The Elektrotone incorporates active learning with a topic many students already hold interest in: music.  The product allows students to explore basic concepts of hardware, software, and variable relationships though an Arduino circuit that mimics the properties of a musical instrument.  Songs can be created with notes of different frequencies, length, and rest periods.  By integrating technology within a musical platform, a greater number of students have potential to become engaged and interested in STEM fields.


Research and Background Information

There exists a need in the US to promote STEM education.  The following statistics highlight the importance of taking action to reach out to students to resolve this growing problem (Knutila). It is predicted that there will be a 17% growth in the demand for STEM jobs that the current system will not support.  In particular, US universities are expected to produce qualified graduates to fill only 29% of the 1.4 million estimated computer specialist job openings.  In addition to the void to fill demand for necessary jobs, women are extremely underrepresented in STEM jobs.  While 74% of girls express interest in STEM courses during middle school, only 0.4% of girls choose computer science as a college major.  This underrepresentation has experience no growth between 2001 and 2014 with an engineering workforce of only a 13% female population.

In the past few years, a significant number of STEM initiatives have been developed ranging from interactive classroom learning modules for teachers to implement, school wide programs, and interactive gadgets that parents can purchase.  Evidence on the effectiveness of such programs highlights the benefits of active engagement.  Although all programs have unique approaches, studies have shown that the hands-on learning aspect they have in common results in better learning outcomes as well as retention of interest (Handelsman & Smith, 2016).


Initial Prototype Development

The original design used a flex sensor which provided the Arduino with an input which was then mapped to a scale corresponding to common musical frequencies. The Arduino then output the frequency through a speaker resulting in a single tone which could be manipulated by bending the flex sensor.



Initial User Testing

Troy Middle School

The first user testing took place at Troy Middle School with an 8th grade honors science class. The students seemed to have a positive response to the device though many seemed hesitant at first. After seeing us use the device, they became more confident and started to interact freely with the sensor. We believed the initial hesitation may have been caused by the fear of breaking the sensor or ruining the circuit. For the most part, the students were eager to learn about how the circuit functioned and how the code could be altered to change the noise produced by the speaker.

We passed around slips of paper and asked the students to write down any ideas they had involving the project. Many students suggested integrating more than one flex sensor so multiple people could use it at once. They also compared the notes to music they often hear in video games such as Super Mario Bros.



Troy Boys and Girls Club – Visit #1

After the first visit to Troy Middle School, it was decided that the design was to be perfected as part of our final project. The first change that was made was the addition of a pushbutton, allowing us to program the arduino to only play the sound when the button was pressed. This added an element of rhythm and challenge as the sound coming from the ElektroTone was now controlled by the user as opposed to just being on constantly. The arduino was also programmed in a way that if the button is held down for more than 0.5 seconds at a time, there is an automatic (very short) rest before the sound comes back on. This allows for a standard 120 beat per minute beat, making it easier to learn how to play a tune.

In addition, a second circuit was built and hard wired to allow us to test the prototype with larger groups.

With these changes made we set out to the Troy Boys and Girls club to present our prototype to the children in the “Tech Club”. Our aim was to get an idea for how this group of target users interacted with our new prototype. This group of 13 children also had a substantially more varied demographic compared to the honors class from Troy Middle School: there were substantial differences in age ranging from 8 to 12 years and clearly more ethnic diversity.

Once we were set up we called in the children and briefly explained what the ElektroTone does and how it works. We immediately noticed that many of them were very eager to play with our device despite just having come from playing with legos. However we were also challenged because many of them got distracted very quickly because we only had two prototypes, so they started playing bottle-flip with each other and being loud. Admittedly we were not prepared for this and also did not feel that we were in enough of a position of authority to tell them what to do.

Although these circumstances were inconvenient, we persisted working with the students that were engaging with our product and closely observed them. The main thing we noticed was that these children were not at all afraid of breaking anything compared to the first group – they went in pushing and flexing without a doubt in their minds.

This led to another interesting observation because one of the children ended up accidentally pulling out the pressure sensor from one of the boards. This gave us the opportunity to fix the circuit right in front of the children and see how they experienced this. Interestingly enough, the kids seemed just as interested by this as they were by the ElektroTone itself. This was a pleasant surprize to us because we realized that they were genuinely interested in the subject matter beyond just playing. Furthermore we got to teach them the basic workings of electronics such as the layout of a protoboard, giving us ideas as to how to incorporate the product into an actual lesson plan.


Final Protoype Fabrication

Our final product actually consisted of two different versions, which were used to help gauge whether or not the kids would gravitate toward a more complicated technological solution or an almost overly simplistic version with a completely different aesthetic. In the technologically complicated looking version of the product, the full Arduino setup was exposed – wires and all – as a way to show our test users the bare bones internals of our concept. This was meant to be a very direct representation of the complexity of the circuits and a demonstration of what the Elektrotone looks like under the hood. This showed the circuit off in a way that exposed everything that a user would normally never see, but still allowed for ideal functionality and proper use.

Our second version of the final product was the same exact circuit, but enclosed in a relatively plain wooden model. The flex sensor, button, and LEDs were exposed on the top surface of the box while the speaker was mounted on the side of the box. All sides of the box were hand cut from basswood and hot-glued together for a simple, yet strong and sturdy structure that perfectly enclosed the internal components and hid them from sight. The purpose of this box was originally to be an aesthetically pleasing, attractive box that would interest and intrigue the children. Just before construction, however, our team decided that the best and most effective way to compare our two ideas was actually to create more of a plain and aesthetically unimpressive box as a stark contrast to our cool, technology centric exposed model. This way, we were able to test whether or not the children were more interested in the circuitry and inner workings of the complex-looking model or if they were just interested in the sensor, button, and LEDs that they could play with in the neat, but slightly boring model.



Final User Testing

Troy Boys and Girls Club – Visit #2

For our second visit we decided to test the following hypotheses:

  1. Students will feel more comfortable experimenting with the device if the components are presented in an intuitive way
  2. Increasing the functionality to more closely resemble an instrument will result in students becoming more interested and engaged with the the device
  3. With increased engagement and an interactive lesson, students will feel more comfortable with the technology platform of electronics

To test the first hypothesis, the circuit was integrated into a wooden box in order to make it more visually appealing, giving it the feel of an instrument rather than just a circuit. Furthermore, integrating the product allowed the critical components (sensor, pushbutton and LEDs) to be presented in a more intuitive way.

Furthermore, LEDs were added to the circuit. These were mapped to the sound output such that more LEDs come on as the pitch increases, giving the user a useful visual reference like the keys on a piano. Furthermore this renders the product more accessible for children with hearing difficulties, who would otherwise not be able to interact with the device.

In presenting this second prototype, we were fortunate to have a smaller group of only three children. They were between the ages of 7 and 9.

In this second trial we prepared our devices before the children came in and then observed what device they gravitated towards. It quickly became obvious that the children were equally interested by both devices, regardless of whether it was integrated or not. In fact they were almost more intrigued by the “open” design of the previous iteration as one of them intently looked at the wires and traced them from the Arduino chip to the protoboard. We therefore concluded that hypothesis 1 was false. Presenting the components in an intuitive way had no effect on their level of comfort.

In this second trial we also noticed that the children were overall more engaged with the device. This could in part be the fact that there were less students than in the visit and therefore less distractions, however we noticed that they really started experimenting once we prompted them with questions. We had prepared a poster outlining the basic process of what was going on in the circuit: the concept of sense => think => output and how the sensor is mapped to the output.

We asked prompting questions like “can you figure out what happens with the LEDs (we referred to them as “lights”) as you change the sound? What happens to the sound when you press harder? This got them to really test the device. Our test of the final hypothesis that “with increased engagement and an interactive lesson, students will feel more comfortable with the technology platform of electronics” was a conclusive “yes”

In testing hypothesis 2 however, it seemed that making the ElektroTone more like an instrument did not have any effect on their engagement. In the short time period we had available it would simply be unrealistic to claim that we made the students more engaged. In this respect it is also important to note that the children we were testing our product with were simply too young to get a sufficient grasp of what was going. Furthermore, their age made it extremely difficult for us to direct them and keep them focused on task. This is understandable as a child of this age would rather play with Legos than learn about electronic circuits when given the choice.

Thus despite our efforts to make the device more user friendly particularly to younger students by laying out its functionality like a musical instrument, we cannot claim that this had any effect on this user group’s engagement with the device.



“Demo or Die” Day

During one of the last days of the semester, a final presentation and working prototype was shared with the class and feedback was given to each group.



Final Concept

Elektrotone is now a device that helps students map relationships between two variables while exposing them to the basic concept of how circuits, microprocessors, and code work together in order to accomplish a task. Elektrotone uses music in order to engage students and encourages them to freely interact with the device while providing them with an example of how various electrical components can be combined in order to create something that is fun and easy to use. By incorporating music into their learning, the students are also able to be creative and further explore the relationships they discover by creating their own musical pieces. The LED bar provides a visual feedback in order to help the students better control the pitch while the button allows for more control over the length of the note. All the components are combined in a clear housing which allows the students to see the inner workings of the device in hopes that it makes the components seem more familiar and therefore less intimidating to study and experiment with in the future.



Check out our Flex Sensor and Pressure Sensor codes!



Lesson Plan

  1. Introduce the device to the children, give them a maximum of 5 minutes to play with it and see what it does.
  2. Ask them what they noticed.
  3. Ask prompting questions and allow them to experiment to find the answer:
    • What is the relationship between bend angle and the pitch of the sound?
    • What happens to the LEDs as the pitch of the sound changes?
  4. Explain the concept of sense => think => output (relate it to everyday occurrences like responding to a question: hearing the question, thinking, saying the response)
  5. Ask more challenging questions, hear answers and explain:
    • How do you think the flex sensor works? (explain the concept of a kinked hose. The more you kink it, the less water flows. The more you bend the flex sensor, the less electricity flows)
    • How does the computer think? How does it know what pitch to output (introduce the concept of a linear map)
    • How does the computer communicate with the sensor and the speaker? (explain that wires allow the electricity to carry information from place to place)

Example Lesson Poster


Final Working Prototype – Enclosed























This project was created for PDI V by Erin Burke, Scott Marcella, Jan Schnewlin, Elena Steffan, and Michaela Yamashita under the direction of Dr. Ron Eglash.


Handelsman, J., & Smith, M. (2016, February 11). The White House. Retrieved December 1, 2016, from STEM for All: https://www.whitehouse.gov/blog/2016/02/11/stem-all
Knutila, J. (n.d.). TechRocket. Retrieved November 23, 2016, from The State of STEM Education: http://blog.techrocket.com/2016/03/15/the-state-of-stem-education-in-10-statistics/