Uditha Reddy Level 1 Report

23 / 3 / 2025

Electronic Design

TASK 1: Engineer’s Swiss Army Knife (MATLAB Onramp Course)

For this task, I created a Matlab account and completed the MATLAB Onramp course and obtained the certification for the same.

Key Learnings:

Basic Commands • Use >> in Command Window to run commands • = assigns values to variables • ; hides output • clear removes all variables • clc clears the command window • save and load to handle MAT-files • Built-in functions: pi, abs, trig functions

Arrays and Matrices • Use [] to create arrays • Spaces → row vector, Semicolons → column vector • Use colon : for ranges (e.g., 1:2:9) • Use linspace(start, end, num_elements) for evenly spaced vectors • ' transposes a vector • Single index reads columns first

Plotting • plot(x, y) to plot data • Customize plot with colors, line styles, markers • hold on to plot multiple lines on same axes • hold off to reset • Use name-value pairs for plot settings (e.g., LineWidth=5)

Final Project - Star Spectrum

In this MATLAB project, we can find out if a star is moving toward or away from Earth by studying its light spectrum. You can view a star's spectrum by plotting the intensity of starlight observed at each wavelength. Hydrogen, a major component of most stars, absorbs light and causes a dip in the spectrum. Hydrogen absorbs light precisely at 656.3 nanometers. If the star is moving, the spectrum's dip is observed at a different wavelength. We can use this difference to measure the direction the star is moving and the velocity of the star. If this line appears at a different wavelength in the star's spectrum, it means the light has shifted due to the Doppler effect. A shift toward a longer wavelength (redshift) means the star is moving away from Earth, while a shift to a shorter wavelength (blueshift) means it’s coming closer. Using MATLAB, we load and visualize data from a file to see this shift and calculate the star’s speed an direction of motion.

TASK 2: Band Pass Filter

Filters are used to change the frequency of signals. • Low pass filter (LPF): LPF allows signals with frequencies below a set cutoff frequency to pass through while blocking higher frequencies. • High Pass Filter (HPF): This filter allows only higher-frequency signals above a specific cut-off frequency. • Band Pass Filter (BPF): A band-pass filter is a type of filter that allows signals within a specific range of frequencies to pass through while blocking frequencies outside that range.

Active bandpass filters use active components such as operational amplifiers. Designing a second order band pass filter using IC747 that amplifies the signal to roughly 1.5 times the original signal. Cutoff range between 4kHz and 10kHz.

TASK 3: SPICE Code

SPICE code refers to the text-based input used by SPICE software. It's a structured way to describe the components, interconnections, and desired analysis parameters of an electronic circuit. Inspite of having so many GUI softwares where we can just pick and place the components and simulate them, we use spice code in VLSI simulation because when we use Cadence, Mentor Graphics etc, we might face simulation issues. CMOS Inverter: CMOS AND: CMOS OR:

TASK 4: Voltage Multiplier

The voltage multiplier using capacitor pumps and a 555 Timer IC operates by converting a low DC voltage (9V) into higher DC voltages (first 18V, then 27V) through a series of charge-pump stages driven by a square wave. In this setup, the 555 Timer is configured as an astable multivibrator to produce a continuous square wave signal, typically in the kilohertz range. This oscillating signal is used to alternately charge and discharge capacitors through diodes, effectively shifting voltage levels. In the first stage, the circuit doubles the 9V input to approximately 18V using a diode-capacitor arrangement known as a voltage doubler. The output of this stage then feeds into a second similar stage, which adds another 9V, resulting in a final output of approximately 27V. Each diode ensures current flows in the correct direction, while capacitors store and transfer the charge.

TASK 5: The Power Shuffle: Buck-Boost Edition

Boost converters increase the voltage of a power source. For example a boost converter could take a 5V power source and boost it up to 25V. Typically, you find DC-DC boost converters in battery chargers or solar panels. They can also be used to supply components with different operating voltages from the same battery. Buck converters reduce the voltage of a power supply. This is a power electronics circuit that steps down the DC voltage to a level determined by the choice of components in your circuit. Unlike linear regulators that reduce the voltage by dissipating power as heat, buck converters reduce the voltage by increasing the current.

TASK 6: 4 bits to rule them all

To implement the 4-bit Arithmetic Logic Unit (ALU) in CircuitVerse, I began by designing a 4-bit adder using four full-adder modules. Each full adder takes two input bits and a carry-in, producing a sum and carry-out. Subtraction was enabled by leveraging 2’s complement: I implemented a control line that, when active, inverts the second operand using XOR gates and adds 1 via an initial carry-in, effectively turning the addition module into a subtractor. Logical operations (AND, OR, XOR, NOT) were realized using corresponding gates applied across the 4-bit inputs. I’ve used a 8X1 Multiplexer, through which based on the control input we can select the operation to be formed. 3-bit code to select between the five functions:

1. Addition/Subtraction (000)
2. AND (001)
3. OR (010)
4. XOR (011)
5. NOT A(100)
6. NOT B(101).

TASK 7: The PCB Revolution

I have completed the task of learning the basics of PCB designing. I applied for and received the Altium student license, which gave me access to the required tools. I then finished the Altium Student Lab PCB coursework, where I learned how to create schematics, place components, and design simple PCBs. This helped me understand the basic steps involved in PCB design using Altium Designer.

TASK 8: Convolution Countdown

A signal is a function that carries information about a physical event or phenomenon. It can vary with time, space, or other variables. Types of Signals:

1. Continuous-Time Signal - Defined at every instant of time. Eg: Analog audio, sine wave x(t): where t is continuous time.
2. Discrete-Time Signal - Defined only at specific time intervals (samples). Example: digital audio x[n]: where n is an integer (sample number).
3. Periodic Signal - Repeats after a fixed time interval. Example: Sinusoidal wave, square wave x(t) = x(t + T)
4. Aperiodic Signal - Does not repeat over time. Example: Human voice, random noise
5. Deterministic Signal - Can be exactly described using a mathematical equation. Example: x(t) = 5sin(2πt)
6. Random (Non-Deterministic) Signal - Unpredictable, varies randomly. Example: Stock market data, thermal noise
7. Even Signal- Symmetric around the y-axis. Condition: x(-t) = x(t) Example: Cosine wave
8. Odd Signal Asymmetric around the y-axis. Condition: x(-t) = −x(t) Example: Sine wave
9. Energy Signal - Has finite energy, but zero power over infinite time. Example: Pulse that lasts a short time
10. Power Signal- Has finite power, but infinite energy over infinite time. Example: Sine wave, constant DC signal What is a System? A system takes an input signal and gives an output signal (response). Example: Microphone converts sound (input) to electrical signals (output). Types of Systems:
11. Linear System • Follows superposition: o Additivity: Input1 + Input2 → Output1 + Output2 o Homogeneity: Scaling input scales output
12. Time-Invariant System • System's behavior doesn’t change with time. • Example: A resistor circuit behaves the same today or tomorrow.
13. Causal System • Output depends only on present and past inputs. • Real-world systems are always causal.
14. Stable System • If the input is bounded, output is also bounded. • Known as BIBO Stability (Bounded Input → Bounded Output)
15. LTI System (Linear Time-Invariant) • Most commonly analyzed system in signals and systems. • Easy to model and analyze using tools like impulse response and convolution. Z-Transform: Fourier Transform: Linear Convolution: I performed a simple Linear Convolution in MATLAB for two 4 sample discrete signals.

TASK 9: Whose Array is it anyway?

In this task, I began by studying PROM, PLA, and PAL architectures to understand how they differ in programmability and structure. I designed a logic function that outputs ‘1’ when the number of 1’s in a 3-bit input is odd. I implemented it first using a PAL by programming the AND array and using the fixed OR array, then again using a PLA by programming both AND and OR arrays. I created fuse tables for both designs showing the connections and blown fuses.

TASK 10: Your logic, Preloaded

In this task, I learned about Look-Up Tables (LUTs), which are memory-based elements used to implement logic functions in digital circuits. I manually created a truth table for a 2-input XOR function and then programmed a 4×1 LUT by storing the XOR output for all 4 possible input combinations. I simulated the behavior by selecting the output stored at a particular address based on the binary input values. This exercise helped me understand how LUTs can replace traditional logic gates by using stored data to determine output.

Mechanical Design

Mechanical design is the process of designing effective parts or components for machinery. It is the study of how mechanical components operate in various situations in order to create a reliable system.

CAD – Computer Aided Design

• CAD stands for Computer Aided Design. • It is used to create, modify, and improve 2D and 3D models using computer software. • CAD helps in designing the shape, size, and features of a product. • It is commonly used in mechanical design, architecture, and product development. • Eg: AutoCAD, SolidWorks etc.

CAM – Computer Aided Manufacturing

• CAM stands for Computer Aided Manufacturing. • It uses computer software to control machines and tools used in the manufacturing process. • CAM helps in generating NC (Numerical Control) programs, which tell machines how to cut, drill, or shape the part. • CAD is for designing whereas CAM is for making the design using machines. • Eg: NX CAM, MasterCAM etc.

CAE – Computer Aided Engineering

• CAE stands for Computer Aided Engineering. • It uses computer tools to analyze and test how a product will perform in the real world. • CAE helps engineers to simulate, validate, and improve designs before making physical prototypes. • Eg: Ansys, Hypermesh etc.

Isometric and Orthographic Projections

I drew 7 Orthographic Projections and 7 Isometric Projections on the Drawing Sheet. I also drew a Sierpinski Triangle. The Sierpiński Triangle is a self-similar fractal formed by recursively removing the central triangle from an equilateral triangle. It is used in computer graphics, fractal antennas, and to demonstrate recursive algorithms and mathematical properties of infinity. For the following task, I have applied for Autodesk Educational License and used Fusion 360 to perform the following tasks.

2D Drawings in CAD:

3D Drafting

TASK 1: Allen Key

An Allen key is a small handheld tool used to drive bolts and screws with hexagonal sockets. Allen keys are typically made from high-grade steel, such as chrome-vanadium steel or carbon steel, known for their strength and resistance to wear. The steel is often supplied in long wire rods or bars.

TASK 2: 3D Drafting

I created 3D models of three machine parts using Fusion 360. First, I made 2D drawings based on the given dimensions. Then I used 3D tools like Extrude and Hole to shape the parts. Each part was modeled carefully to match the technical details. The final models show accurate 3D versions of the original drawings.

TASK 3: Prerequisite for assembly in Fusion 360

While working on Fusion 360, I gained a clear understanding of the difference between bodies and components. I learned that bodies are individual shapes or solid parts used primarily for modeling and do not move independently, making them suitable for single-part designs. Components act as separate, independent parts with their own origin and timeline, allowing for movement and assembly using joints. It is used for building assemblies with multiple parts and for applying joints and creating motion.

Top-down: Design parts inside the assembly file. Bottom-up: Import or insert already-created parts into an assembly.