 I am Dr. Gannap A. Waliker, works in the Department of Computer Science and Engineering, Walsh and University of Technology, Singapore. Today, I am going to deliver a lecture on sensor technology used in Internet of Things. As part of our learning outcome, at the end of this session, students will be able to describe the different sensor technology used in Internet of Things. So, before discussing architecture of sensor technology and its applications and its components, let's we will begin with a definition of a sensor technology. The sensor technology is a technology that is used to design a sensor and its associated electronics, circuits, devices, activators and arduates. Sensing technology simply put is a technology that uses sensors to acquire information by detecting the physical, chemical, biological property across a sensing area. So, this sensors will senses a physical condition or environmental conditions such as temperature, wind, pressure, molecular and other parameters. So, that are required to analyze and extract the knowledge in order to carry out the sensing or in order to perform the analysis process. Nowadays, the sensor technology introduces in a new application fields and mass markets like automobiles and smart homes. Sensor technology allows objects to be sensed and are controlled remotely across existing network infrastructure. Creating opportunities for more direct integration of the physical world into a computer-based systems. Here, sensors will senses data from remote areas and feed that information to the central system, so where the user can access through computer-based systems. Due to the use of sensors in the different applications, so all type of applications are improved with their efficiency, with accuracy and economic benefit. And nowadays, the sensors are being used widely due to the following reason. So, one is eye accuracy in collecting and sensing the data, high resolution, high reliability, energy efficient and easy to integrate with already existing systems. We can find the sensor in different applications like automated cars, smart phones, ATMs, homes and offices and airports, etc. So, now sensor technology also being used in designing wireless sensor network. So, now we will look at first architecture of wireless sensor network and then later we will discuss how sensor technology being used in designing a spatial sensors. Here, so this is a sensor field filled with or spreaded with a spatial sensors and those sensors will also called a sensor nodes and these sensor nodes senses the sensing informations such as temperature, wind, lights and other chemical particles, etc. from within this sensing field. Then that information will be sent to the central system where the computer applications are installed and user can process, analyze and extract the knowledge from that sensor information. So, here the sensor technology is play a vital role in designing and deploying a spatial smart sensors. So, these are the different types of sensors. First and the functionality of sensors basically sensors are classified into two types one is analog sensors and second one is a digital sensors. So, analog sensors are one which will converts a physical energy into analog signals and digital sensors one in which sensors are convert a physical environment or physical energy into a digital energy that is 0, 0, 1 or on state or off state and based on applications of sensors the sensors are classified into a different types. These are the some examples I listed here one is ultrasonic sensor, gas sensor, color sensor, PR sensor, accelerometer sensor, potential meter, IR sensor, flex sensor, LDR, thermistor, rain sensor, IR transmitter, proto diode, LM35, microphone, all sensors. These are the some of the important sensors I listed. So, likewise N number of sensors are there in market. So, based on the applications we can purchase and we can use in our day to day applications. Here I am explaining some of the examples what I listed in the previous slides. So, proto electric sensor is in a type of a sensor. So, that is used to detect the distance, absence or presence of an object by using a light transmitter and proto electric receiver. Usually these are used in industrial manufacturing in order to detect the distance, absence and presence of the object placed in that particular industrial area. Next one is infrared sensor and these are used in houses and in hotels at automatic lights and water tabs. So, wherever they want or user wants to control lights in their houses or in hotels. So, they can use these infrared sensors and with the help of these sensors they can remotely monitor on and automatic on and off of their waters and lights. Next, immodality sensor and this is also one type of a popular sensors and being used in home heating, ventilating and air conditioning systems, offices, cars, industrial spaces and green house, smart houses, smart cities, etc. And these are the typical sensors I listed here and the sensors are exist with a different size, with a different configurations, with a different hardware and its associates and they are designed based on the applications and also the cost is depends upon their configurations, their peripherals and their real-time applications. And now we will move to working of sensor technology. The first, the sensor technology will enables sensors to get ready to change the informations. So, once sensor technology makes sensor in a position to read the data, then the sensor will start reading the information from sensing area either remotely or locally. So, once it detect the information from sensing area, then it will send it to the storage device. That storage devices either may be local servers or it may be cloud applications and that data will be stored into these storage devices via wireless links. So, once the data being stored successfully, so that data is available for the user to process, to analyze and extract the knowledge from the sensor data. So, once the data collection or data gathering process is over, so then the sensor technology will disables sensors from active operations. And this process is usually called data collection and processing of sensor within a sensing area. Think and write. So, what do cows, shoes and trees have in common? Pause the video now and answer the questions. Here, there are three pictures, trees, cow and shoes. They all are enabled with sensor technologies. That is the common thing among all these three pictures. They appears to be different, but by functionally they are having enabled sensor technology or they are enabled with sensor technology. Look at the tree. So, tree contains sensors. That sensor will continuously senses a vehicle passing through that road that is before the tree. As per the survey, so single sensor can sense the more than 3,000 vehicles in a day. And look at the cow. So, cow carrying the sensor and that sensor will senses information wherever this cow goes. As per the survey, so this sensor will senses 200 MB of information per year. Look at the third picture. This is shoes and it is enabled with sensor technologies. So, if people wear these shoes, so wherever they will move, it will senses information of that particular area. That information might be temperature. If there is a raining season, the rate of raining fall, wind, light and other the smart cities wherever they are going, they can collect the information about area. So, this is a common thing between tree, shoes and cow. So, now we will discuss about applications of sensor technologies. There are tremendous applications are there. So, but here I will state few. So, one is the most of the sensors are being used in industrial land, home appliances, for example, TV, fridge, right. And then sensors also used in establishing wireless sensor networks in order to gather the information wirelessly. Water level indicator to send a firing alarm system to the control system, automatic braking and speed control mechanism, smartphone touch screens, railway gate control mechanism and fully automated control system. Among these applications, 99% are having sensors in place. So, these are the references I referred to prepare this slides out of which two are books and remaining all are references where I collected the informations.