Digital Theremin Design Plan
A Project Summary
MeeraPetroff
Electrical and Computer Engineering
Oregon State University
Corvallis, OR
Ernie Bodle
Electrical and Computer Engineering
Oregon State University
Corvallis, OR
Tristan Massey
Electrical and Computer Engineering
Oregon State University
Corvallis, OR
Abstract— The purpose of this document is summarize the plans for the digital theremin project and help the stakeholders and other readers understand how and why we are executing this project. First the overall aim of the project is explained. Next the ‘Project Need and Solution’ describe the digital theremin’s ultimate purpose. Throughout this document, different technologies are defined that will be used in the implementation of the project. Next the goals of the digital theremin are clearly defined. A thorough risk assessment is written in order to alert the reader to potential project setbacks. Finally a timeline is listed in order to provide a chronological guide for the reader.
Keywords— PCB - Printed Circuit Board, microcontroller - a low level computer, digital - a device that uses 1s and 0s to operate, high frequency signal - a signal that outputs at a high rate, IDE - Integrated Development Environment is a application that helps the user develop programs, I/O - input and output are the connection ports for hardware that interact with the microcontroller,
I.Introduction
A theremin is an electronic musical instrument in which the tone is generated by two high-frequency oscillators and the pitch is controlled by the movement of the performer's hand toward and away from the circuit. The aim of this project is to modernize the system, controls, and features of the theremin.
Outlining the project need is important for giving purpose and meaning to the work we will do.
II.Project Need and Solution
The theremin could be a useful and successful instrument for a modern-day musician if it had more features and was able to be used in more creative ways. The format of the instrument is natural and intuitive, requiring only the placement of one’s hands to generate sound. However, the instrument, being almost a century old, is outdated and no longer popular. This could be changed with an overhaul to the instrument, reviving it to a usable state in today’s music.
This project is aimed at the modernization of this classic instrument, adding features such as selectable sound effects, changeable parameters, or mp3 playback with controllable effects. With these features, electronic musicians could utilize the instrument to create a plethora of sounds or songs.
Proposing technologies will give us a framework of devices and will help our stakeholder align their needs with ours.
III.Proposed Technologies
We must interface several technologies together to achieve the best digital theremin within our design capabilities. Some options for technologies are listed below.
A.Arduino
Basing our design on an Arduino board will allow us to have increased access to I/O versus using solely a microcontroller. Additionally having the Arduino based IDE will provide further flexibility with C programming for the features on the project.
B.IR Proximity Sensor
An IR proximity sensor will in effect replace the traditional theremin’s antennae. The IR proximity sensor will parameterize the distance sensed and various frequencies will be assigned to the respective parameters.
C.Filters, Amplifiers, Distorters
Filters will be used to clean up the signals through the system. Amplifiers will be used to increase signals at necessary points. Distorters will be used to create unique and interesting sounds from the theremin.
D.DACs (Digital to Analog Converters) and ADCs (Analog to Digital Converters)
Digital to Analog converters will be important between the infrared proximity sensor and the Arduino. Analog to digital converters will be important between the Arduino and the speakers.
Referencing other theremin designs can help us understand how to better build ours.
IV.Additional Considerations
While the modern theremin market is quite small, there are some still sold today. For example, the Moog Theremini is a digitally based theremin that uses electromagnetic field antennae for the classic theremin look [6]. Our design, however, will not include the antennae which will make the instrument more streamline and portable.
Understanding our past experiences and knowledge will give us insight on the skills we will need for this project.
V.Fundamental Aspects
Our combined experience includes the design and implementation of a power supply and an audio amplifier. The audio amplifier design experience benefits us because we understand audio signals and how to manipulate them through circuit design. This gives us confidence in our ability to design an audio amplifier PCB for the project. We also have programming experience through various computer science courses. Our proficiency with multiple programming languages will allow us to create functionality for several aspects of the theremin.
It’s important to list goals to keep us on track for the remainder of the project, the key project goals are outlined below.
VI.Key Project Goals
●Create a sellable and useful product. The most important aspect to the project is finishing with something that musicians will want to purchase for their own use.
●Modernize the theremin. Achieving this goal will help us achieve the first goal. The theremin is a classic instrument that many musicians know and appreciate, but it just doesn’t have enough variety and functionality to be useful for music creation today. Adding these characteristics will intrigue modern musicians.
●Innovate new and unique ideas into the instrument. The instrument must stand out to compete in a competitive market, and this will be achieved by adding useful features that make the instrument shine. These features will need to be tested for viability before their implementation, but current ideas include mp3 playback and modulation, selectable sound effects, and perhaps recording capabilities for sound looping.
Next a summary of the people who hold a vested interest in the completion of the digital theremin is listed below.
VII.Meet the Stakeholders and Contributors
Jordan Valentine is our main stakeholder. She is reachable at . She supports this project as a proponent of musical literacy and education. Our other stakeholders include our manager Mckay Lindsay and our instructors, Dr. Rachael Cate and Donald Heer. They are all reachable at . The project members are Tristan Massey, , Ernie Bodle, , and MeeraPetroff, .
The next section outlines the risk assessment which helps us prepare for possible failures and have a back up plan.
VIII.Risk Assessment
●Power issues
○It is important to consider how much power we need per component and through the system as a whole. If not enough power is supplied, the system will not work. If too much power is supplied, parts can start breaking.
●Receiving broken components from vendors
○The build section of the project relies on receiving robust and working parts from vendors. If vendors send us broken parts, it could set us back in regards to time and money.
●Budget
○IR sensors, aesthetic design, microcontrollers, and various other aspects of the project will require funding to acquire. If too much money is spent on these things we may go over budget. This would set us back and we would need to find a way to finance the rest of our project
●Component compatibility
○If the IR sensors and central controller are incompatible, we may need to order different parts. This might also result in a redesign.
●Achieving clear and pleasant audio
○If we can’t determine a way to mix our audio signals well, it could result in frequencies that sound bad. Even if all the other requirements are met, bad sounding audio would render the digital theremin useless.
●Microcontroller unit lacking required memory
○If we choose a microcontroller with an inadequate memory size, it may not be able to handle all the functionality we hope to implement.
●Microcontroller unit not having enough speed
○If we choose a microcontroller with an inadequate clock speed, it may result in loss of sound quality.
The following timeline provides a chronological guide for all parties to track progress.
IX.Timeline
The timeline for the project’s creation is as follows.
●Design finished by end of fall term
○Top-level design finished by November 4th
○Sub-level design finished by December 2nd
●Prototype finished by end of winter term
○IR sensors communicating with microcontroller by January 13th
○Working audio circuit prototype by January 27th
○Generating audio by February 10th
○Controlling audio with IR sensors by February 24th
○Finished prototype in box by March 17th
●Finishing touches and preparation for Engineering Expo by Expo event
○Finish any nonworking parts
○Get PCB for audio circuit
○Clean up aesthetic design
○Add extra software features if time permits (mp3 playback, more sound effects, etc)
○Prepare for presentation
References
[1]"Arduino - Introduction". arduino.cc. October 6, 2016
[2]"How many Arduinos are "in the wild?" About 300,000". Adafruit Industries. May 15, 2011. Retrieved 2016-10-06.
[3]"Proximity sensor on Android smartphones". TheCodeArtist.
[4]Digital proximity sensor, October 6, 2016
[5]Lathi, B.P. (1998). Modern Digital and Analog Communication Systems (3rd edition). Oxford University Press.
[6]"Theremini | Moog Music Inc", Moogmusic.com, 2016. [Online]. Available: [Accessed: 07- Oct- 2016].
[7]."Using an IR Sensor | IR Sensor | Adafruit Learning System", Learn.adafruit.com, 2016. [Online]. Available: [Accessed: 07- Oct- 2016].