Wearable computing meets Bluetooth Smart
ABI Research predicts that wearable computing devices such as smart watches will "explode in popularity" and grow to 485 million annual device shipments by 2018. Behind these devices exists a technology called Bluetooth Smart, designed to consume less power than traditional Bluetooth technology.
There are numerous additional reasons for designing wearable technology around Bluetooth Smart, such as the connectivity, flexibility and power management benefits offered by the technology's platform solutions which help speed the hardware design and software development of this new wave of wearable devices for end users.
What Makes Bluetooth Smart Different?
Bluetooth Smart (often referred to as Bluetooth low energy or Bluetooth LE) enables low-power connectivity and low volume data transfer for applications previously limited by the power consumption, size constraints and complexity of other wireless data communications standards.
Introduced with the Bluetooth 4.0 specification, it uses ten to 20 times less power than previous standard Bluetooth versions, keeping products connected even with the radio off most of the time, but rapidly waking when data is available. This combination enables longer battery life in consumer products that require it and connection to the latest smartphones and tablets.
Bluetooth Smart is driving major innovations in consumer electronics, including new types of gesture-based TV remote controls, smart watches, sports equipment, health and fitness monitors and home automation products. It is also enabling a new range of innovative 'appcessories' - defined as an accessory device with a companion application. Bluetooth Smart Ready products, such as those based on Apple iOS, use a software API that enables developers to create applications to communicate with Bluetooth Smart accessories in a standard way.
With Bluetooth Smart, it is possible to develop an application and an accessory without the need to wait for a standard profile to be developed and approved by the Bluetooth SIG. Innovators can build new products that work seamlessly with a smartphone and benefit from the rich user interface and connectivity it provides, while supporting compact hardware accessories with years of battery life.
Making a Watch Smarter
A smart watch supports features beyond time-keeping. It is capable of performing tasks as simple as mathematical calculations and exotic timing modes to more complex applications such as games, multimedia messaging, phone alerts and proximity awareness. They are powerful accessories to smartphones, enabling innovative user information and interaction.
For example, a smart watch could display your exercise metrics, such as your heart rate – before and after exercise – and the calories you burn. It could also locate your smartphone, let you know that your wallet is sitting on the counter, or remind you that lights were left on at your home.
The main components of a basic smart watch are a Bluetooth Smart chip, a microcontroller (MCU) and an LCD. For example, the CSR µEnergy CSR101x family of devices deliver a platform which offers a single-mode Bluetooth low energy radio, an integrated 16-bit processor and 128kB of memory. It acts as the heart of the system and controls all the peripheral devices.
The LCD displays information to the user and may have a capacitive/resistive touch capability so that physical buttons are not required in the product. A touch-based LCD significantly improves the user experience with touch, tap and swipe gestures to control the watch application. The MCU typically communicates with the LCD via a serial bus, such as SPI. The product may also have a speaker or piezoelectric buzzer for notifications, such as alarms.
To provide a scalable platform, an additional microprocessor can be integrated in the solution with the additional processing power and expanded IO enabling more sensors (such as a barometric pressure sensor) and peripherals (like GPS to determine the current location) to be included in the product design. It also enables more complex data processing algorithms to be implemented and operating systems with a rich graphical interface to be used. The MCU interfaces to the CR101x device using a simple, standard control protocol over a serial bus.