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A huge barrier of entry for people in the field of music is the idea of cost. The purchase of a musical instrument is often a significant investment, with even low-quality instruments costing up to hundreds of dollars. This leads to a large portion of underprivileged people being unable to experience fields of music by way of cost barriers. Even when not underprivileged, the uncertainty of commitment leads to users often deciding not to engage in learning an instrument due to the risk of significant wasted funds in the event that they do not enjoy the experience.

Part of the barrier for scalability also involves the portability of instruments; with instruments being often heavy and unwieldy, people often have to go to the locations of instruments in order to access and practice with them. That aside, transporting significant numbers of instruments for the sake of educating youths also poses significant logistical concerns, due to the value, size, and fragility of equipment being transported.

What it does

Our developed product has a total component cost of $5 - with the most expensive components, an Arduino and a USB OTG adapter, costing $3 and $2 respectively. All other instruments are made out of cardboard, paper, and inexpensive jumper wires, allowing for huge potential in scalability. As our product has dimensions identical to those of existing instruments, users can experience playing the ukulele, piano, or recorder with virtually no investment, and completely reusable and scavenge-able parts.

Electrical signals are gathered through capacitative touch and forwarded to a smart phone, where our application converts the received signals to polyphonic audio signals depending on the instrument being used. Every single part is configured to fit within an A4, folder, allowing the product to be easily transported, and giving it its name, "Sheet Music".

How we built it

The entire product is built of recyclable materials - cardboard, paper, an Arduino, and electrical wires. Capacitative touch was built by forming a capacitor between a small sheet of aluminum foil and a wire; when touched, the electrically conductive hand would drain the charge of the capacitor, functioning as a signal. This reliable yet inexpensive means allowed us to generate useful si

Challenges we ran into

Minimizing the latency is a critical element, as an off-latency musical instrument is very off-putting to users (from feedback). As a result, the process of optimizing the signal transmission from the Arduino to a processing platform was very difficult - with the requirement of polyphony, a simple Arduino MP3 shield was inadequate. We experimented on numerous means, from Serial to WiFi (TLS) to finally a socket server hosted on react-native.

Management of the wiring was also an issue, given the significant amount of wiring involved (20 I/Os per instrument). No surprises that we spent half of the night soldering, tweaking, and re-organizing our wires. However, this is only a problem for our prototype - when PCBed, manufacturing costs will drop significantly due to scale, making the product more reliable as well.

Accomplishments that we're proud of

We managed to pull off the development all three of our original proposed instruments, with very well organized circuitry and clean functionality. As a proof of concept, our own investment into the project was negligible - all our components were and can be recycled.

What we learned

The nature of serial communications and the importance of asynchronous data processing via threading was a key learning point - without research into this, our audio output would have been very disjointed.

The versatility of capacitive touch as a means of input was also very surprising - it gave an analog signal, and could be manufactured with a simple resistor and aluminium foil.

What's next for EV - Sheet Music

Further streamlining of the design and organizing the circuitry into a PCB, and designing a custom board rather than using the Arduino's ATMega will allow us to cut costs even further, potentially offering a $1 product that has the functionality of multiple customizable instruments.

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