Signal Processing Commons^™

Digital Guitar Effects Unit And Amplifier, Kevin Salvador

Electrical Engineering

This report outlines the design and implementation of a digital guitar effects unit and amplifier. The main portion of this project consisted of the digital equalizer and effects. Several commercial equalizers were researched in order to decide the typical frequency bands and average amount of bands total. Eventually 8 bands were selected. A range of approximately 20Hz-3kHz was chosen based on test data of guitar signals. Popular effects that were incorporated in this project include Distortion, Echo, Reverb, Chorus and Flanger. The digital processor chosen was a Texas Instruments c6713 floating point processor. Designs for the various filters were done …

Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn

Electrical Engineering

As the demand for more devices to become wireless increases, there is a need for linear, efficient monolithic power amplifiers to deal with the variations in modulation of signals. With partial support from Cal Poly C3RP Grant #52268, this paper explains the implementation of and analyzes a circuit that actively biases a bipolar transistor to operate as a Class C amplifier. The Class C amplifier can maintain constant conduction angle over a range of output powers by using a Class B amplifier to force a scaled DC current vs. input magnitude curve on to a Class C amplifier. The knee …

Audio-Triggered El Wire Sequencer, Benjamin (Ben) Paik

Electrical Engineering

“Development of an Audio-Triggered EL Wire Sequencer” California Polytechnic State University 2011, Ben Paik and John Oliver, Ph.D. (advisor)

The purpose of this project is to investigate and develop a method for switching electroluminescent wire (EL wire) such that it can be activated by some audio source.  EL wire is essentially a coaxial capacitor that luminesces when an alternating electric field excites the insulating phosphor layer in the wire (a 100Vp, 1kHz AC source is sufficient for this).   The system involves the EL wire, a six channel sequencer to switch the EL wire, an method for processing the audio signal, …

Rem Sleep Alarm, Shaun Kelsey, Brendon Soltis

Electrical Engineering

This paper explores the REM Sleep Alarm project that deals with the sleep cycle of the average human, and how it affects our ability to function when waking up in the morning.

The purpose of this project is to build a device that has the ability to wake a person up when they will feel the most rested. From research done, it appears that most people feel the most rested when woken up during the REM stage of their sleep cycle. Our goal is to have the device detect when the user is in this stage of sleep, determine how …

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

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.

Smooth Ternary Signaling For Deep-Submicron(Dsm) Buses, Robert Endicott Hanson, Ryan Ian Fullerton

Electrical Engineering

This project demonstrates the error mitigating effects of using a three-level “smooth ternary” signal on a Deep-Submicron(DSM) bus with large inter-wire capacitance. An RC circuit used to simulate and exaggerate (for easier testing) the charging and discharging of the DSM bus. An encoder stage translates binary input data into a three-level signal before sending it to the bus. A decoder stage then translates the three-level signal back to binary that is ideally identical to the original signal. Our results show that the three-level signal has much cleaner transitions than a traditional binary signal. A few glitches that appeared when decoding …

Ultrasonic Listener: Microcontroller Based Frequency Shifter, Troy Fredriks

Electrical Engineering

No abstract provided.

Mixing Digital And Analog Audio Signals, David Robison

Electrical Engineering

I have been playing the drums for thirteen years. I started out on an electric drum set and then progressed to an acoustic set. I have always wondered what it would sound like to combine the two types of sounds and this senior project dissected that interest to its raw form. Delving into the problems and solutions of combining digital and analog audio signals intrigued me and thus, became my senior project. The design process included research into the analog and digital realms, computer simulations, and actual implementation successes and failures.

The signal path begins at the bass drum where …

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 …

Violin Note Detector Using Digital Signal Processing, Nathaniel Kyle Mopas

Electrical Engineering

No abstract provided.

Psuedo-Randomly Controlled Analog Synthesizer, Jared Huntington

Electrical Engineering

The goal of this project was to design and build a portable box recreating classic sounds heard in science fiction films. These include sounds ranging from droning hums to bloops and bleeps. Currently no other device is made specifically for generating these sounds. The user controls and manipulates the sounds produced using a combination of switches and knobs to shape the sound generation. The sounds are generated using analog electronics. The project was successful in meeting the desired goal by designing and building a Randomizer, MIDI controller, VCO, LFO, VCA, Ring Modulator, and Fuzz Section. The resulting device is useful …