Notes

• A digital device is an electronic device that uses digital data by sending, receiving, storing, or processing information.
• Digital devices are used for social interaction, education, home chores, and many other things. Computers are an example of digital devices.
• Digital transformation is the process of employing digital technology to build new or adapt existing business processes, culture, and consumer experiences to meet changing business and market requirements.
• The Internet of Things (IoT) is a network that connects millions of smart gadgets and sensors to the Internet. Many organizations can use and evaluate the data collected and shared by these linked devices and sensors. Businesses, cities, governments, hospitals, and individuals are among these organizations. One of the main reasons for the IoT revolution is the invention of the Internet.
• Many devices have sensors that influence the operation of processes or create data for governments and corporations to use. Consider what kinds of equipment could be made more useful if they included intelligent sensors.
Benefits of IoT
Any person
Any business any person
Any path or network
Any place and any where
Any Device
• IoT devices are sensors and actuators which can connect to the Internet. They are able to interact with each other over the Internet and grant remote access to a user for managing the device according to their needs. Since they connect over the Internet, the user could operate these devices remotely from across the globe.
• An IoT system consists of IoT sensors and actuators managed through a controller that can be connected to a fog node.
• What are sensors?
• A sensor is a device that detects events or changes in the environment and converts them into electrical impulses which then can be meaningfully interpreted e.g. accelerometer (detects acceleration), ultrasonic detector (detects motion), and thermistor (detects temperature).
• Why do sensors need to be connected to a network?
• Sensors can collect data without requiring a network. However, in order to send this data so that other devices can store it and analyse it to make decisions, sensors need to be connected to a network. To do so, we need a wired or a wireless connection.
• What is the controller’s responsibility?
• Controllers are responsible for communicating with the sensor to get data as well as providing network or Internet connectivity. Sometimes controllers make immediate decisions, or they can wait until they receive a response from another device which could be on the same local network or connected to another network via the Internet.
• Sensors work together through actuators. So what is an actuator?
• An actuator is a device that interprets the electrical impulses sent from the control system (controller) and converts them into mechanical motion or actions e.g. motors, relays, and solenoids.
• What are Fog nodes?
• Fog networking, often known as fogging, is a decentralized computer framework that sits between the cloud and data-generating devices
• A circuit is a path for electric current to go through. A simple circuit, such as the one shown in the figure, can be created using a battery, a metal wire, a light bulb, and a switch. A closed circuit is a conduit for electricity to follow that is completely closed.
Every electric circuit, regardless of its size, has the following four components:
• Energy Source
It is the source of electricity. It could be DC (direct) current or AC (alternating) current. in this example its a battery Electricity flows out of the battery and into a wire.
• Conductor:
A wire is made of metal, which allows electricity to flow through it.
• Electrical load
The light bulb is the device that uses the electricity. Electric current flows through a very thin wire in the bulb called the filament.
• Controllers
Devices that regulate the flow of the current in the circuit such as a switch
• Electricity is the energy of moving electric charges. A flow of electricity is called an electric current. There are two types of current Alternating Current (AC) and Direct Current (DC).
In general terms, Alternating Current (AC) describes the flow of electric charge that changes direction periodically examples on AC could be the current used to deliver power to houses and buildings. While Direct Current (DC) is easier to understand than AC. It describes the flow of electric charge in one direction. It provides a steady level of voltage or current.
• There are two ways to connect the circuit components; series and parallel. The following is an explanation of both.
• Series Circuit:
• In a series circuit, all components are connected end-to-end, forming a single path for current flow. In a series circuit there is only one path for the electrons to flow. The main disadvantage of a series circuit is that if there is a break in the circuit, then the entire circuit will open and hence, no current will flow. The following is a schematic representation of a series circuit.
• A real-life example of a series circuit would be the string of Christmas lights. If one light goes off, all of them will. Can you give other examples of series circuits in real-life?
• In a parallel circuit, all components are connected across each other, forming exactly similar sets of electrically common points. The different parts of the electric circuit are on several different branches as you can see in the figure. There are several different paths that electrons can flow. If there is a break in one branch of the circuit electrons can still flow in other branches.
• For example; Your home is wired in a parallel circuit so if one light bulb goes off the others will stay on. Can you give other examples of parallel circuits in real life?
• The Internet of Things, is considered one of the fastest growing fields in modern technology. the Internet of Things facilitates communication between various machines and other objects, allowing them to coordinate with one another to perform a wide variety of functions.
• A system architecture can be used to formalize the arrangement of components and their interactions.
Three-Layer IoT System Architecture
The architecture of the Internet of Things is a conceptual model that defines the structure, behavior, and other views of a system. This framework is defined by the following:
• The physical components
• The functional organization
• The configuration of the network, operational procedures and the data formats to be used.
The most basic architecture associated with IoT systems is known as a “three-layered” architecture, which consists of the perception, network, and application layers as shown in the figure below
• Three-Layer IoT System Architecture, what happens in each layer?
1. Perception:
• The perception layer is the physical layer. This is where the sensors and other devices start working to collect data according to the type and nature of the project. Examples include edge devices, sensors, and actuators that interact with their environment.
2. Network:
• The network’s layer function is to transmit and process all data collected in the perception layer. It connects these devices to other smart objects, servers, and network devices.
3. Application:
• The application layer is responsible for delivering application services to the user to interact with. For example, it is when a user taps a button in the app to turn on a coffee maker in a smart home implementation.
• The Perception Layer
This layer helps the system “see” the current world around it. It is the physical layer of the architecture, which consists of the physical sensors and actuators.
Devices in this layer interact with the surrounding environment in which they collect and receive information. A sensor collects data and sends it through the network layer while an actuator receives data through the network layer and acts accordingly.
There are many devices that could be part of this layer and a few examples are shown below.

• The Communication Layer
This layer acts as a midway between the perception and application layers. It allows exchanging the collected data from the perception layer with the services on the application layer. The communication layer includes multiple protocols and standards for messaging and networking.
We Do. With your peer, search what are protocols and type the answer in SCHOOLOGY Channel?
• What are protocols?
 A protocol is a set of rules governing the exchange or transmission of data between devices.
 Well-known messaging protocols are Hypertext Transfer Protocol (HTTP), Message Queuing Telemetry Transport (MQTT), and Constrained Application Protocol (CoAP).
 Well-known networking standards and technologies are XBee, WiMAX, and 3G/4G.
 The Application Layer
The application layer enables end-users to interact with the perception layer. It hosts different services such as middleware, data processing units, and data visualization tools based on the intended application by the user.
Middleware is a type of computer software that provides services to software applications beyond those available from the operating system. Examples on middleware may include distributed cache, message queue, and automated backup systems.
• Cisco Packet Tracer is a comprehensive networking technology teaching and learning tool that offers a unique combination of realistic simulation and visualization experiences, assessment, activity authoring capabilities, and multiuser collaboration and competition opportunities. Innovative features of Packet Tracer help users collaborate, solve problems, and learn concepts in an engaging and dynamic social environment.
• In this task we will explore the main components needed to build an IoT system and learn more about each one of them.
• Click on the Components icon in the bottom left corner as shown below, this will enable you to view all available boards or controllers.
• To view the available boards, click on the boards icon in the bottom left corner to display available controllers as shown in the figure below. To add a controller, click on it and then click on the white area.
• To view the available actuators, click on the actuators icon in the bottom left corner to display the available actuators. To add an actuator, click on it and then click on the white area.
• To view some of the available sensors, click on the sensor’s icon in the bottom left corner to display the available sensors. To add a sensor, click on it and then click on the white area.
• In computing, a home network gateway connects a residential building's local area network (LAN) to the Internet. It is set up depending on the configuration and needs of the household so every home network gateway installation can be considered unique and one of a kind. Every home network configuration requires certain settings from its home network gateway. The more connections there are in a house, the more configuration time it needs to set up.
• Smartphone and home gateway are used to control the devices such as smart window, smart fan, smart garbage and sensor. The smart devices are connected to the IoT home gateway ports and smart phone is used to communicate with the smart devices.
• A network adapter is the component of a computer’s internal hardware that is used for communicating over a network with another computer. It enables a computer to connect with another computer, server or any networking device over a local area network (LAN) connection. A network adapter can be used over a wired or wireless network.
• Since the Fan and Window will be controlled using the smartphone then the wireless connections should be enabled in both componenets (Fan and Windoew). To do that, the Network adapter should be selected in each componenet.
• To access the Network adapter, click Fan, then advanced button.

• The SSID (Service Set Identifier) is a unique identifier that wireless networking devices use to establish and maintain wireless connectivity.
• All wireless networks have an SSID, in everyday speech often known only as network names or Wi-Fi names. You need to know or find this name in order to connect to a wireless network.
• Technically speaking, the name of your network does not need to be unique, but it is highly practical to have an SSID that will stand out on the list of available networks--unless, of course, there are no other networks around.
• In Activity 2 , the smart phone should have the same SSID as the Home Gateway which is “HomeGateway”.
• Click on the Home Gateway component
• To access the Home Gateway form the smartphone, the IoE monitor application will be used.
• The Internet of Everything (IoE) is the Networked Connection of People, Process, Data, Things.
• The IoE is a term describing the intelligence added to every device in order to give it some added functionalities, the device could be any of the following: smartwatches, smart appliances, smart beds, health monitoring devices, smart connected cars, and others.
• The difference between IoE and IoT is that IoE consists of four parts: “people,” “process,” “data,” and “things” and builds on top of IoT, which consists of one part, which is “things”.
• IP (Internet Protocol) addresses are used to identify hardware devices on a network. The addresses allow these devices to connect to one another and transfer data on a local network or over the internet.
• In simple terms, an open-loop control system is a system where the output does not affect its input. The input feeds into a controller and a process to generate a specific output takes place. Below is a simple representation of the open-loop control process.
• Let’s discuss an example on open-loop control systems. The open-loop system can be exemplified by the automatic washing machine. The machine’s operating time is manually set by the operator. The machine turns off once the predetermined amount of time has passed, even if the desired level of clothing cleanliness has not been achieved. This occurs because the machine lacks a feedback system that indicates the system’s control action for a desired output.
• The open loop system is not complicated and requires low-maintenance. It’s also simple to use and cost-effective. However, the system’s accuracy and dependability are quite low.
• A closed-loop control system is a more complex way of controlling a system where the output continuously feeds into the input. This control system can have one or more feedback loops between its input and output. It generates the required output by evaluating the input through an error signal. This error signal is the main disparity between the output and input. Below is a simple graphical representation of a closed-loop control system.
• The main advantages of closed-loop systems evolve around it high accuracy and reliability. However, these systems are very expensive and require continues maintenance.
• An example on closed-loop control systems is the Air Conditioner (AC). The temperature is regulated by the AC and compared to the ambient temperature. With the help of the thermostat, temperature comparisons are made. The thermostats switch on or off the compressor when the AC sends an error signal, which is the difference between the ambient temperature and the room temperature.
• As explained in the previous slides, any IoT system requires control, which is usually done by a controller. There are two common types of controllers; microcontrollers and single board computers. Here will explain these two types of controllers and discuss the differences between them.
• A Microcontroller is a small computer with low-memory and programmable input/output peripherals, also known as a Microcontroller unit . It is an integrated circuit (IC) device used for controlling other portions of an electronic system, usually via a microprocessor unit (MPU), memory, and other peripherals. It can only run one program repeatedly — hence it cannot be or have a full operating system.
• Note. An Operating System is the system software that manages the computer hardware and software resources. It also provides common services for computer programs.
• To run a program, the microcontroller takes input from the device it is controlling and retains control by sending the device signals to different parts of the device. The following architecture demonstrates the components of a microcontroller.
• Examples of well-known microcontrollers are the Atmel (Arduino is one of its applications) and the ESP32 shown in the figures below.
• But why do we need microcontrollers if they are that simple?
• In fact not all computing tasks are complex enough to require significant computing resources. For example, flipping a switch or controlling simple operations for LEDs. In this context, microcontrollers fit best as they are incredibly trivial and require simple logic. Accordingly, their low power and low memory demand makes them affordable at low-cost.
• Microcontrollers are used for multiple applications such as Communication systems, Robotics fields, peripheral controllers in PCs, Biomedical instruments and IoT.
• A Single Board Computer (SBC) is a full computer built on a single circuit. It is a small computing device that has all of the elements of a complete computer contained within one single circuit board. It is low-cost, self-contained and simple, and could be easily connected to other hardware. The SBCs use a System-on-Chip (SoC), which integrates all or most components of a computer or other electronic systems. It works exactly like how a microcontroller does and even better It can be used for for signal processing, wireless communication, artificial intelligence, etc.
• Well known single board computers are the Raspberry Pi, and NVIDIA.

• Well known single board computers are the Raspberry Pi, and NVIDIA.
• SBCs are used for various applications such as Programming, Embedded Applications, Backplane, Robotics and Home automation.
• There a lot of similarities and differences between Microcontrollers and Single-Board Computers, they can be summarized as follows:
• Sensors, actuators, and communication modules in an IoT system need to be connected to a microcontroller or a single board computer for the system to operate. Some sensors might be embedded within the microcontroller such as the temperature sensors. It also has built-in Bluetooth and Wi-Fi capabilities for data transfer. Additional sensors and actuators can be connected to a microcontroller or a single board computer through input/output pins to extend the capabilities of the system.
• For example, look at the figure showing a cellular-enabled IoT board. It can be used as a gateway to link an entire group of local endpoints where Wi-Fi is missing or unreliable; it is also ideal for connecting projects to the Particle Device Cloud.