University of Massachusetts Amherst Theremillusion Imen Ben Neticha Snigdha Jonna Sandra Jenkins Steven Bennett Advisor: Professor Siqueira

2 Grenzebach Glier & Associates, Inc. Team Members Snigdha Jonna EE Steven Bennett CSE Imen Ben Neticha EE Sandra Jenkins EE

3 Grenzebach Glier & Associates, Inc. Invented by Léon Theremin in 1920 Background Originally got the idea while working on short wave ratio equipment and capacitive sensing during the Civil War in Russia

4 Grenzebach Glier & Associates, Inc. Theremins in Real Life Popular in Hollywood Used in the 1966 popular Beach Boys song “Good Vibrations” Kits widely used by electronics enthusiasts Used in The Outer limits TV show among others

5 Grenzebach Glier & Associates, Inc. How Does it Work

6 Grenzebach Glier & Associates, Inc. Schematic for analog Theremin Will modify the schematic as we build

7 Grenzebach Glier & Associates, Inc. Motivation  You don’t need to touch anything − Magical aspect  Wanted to learn how to play − Pick up music knowledge  Electrical Engineering Base

8 Grenzebach Glier & Associates, Inc. Problems with Theremin  No Reference  Continuous Pitch and volume  Theremin uses are limited − Spooky sounds and sound effects

9 Grenzebach Glier & Associates, Inc. Solutions for Problems  Visual Reference: − Optical Fibers for hand positions − Feedback on note accuracy  Create discrete playing mode

10 Grenzebach Glier & Associates, Inc. Visual Component Optical Fibers for strings of harp − Don’t effect electromagnet field − Don’t take up that much space − Edge Emitting fibers − Inexpensive

11 Grenzebach Glier & Associates, Inc. What will the Program Do?  Teaching (guide user to play a song)  Note accuracy (show how close the sound produced by user is to the target note) − Score shown with how many of the strings light up at the end of a song.

12 Grenzebach Glier & Associates, Inc. PIC32 Microcontroller Note file Optical Fibers LED Illuminators Visual Component Block Diagram See handout for more details

13 Grenzebach Glier & Associates, Inc. Why PIC32MX7XX? Analog Features Fast and Accurate 16 channel 10-bit ADC MCU Core 80MHz, 1.56 DMIPS/MHz, 32-bit MIPS M4K® Core

14 Grenzebach Glier & Associates, Inc. Programmable MPLAB C Compiler for PIC32 MCUs! PIC32 DSP Library Applicable to audio, video and other multimedia applications. mips_fft16 - Compute the complex FFT of a vector containing Q15 complex samples, i.e., 16-bit fractional real and imaginary parts.

15 Grenzebach Glier & Associates, Inc. Challenges ● Building the Theremin ● Learning Music ● Lack of music background for team members ● Need to work with professors in Music Dept. ● Visual component and Optical Fibers ● Difficult to cut ● Make sure that they are edge-illuminated ● Theremin Teaching: ● Music Storage and song generation ● Different people changing sound differently

16 Grenzebach Glier & Associates, Inc. Traditional Theremin Modular Design Software

17 Grenzebach Glier & Associates, Inc. Timeline

18 Grenzebach Glier & Associates, Inc. Responsibilities  Imen − Fiber Optics and LED Circuitry − Discrete Circuitry (Frequency to voltage and vice versa) − Output Control  Sandy − Pitch Circuitry − Discrete Circuitry (voltage comparison)  Snigdha − Volume Circuitry − Discrete Circuitry (voltage comparison)  Steven − Teaching mode programming − Displaying note accuracy programming

19 Grenzebach Glier & Associates, Inc. Preliminary Costs Part Quantity Cost Inductors11$20.00 Microcontroller (PIC32)1$40.00 Resistors/Capacitors81$3.66 Pitch Antenna1$2.00 Transistors8$0.72 Volume Antenna (knob?)1$0.30 Diodes5$0.10 LM13700 (Amplifer)1$0.53 Voltage Regulator2$2.30 LM331 (V to Freq converter)2$3.02 PIC16F870 (A to D converter)1$2.74 LM239 (Voltage Comarator)1$0.25 Fiber Optic Cable200ft$20.00 LEDs40$20.00 Plastic Rod for Structure1$20.00 Box1$10.00 Total$ Total with Shipping$200.00

20 Grenzebach Glier & Associates, Inc. SDP Day  Working Theremillusion will look like a harp, but will sound like a theremin.  The fiber optic cables will light up to teach the use how to play the theremin. Theremin and Microcontroller Pitch Antenna Fiber optic cables

21 Grenzebach Glier & Associates, Inc. END  Thank You!!!

22 Grenzebach Glier & Associates, Inc. References  Kenneth D. Skeldon, et al. Physics of the Theremin. Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland. Received 15 May 1998; accepted 12 June  Way, Beng Koay; Douglas Beard, Micah Caudle, and Jeffrey Jun-Fey Wong. Theremin. Department of Electrical and Computer Engineering at Mississippi State University..  Holloway, Barry. Theremin. Strange Apparatus  Sparkfun Electronics. “USB 32-bit Whacker – PIC32MX795 Development Board”..

23 Grenzebach Glier & Associates, Inc. Physics of Theremin  Antennas  Difference between Analog/digital theremins  Physics of the variable capacitance and how that changes the oscillators (how oscillators change sound)  Sandy about finding theremin player

24 Grenzebach Glier & Associates, Inc. Powering the theremin  Theremin can be powered by 12 volts.  This can be done by building a step- down transformer that will convert the normal house voltage or buy a power cord with a built in converter.

25 Grenzebach Glier & Associates, Inc. Design Requirements  Visual Display − Will display current note being played and if in teaching mode, indicate how close the note is to target note.  Visual Reference (Fiber Optics) − Lights will indicate the general location the hand has to be in to play a particular note. − (tentative) A light will change color depending on how close or far away the sound is from the target note.  Continuous and Discrete Playing Mode − Device will be able to be switched between playing in the traditional continuous range and playing only discrete notes in specific frequency ranges.

26 Grenzebach Glier & Associates, Inc. Software Interface Modular Design Visual Interface Optical Fibers Display Output Processing Frequency to Voltage Tuning Learning Mode Output control VCA Audio Amplifier Pitch Control Variable Oscillator Fixed Oscillator Mixer/ Detector Volume Control Variable Oscillator Knob Volume Tuning Voltage to Frequency Voltage Comparison/Discrete Output Switch

27 Grenzebach Glier & Associates, Inc. FFT Complexity FFT length Multiplies (real)Adds(real)Mults + Adds Radix Split Radix Prime Factor Alg Winograd FT Alg TABLE 1: Representative FFT Operation Counts