Theremillusion

1. Theremillusion Imen Ben-Neticha, Snigdha Jonna, Steven Bennett, Sandra Jenkins Faculty Advisor: Prof. Paul Siqueira ABSTRACT The end goal in the design and implementation of the Theremillusion has been the notion of creating a user friendly interface that would teach people how to play a Theremin. The Theremin is an instrument that has existed for many decades. It can be played by moving your hand through the electric field, disrupting the electric field, and outputting a note. However, due to lack of a reference, it is very difficult to master playing the Theremin, especially those new to musical instruments in general. The initial goal of the Theremillusion is to make the Theremin more accessible to everyday people by creating a friendly interface that would serve as a guide to the user. As mentioned above, the Theremin is lacking a reference. To address this shortcoming, the Theremillusion is designed with Electro-Luminescent (EL) wires to lead the user through playing a song. The wires are positioned to match specific notes needed to play a song and LED displays give note values. Time Spent: on average 5hrs/week for 22 weeks * items found in SDP lab, or borrowed from M5 Electro-luminescent wire (EL wire) is a thin copper wire that is coated with phosphor. This wire glows when an alternating current is applied. EL wire produces a 360 degree unbroken line of visible light. It is also very thin and flexible which is very ideal for this project as it would allow more precision as to the location of the notes on the Theremin. We controlled the EL wire using an EL Sequencer and interfacing it with the PIC32. The Thereminators System Diagram Theremin Arduino Seven Segment Display Seven Segment Display PIC32 Best SDP Advisor EL Wires EL Sequencer Objective: Make Theremin more user friendly for beginners Department of Electrical and Computer Engineering ECE 415/ECE 416 – SENIOR DESIGN PROJECT 2012 College of Engineering - University of Massachusetts Amherst SDP 12

2. Theremin Audio signal • pulseIn() Determine Frequency • Freq = 1/Period Filter noise • Setting limits Set note frequency values • Determine note ranges Set Discrete Note ranges • Assign single freq to range Output Note to LED Output quantized sound for speaker Discrete Mode Software Diagram Results: Results The graph above shows some the frequencies measured by the Arduino software for the Continuous Mode while a person is playing it to increase the pitch over time. EL Sequencer Software/Hardware Structure Binary Number 0000-1111 Analog Input EL Sequencer EL Wire A-H Driver 9 Volt Battery The graph above shows the frequencies measured by the Arduino software for the Discrete mode. The frequencies are distinct with an absence of a continuous sweep between two notes. These values correspond with our chosen note frequencies.