This project was wired using breadboards, and coded in C language. The code is available below. 

https://github.com/kevynvital/Smart-Car-2025

Project Description: 

For this project, I worked in a team of three to design and program a smart car on the Arduino Uno (ATmega328P). The car used ultrasonic sensors for barrier detection, line-following sensors, and wheel encoders for distance feedback. I developed interrupt-driven motor control with PWM signals through an H-Bridge, enabling the car to autonomously navigate a maze in 12.68 seconds and follow a track using sensor feedback. We also added enhancements such as an LCD odometer and a three-point turn routine, while experimenting with proportional control for more accurate line following.

This project was completed on a breadboard.

Project Description: 

For this project, I wanted to create a dice roller circuit that would generate a "random" unsigned binary number (1-6) each time a user would push and let go of a pushbutton. My design includes a debounced pushbutton PCB, the output of which acts as a clock signal for a D Flip-Flop. My reason for using this D Flip-Flop was that I needed some sort of logic to inhibit the dice roller from continuing to scroll through numbers. I found connecting the output of the Flip-Flop to the VCC of a 555 timer in astable mode was adequate for my design. Unfortunately, generating a random number is not truly possible. To counter this, I decided to use 47 Ω resistors so that the clock signal would go faster, making it nearly impossible for the user to react quick enough to guess the same number repeatedly. Then, I used a Schmitt inverter to clean up the output of my clock signal. Since my range of numbers was 1-6, I needed to use three D Flip-Flops in my design. I used the clock signal of my 555 timer as the clock input for my next three D Flip-Flops. Ground and preset were not used in any of these Flip-Flops, so I connected them to VCC. After making a state diagram, and then a transition table, I came up with expressions for each Flip-Flop (shown below), and I wired each FF accordingly. To display the user's number after rolling the dice, I opted for 3 LED's. The MSB LED connected to the output of the A Flip-Flop, and the LSB LED connected to the output of the B Flip-Flop. 

This project was completed on a breadboard.

Project Description:

For this project, I programmed a 27C1024 EPROM Chip with a truth table. This truth table I designed to translate all unsigned 4-Bit binary numbers (decimal 0-15) to Greek Acrophonic numerals. The truth table corresponded with a 16-segment common anode PCB display created by Doctor Pasquale. My procedure for this truth table was to figure out which values were 0 = ON, and 1 = OFF for each segment A-U on the display. After I filled out my truth table, I divided the truth table into 4 sections. A-D, C-H, K-P, and R-U. The 4-Bit binary numbers of each of these sections would be condensed into a single hexadecimal letter, in order for the EPROM program to accept such a large amount of data for each decimal number 0-15. After translating each 4-Bit binary number from each section, I programmed my EPROM chip to display a certain numeral when given a specific 4-Bit binary input.

This project was completed on a breadboard.

Project Description: 

For this project, I designed a circuit that serves two different purposes: adding/subtracting 2 4-Bit binary numbers. This circuit design is capable of signed addition/subtraction. It uses a full adder which receives a 4-Bit binary input (A) from a DIP-Switch, and another 4-Bit binary input (B) that goes through a 74LS86 XOR Logic Chip. The purpose of this XOR Logic Chip is to invert the B inputs. In order for this adder to have the ability to toggle to subtraction, I used the CIN pin from the full adder, and connected it to my "B" values on the XOR chip. This CIN pin was then wired to a pushbutton, which when pressed and held down allows the user to perform subtraction. Essentially what happens when the pushbutton is pressed and held down is the B values are inverted and 1 is added to the end of the 4-Bit binary number, successfully turning the operation from A+B to A + (-B). Since this design is capable of signed addition and subtraction, we must include overflow logic. The way I implemented this into my design was by using the equation: O = A4E4'(B4⊕ T) + A4'E4(B4⊕ T)'. This equation allowed me identify overflow when the result exceeded the maximum representable value [-7,7], when the sign-bit and MSB are not the same, or when positive + positive yields negative/negative + negative yields positive.  In all of these cases, an LED will light up on my circuit board indicating overflow. 

This project was completed on CircuitVerse. Click here for the link. 

Project Description:

For this project, I designed a circuit that can multiply two unsigned 2-Bit binary numbers (A1A0 * B1B0) and display it as an unsigned 4-Bit binary number on a series of 4 LED's (Sum 3= MSB & Sum 0 =LSB).  This circuit uses four AND gates, which are essential for performing multiplication in the circuit, and two half adders composed of 2 AND & XOR gates which add both of the partial product terms together to obtain the result. The XOR gates are essential because inside our half adder, the sums 1 & 2 are produced by the XOR gates. When designing my circuit, I had to reflect this reasoning onto my equations for sums 1 & 2 by simplifying them into XOR equations. 

This project was completed on Logisim. 

Project Description: 

For this project, I utilized two 4 to 16 decoders in order to check for two equal 4-Bit binary numbers. A decoder is great for this type of situation because of its functionality. The decoder accepts an unsigned 4-Bit binary input (0-15), which is represented by A, B, C, and D on the truth table below. The 16 output lines (X0 to X15) correspond to all of the combinations of the input lines. Each output line is HIGH (1) for a specific input combination. Essentially, the decoder decodes the binary input into one specific output. This logic enabled me to use the two decoders in conjunction with 16 AND gates to cover every possible binary input combination. Each output pin on the decoder was connected to an AND gate with a fan-in of 2 that corresponds to each possible decimal number in order to compare the two 4-bit binary inputs. If both 4-Bit inputs are equal, a signal will be sent to an OR gate with a fan in of 16, which sends a HIGH signal to active HIGH  7-segment displays that will read "EQUAL". If both inputs are not equal the 7-segment displays will remain off. You could use this logic for however big of a binary number you'd like, you would simply have to increase the decoder size, and your amount of AND gates.