Design strategies for the wearables market
Wearable devices, from smart watches to portable health and fitness trackers, are changing many aspects of our daily lives. The desktop revolution of the 1980s ushered in an era of unprecedented personal productivity for the Information Age. The advent of laptops in the 1990s, coinciding with the expansion of the Internet, freed us from the tethers of power cords and Ethernet cables. Then the explosive growth of cell phones and smartphones brought us unprecedented mobility and wireless connectivity. Today's "wrist-top revolution," coupled with the meteoric rise of the Internet of Things (IoT), is taking mobility to a whole new level: wearable computing.
The wrist-top revolution is rewriting the playbook for designing portable electronic products. In this article, we'll examine the concepts behind the user-experience-driven design methodologies that are being used to create some of the most successful wearable products on the market. We'll also consider the features and functions that drive a wearable product's energy budget and computational requirements including the selection of microcontrollers (MCUs) that meet the product's design requirements.
New Realities of the Wrist-Top Revolution
Smart watches, activity trackers, wearable GPS devices, heart rate monitors and smart glasses are prime examples of the wearable products that generated an estimated $8 billion in global sales in 2013, according to Futuresource Consulting. Offering novel combinations of sophisticated functionality, easy-to-use connectivity, compact form factors, ultra-low-power processing and wireless connectivity, wearable devices are giving rise to entirely new classes of personal electronics that help us stay healthier, better informed and better equipped than ever before.
Although several leading smartphone manufacturers began experimenting with bulky wrist-top versions of their existing handset products several years ago, the wrist-top revolution kicked into high gear in early 2012 when innovative upstarts like the Pebble Smartwatch leapfrogged the smartphone makers with a new class of lightweight wrist-top devices that made it easier for end users to leverage the smartphones they already own. Garmin, Samsung, Sony, Fitbit, Magellan (see Figure 1) and other consumer electronics makers also joined the wrist-top revolution with their own smartwatches, activity trackers and other wearable products.
This disruptive market environment has also encouraged the emergence of small, agile startups whose innovative products such as the Misfit Shine fitness tracker (shown in Figure 2) are successfully competing for market share with established players.
A successful wearable device must deliver the right combination of price, performance, functionality and battery life, as well as a unique look, feel and behavior to differentiate itself from its competitors. MCUs, sensors, wireless electronics and attractive user interfaces must be shoehorned into a small footprint that can be comfortably worn on the wrist or elsewhere on one's body. Since such form-factor constraints leave little room for a battery, wearable systems must be extremely energy-efficient to achieve the longest possible operating periods between battery replacements or charges.
User Experience Drives Winning Designs
Integrating these diverse elements into a market-winning product requires complex design trade-offs to balance power, performance, functionality and form factor. Several manufacturers have successfully navigated this unfamiliar territory using a so-called "user experience-driven" design methodology that inverts many of the conventional priorities and practices used by embedded developers.
The design process for an embedded system typically begins with defining the functions and capabilities that will serve as the project's top-level drivers. Conversely, designing a wearable product frequently begins with defining the "user experience" it will need to produce. These requirements define a product by the way it looks, feels and interacts with the end user, as well as the impressions, feelings and emotions it evokes. The next step in this design process is to translate the user experience into a "use case," a set of top-level functional requirements used to define the product's hardware and software elements.
Apple was one of the early pioneers of this strategy. They used it with great success to define new markets - and capture existing ones. If you have any doubts about the importance of a well-crafted user experience, consider how the Apple iPod's unique control wheel, jewel-like case designs and easy-to-use iTunes software helped the company transform and eventually dominate the digital music player market.