Interview with Vishal Goyal, Senior Technical Marketing Manager, STMicroelectronics
What is the role of sensors in wearable technology?
Sensors are driving the emergence of innovative wearable gadgets. They measure what’s happening around us, from how fast we’re moving and in which direction to ambient air pressure, temperature and relative humidity. They detect any change in our environment and process data accordingly, thereby giving us the desired outcome.Some of the most popular sensors are mentioned below-
a) Accelerometer
Also called a g-sensor, accelerometer can be used to detect linear acceleration, vibration, tilt, free fall detection etc. Accelerometer is used to implement features such as horizontal levelling, antitheft, vibration alert, pedometer, remote monitoring of adults and kids etc.
b) Gyroscope
Gyroscope measures angular velocity and used to implement features such as gaming, 3D mouse, athlete training etc.
c) Magnetic Compass
Magnetic Compass can detect earth’s magnetic field and can give direction sense to devices. It is widely used in indoor navigation and map navigation in mobile phone.
d) Pressure Sensor
Pressure sensor can detect earth’s atmospheric pressure. This feature can be used to implement barometer and altimeter. LPS25H pressure sensor from STMicroelectronics is so accurate that it can even be used to tell the floor of building accurately. This feature can be used to implement indoor navigation, augmented reality and 3D GPS.
e) Temperature and Humidity Sensor
Temperature and humidity sensor can detect temperature and humidity parameter which can be used to control the performance of devices as well as wearable gadgets.
State some recent trends in development of wearable technology.
Wearable applications are making a growing impact in markets that range from new healthcare technologies including remote heart-rate monitoring to consumer applications such as smart fashion accessories. Wearable-device requirements are currently driving significant changes in the MEMS industry. They are driving the development of even smaller components with even lower power consumption but with more embedded features. To satisfy these needs, sensor manufacturers are creating highly integrated devices with multiple sensors (e.g., accelerometer, gyroscope and magnetometer) embedded in a single package.
Emerging Applications of Wearable
Fitness and Wellness
Connected Smart watches, activity monitors, pedometers enable users to monitor their fitness activity through their smartphones. Wearables are also available as activity monitors, foot pads, sleep sensors and heart rate monitors. Wearable also allows to optimize sports performance, goal monitoring, weight control, direction data and location sharing.
Healthcare
Heart rate monitors, glucose monitors, pulse oximeters can now be connected to Smartphones through BLE. BLE not only allow these gadgets to connect to smartphones wirelessly but also get connected to internet through smartphones. It will enable information to be stored on cloud and share with doctors and family members. BLE has also enabled these gadget to be placed at strategic locations such as shoes, wrist etc. BLE support many healthcare related profiles such as glucose meters, heart rate monitoring, thermometer and blood pressure.
Proximity and Anti-theft accessories
A small BLE accessory when tagged to pets and kids can alert the smartphone if they sneak out of reach. BLE enabled car keys can be found easily with the help of connected Smartphone. Wallets and luggage tagged with BLE can alert the Smartphone if some try to steal them.
Security and tracking
A wearable watch or tracking devices allows parents to monitor their kids remotely. These devices are also used as SOS device by kids and women when in danger. A connected device will send signal to smartphone which in turn will SMS user location to the concerned authorities and family members.
What are some of the attributes of this technology?
As the name suggest, wearable are worn by user for an extended period of time and continuously remain on and connected. So a typical wearable device should have following attributes-
a) Always on
Wearables are continuously on the job and monitor or output key data for the user. They may be in sleep mode but never OFF. Hence they require a rugged power backup
b) Low Power
As wearables are miniature devices and run on small battery they should consume ultra-low current. A wearable device which requires frequent charging will lose its purpose. The emergence of low power technologies has enabled the revolution in this industry.
c) Compact
As they are worn by user they should be small enough to take various usable and aesthetic forms. A bulky device will be extra burden on user and will lose its acceptance.
d) Environment aware
Environment sensing is emerging as a key driver for wearable acceptance. Today wearable devices can monitor not only user activity information but also temperature, humidity, UV radiation etc.
e) Intelligent
Wearable devices should be intelligent enough to filter out noise from the real data. They should be able to alert user when any important information needs to be shared. For example, a security wrist band should be able to send alert when user has met accident or need SOS help.
f) Connected
Connectivity is the most important factor for emergence and acceptance of wearables. These devices can be connected to smartphones or tablet using technologies such as Bluetooth, wifi etc. Besides, they can also be connected to GPS satellites to monitor user location.
Latest products & development at your company on this technology
With a product portfolio that spans the full range of low-power and high-performance sensors, connectivity ICs, audio amplifiers, op amps, analog switches, and battery gas gauges for the wearables market, along with an industry-leading family of STM32 ARM® Cortex®-M microcontrollers and an outstanding choice of development tools, ST is positioned to continue its success in the wearables market and will continue to grow its ecosystem with specialized shields. We are also world leader in RF and sensor technologies and fits perfectly to the fast growing WT market making us the clear one-stop supplier-of-choice for customers developing innovative wearable applications.
Examples of devices suitable for wearable applications include ST’s single, dual, and quad op amps, such as the OA4NP33 quad low-power op amp, that offer an ultra-low-power typical consumption of just 580nA per channel (at 1.8V power supply), making them ideally suited for functions such as sensor signal-conditioning in battery-operated wearable devices. Another product, the GG25L gas gauge, uses a patented OptimGauge™ algorithm to monitor battery voltage to an accuracy of 0.25%.
Examples from ST’s rich portfolio of motion sensors include the LIS2DH12 ultra-low-power digital 3-axis accelerometer and the award-winning4 LSM303C ultra-compact high-performance e-compass module. ST’s M24SR dynamic tags add NFC connectivity to wearable applications for convenient wireless pairing, automatic connection to websites, or warranty-card activation.
Latest product
MEMS Microphone
MEMS Microphone is audio sensor that converts sound signals into electrical signals. MEMS Microphones are increasingly preferred over conventional microphones as they offer higher SNR, small form factor, digital interface, better RF immunity and high robustness against vibration.
Microphone makes the interaction easier, faster and smoother. It also enables fashionable and stylish designs by reducing the number of buttons.
The upcoming trend in microphones is dual mode operations.
• Sniffing/low power mode: the device reduces the power consumption at minimum whilst guaranteeing an adequate set of performances for voice activity detection.
• Normal mode: the acoustical parameters are set to the optimal level for voice control applications.
Bluetooth Smart [BLE]
Bluetooth Smart or Bluetooth Low Energy [BLE] is a standard that enables connectivity of low power devices and sensors. It uses short wavelength radio transmission at 2.4GHz band. Using Bluetooth Smart it is possible to enable two way communications between various devices wirelessly with incredible battery life. BLE enabled devices can also work seamlessly with the compatible smartphone and benefit from the rich user interface. Smartphone can also transfer data over the cloud using other connectivity such as GPRS.
Bluetooth low energy technology operates in the same spectrum as Classic Bluetooth technology but it enables ultra-low power connectivity and basic data transfer for applications previously limited by the power consumption.
