Iot notes
1. INTERNET OF THINGS (IoT)
Meaning
IoT = Internet of Things
IoT means connecting physical things/devices to the Internet so they can:
collect data
exchange data
communicate
IoT devices can contain:
Electronics + Software + Sensors + Actuators + Network
Examples
Smartphone
Vehicle
Building
Smart device
Remember:
Things → Sense → Connect → Collect & Exchange Data
Exam keywords:
Physical devices, sensors, actuators, software, connectivity, collect data, exchange data. iot 1.pptx
2. CHARACTERISTICS OF IoT
There are 8 characteristics.
Remember this order:
T C I S U D H S
Things services → Connectivity → Intelligence → Scalability → Unique Identity → Dynamic → Heterogeneity → Safety
2.1 Things-related Services
IoT provides services related to things.
These services should consider:
Privacy protection
Physical things
Their virtual things
Easy line:
IoT provides useful services while protecting the thing and its privacy.
Keyword: Services + Privacy iot 1.pptx
2.2 Connectivity
IoT things must be connected to infrastructure.
Without connection, IoT cannot work.
Remember:
No connection = No IoT
Keyword: Connected to infrastructure. iot 1.pptx
2.3 Intelligence
Sensors generate data.
The data must be properly interpreted to get useful knowledge.
Flow:
Sensor → Data → Interpretation → Knowledge
Remember:
Data is useful only when we understand it.
Keyword: Extract knowledge from data. iot 1.pptx
2.4 Scalability
The number of IoT devices keeps increasing.
Therefore, an IoT system must handle a large number of connected devices.
Remember:
More devices → System must handle them
Keyword: Massive expansion. iot 1.pptx
2.5 Unique Identity
Every IoT device has an IP address.
It helps to:
identify the device
track the device
check its status
Remember:
IP address = Device identity
iot 1.pptx
2.6 Dynamic and Self-Adapting
IoT devices should change/adapt according to changing conditions.
Example:
A surveillance camera works in:
Morning → Afternoon → Night
Light conditions change, so the camera should adapt.
Remember:
Changing condition → Device adapts
iot 1.pptx
2.7 Heterogeneity
IoT devices can have:
different hardware
different networks
But they should still be able to interact with each other.
Remember:
Different devices → Still communicate
iot 1.pptx
2.8 Safety
Connecting many things to the Internet creates risks.
Personal data can be tampered with if proper safety measures are not used.
Remember:
Connected devices → Data risk → Need safety
iot 1.pptx
3. IoT CATEGORIES
There are 2 categories:
1. Consumer IoT (CIoT)
2. Industrial IoT (IIoT)
4. CONSUMER IoT (CIoT)
Meaning
CIoT means IoT used for personal/consumer devices.
Examples:
Smartphones
Wearables
Fashion items
Smart home appliances
These devices connect to the Internet to:
Collect + Share data
Typical CIoT network:
Few consumer devices
Devices have a limited lifetime of several years
Common connectivity:
Bluetooth
Wi-Fi
ZigBee
These are mainly short-range communication technologies.
Used in:
Houses
Small offices
Remember:
CIoT = Consumer + Personal devices + Short range
iot 1.pptx
5. INDUSTRIAL IoT (IIoT)
Meaning
IIoT means connecting industrial sensors, instruments and devices with computers.
Used in:
Manufacturing
Energy management
What does it do?
Collect data → Exchange data → Analyze data
Benefits:
Better productivity
Better efficiency
Remember:
IIoT = Industry + Devices + Data + Efficiency
iot 1.pptx
6. BASELINE TECHNOLOGIES
Three technologies are closely related to IoT:
1. M2M
Machine-to-Machine
2. CPS
Cyber-Physical Systems
3. WoT
Web of Things
Remember:
M2M + CPS + WoT = IoT baseline technologies
iot 1.pptx
7. MACHINE-TO-MACHINE (M2M)
Meaning
M2M means machines/devices communicate with other machines/devices.
Purpose:
Remote monitoring
Remote control
Data exchange
Remember:
Machine ↔ Machine = Monitor + Control + Data
iot 1.pptx
M2M Area Network
It contains:
Machines / M2M nodes
M2M nodes have network modules for:
Sensing
Actuation
Communication
Protocols:
ZigBee
Bluetooth
M-Bus
Wireless M-Bus
iot 1.pptx
Communication Network
It connects remote M2M area networks.
It can be:
Wired
Wireless
It uses IP-based networks.
Important:
Inside M2M area network → Non-IP/proprietary protocols
Communication network → IP-based network
iot 1.pptx
M2M Gateway
M2M nodes in one area network cannot directly communicate with nodes in another external network because non-IP protocols may be used inside the M2M area.
So:
M2M Gateway = Connects remote M2M area networks
iot 1.pptx
8. CYBER-PHYSICAL SYSTEM (CPS)
Meaning
CPS is the combination of:
Computation + Networking + Physical Processes
Embedded computers and networks:
Monitor + Control physical processes
Important concept: Feedback
Physical process → affects computation
Computation → affects physical process
This is called a feedback loop.
Remember:
CPS = Computer + Network + Physical world + Feedback
iot 1.pptx
9. WEB OF THINGS (WoT)
Meaning
WoT allows real-world objects to become part of the World Wide Web (WWW).
Remember:
Real Things → Web
iot 1.pptx
Thing
A Thing is an abstract representation of:
Physical entity
Virtual entity
Thing Description
Thing Description is an important part of WoT.
It contains:
Metadata
Interfaces
in a standardized form.
Purpose:
It helps Things communicate with other Things in a heterogeneous world.
Remember:
Thing Description = Metadata + Interfaces + Standard communication
iot 1.pptx
10. SENSOR
Definition
A sensor converts:
Physical event/characteristic → Electrical signal
It takes input from the environment and gives the converted information to the system.
Example:
Thermometer → Temperature → Electrical signal
Remember:
SENSOR = Environment → System
iot 1.pptx
11. CHARACTERISTICS OF SENSOR
There are 10.
Write this list first:
Range
Span
Accuracy
Precision
Linearity
Hysteresis
Resolution
Reproducibility
Repeatability
Response Time
11.1 Range
Range = Minimum to maximum value that a sensor can measure.
Example:
RTD:
−200°C to 800°C
Remember:
Range = Start → End
iot 1.pptx
11.2 Span
Span = Maximum value − Minimum value
RTD:
800 − (−200) = 1000°C
Remember:
Range = Values
Span = Difference
iot 1.pptx
11.3 Accuracy
Accuracy tells how close the measured value is to the true value.
Remember:
Accuracy = Correctness
iot 1.pptx
11.4 Precision
Precision means how close the measured values are to each other.
Remember:
Precision = Values close together
Don't confuse:
Accuracy → True value
Precision → Each other
iot 1.pptx
11.5 Linearity
Linearity = Maximum deviation from the ideal curve.
Remember:
Linearity → Ideal curve
iot 1.pptx
11.6 Hysteresis
Hysteresis = Difference in output when input is changed:
Increasing ↑
and
Decreasing ↓
Remember:
Input ↑ vs Input ↓ → Output difference = Hysteresis
iot 1.pptx
11.7 Resolution
Resolution = Smallest change in input that the sensor can detect.
Remember:
Resolution = Smallest detectable change
iot 1.pptx
11.8 Reproducibility
Reproducibility = Ability to produce the same output when the same input is applied.
Remember:
Same input → Same output
iot 1.pptx
11.9 Repeatability
Repeatability = Ability to produce the same output every time when the same input and same conditions are maintained.
Conditions include:
Same operator
Same instrument
Same environment
Same measurement conditions
Remember:
Same input + Same conditions → Same output again and again
iot 1.pptx
11.10 Response Time
Response time = Time taken by the output to reach a certain percentage of its final value after input changes.
PPT example:
95% of final value
Remember:
How fast sensor responds = Response Time
iot 1.pptx
12. CLASSIFICATION OF SENSORS
Sensors are classified in 3 ways.
Based on power:
Active / Passive
Based on output:
Analog / Digital
Based on data:
Scalar / Vector
Remember:
Power → Output → Data
13. ACTIVE SENSOR
Active sensor:
Does not need external energy
Directly generates electrical signal
Examples:
Thermocouple
Photodiode
Piezoelectric sensor
Remember:
Active = No external power
iot 1.pptx
14. PASSIVE SENSOR
Passive sensor:
Needs external power
External power is called excitation signal
Modifies excitation signal to produce output
Example:
Strain gauge
Remember:
Passive = Power required
iot 1.pptx
15. ANALOG SENSOR
Analog sensor produces a continuous output.
Examples of analog quantities:
Temperature
Speed
Pressure
Displacement
Strain
Example:
Thermometer continuously responds to temperature changes.
Remember:
Analog = Continuous
iot 1.pptx
16. DIGITAL SENSOR
Digital sensor produces discrete output.
Usually:
1 = ON
0 = OFF
Digital signals contain discrete values and can be represented using:
Bits
Bytes
Remember:
Digital = Discrete = 0/1
iot 1.pptx
17. SCALAR SENSOR
Scalar sensor measures magnitude.
Examples:
Temperature
Color
Pressure
Strain
Only magnitude is needed.
Example:
Thermometer measures temperature regardless of sensor direction.
Remember:
Scalar = Magnitude only
iot 1.pptx
18. VECTOR SENSOR
Vector sensor measures:
Magnitude + Direction + Orientation
Examples:
Sound
Image
Velocity
Acceleration
Orientation
Example:
Accelerometer measures acceleration along:
X + Y + Z
Remember:
Vector = Magnitude + Direction + Orientation
iot 1.pptx
19. ACTUATOR
An actuator converts:
Electrical signal → Physical output
It takes input from the system and gives output to the environment.
Examples:
Motor
Heater
Remember:
SENSOR: Environment → System
ACTUATOR: System → Environment
iot 1.pptx
20. TYPES OF ACTUATORS
There are 6 types:
Hydraulic
Pneumatic
Electric
Thermal and Magnetic
Mechanical
Soft
21. HYDRAULIC ACTUATOR
Uses:
Fluid-filled cylinder + Piston
Usually produces linear movement.
A spring may help return the piston.
Uses:
Exercise equipment
Steppers
Car transport carriers
Remember:
Hydraulic = Fluid
iot 1.pptx
22. PNEUMATIC ACTUATOR
Uses:
Pressurized gas → Mechanical movement
Advantages:
Reliable
Precise movement
Examples:
Bus brakes
Exercise machines
Vane motors
Pressure sensors
Remember:
Pneumatic = Pressurized gas
iot 1.pptx
23. ELECTRIC ACTUATOR
Requires:
Electricity → Movement
Can produce precise motion.
Examples:
Electric cars
Manufacturing machines
Robotics
Remember:
Electric = Electricity
iot 1.pptx
24. THERMAL AND MAGNETIC ACTUATOR
These can use shape memory alloys.
Heating can produce movement.
Movement can occur through:
Joule effect
Magnetic field
The PPT mentions Laplace-Lorentz force.
Important:
They can produce a wide and powerful range of motion while remaining lightweight.
Remember:
Thermal → Heat
Magnetic → Magnetic field
iot 1.pptx
25. MECHANICAL ACTUATOR
Uses mechanical systems such as:
Pulley
Rack and pinion
A pulling/pushing force is used to create desired movement.
Example:
Gear turns → Rack moves → Object moves
Remember:
Mechanical = Pulley / Rack & Pinion
iot 1.pptx
26. SOFT ACTUATOR
Soft actuators can be polymer-based.
Used for fragile objects.
Applications:
Fruit harvesting
Agriculture
Biomedicine
Robotics
They produce flexible movement.
Remember:
Soft = Flexible + Fragile objects
iot 1.pptx
27. FOUR IoT COMPONENTS
There are 4 fundamental components:
1. Sensors/Devices
2. Connectivity
3. Data Processing
4. User Interface
Remember:
COLLECT → CONNECT → PROCESS → SHOW
iot 1.pptx
28. SENSORS / DEVICES
Sensors/devices collect data from the surrounding environment.
Data can be:
Simple → Complex
Example:
Temperature → Full video feed
One device can contain multiple sensors.
Smartphone example:
GPS
Accelerometer
Camera
Remember:
Device = Collect data
iot 1.pptx
29. CONNECTIVITY
Collected data must travel to the cloud.
Connectivity provides the communication medium.
Methods:
Cellular
Satellite
Wi-Fi
Bluetooth
WAN
Low Power Wide Area Network
Remember:
Connectivity = Carry data
iot 1.pptx
30. DATA PROCESSING
After data reaches the cloud:
Software processes the data.
Simple example:
Check whether AC/heater temperature is acceptable.
Complex example:
Computer vision identifies an intruder in a video.
Remember:
Data Processing = Understand the collected data
iot 1.pptx
31. USER INTERFACE
Processed information is shown to the user.
It can be through:
Phone alarm
Text
The user can also actively check the IoT system.
Example:
Home camera → Web server → User watches recordings/live feed.
Remember:
User Interface = Information reaches user
iot 1.pptx
32. SERVICE ORIENTED ARCHITECTURE (SOA)
SOA can support IoT as an important technology for:
Devices
Heterogeneous systems
Remember:
SOA → Supports IoT services across different systems
iot 1.pptx
33. IoT ARCHITECTURE / LAYERS
There are 4 layers:
Sensing Layer
Networking Layer
Service Layer
Interface Layer
Remember:
S → N → S → I
Sense → Network → Service → Interface
iot 1.pptx
34. SENSING LAYER
IoT devices are equipped with:
Sensors
RFID
It helps in sensing/interconnecting things and supports remote control.
Remember:
Sensing = Sensors + RFID
iot 1.pptx
35. NETWORKING LAYER
Connects IoT devices/things.
Allows them to:
Share information over Internet
It can also collect information from:
ICT systems
Power grids
Business systems
Healthcare systems
Transportation systems
Remember:
Networking = Connect + Share
iot 1.pptx
36. SERVICE LAYER
Uses middleware technology.
Middleware provides functions between:
Applications ↔ Services
It provides a:
Cost-effective platform
Efficient platform
Reusable software/hardware components
Remember:
Service = Middleware + Services + Reuse
iot 1.pptx
37. INTERFACE LAYER
It simplifies:
Interconnection
Management of things
It provides interaction between services and applications.
Remember:
Interface = Interaction + Management
iot 1.pptx
38. CHALLENGES OF IoT
There are 7 challenges:
Security
Privacy
Scalability
Interoperability
Bandwidth
Standards
Regulation
Remember:
S P S I B S R
39. SECURITY
Security is a major IoT challenge.
More connected devices mean more chances for attackers to exploit vulnerabilities.
Poorly designed devices can:
expose user data
leave data streams unprotected
create health/safety risks
Remember:
More devices → More vulnerabilities → Security risk
iot 1.pptx
40. PRIVACY
IoT creates privacy problems because devices can collect information from our environment without us consciously using them.
Examples:
Phone tracking
Car tracking
Smart TVs
Remember:
IoT collects personal/environment data → Privacy concern
iot 1.pptx
41. SCALABILITY
IoT can connect billions of devices.
These devices create huge amounts of data.
Therefore, systems must be able to:
store large data
analyze large data
Remember:
Billions of devices → Huge data → Need scalability
iot 1.pptx
42. INTEROPERABILITY
Different IoT technologies may use different standards.
These standards are still fragmented.
IoT needs:
Common framework + Common standards
This is also important for working with legacy devices.
Remember:
Different technologies → Difficulty working together
iot 1.pptx
43. BANDWIDTH
As IoT grows, more data needs to be transferred.
Bandwidth-intensive applications can create problems.
Example:
Video streaming
Remember:
More data → More bandwidth needed
iot 1.pptx
44. STANDARDS
There is a lack of:
Common standards
Documented best practices
Without standards, manufacturers/developers may create poorly designed products.
These can negatively affect:
Network resources
Internet
Remember:
No standards → Poor design → Network problems
iot 1.pptx
45. REGULATION
Strong IoT regulations are important because connected devices can create security risks.
As more important devices connect to the Internet, the attack surface increases.
Examples:
Medical devices
Cars
Children's toys
Remember:
Important connected devices → Need proper regulation
🧠 NOW PUT THE WHOLE PPT IN YOUR HEAD
Don't try to memorize 45 headings separately. This is the structure you should memorize:
IoT
↓
8 Characteristics
↓
2 IoT Categories
↙ ↘
CIoT IIoT
↓
3 Baseline Technologies
↓ ↓ ↓
M2M CPS WoT
↓
Sensor
↓
10 Characteristics
↓
Sensor Classification
↙ ↓ ↘
Active/ Analog/ Scalar/
Passive Digital Vector
↓
Actuator
↓
6 Types
↓
4 IoT Components
↓
Collect → Connect → Process → Show
↓
4 IoT Layers
↓
Sensing → Networking
→ Service → Interface
↓
7 Challenges
↓
Security → Privacy → Scalability
→ Interoperability → Bandwidth
→ Standards → Regulation
⭐ The exact memory lines to learn
IoT:
Physical things + Sensors + Actuators + Connectivity → Collect & exchange data.
Characteristics:
Connectivity, Intelligence, Scalability, Identity, Dynamic, Heterogeneity, Safety + Things-related services.
Categories:
CIoT + IIoT.
Baseline:
M2M + CPS + WoT.
Sensor:
Physical → Electrical.
Actuator:
Electrical → Physical.
IoT Components:
Collect → Connect → Process → Show.
Layers:
Sense → Network → Service → Interface.
Challenges:
Security → Privacy → Scalability → Interoperability → Bandwidth → Standards → Regulation.