a simple & small interaction for an expressive instrument


I want to create instruments that have a simple easy to use/difficult to master interface. My initial idea involved using subtractive synthesis in a MIDI aspect (more like subtractive composition), but I was struggling with the interaction itself. Amongst my iterations, there was one that really stood out: a slider on top of a rotating platform. This was what gave birth to arc.

A slider potentiometer on a rotating platform

The whole premise is having a slider on top of a potentiometer. The user can move the slider up and down, while rotating the whole piece to modify the value of a potentiometer underneath. Combining these elements, a series of note arrays, filters and effects are manipulated in unison.

Main element of the instrument


I started crafting the main part, the top slider element. I designed a wooden case with an acrylic cover to hold everything in place; and a hole underneath to hold the potentiometer. This would be mounted on top of a wooden base, that also holds other two knobs (volume and base pitch) plus a microUSB port (for power and software update) and a headphone jack.
Table with elements for setup

Assembled instrument with the circuit board

The software was designed for the Teensy Audio Adaptor Board with their Audio System Design Tool.

Teensy's Audio Libraryddiagram


Sadly, the instrument is still in a non-working phase. I ran into so many issues, such as hardware failure and micro-controller crashes. I will update this over the winter whenever there’s progress.

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