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. Responsibilities Sandra Jenkins Pitch Variable Oscillator Pitch Reference Oscillator Mixer Snigdha Jonna Volume Variable Oscillator Volume Fixed Oscillator Circuit and Voltage Control Amplifier Imen Ben Neticha Fiber Optics/ Electroluminescent wires implementation Designing and building driver for wires Steven Bennett Microcontroller Programming Visual Demonstration Circuit

4 Grenzebach Glier & Associates, Inc. Introduction  Focus on making the Theremin easier to play for beginners  Incorporating a visual reference and feedback − Player’s ability to hear tones focusing specifically on the western scale  Motivation: Electrical Engineering based instrument

5 Grenzebach Glier & Associates, Inc. Working with Music Department Professor  Professor Gary S. Karpinski  frequencies used for equal temperament  This will help next semester when we begin implementing the Discrete mode

6 Grenzebach Glier & Associates, Inc. System Block Diagram

7 Grenzebach Glier & Associates, Inc. Theremin (Volume Control Progress)  The Volume Variable circuitry has been built  The frequency is 385kHz which is a little low compared to the goal of 440kHz  There is still some unwanted noise, which is affecting the frequency  Noise due to bad connections in circuit board − Making a PCB will be a good alternative for reducing noise

8 Grenzebach Glier & Associates, Inc. Volume Variable Oscillator

9 Grenzebach Glier & Associates, Inc. Theremin(Volume Fixed Oscillator + VCA)  The Volume Fixed Oscillator and the VCA circuit has been built.  The Volume Fixed Oscillator can be tuned to have the same frequency as the Volume Variable Oscillator.  The VCA and VFO circuit are designed to increase the volume of the Theremin as the player moves his hand away from the antenna.

10 Grenzebach Glier & Associates, Inc. Theremin (Pitch Control and Mixer)  The circuitry has been built  The frequency is a little high, around 230Hz : goal is something closer to172Hz  Lots of unwanted noise from breadboards

11 Grenzebach Glier & Associates, Inc. Fixed Pitch Oscillator

12 Grenzebach Glier & Associates, Inc. Fixed Pitch Oscillator

13 Grenzebach Glier & Associates, Inc. Variable Pitch Oscillator

14 Grenzebach Glier & Associates, Inc. Variable Pitch Oscillator

15 Grenzebach Glier & Associates, Inc. Mixer for Pitch Oscillators

16 Grenzebach Glier & Associates, Inc.  DEMO

17 Grenzebach Glier & Associates, Inc. Software: What’s Been Going on  A Lot of Software Engineering: Source FileLines of Code Analyzer.c340 HardwareProfile.h102 USBDescriptors.c307 USB_Config.h134 NoteIO.c413 Main.c688 HelloUSBWorld.h10 HelloUSBWorld.c435 Total:2429 The Project is growing!

18 Grenzebach Glier & Associates, Inc. Demo Software  USB Control Selects One of Two Sequences.  LED sequences as proposed at PDR.  Proceeded with initial ADC and FFT Code. Incomplete and disabled for demo.

19 Grenzebach Glier & Associates, Inc. Why USB?  Demonstrations − Hooked up for reprogramming firmware. − Power board through USB hub. − Select a Song Sequence using a script.  Debugging − Variables and changes in state can be printed back to PC.

20 Grenzebach Glier & Associates, Inc. USB Demo  Two scripts prepared to transmit control characters to board through PC Com Ports.

21 Grenzebach Glier & Associates, Inc.  Demo

22 Grenzebach Glier & Associates, Inc. “Canon in D”  Original Theremin music is hard to find!  Peter Pringle’s rendition of Pachelbel’s “Canon”.

23 Grenzebach Glier & Associates, Inc. Musical Notes  Note to I/O Database  First 4 Entries

24 Grenzebach Glier & Associates, Inc. Peeking into the Future: Analog and FFT Code implemented… but there is still very much to be done. Primary focus has been preparing LED sequence as outlined from PDR. Goal: Wrap up Note Framework so songs can be implemented in parallel with scoring and teaching implementation.

25 Grenzebach Glier & Associates, Inc. Optical Fibers Problem:  Fiber optics are very dim. Light does not reflect very well because it escapes at the end. Solution:  Attach aluminum foil at ends of the fiber optic to create a mirror like reflection of the light.  Create narrow tubing to direct the light from the LED directly to the Fiber optic

26 Grenzebach Glier & Associates, Inc. Electroluminescent Wires Alternative Solution:  Electroluminescent wires (EL wires) Problem:  The PIC32 outputs a 3V DC and the EL wire requires 120V AC input. Solution: Build a driver (power inverter)

27 Grenzebach Glier & Associates, Inc. EL Wires

28 Grenzebach Glier & Associates, Inc. Pros and Cons Fiber Optics: Pros:  Transparent  thin  Flexible  No added capacitance to system Cons:  Light dims as the fiber length increases  Too dim when lit with LED  An illuminator would be costly Electroluminescent Wires: Pros:  Flexible  Thin  No added capacitance to system  Continuously Bright Cons:  Hard to cut  Requires 120V AC input, but PIC32 outputs 3V DC  Driver needs to be built

29 Grenzebach Glier & Associates, Inc. Visual Interface Alternative: Driver Circuitry 12VDC to 120VAC inverter3VDC to 12 VDC converter

30 Grenzebach Glier & Associates, Inc. Cost Analysis: PARTSQUANTITYCOSTTOTAL BC N mH mH uH Fiber Optics10 feet2.727 Glowing wires10 feet2.727 Microcontroller (PIC 32)140 TOTAL COST (without shipping)112.61

31 Grenzebach Glier & Associates, Inc. Summary of Progress ● Working circuitry for Volume Control ● Working circuitry for Pitch Control ● Working LEDS and optical fiber connections to connect PIC32 ● Working code and circuitry to play song using PIC32 ● Working on switching to Electroluminescent wires (glowing wires).

32 Grenzebach Glier & Associates, Inc. How challenges from PDR have been Met  Solutions to previous problems Working volume and pitch circuitry PIC32 can play a song in correspondence with LEDs  Problems that have arisen Fiber optics are too dim to distinguish in daylight Snowstorm delayed many parts

33 Grenzebach Glier & Associates, Inc. Current Challenges  Limitations of breadboards  Optical Fibers alternative  Integrating separate modules of the theremin

34 Grenzebach Glier & Associates, Inc. Revised Timeline Compare to PDR

35 Grenzebach Glier & Associates, Inc. Update on final version for SDP Day

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

37 Grenzebach Glier & Associates, Inc. Parts List PartPROPVOVVCVRC and VCAMixerTotal.001uF uF uF uF uF uF uF pF pF pF pF pF pf mH mH uH k pot k k k k k k k M M M BC Diode N

38 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”..

39 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

40 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.

41 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.

42 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

43 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