Lecture Notes

Introduction

• Check of microphone audibility.
• Greetings and congratulations on recent success in lunar landing (Chandrayan 3).
• Overview of the day's tasks: creating demo devices and setting up Raspberry Pi virtual environment.

Tasks Overview

Task 1: Creating Demo Devices

• Focus on simulating device data using MQTT (Message Queuing Telemetry Transport).
• Discussion on creating dummy devices to simulate real device behavior.

Task 2: Raspberry Pi Virtual Setup

• Setup involves creating a virtual environment for Raspberry Pi.
• SSH (Secure Shell) setup instructions for those with actual Raspberry Pi devices.

MQTT Overview

• MQTT is a lightweight messaging protocol used in IoT (Internet of Things) environments.
• Previous session ended on publishing test data.
• Today's focus: using MQTT to create devices that behave like real devices.

JSON Data Format

• JSON (JavaScript Object Notation) is used for data interchange.
• Explanation of JSON format in Python, using dictionaries for data representation.
• Example provided for JSON data structure: device ID, temperature, humidity.

Code Implementation

Creating Dummy Devices

• Device 1 (Dev 1): Simulates data using random values for temperature and humidity.

  • Temperature range: 20-25
  • Humidity range: 55-65
  • Timestamp added for data logs.

• Device 2 (Dev 2): Simulates a water quality sensor device.

  • Additional parameters: pH and TDS (Total Dissolved Solids).
  • pH range: 3.0-9.0
  • TDS range: 0.5-2.5

Running Simulated Devices

• Python scripts for devices run in command prompt to simulate continuous data generation.
• Use of Python's random module to generate random sensor data values.

Raspberry Pi Virtual Machine Setup

Installation and Configuration

• Introduction to QEMU (Quick Emulator) for Raspberry Pi virtualization.
• Steps to enable SSH:
  • Access Raspberry Pi Config: Navigate to SSH settings, enable SSH.

SSH Setup with PuTTY

• Download PuTTY for SSH communication.
• Steps to connect to Raspberry Pi: use localhost for connection.
• Login credentials for Raspberry Pi: username 'pi', password 'raspberry'.

MQTT Broker Installation

• Attempt to install Mosquitto MQTT broker on Raspberry Pi VM.
• Troubleshooting steps for installation issues, including alternative repositories.

Next Steps

• Plan to install MQTT broker and set up Python client scripts for MQTT communication.
• Future tasks include building control codes and simulating cloud server interaction on the local machine.

Troubleshooting and Support

• Open invitation for students to reach out with any issues or questions during setup.

Closing

• Encourage students to learn and troubleshoot independently.
• Next class will focus on making up any lost time and completing setup.