Majeed Ahmad explores the latest sensor hub offerings for wearable devices.
By Majeed Ahmad
Atmel has beefed up its sensor hub offerings for wearable devices with SAM D20 Cortex M0+ microcontroller core to add more functionality and further lower the power bar for battery-operated devices. The SAM D20 MCUs offer ultra-low power through a patented power-saving technique called “Event System” that allows peripherals to communicate directly with each other without involving the CPU.
Atmel is part of the group of chipmakers that use low-power MCUs for sensor management as opposed to incorporating low-power core within the application processor. According to market research firm IHS Technology, Atmel is the leading sensor hub device supplier with 32 percent market share.
Sensor hubs are semiconductor devices that carry out sensor processing tasks — like sensor fusion and sensor calibration — through an array of software algorithms and subsequently transform sensor data into app-ready information for smartphones, tablets and wearable devices. Sensor hubs combine inputs from multiple sensors and sensor types including motion sensors — such as accelerometers, magnetometers and gyroscopes — and environmental sensors that provide light level, color, temperature, pressure, humidity, and many other inputs.
Atmel has supplied MCU-centric sensor hub solutions for a number of smartphones. Take China’s fourth largest smartphone maker, Coolpad, which has been using Atmel’s low-power MCU to offload sensor management tasks from handset’s main processor. However, while still busy in supplying sensor hub chips for smartphones and tablets, Atmel is looking at the next sensor-laden frontier: wearable devices.
Wearable devices are becoming the epitome of always-on sensor systems as they mirror and enhance cool smartphone apps like location and transport, activity and gesture monitoring, and voice command operation in far more portable manner. At the same time, however, always-on sensor ecosystem within connected wearables requires sensor hubs to interpret and combine multiple types of sensing—motion, sound and face—to enable context, motion and gesture solutions for devices like smartwatch.
Sensor hubs within wearable environment should be able to manage robust context awareness, motion detection, and gesture recognition demands. Wearable application developers are going to write all kinds of apps such as tap-to-walk and optical gesture. And, for sensor hubs, that means a lot more processing work and a requirement for greater accuracy.
So, the low-power demand is crucial in wearable devices given that sensor hubs would have to process a lot more sensor data at a lot lower power budget compared to smartphones and tablets. That’s why Atmel is pushing the power envelope for connected wearables through SAM D20 Cortex M0+ cores that offload the application processor from sensor-related tasks.
The SAM D20 devices have two software-selectable sleep modes: idle and standby. In idle mode, the CPU is stopped while all other functions can be kept running. In standby mode, all clocks and functions are stopped except those selected to continue running.
Moreover, SAM D20 microcontroller supports SleepWalking, a feature that allows the peripheral to wake up from sleep based on predefined conditions. It allows the CPU to wake up only when needed — for instance, when a threshold is crossed or a result is ready.
The SAM D20 Cortex M0+ core offers the peripheral flexibility through a serial communication module (SERCOM) that is fully software-configurable to handle I2C, USART/UART and SPI communications. Furthermore, it offers memory densities ranging from 16KB to 256KB to give designers the option to determine how much memory they will require in sleep mode to achieve better power efficiency.
Atmel’s sensor hub solutions support Android and Windows operating systems as well as real-time operating system (RTOS) software. The San Jose–based chipmaker has also partnered with sensor fusion software and application providers including Hillcrest Labs and Sensor Platforms. In fact, Hillcrest is providing sensor hub software for China’s Coolpad, which is using Atmel’s low-power MCU for sensor data management.
The company has also signed partnership deals with major sensor manufacturers — including Bosch, Intersil, Kionix, Memsic and Sensirion — to streamline and accelerate design process for OEMs and ensure quick and seamless product integration.
This post has been republished with permission from SemiWiki.com, where Majeed Ahmad is a featured blogger. It first appeared there on February 4, 2015. Majeed Ahmad is author of books Smartphone: Mobile Revolution at the Crossroads of Communications, Computing and Consumer Electronics and The Next Web of 50 Billion Devices: Mobile Internet’s Past, Present and Future. Majeed has a background in Engineering MS, former EE Times Editor in Chief (Asia), Writer for EC Magazine, Author of SmartPhone, Nokia’s SMART Phone.