ARM and Wearables – Cheap is cheerful.

Small, lean and cheap is the way forward for wearables.

• ARM has announced a new platform for wearables called mBed that is designed to run on its new Cortex-M7 processor family that has been specifically designed for this segment.
• There are two pieces to the platform.
  • First. The device software. This is an RTOS (real time operating system) that runs the device itself.
  • This has been designed to be as low power as possible and requires 32Kb to 64Kb of RAM and 256Kb of flash memory to run making it incredibly light weight.
  • In the cheapest smartphone design (Firefox $25 device), one could fit 15,600 copies of mBed meaning that the cost overhead of this system will be tiny.
  • Second. An OS agnostic piece of software (mBed device server) that resides on a smartphone which allows the device to communicate with the smartphone.
  • This allows the radio transmission to be tightly controlled in order to maximise performance of the device at the lowest possible power consumption.
  • Radio communication is the single biggest power requirement for devices such as these.
  • Poorly implemented communication protocols will kill the device’s battery life and with that its appeal to users.
  • Using this sort of control, it is possible to create a device with a single pen battery that communicates via Bluetooth 4 and lasts for several months.
• I see the first generation of wearable devices evolving in this direction as they will be mostly single function sensors.
• The smartphone is very likely to be the centre to which these devices feed their data.
• Apple is already creating APIs that allow all of this data to be aggregated.
• Consequently, these devices need nothing more than a tiny and simple operating system to run them.
• This is where I think systems like Android Wear and Tizen fall over.
• Using mBed or a proprietary OS one can build a device that is much smaller, much cheaper with a much longer battery life.
• This are all key things that consumers look for which is why these higher end systems for wearable devices are unlikely to get much traction in the first generation.
• As wearables need to become much smarter, then there may be a need for higher powered operating systems, but for now the way forward is the RTOS.
• The aim of mBed is to drive the adoption of the ARM processor over proprietary designs that are still used in many microcontrollers.
• This is why the mBed platform is being offered free of charge.
• It is much too early to say whether this platform will be adopted but as one thing is for sure; ARM is on the right track.
• Higher level OSs have no place in the first generation of wearable devices which will be mostly screen-less, single function sensors.