My name is Victor Garcia Flores and am currently an undergraduate student for the department of Electrical and Computer Engineering. I am currently studying for a Bachelor’s degree, but will continue on and advance onto graduate school to obtain a Master’s in the same field. By doing so, opportunities to work abroad in Europe will widen. Working abroad will enable to obtain a different working mindset, and develop unique qualities I could apply in my career.
Sensor Calibration with MatLab:
The purpose behind this project was to read raw data from the surrounding environment, and output a real-time visual representation of the data collected. In this case, we read light intensity and temperature from both a photo-resistor and thermistor using an Arduino Uno by implementing MatLab to produce a graphical representation in terms of real time. The data collected from the Arduino and sensors were sent to MatLab via serial Communication.
To determine the resistor values corresponding to the photocell and thermistor, a reference voltage and resistance of 5V and 2.2k ohms were used. By doing so, one can use a voltage divider to solve for both resistances because they will be the only unknown variables. Our input voltage is 5V, one of the resistors is 2.2k ohms, and the output voltage is measured using the Arduino. By finding the resistance across the thermistor values, we can model the output temperature in both a linear and Steinhart model. As for the photo-resistor, the resistor value calculated will be sent directly to the modeled graph.
Steinhart-Hart and Linear Model:
In the Steinhart-Hart approximation model, A, B, C, and D are constants for the specific thermistor. These can be found directly on the datasheet, or derived by manually measuring three pairings of temperature and thermo-resistance. Rt is the thermo-resistance at 25 degrees, which is 10 kilo-ohms for this thermistor. Once you have these constants, the above formula gives one the temperature in celsius as a function of resistance.
In the Linear model, M and B are constants calculated from two chosen data points. My group and I used data points at 0 degrees and 25 degrees Celsius as these were provided in the datasheet. This also explains why the Linear model crosses the Steinhart-hart model at 0 and 25 degrees.
MATLAB Code Description:
The MATLAB code is split in two parts. For the real-time temperature readings, MATLAB continuously reads digital voltage from the Arduino. It uses the voltage divider equation to calculate resistances and our models to calculate temperature. In this implementation, we use an animated line graph to plot this in real time for ten seconds.
For the thermo-resistance vs temperature graph, we use the same Steinhart and linear equations to plot each approximation curve. The percent error is then found, and points of intersection are marked.
Local Host Portfolio Tutorial:
In order to prepare for this tutorial, I had to take a few steps towards enabling PHP and apache on my Macbook Pro; the link with instructions have been included below.
After having gotten that set up, I followed the steps towards writing my site from the Youtube link below. This tutorial includes a link in the description that takes one to the template source files. By using this template, I was able to add pictures for three major ECE projects I have worked on, as well as a description of what they did along side them. Since this is a local site, a future step would be to make this web server accessible from anywhere by using NGROK; a tutorial for this has been added on the COP homepage.
- Enabling PHP on a Mac device: https://websitebeaver.com/set-up-localhost-on-macos-high-sierra-apache-mysql-and-php-7-with-sslhttpsPortfolio
- Tutorial: https://www.youtube.com/watch?v=SSA0atvePSI
Resilient Electrical Outlet :
Surge protectors are heavily recommended since the device, which can take the form of any shape and size, is meant to protect anything that is connected to it from sudden voltage spikes. There are various surge protection systems, however most of them require triggered systems to be replaced since hardware tends to burn out. Although many electrical devices have been innovating and have created safety systems so there isn’t any damages to hardware in case of power surges, it’s a very risky gamble not to have additional protection when powering expensive devices such as computers or manufacturing technology. For this reason, our client Joe Rossi requested a system that is compact enough to fit in a wall so it can be implemented internally without having to connect anything externally to the wall plug, as well as implementing a wireless re-enabling method once the system is triggered.
This electrical outlet required thorough planning and background knowledge on IoT projects. The portion of the project that highly associates with this Community of Practice group corresponds to the processor’s communication to a cell phone application. To communicate, both of these devices must be connected to the same wireless network in order to communicate via IP address, which is hard coded to the application.
By the end of this year, my team was able to complete a finalized designed that was capable of being fully enclosed single gang outlet box. A picture of this may be found below:
Figure 1: Enclosed System
The images below depict the contents inside the outlet without the single gang box:
Figure 2: Angled View of System
Figure 3: Top view that depicts sensors, TRIAC (used to enable/disable system), and processor.
Link to project: site: https://sites.google.com/a/oregonstate.edu/ece44x201814/ece-senior-design-example-project