Task 14: Karnaugh Maps and Logic Circuit – Burglar Alarm

https://www.tinkercad.com/things/1ppeT3pxYKr-robbery?sharecode=4S2n4-1CRkqjYguGNPokaerqtkIAEla9F6aD16JffWU

Objective

To design a simple burglar alarm using logic gates by analyzing door and key inputs with a Karnaugh Map (K-map).

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Inputs and Output

• Door (D):
  • 0 = Closed
  • 1 = Open
• Key (K):
  • 0 = OFF (Not pressed)
  • 1 = ON (Pressed)
• Output (A):
  • 0 = No Alarm
  • 1 = Alarm (LED ON)

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Cases Considered

I analyzed the system based on the given conditions:

• Case 1: Key ON (K = 1)

  • Door open or closed → No alarm

• Case 2: Key OFF (K = 0)

  • Door closed → No alarm
  • Door open → Alarm ON

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Truth Table (used ai to generate this table)

K	D	A
0	0	0
0	1	1
1	0	0
1	1	0

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Karnaugh Map (used ai to generate this table)

K\D	0	1
0	0	1
1	0	0

Simplified expression from K-map:

A = K' · D

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My Approach

I used:

• Two slide switches (Door and Key)
• IC 74HC00 (NAND gates)
• LED as alarm indicator

Steps I followed:

1. I wrote the truth table based on given cases.
2. I drew the K-map to simplify the logic.
3. I derived the expression: A = K' · D.
4. Since I used only NAND gates:
   • I inverted the key input using a NAND gate
   • I combined inputs using NAND logic to implement AND
5. I connected an LED to show the alarm output.

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Circuit Description

• Key input is inverted to get K'
• K' is combined with Door input
• Output is connected to LED
• LED acts as the alarm indicator

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Working

• If key is ON, alarm is always OFF
• If key is OFF:
  • Door closed → No alarm
  • Door open → LED glows (alarm ON)

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Result

I successfully implemented the burglar alarm circuit.
The LED glows only when:

• Key = OFF
• Door = OPEN

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Conclusion

• K-map helped me simplify the logic easily
• NAND gates were used to implement the circuit
• The circuit works correctly as a basic burglar alarm

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https://github.com/user-attachments/assets/a79e8741-9bf8-4c03-9b42-da807c6c61c0

Active Participation

Result

(Thumbs up emoji). Participated in a healthcare hackathon at BNMIT.

Document.19.pdf

L293D Motor Driver Datasheet Study Report

Introduction

While researching motor driver circuits, I studied the datasheet of the L293D motor driver IC. I found that this IC is commonly used to control DC motors using microcontrollers. Since motors require more current than a microcontroller can supply, the L293D works as an interface between the controller and the motor.

The IC allows control of motor direction and speed and can drive two DC motors at the same time.

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Overview of L293D IC

The :contentReference[oaicite:0]{index=0} is a 16-pin integrated circuit designed to control motors.

Main features I found from the datasheet:

• Dual H-bridge motor driver
• Can control two DC motors
• Output current up to 600 mA per channel
• Motor voltage range 4.5V – 36V
• Built-in protection diodes
• Compatible with TTL logic

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Pin Configuration

Pin	Name	Description
1	Enable 1,2	Enables motor driver 1
2	Input 1	Control signal
3	Output 1	Motor terminal
4,5	Ground	Common ground
6	Output 2	Motor terminal
7	Input 2	Control signal
8	Vcc2	Motor supply voltage
9	Enable 3,4	Enable motor driver 2
10	Input 3	Control signal
11	Output 3	Motor terminal
12,13	Ground	Common ground
14	Output 4	Motor terminal
15	Input 4	Control signal
16	Vcc1	Logic supply (5V)

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H-Bridge Circuit

From the datasheet, I learned that the L293D works using the concept of an H-bridge motor driver circuit.

An H-bridge allows current to flow through a motor in two directions, which makes the motor rotate clockwise or anticlockwise.

Input 1	Input 2	Motor Direction
1	0	Clockwise
0	1	Anticlockwise
0	0	Motor Stop
1	1	Motor Stop

This switching arrangement helps control the direction of the motor.

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PWM (Pulse Width Modulation)

During my research I also found that motor speed is controlled using Pulse Width Modulation (PWM).

PWM works by sending a series of ON and OFF pulses to the motor. By changing the duty cycle, the average power supplied to the motor changes.

Duty Cycle	Motor Speed
20%	Slow
50%	Medium
80–100%	Fast

Usually the Enable pin of the L293D receives the PWM signal to control speed.

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Working Principle

From the datasheet, I understood the working process like this:

1. A microcontroller sends control signals to the input pins.
2. The L293D processes these signals internally.
3. The H-bridge circuit directs current through the motor.
4. The motor rotates in the required direction.
5. PWM signals control the speed of the motor.

So the L293D acts as a current amplifier between the controller and the motor.

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Applications

I found that the L293D motor driver is used in many electronics and robotics projects such as:

• Robotics systems
• Line follower robots
• Automated vehicles
• DC motor control circuits
• Stepper motor control
• Small automation systems

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Advantages

Some advantages I found while studying the datasheet are:

• Can control two motors simultaneously
• Easy to interface with microcontrollers
• Built-in protection diodes
• Simple circuit design
• Supports bidirectional motor control

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Disadvantages

There are also a few limitations:

• Maximum current is limited to 600 mA
• Not suitable for high-power motors
• Can generate heat during heavy load

Virtual Reality & Augmented Reality

Basic overview

Augmented reality (AR) and virtual reality (VR) are technological experiences that change how digital technology interacts with the physical world.

• AR uses a camera to allow you to interact with the physical world via a digital overlay.

• VR immerses you fully into a digital world via a headset, sound, and haptic feedback.

• You can use both AR and VR for entertainment, gaming, education, health care, and marketing.

Virtual reality aims to create a virtual experience with headsets and tracking to place the user in a different world. Augmented reality focuses on augmenting the physical world with digital artifacts, images, videos, or experiences overlayed with computer-generated imagery (CGI) and 3D models.

Advantage of Augmented Reality (AR)

The advantage of augmented reality is its ability to combine the physical world with a digital interface, creating a new experience of the world. Doing so also creates new ways of experiencing the world, from how you monitor manufacturing machines to how surgeons learn about the human body. AR also provides new ways for you to interact within the digital environment.

Disadvantage of Augmented Reality (VR)

The disadvantages of AR include the cost of implementing the technology in education. Future consideration must ensure equitable access across a diverse range of schools. AR also requires a reliable internet connection and access to smartphones or other connected devices to use. On the programming end, it requires skills and technology to produce, which can put it out of the budgets of small businesses.

Advantages of Virtual Reality (VR)

VR has advantages similar to AR, including its advantages in education by allowing learners to explore the physical world in ways not possible without virtual reality. VR gives users a safe space to experience or train for things that might be dangerous or fearful in the physical world without putting them in harm's way. VR also allows users to travel anywhere in the physical world through a virtual experience.

Disadvantages of Virtual Reality (VR)

One disadvantage of VR is motion sickness, which some users experience. It creates nausea, dizziness, and headaches for some users. VR motion sickness occurs in users with a predisposition to motion sickness or prolonged experience in a simulation. Challenges in VR hardware and cost make it harder to implement than AR. In addition to the upfront cost of the headset, VR requires you to already have a computer with a high-end graphics card to run VR software.

Use Cases

AR

• Visualization : To see deeper acpects
• Instruction : Instruction and training by providing real time info and diagrams
• Interaction : Unique way of interacting with physical world

VR

• Entertainment : Movie, Places & VideoGames with great effects _ Health Care : Surgeon Training and surgery simulations
• Training : Training drivers
• Education : Hands on practical learning experience while still being on the simulations

Immersive Tech in Space

Immersive technologies, such as virtual reality (VR), augmented reality (AR), and mixed reality (MR), create digital experiences by merging real and virtual worlds, offering enhanced spatial engagement and sensory immersion. This study examines immersive technologies’ possible advancements to space research, along with application examples in data visualization, astronaut training, and mission planning. Research on space includes a wide array of scientific and technological activities aimed at understanding the universe, enhancing space travel, and exploiting space-based technologies for applications on the Earth.

Indian Companies in AR and VR Technology

• AnjaLens
• Tesseract(Jio XR)
• Abhiwan Technologies
• Simulanis
• Fusion VR

Express Web App – Life Problem Resource Library

https://filebin.net/9ltc7l4tv59lk908/lifeproblemslibrary.zip (zip file for whole library)

Introduction

For this task I created a small web application using Node.js and Express.js. The idea was to make a simple resource library website. Instead of normal articles or books, I made a funny "life problem library". Users choose a problem and get redirected to a YouTube video that gives a solution.

Example problems include:

• How to get a girlfriend
• How to fart quietly
• How to study the night before exam
• How to eat air
• How to touch grass

Each problem redirects to a related YouTube video.

Tools Used

• Node.js
• Express.js
• HTML
• Visual Studio Code
• Linux (Fedora)

Project Structure

The project folder structure is: life-problem-library │ ├── server.js ├── package.json └── public └── index1.html

server.js contains the Express server code and routing logic.
index.html contains the webpage that lists the problems.

How It Works

The Express server runs on localhost and serves the HTML page.
When a user clicks on a problem, the request goes to a route like:

/problem/1

The server then redirects the user to the corresponding YouTube video.

Running the App

To start the application I ran: node server.js

The website can be opened in a browser at: http://localhost:3000/index1.html

Conclusion

In this task I created a simple Express web app that works as a humorous resource library.
This helped me understand how to set up a Node.js project, create routes in Express, serve HTML files, and redirect users to external links.

https://github.com/user-attachments/assets/fc5d2c87-3a0d-4cc8-9e05-84d7cfb96703