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Articles 31 - 60 of 63
Full-Text Articles in Engineering
Underwater Optical Wireless Audio Transceiver, Angel Ayala
Underwater Optical Wireless Audio Transceiver, Angel Ayala
Electrical Engineering
Scuba diving carries risks that can endanger lives. Many of these risks are preventable. However, an underwater communication system can increase a diver’s safety. Along with providing safety, an underwater communication device can enhance the scuba diver’s enjoyment.
A low cost underwater optical wireless audio transceiver is designed. The project consists of the off-the-shelf parts that uses a microphone and speaker to transmit and receive sound. The project uses the concepts of visible light communications and pulse width modulation to transmit and receive sound. Although sound is commonly transmitted through ultrasound methods, visible light communications has several advantages. Visible light …
Uav Avoidance System, Zachary Stargensky
Uav Avoidance System, Zachary Stargensky
Electrical Engineering
This is an ongoing design project being funded by Northrop Grumman in which Cal Poly SLO is working in collaboration with Cal Poly Pomona to complete a working design at the end of each academic school year. The project consists of two UAVs that can navigate around a given area without running into each other or other obstacles. There are sensors to be mounted on the vehicles that can detect objects within a given distance and a microcontroller is used to control how the vehicle responds to an object being detected. The avoidance code has been written for previous years’ …
The Electric Reel For Soccer Fields, Stephen Taylor
The Electric Reel For Soccer Fields, Stephen Taylor
Electrical Engineering
Painting a soccer field consumes too much time. The process of reeling the string after laying out string along the field needs to improve. As a result, my project addresses improvements in how the workers retrieve the string through the production of an electric reel. This electric reel allows the worker to have control of the speed, direction, and on/off state of the device. Direction control allows the user ability to reel and unwind the string. Variable speed allows the user to control how fast the reel unwinds and reels the string. The device gathers string in an orderly manner …
Rapid Battery Exchange Safety And Sensing, Ben John Froelich, Isaac Sungjin Kim
Rapid Battery Exchange Safety And Sensing, Ben John Froelich, Isaac Sungjin Kim
Electrical Engineering
The Rapid Battery Exchange system (RBX) swaps batteries in an electric van, allowing almost continuous operation of the vehicle. The RBX system is designed and built by The Cal Poly Electric Vehicle Engineering Club (EVEC). The system includes the exchange ramp, two battery packs, and the electric “G-Van.” While the vehicle drives using one of the battery packs, the other pack charges in the exchange ramp. When the van’s battery depletes, it drives onto the ramp and swaps the dead battery for the charged one, and the process repeats.
The RBX battery pack safety and sensing project divides into two …
Design Improvement For The Smart Dc Wall Plug, Cory Yee, Haoyan Huang
Design Improvement For The Smart Dc Wall Plug, Cory Yee, Haoyan Huang
Electrical Engineering
The DC smart wall plug is a subsystem within the Cal Poly DC House Project. The previous version faces challenges supplying DC voltage to meet household appliances’ nominal values. Specifically, it can only output the minimum required voltage for DC appliances to operate, resulting in unwanted power loss. In addition, the maximum output voltage is rated at 15V, which is insufficient to power most DC appliances. This design improvement project incorporates NFC technology as a solution to overcome the power loss and a new buck converter configuration to increase the output voltage range. Additionally, the new design introduces short-circuit and …
High Frequency Open Air Optical Communication System, Alexander C. Wolff
High Frequency Open Air Optical Communication System, Alexander C. Wolff
Electrical Engineering
The goal of this project is to create a wireless optical communication system that operates at high frequencies (up to 3 GHz). The system will function by taking a digital electric input signal, converting it to a photonic signal, recovering the signal at the other end of a short distance (~1 foot) and converting it back into a digital signal. Unlike the more common fiber-optic data transmission systems, this system will transmit light through air, instead of fiber, as its medium. Doing so will have the benefits of a wireless system combined with the benefits from an optical system, including …
Buddy: A Breathalyzer For Iphone, Douglas Blaalid, Brandon Bevans
Buddy: A Breathalyzer For Iphone, Douglas Blaalid, Brandon Bevans
Electrical Engineering
Buddy is a Breathalyzer for the iPhone designed to be more a product than a project. Through proprietary hardware and a custom iOS application, Buddy provides users with a previously untapped link from the alcohol in their body to the display on their phones. Buddy uses an alcohol sensor connected to an Arduino Uno to accurately detect the BAC of the user’s breath. The BAC is then transmitted to an iPhone via the headphone jack where it is displayed and logged in a captivating app. The finished prototype successfully measured the approximate BAC of intoxicated users. The product website has …
Radio Link Analysis And Characterization Of Past And Future Cal Poly Cubesats, Brian Gilbert Tubb
Radio Link Analysis And Characterization Of Past And Future Cal Poly Cubesats, Brian Gilbert Tubb
Electrical Engineering
Cal Poly's satellites design team, PolySat, has three satellites in Low Earth Orbit (LEO) and four more planned to launch within the next two years. Radio communication of past and current orbiting satellites has been an exercise in frustration, prompting significant research into the satellite-side of the radio link by several other Senior Projects and Thesis papers. However, minimal effort has been spent on evaluating why these problems were discovered only once the satellites reached orbit. This paper details the downfalls of relying heavily on link budgets and improper long range test setups, then experimentally determines the sensitivity of PolySat's …
3.5 To 30 Mhz Automatic Antenna Impedance Matching System, William Blodgett
3.5 To 30 Mhz Automatic Antenna Impedance Matching System, William Blodgett
Electrical Engineering
Two-way communications using 3 to 30 MHz, high-frequency (HF) radio, also known as shortwave radio, provides worldwide coverage with no infrastructure required between stations. Amateur or “Ham” radio operators apply this advantage to long distance communications and to provide disaster relief communications. Optimum frequencies for long distance propagation are time-of-day variant necessitating an operating frequency range of 3 to 30 MHz. HF half wave dipole antenna length varies from 15 to 150 ft over this range. Fixed-length antenna impedance varies with frequency due to physical dimension dependent capacitance and inductance. Maximum transmitter to antenna power transfer occurs when the transmission …
802.15.4 Low Intermediate Frequency Radio Receiver, Sanjay Avasarala
802.15.4 Low Intermediate Frequency Radio Receiver, Sanjay Avasarala
Electrical Engineering
This project involves the design, building, and testing of a low intermediate frequency 802.15.4 receiver that uses an FPGA to perform final demodulation to baseband.
Pulsed Class-G Rf Amplifier System, Kevin Maulhardt, Kevin Haskett
Pulsed Class-G Rf Amplifier System, Kevin Maulhardt, Kevin Haskett
Electrical Engineering
No abstract provided.
Lyfi, Kianoosh Salami, Justin Cotton, Elush Shirazpour
Lyfi, Kianoosh Salami, Justin Cotton, Elush Shirazpour
Electrical Engineering
This paper will cover the steps necessary to design, build, and manage networkable smart light switches over WiFi via a mobile application. It contains a microcontroller running a real time operating system, a WiFi module, a Java server with SQLite databasing, and a mobile phone application.
LyFi is designed to turn on/off and dim household lights while only requiring the same installation procedure as a less capable dimmer switch. Once installed and connected to a network, LyFi will self-discover and configure. The server automatically propogates a database of nodes where any mobile device running an application can receive an updated …
Rfid Check-In System For Safe Routes To School At Hawthorne Elementary, Paul Banel
Rfid Check-In System For Safe Routes To School At Hawthorne Elementary, Paul Banel
Electrical Engineering
The system uses a low frequency Radio Frequency Identification (RFID) reader and passive RFID tags to help the Safe Routes to School program at Hawthorne Elementary in San Luis Obispo track the number of children who participate in the program. Children will carry passive RFID tags and scan them at the reader each morning that they walk or bike to school. The system tracks the total number of students that walk and bike each day, as well as the number of times each individual child participates over the course of many days. The Safe Routes program hopes to use this …
Auto-Tuning Antenna, John Chen, Jennifer Tighe
Auto-Tuning Antenna, John Chen, Jennifer Tighe
Electrical Engineering
Radio transmitters and antennas have differing impedances at the output and feedpoint, depending on frequency. Modern antenna tuning methods involve manual or automatic resistance and reactance network adjustment to match transmitter and antenna impedance. This reduces power reflections to the transmitter, but introduces losses and prevents full transmitter power from being radiated at the antenna. This project utilizes a variable length antenna element to tune and match transmitter and antenna impedances, allowing efficient power transfer to the antenna. The antenna length varies from 0 to 30.5 inches. The method involves an RF signal with a maximum power of 2 watts …
Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang
Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang
Electrical Engineering
This project tests and analyzes the efficiency of directional and omnidirectional antennas in wireless power transfer for charging. The project demonstrates the steps of construction and properties of dipole, monopole, and Yagi Uda antennas. A low power high frequency DC rectifier circuit converts the received RF power from the antenna and stored it as DC voltage on a capacitor. The receiver circuit also estimates the power received by the antenna. Wireless RF power transmission proves to be inefficient for short distances. The best efficiencies of the antennas were under 50% even at 0.1meter. The near field attenuation starts at around …
Wirelessly Operated Pa Loudspeaker System For Rmax Search-And-Rescue Uav: A Preliminary Design, Travis Luke, Nolan Uchizono
Wirelessly Operated Pa Loudspeaker System For Rmax Search-And-Rescue Uav: A Preliminary Design, Travis Luke, Nolan Uchizono
Electrical Engineering
This paper discusses the approach used to implement a wireless PA loudspeaker system on a search-and-rescue RMAX UAV.
The purpose of this project is to allow the continuation of communication between search-and-rescue workers as well as potential rescuees in an environment that won't always allow it. Since rugged terrain tends to cause interference between two radio communications, there needs to be a way to bypass this problem. In addition, people in need of rescue are unlikely to be using a radio on an emergency frequency, so there needs to be a way to efficiently issue orders or evacuation notices without …
Digital Modulations Using The Universal Software Radio Peripheral, Daniel Keith Artis
Digital Modulations Using The Universal Software Radio Peripheral, Daniel Keith Artis
Electrical Engineering
Software defined radios (SDRs) are versatile systems that integrate hardware and software to create a reprogrammable wireless system. Due to the versatility and hardware requirements of a SDR, they are typically expensive and not always affordable for educational institutions. GNU Radio is a free software package that allows users to do signal processing on any computer using python and C++. Using the Universal Software Radio Peripheral (USRP) board in conjunction with a standard personal computer (PC), a RF daughterboard, and the GNU Radio software, we can create a software defined radio that can transmit, receive, and process signals. Because the …
Laser Cursor, Michael Liman
Laser Cursor, Michael Liman
Electrical Engineering
A user controls a cursor on a computer screen using a laser pointer. A camera picks up the laser pointer’s position and sends the data to the computer to move the cursor in the correct position.
An Investigation Into Ultrasonic Communication For Near-Body Networks, Eric Joshua Escudero Jr., Gursewak Singh Rai
An Investigation Into Ultrasonic Communication For Near-Body Networks, Eric Joshua Escudero Jr., Gursewak Singh Rai
Electrical Engineering
The following report presents a study of body-area, free-space ultrasonic communication system. Two analog communication systems are investigated. The initial communications system setup relies upon the amplitude modulation (AM) techniques to transmit the signal. Such a system is prone to noise since the amplitude of the signal is directly affected by distance and the signal strength will deteriorate. The secondary communication system involves utilizing frequency modulation (FM). This method avoids the issue of losing information due to amplitude deterioration, but encounters delay issues. The main hardware components used in the approach outlined include ultrasonic transducers (UTs) used for both transmitting …
Wireless Sensor Network For Energy And Environmental Monitoring: Helping Old Buildings Go Green, Jacob Power
Wireless Sensor Network For Energy And Environmental Monitoring: Helping Old Buildings Go Green, Jacob Power
Electrical Engineering
Today, the rising cost of energy and social trend of “going green” has put increasing pressure on commercial property owners to improve the efficiency of their investments. There is good reason for this, too. In the State of California, office buildings represent the single largest user of energy in the commercial sector. This project consisted of the design, implementation, construction, testing, and deployment of a wireless sensor network for energy and environmental monitoring in retrofit commercial office installations. The analyzed data generated by this system can be used by building management and owners to identify areas of inefficiency within the …
Discrete Alarm Clock, Travis Moore, Collin Barth
Discrete Alarm Clock, Travis Moore, Collin Barth
Electrical Engineering
The standard alarm clock, as used daily by millions worldwide, has clear room for modification and improvement. This paper documents an implementation that rectifies many of these flaws. Improvements include adjustable snooze length, an IR remote for ease of use, and an RF headset for discrete alarm use or potential incorporation into a device much like a hearing aid. The processes involved in creating a digital alarm clock, as well as the obstacles met in the implementation of the enhanced design, are detailed within.
Audio-To-Optical Conversion And Transmission, Jason Moritz
Audio-To-Optical Conversion And Transmission, Jason Moritz
Electrical Engineering
The purpose of this project is to understand free-space optical transmission of signals in the application of transmitting an audio signal. An audio signal will be taken from the headphone output of a computer and used to modulate a current source driving an LED and a laser diode. The optical signal will then be transmitted through free space as well as two different focal length lenses and converted back to an audio signal to measure any attenuation or gain in the original signal. My experimental results showed that the LED was able to transmit up to 10 dB more power …
Aether, Thomas Cameron, Kristine Colton, Daren Childers
Aether, Thomas Cameron, Kristine Colton, Daren Childers
Electrical Engineering
Aether is a RC-style autonomous air vehicle that utilizes GPS positioning along with a wireless communication system to achieve a computer-controlled flight.
This report will incorporate the acquisition, design, integration, implementation and testing phases of the UAV development. Furthermore a discussion of troubleshooting as well as improvements for future projects will be included.
Directional Patch Antenna Array Design For Desktop Wireless Internet, Noah Snyder
Directional Patch Antenna Array Design For Desktop Wireless Internet, Noah Snyder
Electrical Engineering
To improve desktop wireless internet access, two patch antenna configurations were investigated in order to find an alternative for a dipole antenna, which is commonly used for Wi-Fi access. A Linksys WMP54G pci-card wireless adapter was used to test three antennas for 802.11g communications. The standard WMP54G dipole antenna and two patch antenna configurations were tested for Wi-Fi signal strength. The antennas were also tested in Cal Poly’s anechoic chamber to obtain resonant frequency and gain measurements. A 2.437 GHz center frequency, 72 MHz bandwidth antenna consisting of a single microstrip patch was constructed. After the patch antenna was determined …
Circular Polarized Splatch Antenna, Cynthia Truong
Circular Polarized Splatch Antenna, Cynthia Truong
Electrical Engineering
The Splatch Antenna combines excellent performance and cost-effectiveness into an antenna package that can be integrated. The goal of this project is to figure out how to connect two Splatch antennas to realize a Circular Polarized (CP) antenna. The advantage of CP versus linear polarization is that CP eliminates polarization mismatch losses caused by Faraday’s rotation.
Ofdm Simulation In Matlab, Paul Guanming Lin
Ofdm Simulation In Matlab, Paul Guanming Lin
Electrical Engineering
The objective of this project is to demonstrate the concept and feasibility of an OFDM system, and investigate how its performance is changed by varying some of its major parameters. This objective is met by developing a MATLAB program to simulate a basic OFDM system. From the process of this development, the mechanism of an OFDM system can be studied; and with a completed MATLAB program, the characteristics of an OFDM system can be explored.
Micro Forest Fire Detection, John Cape
Touch Screen Sound Controller, James Fenley, Jonathan Law
Touch Screen Sound Controller, James Fenley, Jonathan Law
Electrical Engineering
The Touch Screen Sound Controller sets out to explore the use of a touch screen as a sound control interface for the disk jockey profession. In addition, the project aims to provide an alternate means of transferring audio data by way of TCP/IP communications as opposed to MIDI. By applying our method, a user may stream pulse-code modulated data from a server onto a client’s RAM via an Ethernet connection. A 32bit, 200MHz ARM9 microprocessor addresses data from the RAM and proceeds with executing DSP instructions from the user. The connection between the touch screen and the central microprocessor is …
Fm Radio Receiver With Digital Demodulation, Nicholas Burnett
Fm Radio Receiver With Digital Demodulation, Nicholas Burnett
Electrical Engineering
This paper reports on the design, construction, and testing of an FM receiver. The design is split into two portions, the analog FM front end and the digital demodulator. The job of the front end is to down convert the RF signal to a frequency that is low enough to sample with an analog to digital converter. The construction of the front end is done using what is known as “Ugly Construction.” That is, all the components are soldered together floating over a ground plane.
The second portion of the design is the demodulator. The phase lock loop method of …
Sign Language Glove, Nicholas Born
Sign Language Glove, Nicholas Born
Electrical Engineering
Between 500,000 and 2 million Americans use American Sign Language (ASL) as their primary language. As such, a device capable of translating those movements into text would be useful in many areas, such as teaching and the entertainment industry.
The goal of this project was to show that the creation of a glove device that takes in sign language letters, interprets them into the desired characters, and can input those characters into a computer is feasible. I chose to work on this project for many different reasons. One reason is many members of my family know sign language and use …