Theremillusion

1. ImenBen Neticha SnigdhaJonna Sandra Jenkins Steven Bennett Advisor: Professor Siqueira Theremillusion

2. Team Members ImenBen Neticha EE Steven Bennett CSE SnigdhaJonna EE Sandra Jenkins EE

3. Responsibilities • Sandra Jenkins • Pitch Variable Oscillator • Pitch Reference Oscillator • Mixer • SnigdhaJonna • 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. 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. 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. System Block Diagram

7. 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. Volume Variable Oscillator

9. 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. 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. Fixed Pitch Oscillator

12. Fixed Pitch Oscillator

13. Variable Pitch Oscillator

14. Variable Pitch Oscillator

15. Mixer for Pitch Oscillators

16. DEMO

17. Software:What’s Been Going on • A Lot of Software Engineering: • The Project is growing!

18. 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. 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. USB Demo • Two scripts prepared to transmit control characters to board through PC Com Ports.

21. Demo

22. “Canon in D” • Original Theremin music is hard to find! • Peter Pringle’s rendition of Pachelbel’s “Canon”.

23. Musical Notes • Note to I/O Database • First 4 Entries

24. 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. 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. 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. EL Wires

28. Pros and Cons 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 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

29. Visual Interface Alternative: Driver Circuitry • 3VDC to 12 VDC converter • 12VDC to 120VAC inverter

30. Cost Analysis:

31. 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. 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. Current Challenges • Limitations of breadboards • Optical Fibers alternative • Integrating separate modules of the theremin

34. Revised Timeline Compare to PDR

35. Update on final version for SDP Day

36. END • Thank You!!!

37. Parts List

38. 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 1998. • Way, BengKoay; Douglas Beard, Micah Caudle, and Jeffrey Jun-Fey Wong. Theremin. Department of Electrical and Computer Engineering at Mississippi State University. <http://www.ece.msstate.edu/courses/ece4522/projects/2001_spring/theremin/>. • Holloway, Barry. Theremin. Strange Apparatus. 2009-2011. <http://www.strangeapparatus.com/Theremin.html>. • Sparkfun Electronics. “USB 32-bit Whacker – PIC32MX795 Development Board”.<http://www.sparkfun.com/products/9713>.

39. 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 email about finding theremin player

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

43. FFT Complexity TABLE 1: Representative FFT Operation Counts