Ayush Labs

IoT Basics

What is IoT? IoT (Internet of Things) means connecting everyday objects to the internet so they can collect data, communicate with each other, and perform actions automatically. Simple Example: A smart bulb that you can turn on/off from your phone us...

Ayush Basak
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IoT Basics

What is IoT? IoT (Internet of Things) means connecting everyday objects to the internet so they can collect data, communicate with each other, and perform actions automatically.

Simple Example: A smart bulb that you can turn on/off from your phone using Wi-Fi.

Real-World Applications:

  1. Smart Homes - Lights, thermostats, security cameras controlled via phone

  2. Wearables - Smartwatches, fitness trackers monitoring health

  3. Smart Agriculture - Soil sensors automatically watering crops

  4. Connected Cars - Cars that can self-drive and communicate with traffic systems

🔹 IoT Architecture (Main Parts)

Think of IoT as a 4-layer system:

  1. Sensors - Eyes and ears that collect data

    • Example: Temperature sensor reads room temperature

  2. Actuators - Hands that perform actions

    • Example: Motor that opens/closes a window

  3. Gateway - Bridge between sensors and internet

    • Example: Raspberry Pi connecting home sensors to cloud

  4. Cloud - Brain that stores and processes all data

    • Example: AWS IoT storing your smart home data

Data Flow: Sensor → Gateway → Cloud → Decision → Actuator performs action

🔹 Important Hardware Components

1. Sensor

Detects changes in the environment and sends signals.

  • Example: Motion sensor detects someone entering a room

2. Actuator

Takes commands and performs physical actions.

  • Example: Smart lock that automatically opens when you approach

3. Servo Motor

A special motor that rotates to exact angles (0° to 180°).

  • Example: Robot arm moving precisely to pick up objects

4. DC Motor

A simple motor that spins continuously when powered.

  • Example: Fan motor, toy car wheels

5. Arduino Uno

A small programmable board (microcontroller) that acts as the brain of simple IoT projects.

  • Uses ATmega328P chip

6. Raspberry Pi

A mini-computer used as an IoT gateway to connect sensors to the internet.

🔹 IoT Communication Technologies

1. Wi-Fi

  • Purpose: Connects devices to the internet at home/office

  • Range: Short (50-100m)

  • Power: High consumption

  • Example: Smart TV, laptop

2. Bluetooth / BLE (Bluetooth Low Energy)

  • Purpose: Short-range communication between nearby devices

  • Range: Very short (10m)

  • Power: Low (BLE is ultra-low power)

  • Example: Wireless earphones, fitness trackers

3. Zigbee

  • Purpose: Low-power mesh networking for smart homes

  • Range: Medium (10-100m)

  • Power: Very low

  • Example: Smart bulbs, door locks communicating with each other

4. LoRaWAN (Low Power Wide Area Network)

  • Purpose: Long-range communication for IoT devices in remote areas

  • Range: Very long (up to 10km)

  • Power: Extremely low

  • Example: Smart agriculture sensors in fields

5. MQTT (Message Queuing Telemetry Transport)

  • Purpose: Lightweight protocol for sending small messages between devices

  • How it works: Publish/Subscribe model over TCP

  • Example: Temperature sensor publishing data to cloud

6. CoAP (Constrained Application Protocol)

  • Purpose: Like HTTP but for low-power IoT devices

  • How it works: REST-based, works over UDP

  • Example: Smart light bulb receiving commands from phone app

7. RFID (Radio Frequency Identification)

  • Purpose: Identify and track objects wirelessly

  • Range: Long-range tracking

  • Example: Library books, warehouse inventory tracking

8. NFC (Near Field Communication)

  • Purpose: Very short-range secure communication

  • Range: Few centimeters

  • Example: Contactless payment, access cards

9. 4G / 5G

  • Purpose: Cellular network connectivity for IoT

  • 5G advantages: Ultra-low latency, supports millions of devices

  • Example: Connected cars, smart city infrastructure

🔹 Cloud Computing in IoT

Cloud Computing = Using internet servers to store and process data instead of local computers.

Example: Saving photos on Google Photos instead of your phone.

Types of Cloud Services:

1. SaaS (Software as a Service)

Software you use online without installing.

  • Example: Google Docs, Zoom, Gmail

2. PaaS (Platform as a Service)

Platform to build and run apps without managing servers.

  • Example: Heroku, Google App Engine

3. IaaS (Infrastructure as a Service)

Rent virtual servers and storage instead of buying hardware.

  • Example: Amazon AWS EC2, Microsoft Azure

4. ThingSpeak

An IoT cloud platform for collecting, storing, and visualizing sensor data.

  • Example: Soil moisture sensor sends data → ThingSpeak shows it in graphs

🔹 Edge Computing vs Cloud Computing

Cloud Computing:

  • Data sent to distant servers for processing

  • ✅ Pros: Unlimited storage, powerful processing

  • ❌ Cons: High latency (delay), needs constant internet

Edge Computing:

  • Data processed locally near the sensor/device

  • ✅ Pros: Fast response (low latency), works offline, more secure

  • ❌ Cons: Limited storage and processing power

Example: Smart security camera analyzing video locally (edge) vs sending to cloud.

Fog Computing:

  • Middle layer between edge and cloud

  • Processes data at intermediate points (like local servers)

🔹 Key IoT Concepts

1. Digital Twin

A virtual copy of a physical device/system.

  • Example: Virtual model of a factory machine to predict maintenance needs

2. Context Awareness

Devices that adapt based on surroundings and user behavior.

  • Example: Phone automatically silencing in a meeting room

3. IPv6 Importance

Provides billions of unique addresses for all IoT devices to connect to internet.

  • Old IPv4 = limited addresses

  • IPv6 = enough addresses for every IoT device on Earth

🔹 IoT Security Challenges

Main Problems:

  1. Weak passwords - Easy to hack

  2. No encryption - Data can be intercepted

  3. Outdated firmware - Security holes

  4. Large attack surface - Many connected devices = more entry points

Solutions:

  • Strong encryption (scrambling data)

  • Regular firmware updates

  • Multi-factor authentication

  • Secure boot mechanisms

🔹 Arduino Programming Basics

Important Functions:

  1. pinMode(pin, mode) - Set pin as INPUT or OUTPUT

  2. digitalWrite(pin, value) - Send HIGH or LOW to a pin

  3. digitalRead(pin) - Read HIGH or LOW from a pin

  4. analogRead(pin) - Read analog value (0-1023)

  5. delay(milliseconds) - Pause program

  6. Serial.begin(9600) - Start serial communication

  7. Serial.print() - Send data to computer

Built-in Constants:

  • HIGH / LOW - For digital pins

  • INPUT / OUTPUT - For pinMode

  • LED_BUILTIN - Built-in LED pin

🔹 Simple IoT Security System Project

Goal: Detect motion and move a servo motor (like opening a door)

Components:

  1. Arduino Uno (brain)

  2. PIR Motion Sensor (detects movement)

  3. Servo Motor (opens/closes)

  4. Jumper wires (connections)

  5. Breadboard (for easy wiring)

Connections:

PIR Sensor:

  • VCC → 5V (power)

  • GND → GND (ground)

  • OUT → Pin 2 (signal)

Servo Motor:

  • VCC → 5V (power)

  • GND → GND (ground)

  • Signal → Pin 9 (control)

How It Works:

  1. PIR sensor detects someone approaching

  2. Sends HIGH signal to Arduino Pin 2

  3. Arduino tells servo motor to rotate (unlock door)

  4. After 3 seconds, servo returns (locks door)

Real Example: Automatic door that opens when you walk near it.

🔹 Component Definitions Summary

ComponentWhat It DoesExampleSensorDetects environment changesTemperature sensorActuatorPerforms physical actionDoor lock motorServoRotates to exact anglesRobot armDC MotorContinuous rotationFan, toy carArduinoProgrammable controllerSmart home hubBreadboardTest circuits without solderingPrototyping projectsJumper WiresConnect componentsWiring sensors

🔹 Important Questions & Answers

Q1: Define IoT and give 4 examples

Answer: IoT connects physical devices to the internet so they can collect data and work smartly together. Examples: Smart lights, fitness trackers, smart agriculture sensors, connected cars

Q2: What's the difference between sensor and actuator?

Answer:

  • Sensor = Collects data (thermometer reads temperature)

  • Actuator = Performs action (motor opens window)

Q3: Why is edge computing important in IoT?

Answer: It processes data locally near sensors, which reduces delay, saves internet bandwidth, and improves security.

Q4: Compare MQTT and CoAP

Answer:

  • MQTT: Publish/subscribe model, uses TCP, lightweight messaging

  • CoAP: REST-based like HTTP, uses UDP, for very simple devices

Q5: Why is 5G better than Wi-Fi for large IoT networks?

Answer: 5G supports millions of devices simultaneously with ultra-low delay, making it perfect for smart cities and industrial IoT.

Q6: What are security risks in IoT?

Answer: Weak passwords, data interception, device hacking, privacy invasion Solution: Strong encryption, regular updates, secure authentication

Q7: Difference between Cloud, Edge, and Fog computing

Answer:

  • Cloud: Data processed in distant servers (high storage, high delay)

  • Edge: Data processed locally on device (fast, limited storage)

  • Fog: Middle layer between edge and cloud (balanced approach)

🔹 Bloom's Taxonomy Question Types

Remembering: List, Define, Name

Example: Name two IoT sensors

Understanding: Explain, Describe, Differentiate

Example: Explain edge computing

Applying: Suggest, Apply, Demonstrate

Example: Suggest IoT solution for agriculture

Analyzing: Compare, Analyze, Identify

Example: Compare MQTT vs HTTP

Evaluating: Evaluate, Assess, Justify

Example: Is 5G suitable for IoT? Justify.

Creating: Design, Develop, Create

Example: Design an IoT disaster management system

IoT Basics