An introduction to Internet of Things
Electronic devices have become an 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 to 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 including BLE and subGhz wireless.
This article will elaborate more on sensor based IOT concepts and the innovative technologies transforming our lives.
A typical IOT architecture comprises of the following elements:
Base system refers to the classical device, which is executing its defined task such as home appliances, lighting, energy meter, television etc.
Wireless technology connects the base system to other devices, intranet or cloud. It allows monitoring and control of the base system remotely. The various wireless technologies prevalent are Bluetooth, Bluetooth Smart, Zigbee, subGhz, Wi-Fi etc.
Control system is used to monitor the base system using the wireless technology. It can be a dedicated device such as a remote control, smartphone or tablet. Smartphones and tablets have simplified the integration of IOT devices.
Gateway is the window of the local IOT system to the outside world. It can either be a dedicated home gateway or a smartphone. The various technologies used as gateway include GSM, GPRS, optical fibre or wire line internet.
Smart sensors have emerged as a very important driver for the growth of the 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.
As IOT devices are increasingly powered by battery, innovative lower power and precision operational amplifiers and comparators have become a critical factor for signal bridging between sensors and the controller. Besides, a precise state of charge of battery is needed to optimise the performance and maximise life.
Widely used in a typical IOT system, sensors are also driving the emergence of innovative wearable gadgets. Popular sensors include:
Also called a g-sensor, the accelerometer can be used to detect linear acceleration, vibration, tilt, free fall etc. The accelerometer is used to implement features such as horizontal levelling, antitheft, vibration alert, pedometer and remote monitoring of adults and kids among many other applications.
Gyroscopes measure angular velocity and are used to implement features such as gaming, 3D mouse, athletic training etc.
Magnetic compasses can detect the earth’s magnetic field and give direction sense to devices. It is widely used in indoor navigation and map navigation in mobile phones.
Pressure sensors can detect the earth’s atmospheric pressure, and are used to implement barometer and altimeter functions. The LPS25H pressure sensor from STMicroelectronics is so accurate that it can even be used to tell the floor of the building accurately. This feature can be used to implement indoor navigation, augmented reality and 3D GPS.
Temperature and Humidity Sensor
Temperature and humidity sensors can detect temperature and humidity parameters, which can be used to control the performance of devices as well as wearable gadgets.
The MEMS microphone is an 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.
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 a compatible smartphone and benefit from its rich user interface. A smartphone can also transfer data over the cloud using other connectivity options such as GPRS.
Bluetooth low energy technology operates in the same spectrum as Classic Bluetooth technology but enables ultra-low power connectivity and basic data transfer for applications previously limited by the power consumption.
Applications of IOT
BLE allows the user to control lights, home appliances, door locks, garage doors, security system, air conditioning and heaters. When fitted with Bluetooth Smart, these devices can communicate with Bluetooth Smart-ready phones or tablets. Innovative Apps can be developed to control the various elements of a smart home according to the person’s own requirement.
BLE also provides secure wireless communication that ensures accurate metering and control of electricity consumption at home.
Industrial equipment can now send key performance and safety data without the need for long cables, directly to Bluetooth Smart-ready phones, tablets or computers. It allows for higher flexibility in machinery installation and easy integration into the network.
Using this concept machines can automatically send data about their key parameters, replacement requirement, fuel shortage or raw material requirement without virtually any human intervention.
Healthcare and Fitness
Sport watches, heart rate monitors, glucose monitors, pulse oximeters and pedometers can now be connected to smartphones through BLE, which not only allows these gadgets to connect to smartphones wirelessly but also get connected to the internet. It will enable information to be stored on the cloud and shared with doctors or family members. BLE has also enabled these gadgets to be placed at strategic locations such as shoes or the wrist. BLE supports many healthcare related profiles such as glucose, heart rate, temperature and blood pressure monitoring.
Proximity and Anti-theft accessories
A small BLE accessory when tagged to pets or kids can alert the smartphone if they sneak out of reach. BLE enabled car keys can be found easily with the help of a connected smartphone. Likewise, wallets and luggage tagged with BLE can alert the smartphone if someone tries to steal them.
IOT has the potential to change the world just as internet did. IOT has enabled information to be shared and decisions to be taken without much human intervention. It has enabled enormous savings of power, time and human resources. Smart sensors and BLE have equipped devices with the power of sensing and communication to take complex decisions.
At STMicroelectronics we are committed to this new revolution with our innovative products and solutions.
Written by Vishal Goyal, Senior Technical Market Manager, STMicroelectronics Pty Ltd