressed an interest in mobile health and fitness apps and fitness sensors such as the Misfit Shine that connect to smartphone apps.

The Misfit Shine requires extreme energy efficiency to maximize battery life, running on a single, user-replaceable CR2032 lithium-ion watch battery for four months. The end user wears the Shine and monitors his or her fitness activity daily without interruption until it is time to replace the battery, arguably much easier than having to recharge the device every few days.

The Leopard Gecko MCU was chosen primarily for its industry-leading energy efficiency across all energy modes, enabling exceptionally long battery life coupled with optimal processing performance and a high level of integration in a small-footprint package. Low-energy sensor interface and peripheral reflex system were also attractive features for Misfit’s ultra-low-energy budget: the LESENSE interface autonomously collects and processes sensor data even when the MCU is in deep-sleep mode (enabling the MCU to remain in a low-energy mode for a long time while tracking sensor status and events); the PRS monitors complex system-level events and allows different MCU peripherals to communicate autonomously while keeping the CPU in an energy-saving sleep mode as long as possible to reduce overall system power consumption.

Sonny Vu, CEO and co-founder of Misfit Wearables, comments: “Achieving extreme energy efficiency in a wearable computer like the Shine is a formidable design challenge. The Leopard Gecko MCU is a perfect match for the Shine’s low-energy, data-intensive requirements, and Silicon Labs’ Simplicity Studio development tools accelerated our design team’s learning curve, meeting our critical need for fast time to market.”

Available at no charge, Simplicity Studio (a comprehensive graphical development environment for EFM32 Gecko MCUs) provides developers with one-click access to all the information, documentation, energyAware tools, and software and source code libraries needed to quickly develop energy-friendly applications.

“The Shine represents a rapidly growing class of energy-sensitive, battery-powered, tiny-footprint wireless devices for which our energy-friendly EFM32 Gecko MCUs are exceptionally well-suited,” commented Geir Førre, senior vice president and general manager of Silicon Labs’ microcontroller products.