By Vishal Goyal
Internet of Things[IOT] Introduction
Electronic devices have become integral part of our lives. We can see electronics in our Appliances, lighting, fan, energy meter, weighing scale, television as well as gadgets such as mobile phone, tablet, watches and medical devices. Internet of things [IOT] enables these devices to be connected and interact with each other. IOT allows devices to have their own machine readable identification and ability to transfer data over network without human interaction. The enablers of IOT are smart sensors such as Motion sensors and environment sensors as well as ultra-low current consumption wireless technologies such as BLE and subGhz wireless. This article will elaborate more on sensor based IOT concept and the innovative technologies which are transforming our lives.
IOT architecture
A typical IOT architecture comprises of following elements
a) Base system
It refers to the classical device which is executing its defined task such as home appliances, lighting, energy meter, television etc.
b) Wireless technology
Wireless technology connects base system to other devices, intranet or cloud. It allows monitoring and control of the base system remotely. Various wireless technologies prevalent are Bluetooth, Bluetooth Smart, Zigbee, subGhz, Wi-Fi etc.
c) Control system
Control system device is used to monitor the base system using the wireless technology. It can either be a dedicated device such as remote control or smartphone and tablet. Smartphone and tablet have made it very easy to integrate the IOT devices.
d) Gateway & Internet
Gateway is the window of local IOT system to the outside world. It can either be a dedicated home gateway or a smartphone. The various technologies which are used as gateway are GSM, GPRS, optical fibre or other wire line internet.
e) Smart Sensors
Smart Sensors have emerged as a very important driver for the growth of IOT system. Sensors have made it possible to monitor motion, environment and other parameters remotely and transfer to the control system or gateway via wireless technology. It has transformed human life and made the existing device even smarter.
f) Signal Conditioning and battery management
As IOT devices are increasingly powered by battery innovative lower power and precision Operational Amplifiers and Comparators have become a critical factor for signal bridge between sensors and controller. Besides, a precise state of charge of battery is needed to optimize the performance and maximize life.
We will learn more about Smart Sensors and Bluetooth Smart in the next section.
Smart Sensors
Sensors are widely used in a typical IOT system. They are also driving the emergence of innovative wearable gadgets. 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.
Ultra-compact high-performance e-compass : 3D accelerometer and 3D magnetometer module
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.
MEMS pressure sensor: 2.5 X 2.5 mm High Accuracy barometer
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.
f) 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.
Analogue MEMS Microphone: Bottom port with high bandwidth, omnidirectional and high SNR
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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
Layered Architecture of BlueNRG – Bluetooth Smart IC from STMicroelectronics
Applications of IOT
Smart Home
BLE allows controlling lights, home appliances, door locks, garage doors, security system, air conditioning and heater. These devices when fitted with Bluetooth Smart can communicate with Bluetooth Smart ready phones or tablet. Innovative Apps can be developed to control the various elements of smart home according the person’s own requirement.
BLE also provide secure wireless communication that ensures accurate metering and control of electricity consumption at home.
Industrial Automation
Industrial equipment’s can now send key performance and safety information without the need of long cables directly to Bluetooth Smart ready phone, tablet or computers. It allows for higher flexibility for machinery installation and easy integration into the network.
Using this concept machines can automatically inform about their key parameters, replacement requirement, fuel shortage or ordering of raw material without virtually any human intervention.
Healthcare and fitness
Sport watches, heart rate monitors, glucose monitors, pulse oximeters, pedometers 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 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.
Conclusion
IOT has the potential to change the world just as internet did. IOT has enabled information to be shared and decision be taken without much human intervention. It has enabled enormous saving of power, time and human resources. Smart Sensors and BLE have empowered devices with power of sensing and communication to take complex decisions. At STMicroelectronics we are committed to this new revolution with our innovative products and solutions.
The author is the senior technical market manager for India at STMicroelectronics.
