Names
Andrew, Peter, Adam, Matt

Group Number
12

What we built

We built a “magic wand,” similar to a conductor’s baton. We attached an accelerometer to the end of the wand to detect the downbeat, which triggered playing a note. We included our potentiometer prototype to allow the conductor to control what note will be played. We believe our project achieved a fair degree of success — it was intuitive enough that Adam was able to play “Twinkle Twinkle Little Star,” the “ABC’s”, and “Baa Baa Black Sheep”” with only three minutes of practice. Originally, our prototype played notes at a constant interval with no rests, so the introduction of the wand to control the timing of the notes was a large improvement. The wand interface worked well, and there’s little we would change about it. However, the potentiometer was difficult to use to control pitch, and sometimes resulted in the wrong note being played. This is the same for any musical instrument, but a better interface may have made it easier to play.

Prototype

1 — Simple Potentiometer. We built a simple circuit to assess how easily a potentiometer could be used to control pitch (and by extension, a flex sensor, a soft potentiometer, etc.) The arduino played a note of fixed duration at a fixed time interval

2 — Light Flute. We built a cardboard housing with three LEDs inside, and two slots insert cards into. When cards were inserted, they blocked the light, changing the amount of light that fell on the photosensor, which determined the pitch.

3 — Light Flute, version 2. We weren’t happy with having the notes be fixed duration. We included a flex sensor, where the amount of flex controls the duration of the note. We also added semi-transparent cards, to allow a broader array of notes to be played.

Video

You can see Adam playing “Twinkle Twinkle Little Star”. The downbeat of the wand controls when the note is played, and the position of the potentiometer controls the pitch.

Parts List

• Breadboard
• Wires
• Arduino
• Accelerometer
• Rotary Potentiometer
• Buzzer
• Cardboard
• Tape

Instructions

1. Roll cardboard into tube. Mount breadboard and accelerometer on end of wand. Make sure the wire is long enough to allow for a free range of motion. Connect accelerometer to arduino with wires. (see tutorial here, but plug Vin to 5V instead of A0) Reinforce with tape.
2. Attach buzzer to arduino (see tutorial here, connect to pin 8)
3. Attach potentiometer to arduino (see tutorial here, connect to A0)
4. Send below code to arduino

Code

(see code here)