Week 5 Progress

Design Adjustments

• Will have acrylic and 3D printed pieces
• Use of laser cutter to obtain piece to mount potentiometer
• Camcorder-like strap on outside, for easier grip
• Drafted possible configurations of inner parts
• 9V battery
• Potentiometer and pull-string reel
• Spit Valve
• Outer shell will have buttons/touch sensors to allow for variation in sound
• Vibrato
• Portamento
• Timbre cycle button
• On/Off switch

Troubleshooting Microphone

• Responds to breath/blowing into sensor
• Unexpected movements create wind, also noticed by sensor
• Design of wind sensor housing may be critical for producing a usable signal on the microphone.
• Switching to an adjustable-gain microphone board may solve sensitivity
• Testing Arduino output with iPhone earbuds
• Changes pitch; plays a chromatic scale
• Adjustment of programming for a smoother sound
• Code to specifically output a major scale

Testing the wind sensor software

Wind Sensor with 3d-printed housing

Printing the reel on the MakerBot Replicator II

Prototype reel assembly.  The released spring force broke the internal end stops of the potentiometer during testing.
This pointed out the need for some sturdy plastic end stops on the 3D-printed reel.  These will engage with the spring fixing screw and prevent potentiometer damage.

Using CAD to arrange major components of the DUBone helps to determine the shape of the case design

Week 4 Progress

Pull-string controller

• Keeping the instrument as aesthetically close to a trombone as possible
• Designing a spring-loaded reel to be fitted onto a potentiometer

1. Approximate 2 octave range
2. Will unwind like a spool; spring attached to potentiometer
3. Difference in voltage -> indicates pitch of note output

AutoCAD sketch of inner reel

Week 3 Progress

Mouthpiece

Comprised of: microphone, interchangeable mouthpieces

• Electret-condensor microphone with integrated amplifier
• Interchangeable mouthpieces, similar to hookah tips
• Produces an output proportional to intensity with which player blows into instrument 
• Necessary to implement a drain/"spit valve" to remove moisture from inside

Pencil sketch of wind sensor housing cross section, with Sparkfun condenser microphone breakout board.  The board features a built in microphone amplifier.
(Click to enlarge picture)

AutoCAD sketch of wind sensor housing.  This holds the mouthpiece and microphone board as well as providing mounting holes to the final assembly of the instrument.
(Click to enlarge picture)

Week 2 Progress

Disassembling competitive product

Taking apart Casio DH100 to understand and analyze design:

• Electronic saxophone, midi controlled
• Uses microphone element as wind sensor
• Necessary spit valve

Work on internal hardware setup

• 9V battery to power Arduino
• Sliding pitch sensor: combination of a spring, reel, and potentiometer
• Degree of pull -> winds spring, potentiometer -> reading of pitch
• Plan on approx. 1 - 1.5 octave (range of 13-20 semitones)

Image is early sketch of spring-reel potentiometer prototype, featuring 3D printed spring.

Necessary research into competitive products

Goals of DUBone:

• A compact instrument, 10cm in width
• First of trombone type toy, not a general wind instrument
• A toy aimed at children, not adult professionals
• Generates its own sound

Competitive Product Analysis

Comparison of Similar Existing Products

Akai EWI series

 

• Manufactured by Akai Professional. 
• Series of wind controllers aimed at professional or home musicians, likely adults.
• Resembles a flute or recorder, with a breath-sensing mouthpiece at one end and flute-like keys used to change the pitch.
• Functionality ranges from being a simple USB controller (requiring an external computer to perform the synthesis) to fully synthesized, high quality sounds built into the instrument on the higher-end models. 
• Has wireless connectivity for onstage use; no built-in loudspeaker on any EWI model.
• Price ranges from $300-$800 retail depending on the model.

Like the DUbone, it incorporates a wind controller, but the key (pitch control) system is much more complicated and less intuitive than our trombone-like continuous controller design. 

Yamaha WX5

 

• Manufactured by Yamaha.
• Marketed at adult musicians and professionals.  
• USB wind controller, remarkably similar to the Akai EWI USB model in both form and function.
• Shaped like a traditional wind instrument with a more classical design aesthetic than the Akai.
• Controller that performs no synthesis.
• Price is around $700 retail. 

Note that we were unable to find a wind-sensing instrument currently being marketed to children, like we are intending for the DUbone.

Otamatone

• Manufactured by Otamatone. 
• Simple audio frequency oscillator controlled by a resistive ribbon. Player slides their finger along the ribbon to control the pitch.
• Produces a harmonic-rich tone from a small speaker.
• Speaker enclosed in a deformable acoustically resonant chamber, which can be squeezed and manipulated to change the tone of the sound produced.
• Whimsically shaped like a musical eighth note, with a “face” on the dot of the note, its “mouth” forming the resonant cavity for the speaker.
• Controls provided for volume and pitch range selection.
• Cost $40, directly from the manufacturer.

While it is not a wind controller like the DUbone, this toy is designed to appeal to children and places simplicity and ease of use over professional features.  Unlike the aforementioned professional instruments, the Otamatone and DUbone designs both run on batteries and feature built-in loudspeakers to allow children to make noises without external hardware or power connections.

Project Overview

The Digital Trombone Project aims to create an electronic musical instrument comprised of several subsystems, modeled around the functionality and design of a trombone. The major components of the proposed design are:

• Wind sensor mouthpiece, to control output sound levels
• Sliding pitch control
• Touch sensors, for instantaneous tone changes
• Push-buttons, for changing octaves

All of the sensors will be connected to an Arduino, which will synthesize and produce an audio output, either to a small speaker or to a headphone jack. The goal of this venture is to create and combine these various pieces into an attractive and ergonomic musical toy.