How Project management module helps in designing Engineering Exploration course Project?

This module is vital because as it prepares for the project. It specifically focuses on teaching key professional skills, such as working effectively in a team, setting clear goals, managing time efficiently, and mastering clear communication and professional interaction.

In your opinion, what are the benefits of working in a team?

Benefits of teamwork

• • The workload is divided, so projects or tasks are completed much faster.
• • Having different ideas leads to more creative and high-quality results.
• • We can focus on our talents, improving and mastering our strongest skills.
• • Working with others provides a constant opportunity to learn new methods and skills from colleagues.
• • Teams offer mutual support, which boosts motivation and makes it easier to handle challenges.
• • Risks and burdens are shared across the group, which reduces individual stress.

Can you provide examples of how teamwork contributes to the success of a project?

• • Like how a kitchen crew works together in a restaurant.
• • Plumbers, electricians, and carpenters must all work in the right order so the house is built safely and on time.

1. What is scrum methodology and how does it fit into the agile framework?

Scrum is a super helpful, easy way to manage tough projects. It follows Agile ideas and helps teams get things done by breaking them into small bursts called sprints. During sprints, a team with all the skills needed works together to make something useful. The whole thing is about being open, checking in, and changing things up as needed through meetings, and it includes roles like a Product Owner, Scrum Master, and developers.

2. What is a sprint in the context of Agile development?

In Agile development, especially with Scrum, a sprint is like a short, timed burst, usually lasting 1 to 4 weeks. It's the project's main rhythm, giving a specific time to finish important tasks, which helps get rid of any problems and makes the project a success.

3. How do you envision using Agile principles, scrum, and sprint in your course project?

We'll divide the project tasks, giving each team member specific things to do. This way, we can easily adjust and check in often. We'll have quick discussions to make sure everyone's on the same page. After each one, we'll show our progress, get feedback, and plan what to do next.

1) How did the collaborative exploration of various design concepts within you team contribute to a more comprehensive understanding of creative problem-solving in engineering design?

1. Different viewpoints: Working together helped us see the problem from all sides and get a better picture.
2. Idea mix: Everyone brought their own ideas, which really boosted our creativity and the range of solutions we could come up with.
3. Checking things out: Talking about different ideas helped us see what was possible and what would actually work.
4. Making decisions as a team: We learned how to be creative and logical at the same time when we worked together on decisions.
5. Good balance: We figured out how to make cool ideas work with real-world limits.

2) Reflect on the significance of selecting a design concept that aligns with functional requirement and ethical considerations.

1. Functionality: Makes sure the design works well and meets all the needs.
2. Safety First: Ethical stuff helps keep people safe and the design reliable.
3. Eco-Friendly: Thinking ethically means using good materials and energy, helping the environment.
4. Good for Everyone: Designs that respect society help the community and make people trust us.
5. Being Honest: Following ethics means being honest, fair, and responsible.
6. Lasting: Good, ethical designs are more likely to stick around and work.
7. Smart Ideas: It encourages us to come up with new ideas without cutting corners on safety or ethic.

3) In what ways considering alternative design approaches enhance your ability to address complex engineering challenges?

1. Broader Perspective – Exploring multiple design approaches exposes you to different ways of thinking and prevents tunnel vision.
2. Problem-Solving Flexibility – Alternative approaches allow quick adaptation when one solution fails.
3. Creative Innovation – Comparing methods sparks new ideas and hybrid solutions.
4. Risk Reduction – Evaluating options helps identify potential failures and ensures safer designs.
5. Ethical & Sustainable Design – Alternatives can reveal more responsible and environmentally friendly solutions.
6. Stronger Decision-Making – Weighing pros and cons of approaches develops critical thinking.

Describe how the collaborative nature of the role-play activity influenced the team's ability to systematically define and approach engineering problems by identifying objectives, functions, and constraints.

1. Clear Goals – Working together helped the team clearly define what we wanted to achieve.
2. Understanding Functions – Team discussions made it easier to understand what the design was required to do.
3. Identifying Constraints – Collaboration helped us recognize limitations such as cost, materials, and time.
4. Step-by-Step Approach – Sharing ideas allowed us to solve the problem in a more structured and organized way.
5. Team Coordination – Each member understood their role and contributed effectively.
6. Practical Solutions – Combining different ideas resulted in solutions that were realistic and workable.

Concept Generation.

3. JUSTIFICATION FOR THE SCORES

SELECTED DESIGN

DESIGN 4

Based on the Pugh Chart analysis, Design 4 achieved the highest total score of 12. Its superior circular operation (++) and robust safety features (+) outweighed its slightly higher installation complexity and automatic control limitations.

1. Define basic linkage mechanisms and its component.

A linkage mechanism is a mechanical system made of rigid bodies (links) connected by joints (kinematic pairs) to transmit motion and force. The basic components include:

• • Links — Rigid bodies that form the skeleton of the mechanism.
• • Joints (Kinematic Pairs) — Connections between links that allow relative motion (revolute, prismatic, etc.).
• • Fixed Link (Frame) — The stationary link that serves as the reference for the mechanism.
• • Input Link (Driver) — The link to which motion/force is applied.
• • Output Link (Follower) — The link that delivers the desired output motion.

2. Briefly explain the real-life applications of linkage mechanisms.

• • Windshield Wipers — Use a four-bar linkage to convert rotary motor motion into oscillating wiper movement.
• • Bicycle Pedal System — A crank mechanism converts the rider's leg motion into wheel rotation.
• • Doors & Hinges — Simple revolute joint linkages allow controlled opening and closing.
• • Robotic Arms — Multi-bar linkages enable precise positioning and movement in manufacturing.
• • Sewing Machines — Crank-slider mechanisms convert rotary motion to linear needle movement.

1. What challenges did you encounter while programming the ESP32, and how did you overcome them?

Programming the ESP32 presented several challenges, primarily involving pin multiplexing conflicts and multi-threaded execution stability.

• Pin Conflicts & GPIO Selection: The ESP32 has specific bootstrap pins (e.g., GPIO 0, 2, 5, 12, 15) that can cause boot loops if held high/low during startup. We encountered boot failures when first connecting the IR sensors to these pins. We solved this by consulting the ESP32 pinout reference and remapping our inputs to safe general-purpose inputs (GPIO 13, 14, 27).

• Non-blocking Code: Integrating the LDR light readings, IR sensor polling, and motor speed control using standard delay() functions caused the system to become unresponsive to real-time safety triggers (obstacle detection). We overcame this by refactoring the codebase to use non-blocking timing with the millis() function.

2. Describe a specific moment during the ESP32 programming process when you had to troubleshoot and debug your code.

During the integration of the IR obstacle sensor and the motor driver (L298N), we noticed the DC motor would intermittently run at maximum speed or lock up entirely when the sensor detected an object, instead of stopping instantly.

To troubleshoot, we first isolated the components:

1. We monitored the digital output of the IR sensor via the Serial Monitor (Serial.println(irValue)) and confirmed it triggered correctly (0 for object detected, 1 for clear path).

2. We inspected the motor driver pwm control logic. We realized that in our software interrupt handler, we had a race condition where the speed variable was being modified in the main loop while the interrupt was firing.

3. We resolved this by adding the volatile keyword to our shared variables and temporarily disabling interrupts (noInterrupts() / interrupts()) when reading/writing the speed parameter in the main loop.

3. In what ways were you able to implement the IR sensor's functionalities in your project?
or
4. In what ways were you able to implement the LDR sensor's functionalities in your project?

We successfully implemented both sensors to achieve high-fidelity automation and safety:

• IR Sensor (Safety & Obstacle Detection): We mounted an IR sensor along the leading edge of the circular curtain mechanism. When the curtain is closing and an obstacle (like a hand or a person) blocks the path, the IR sensor's receiver detects the reflected infrared signal, sending a digital LOW signal to ESP32 GPIO pin 13. The controller instantly interrupts the motor driver, stopping the curtain immediately to prevent injury or damage.

• LDR Sensor (Automatic Day/Night Mode): An LDR is connected to analog input pin GPIO 34 in a voltage divider configuration with a 10k ohm resistor. The ESP32 continuously reads the analog voltage (0–4095 range for 12-bit ADC). In automatic mode, when the light intensity rises above a calibrated threshold (e.g., sunrise), the ESP32 commands the motor to open the curtains. Conversely, when light drops below a threshold (e.g., sunset), the curtains close.

5. Consider the testing of components like IR sensors, ESP32, and DC motor. How did you approach testing, and what were the key lessons learned from the testing phase of the activities?

We approached testing systematically using a bottom-up methodology, verifying individual components before full-system integration:

• Unit Testing: We verified each component independently. First, we tested the ESP32 using the basic Blink sketch. Second, we tested the IR sensors by measuring their digital output with a multimeter under different distance profiles. Third, we tested the DC motor directly with a bench power supply to verify raw gear performance.

• Integration Testing: We connected the ESP32 to the L298N driver and DC motor to verify direction control and PWM speed modulation. Finally, we integrated the IR and LDR sensors to run the full automated state machine.

• Key Lessons Learned:
1. Common Ground: Always ensure that all components (ESP32, motor driver, external battery/adapter) share a common ground pin. In early tests, the motor jittered wildly because the L298N ground was not tied to the ESP32 ground.
2. Sensor Calibration: IR sensors are highly sensitive to ambient daylight. We learned to calibrate the potentiometer on the IR sensor module in the actual environment where it would operate.

PBD 1 Activities

Activity 1.1

ESP32 LED Blink Test

Activity 1.2

LDR Sensor Calibration

Activity 1.3

IR Sensor & Buzzer Setup

1. Reflect on the collaboration and communication aspects of ESP32 programming, especially if you worked in a team. How did effective communication contribute to the success of your assessment activity.

Collaborative programming on an embedded hardware project like the ESP32 requires tight coordination since code is deeply tied to physical wiring.

• Role Division: We divided tasks based on strengths: one team member worked on the mechanical assembly and motor mounting, another on the electronic circuit wiring, and others worked on the ESP32 firmware development.

• Shared Documentation: We created a shared pinout spreadsheet and circuit schematic diagram. This ensured that the software developers knew exactly which GPIO pins the hardware team had wired to the LDR, IR, and motor driver inputs.

• Success through Communication: During integration, we ran into an issue where the motor turned in the opposite direction of the open command. Because of our clear schematics, we quickly identified that the software team had inverted the IN1 and IN2 control pins in the code, rather than rewiring the hardware. This saved hours of debugging.

2. Describe a specific moment during the ESP32 programming process when you had to troubleshoot and debug your code.

When testing the automatic day/night curtain control using the LDR, the ESP32 would trigger the motor to open and close repeatedly in rapid succession when the light level was exactly at the threshold boundary.

To troubleshoot:

1. We logged the raw analog readings from GPIO 34 to the Serial Plotter. We observed that the ambient light fluctuated by ±15 units due to minor noise and sensor placement.

2. The raw conditional check (if (val > THRESHOLD) open(); else close();) was directly vulnerable to this noise.

3. We resolved this by implementing Hysteresis in software. We set two separate thresholds: an 'Open threshold' of 2500 and a 'Close threshold' of 2000. The motor would only trigger once the reading completely cleared these boundaries, ending the rapid oscillation.

3. What strategies did you employ, and what did you learn from that experience?

We employed several debugging and coding strategies:

• Serial Logging: We used Serial.print() to output raw sensor data and state transitions to the console, allowing us to visualize what the ESP32 was 'thinking'.

• Modular Programming: We wrote separate functions for sensor reading (readLdr(), checkObstacle()) and actuation (setMotorSpeed(), stopMotor()) rather than putting all logic in the loop() function.

• What We Learned: Embedded debugging is unique because bugs can be either hardware-based (poor connections, voltage drop) or software-based. We learned to always verify power supply stability first before rewriting code, as low-voltage drops can cause the ESP32 to brownout and reset.

PBD 2 Activities

Activity 2.1

Multi-Developer Code Collaboration Setup (Relay & DC Motor Wiring)

Activity 2.2

Stepper Motor Control (ULN2003 Driver & 28BYJ-48 Stepper Integration)

1. What challenges you faced while working with transport activity kit and how did you over them?

Working with the Transport Activity Kit (stepper motors, lead screws, and limit switches) presented mechanical and synchronization challenges:

• Backlash and Binding: The lead screw mechanism would occasionally bind or stall at certain points of the travel due to slight misalignment of the guide shafts. We overcame this by loosening the mounting brackets, aligning the shafts precisely with a digital caliper, and lubricating the screw with dry PTFE lubricant.

• Stepper Resonance and Noise: At certain speeds, the stepper motor vibrated excessively and skipped steps. We resolved this by adjusting our microstepping settings on the driver (from full-step to 1/8-step) and implementing an acceleration/deceleration ramp using the AccelStepper library.

2. What are the possible real-time applications of the limit switches, Stepper motor and Servo motor?

Each actuator and sensor plays a crucial role in real-world automation:

• Limit Switches: Used for safety, homing, and travel containment. Real-time applications include elevator shafts (to prevent overtravel), 3D printers/CNC machines (for axes homing at startup), and garage door openers (to stop the motor when fully closed).

• Stepper Motor: Excellent for precise angular positioning and high holding torque without feedback. Applications include 3D printing axes, automated telescope mounts, paper feed mechanisms in printers, and robotic joint rotation.

• Servo Motor: Ideal for fast, highly precise angle control (typically 0-180 degrees) with feedback. Applications include robotic arms, remote-controlled aircraft control surfaces (ailerons/rudders), automotive throttle valves, and lock mechanisms.

3. How do interface the Keypad and I2C LCD to ESP 32 Controller?

Interfacing these components to the ESP32 is highly efficient and requires minimal pin count:

• I2C LCD Interface: The standard 16x2 LCD is configured with an I2C backpack (PCF8574). We connect:
- SDA (Serial Data) to ESP32 GPIO 21
- SCL (Serial Clock) to ESP32 GPIO 22
- VCC to 5V and GND to GND
We use the LiquidCrystal_I2C library, specifying the I2C address (usually 0x27 or 0x3F) to print system status and light readings.

• Keypad Interface: A 4x4 matrix keypad has 8 pins (4 rows, 4 columns). To interface it with the ESP32, we map:
- Rows to GPIO pins 12, 14, 27, 26
- Columns to GPIO pins 25, 33, 32, 35
We use the Keypad library in Arduino IDE to define the keymap matrix. The library handles the scanning of rows and columns (pulling rows low sequentially and checking column status) so that press detection is abstracted into a simple keypad.getKey() command.

PBD 3 Activities

Activity 3.1

Servo Motor Control (SG90 Servo Angle & Calibration Setup)

Activity 3.2

Keypad Menu & LCD Character Rendering (I2C LCD Hello World Test)

1. What challenges you faced while working with the ESP32 enable control of a servo motor through a web interface?

Interfacing the ESP32 with a servo motor and a web control stack introduced three primary challenges:

• PWM Hardware conflicts: The ESP32 doesn't support the standard Arduino Servo.h library on all pins because of architectural differences in its hardware timers. Using basic libraries caused conflicts with internal Wi-Fi timers, causing either the servo to twitch uncontrollably or the Wi-Fi connection to drop. We resolved this by using the ESP32PWM library which binds to specific hardware LED Control (LEDC) peripheral channels, isolating Wi-Fi interrupts.

• Web Socket Latency & Disconnections: When adjusting the servo position via a slider on the web interface, sending rapid, continuous HTTP GET/POST requests overloaded the ESP32 web server. We overcame this by using WebSockets (via ESPAsyncWebServer) to maintain a persistent, low-overhead TCP connection, and throttled the slider inputs in JavaScript using a debounce function.

• Power Surges: Servos pull significant current spikes when initiating movement. When sharing a power rail, this caused the ESP32 voltage to drop below 3.0V, triggering a hardware brownout reset. We resolved this by powering the servo from an external 5V regulator and sharing only the Ground pin with the ESP32.

2. How does the ESP32 enable control of a servo motor through a web interface?

The ESP32 coordinates this control through a highly integrated hardware-software bridge:

1. Local Network Server: The ESP32 connects to the local Wi-Fi router (Station mode) or acts as an Access Point (AP mode). Using the ESPAsyncWebServer library, it hosts a lightweight web server in its flash memory containing HTML, CSS, and JavaScript.

2. WebSocket Link: When a user accesses the ESP32's IP address on a browser, the frontend page loads and establishes a WebSocket connection. When the user moves the virtual slider, a JavaScript event triggers: websocket.send("servo:" + sliderValue).

3. Parser and PWM Actuation: The ESP32 receives this WebSocket message, parses the numerical angle, and uses the servo.write(angle) command. The LEDC peripheral on the ESP32 translates this angle into a precise 50Hz PWM signal (pulse width between 1ms to 2ms) sent to the servo's signal wire, rotating it exactly to the requested position in real time.

PBD 4 Activities

Activity 4.1

LED ON

LED OFF

ESP32 Wi-Fi AP & HTTP Server Handshake (Web LED Control Test)

1. What challenges you faced while building Web controlled Bot Activity?

Designing and programming a wireless web-controlled robotic bot introduced structural and real-time execution challenges:

• Differential Drive Calibration: Due to minor physical differences between the two DC motors, applying the exact same PWM signal (e.g., 200/255) to both sides caused the bot to drift to one side rather than moving in a perfect straight line. We overcame this by implementing a software calibration scale factor in our motor drive function to balance the left and right motor speeds dynamically.

• Connection dropouts & Runaway Bot: When the bot moved out of strong Wi-Fi range, it would occasionally lose connection while in motion, continuing to run forward indefinitely and crashing into walls. We resolved this by implementing a software "Heartbeat" or "Keep-Alive" timer. If the ESP32 does not receive a WebSocket control ping from the web page for more than 500ms, it automatically shuts down all motor outputs, stopping the bot instantly.

2. How does the ESP32 enable control of Web controlled Bot Activity?

The ESP32 coordinates the Bot's movements by operating as a wireless control bridge:

1. Wireless Host: The ESP32 acts as a Soft-Access Point (SoftAP), broadcasting a dedicated local network. Users connect directly to this Wi-Fi network and access a web interface featuring touch buttons or a virtual joystick.

2. Bi-directional Communications: The web page listens to touch gestures. For example, holding the "Forward" button sends a "F" command via WebSockets. Releasing the button sends a "S" (Stop) command.

3. Motor Actuation Bridge: The ESP32 maps these parsed characters directly to the input control pins of an H-bridge motor driver (such as L298N or L9110S). To move forward, it pulls GPIO IN1 High, IN2 Low (left motor forward), and IN3 High, IN4 Low (right motor forward). Speed is adjusted in real-time by modulating the PWM duty cycle on the enable pins.

PBD 5 Activities

Activity 5.1

Differential Drive Motor Balance Calibration (Bot Chassis & ESP32 Setup)

Activity 5.2

Gear Mechanism Integration (3D-Printed Gears & Motor Mount)

Activity 5.3

Belt Pulley System Integration (Pulley Wheel & Drive Belt Linkage)

Activity 5.4

Lead Screw Assembly Integration (Threaded Shaft & Linear Slider Setup)

Activity 5.5

Conveyor Belt System Integration (Friction Roller & Driver Belt Setup)

What is the Significance of the SDG you got?

Our project directly addresses SDG 7 (Affordable and Clean Energy) and SDG 11 (Sustainable Cities and Communities):

• SDG 7 - Affordable & Clean Energy: Real estate and buildings represent over 30% of global energy consumption. Heating, ventilation, and air conditioning (HVAC) systems are major contributors. Dynamically automated curtains optimize passive heating and cooling. By opening to let sunlight in during cold mornings and closing to block heat during peak summer hours, they reduce the energy demands on artificial climate control systems.

• SDG 11 - Sustainable Cities and Communities: Future metropolitan areas rely on smart infrastructure to reduce environmental impacts. Our curtain automation system enables smart passive window management. This creates a scalable micro-automation element that transforms standard residential structures into energy-resilient, sustainable building complexes.

Reflections on Engineers role:

Engineers act as the primary implementers of sustainability, transforming abstract environmental goals into functional, physical systems.

• In building automation, an engineer's role is to ensure **resource stewardship** through design optimization. Before developing power-heavy heating or cooling equipment, engineers should incorporate smart controls to utilize passive natural resources (such as sunlight and shade).

• This requires interdisciplinary systems thinking, combining thermodynamics, mechanics, and software logic. This ensures that every line of code written on the controller translates to direct energy savings in the home.

Statistics:

1. How do embodied energy calculations impact material selection for your project, and what challenges do you foresee in implementing sustainable choices?

Embodied energy refers to the sum of all energy required to produce a material, from mining and extraction to processing and delivery.

• Material Optimization: Calculating embodied energy shifted our focus away from heavy metals. We selected **recycled aluminum** for our circular track guide rails instead of virgin steel. Producing recycled aluminum uses 95% less energy than virgin manufacturing (~10 MJ/kg vs. ~190 MJ/kg). Additionally, we chose bio-derived **PLA plastic** for 3D-printing our controller casing instead of petroleum-based ABS, cutting plastic embodied energy in half.

• Challenges: The primary challenge is balancing durability with low embodied energy. High-durability materials (such as carbon fiber or alloy steels) often carry massive manufacturing carbon footprints, while low-impact biological materials (like untreated bamboo or wood) face mechanical wear under constant friction, potentially shortening the system's 5-year target lifespan.

2. Reflect on the embodied energy of a chosen materials for your project. How might this inspire design approaches or alternative selections for reduced environmental impact?

Evaluating the embodied energy of our components inspired a circular design approach:

• Topology Optimization: Knowing the high embodied energy of polymers, we used topology-optimized truss designs in our mounting brackets. This reduced the raw plastic mass by 40% without compromising mechanical load stability.

• Alternative Materials: For future upgrades, we could replace the plastic guide rollers with natural hardwood rollers (which sequester carbon rather than emitting it). We also designed all physical connections to use mechanical screws rather than glues, ensuring the copper motor windings and aluminum track can be cleanly separated and recycled at the end of the system's lifecycle.

3. What surprised you most about the carbon footprint of electrical appliances, LPG usage, or transportation and how can this knowledge shape sustainable lifestyle choices?

What surprised us most was the significant impact of **standby power draw** (or "vampire load") in electrical appliances and the massive carbon intensity differences between individual car transit and public electric rail systems:

• Vampire Draw: Standby power consumes roughly 5W–15W per appliance even when turned off, representing up to 10% of residential energy usage.

• LPG Footprint: LPG has a very high direct combustion emission rate (~3 kg CO2 per kg of LPG burned), showing that efficiency in cooking immediately affects local carbon footprints.

• Lifestyle Shifts: This knowledge prompts immediate lifestyle changes, such as unplugging inactive devices, using smart plugs to fully isolate power grids, and transitioning to micro-mobility (like walking or cycling) for trips under 5 kilometers, which completely eliminates transit carbon emissions.

4. Choose one category (appliances, LPG, or transportation) and discuss how its carbon footprint understanding might influence engineering design decisions.

We chose Electrical Appliances & Smart Standby Power:

• Design Influence: Understanding the carbon footprint of standby power directly influenced our ESP32 control logic. An idle ESP32 connected to Wi-Fi draws roughly 80mA–120mA at 3.3V. Left on 24/7, this represents continuous standby power draw.

• Engineering Mitigation: To address this, we implemented **deep-sleep modes** (esp_deep_sleep_start()) in our software architecture. The ESP32 is programmed to shut down its Wi-Fi radio and enter deep sleep (drawing only ~10µA) during the long periods when the curtain is stationary. It only wakes up via an internal timer (e.g., to poll light levels every 15 minutes) or a external hardware interrupt (e.g., emergency obstacle detection or button press). This engineering choice reduces the system's operational carbon footprint by 99% over its lifetime.