Polycrop Smart Irrigation System:

When I first decided to become an engineer, the biggest reason was so my work could help people. I was able to achieve this dream when I was in my Senior Design class: I was given the opportunity to work in a team to make a Polycrop Smart Drip irrigation system to help impoverished farmers in Nicaragua. I was ecstatic since I could begin my engineering career by helping people! We improved off a previous design to make the system polycrop, meaning it can irrigate any type of crop. The system is designed for a 9 [m] ✕ 16 [m] plot. Using sensors, a microcontroller decides if it is time to irrigate the plot. If you would like, you are welcome to look at the project’s REPORT, Summary POWERPOINT, POSTER, Demonstration VIDEO, and PRESENTATION.

I was in charge of 3D design and the Power System. For the Power System, I decided which battery, charge controller, and solar panel to purchase. I also determined how long the battery took to discharge without solar panels. For 3D design, I designed three critical components — the PCB, SHIELD, and BATTERY PLATFORM. For the PCB, I used EasyEDA to design the circuit. I had to make sure that the wiring for the system was perfect, since I only had one chance to get the PCB correct due to time constraints. You are welcome to look at the schematic I designed HERE. You are also welcome to download the files I made for developing the PCB HERE.

For the shield and battery platform - both of which were 3D printed - I used Autodesk Fusion 360 and TinkerCAD for the design work. The shield holds the components that the farmers would interact with, and I had to ensure it was sturdy and intuitive. If you would like, you can click HERE to download and print my shield. The battery platform secures the lead-acid battery so it doesn’t slip in our system. You can access my design’s 3D printing information HERE.

ePortfolio:

For my leadership minor, I had to create my own ePortfolio. I was given the option to use services that allowed me to make a website from a template (such as Wix). However, I decided to take up the challenge of making my own website from scratch so I could enhance my coding skills. I never had experience in web development, and I could not think of a better time to learn! Using online resources like YouTube channels, Web Cifar and Brian Design, I learned how to make my own website using HTML, CSS, and JavaScript. After putting more than 100 hours into this project, I am thrilled by the end result! I learned a lot about web development, like making the website responsive (so it works on everything from a TV to an iPhone), using online form readers for the contact form, the use of GitHub, and so much more. I am grateful that I took this challenge upon myself since I learned a lot, and I can finally say that I created a website!

State-Space Analysis of Bicycle Dynamics:

So that I could understand State-Space analysis, I decided to challenge myself by designing a controller for a bicycle, which I would simulate using MATLAB. I used physics and linear algebra to derive a preliminary State-Space model to describe the motions of a bicycle. I also did research to find values that were typical to a bicycle so I could model the “average bike”. Finally, I used MATLAB and coded a program that analyzed the system. Using my program, I proved that the system is linear, time-invariant,controllable, and observable. Using Simulink, I created Block Diagrams to check different cases of a controller — the initial open-loop scenario, when control and reference tracking is added. I then ran the simulation to analyze the control system and confirmed that my controller was able to stabilize the system quickly.

I made a POWERPOINT that summarizes my project, and I presented it as well. If you would like, please check my VIDEO presentation. You can also see my project REPORT.

Two Signal Frequency Meter and Comparator:

When I took my Electronics Lab, I was assigned to create my own circuit with three other teammates. My team decided to build a device that provided a voltage that is linearly proportional to the frequency of an input signal (any type of signal), with every 1 [kHz] outputting a voltage of 1 [V]. For example, if we had an input signal which oscillates at 10 [kHz], our system would output a voltage of 10V. Our device works with frequencies ranging from 100 [Hz] to 10 [kHz]. My team also added a comparator - which can take in two inputs - and output the difference between the two signals’ frequencies. My group worked together on this project for a semester to do extensive research and countless hours of fine-tuning our device. The device we made was very precise, with error usually being less than 1%.

My role was to research and implement the Transistor Charge Pump, where the actual frequency to voltage conversion occurs. I used two capacitors to filter the frequencies. I used two other capacitors to transform any input signal (such as a sawtooth signal) into a square wave so our device could work with a consistent signal, which gave us precise calculations. I also used a diode to stop backflow into the capacitors. My design used resistors to provide consistent voltages to the pump, with potentiometers allowing the user to fine tune the signal’s voltage. The design also uses a BJT transistor, which ensures that the voltages across the capacitors are about the same.

If you would like, you are welcome to check the device’s SCHEMATIC. You can also read our full REPORT.

Traffic-Light Controller:

For this project, I needed to design a controller for traffic lights placed at an intersection of two streets - one street running north-south and another street running east-west. This problem was so nice, I had to do it twice - once using Logic Gates, and another time using ARM Assembly.

Logic Gates:

To properly track if a light should turn on, we needed to consider ten different states. Using a Karnaugh Map, I created a transition table that modeled the Bit Counter (so the different bits translate to 4 different switches, which model the different cases observed by the light). JK flip-flops were used to create a more concise circuit. Using Boolean Algebra, the outputs were figured out for the controller. Using SimUAid, I was able to run simulations, and saw that my analysis was right. Finally, I was able to build the controller using four JK flip-flops, and a couple of AND and OR gates. You are welcome to see the Karnaugh Maps, Boolean Algebra, SimUAid simulations, and circuit HERE.

ARM Assembly:

I also made this project using ARM Assembly. This language is really precise, and with it, I can individually control what information is stored in individual registers. While it is a complicated language, I was able to compact the circuit that was made using logic gates as the code stored all of the logic information. Using ARM Assembly, with a TI Tiva Launchpad used as the platform for the code to work, I created a successful controller. I had to download different commands into the Launchpad’s ROM, where we got a clock to recognize different scenarios. Finally, I had to program the different scenarios in the RAM section of the Launchpad. If you would like, you are more than welcome to check out the PROGRAM I wrote.

DC Servo Motor PID Controller:

In my Automatic Controls class, I was assigned to develop a PID controller for a DC servo motor. The goal of the project was to make a rail-cart, which had a rod sticking up, go through a spinning, slotted wheel. We were assigned to make a controller that allowed the cart to go through the slotted wheel, with the rod going through the thin slot. I had to research the Dc servo’s transfer function, decide a proper DC servo motor, and derive a proper block diagram for the overall system. Using MATLAB’s Simulink functionality, I was able to conduct an analysis for the PID I was designing. With the simulation, I was able to assign the proper coefficients for the PID values for the M642E DC servo motor. If you are interested, you are more than welcome to read my full REPORT.