Haptic-Feedback Violin Shoulder Rest

Publications: Pending

In collaboration with Dr. Byron Lahey

This is an augmented violin shoulder rest that uses two voice coils to transmit haptic feedback information to the body of the violinist. The project builds on recent trends in development of rich multimodal interfaces, motivated by an enactive theory of cognition in which embodied sensorimotor, action-perception feedback loops are understood to be generative of cognition. The haptic shoulder rest is used in tandem with custom hardware and software systems for augmented violin performance (Alto.glove and Transference). Digitally processed audio signals generated by the system are sent to the shoulder rest, haptically coupling it with the overall sonic dynamics of the system.


Awards: Semifinalist in the Guthman Musical Instrument Competition at Georgia Tech, March 2018.

Publications: Thorn, Seth, “Alto.glove: New Techniques for Augmented Violin." Proceedings of the 2018 Conference on New Interfaces for Musical Expression (NIME18), Virginia Tech. Full paper.

A sensor-embedded, WiFi-enabled data glove designed to extend the performance capabilities of violinists and violists. Uses flex sensors, force-sensitive resistors, haptic feedback, and advanced motion tracking.

Syncretic Brush

The Syncretic Brush embeds an accelerometer, gyroscope, magentometer, and haptic feedback motor controlled by a TI DRV2605L into a Simply Simmons XL Stiff Synthetic Round 50 brush. A Teensy LC board is used in MIDI mode to make the brush easily plugged and played in a wide variety of software. A haptic sequence occurs on startup, indicating that the brush is active. On MIDI channel 10, MIDI CC elements 10 thru 15 send accelerometer values at 8G range and gyroscopic values at 2000DPS; MIDI CC elements 20 thru 25 send more sensitive values (2G / 500DPS), while MIDI CC 30 is reserved for sending haptic feedback codes to the brush.

Special thanks to the very talented Shahab Sagheb, who completed machining aspects of this project, including cutting the brush, hollowing the center, drilling a hole down the center of the brush, and creating custom laster-cut rigs for doing these tasks with great precision.

Granular | Neopixel Ring | WiFi

Visualization of sonic grains with Neopixel ring; source material Altos Transferre (processed and composed viola recordings).


Palimpsest is based on a Hex Schmitt Trigger. The open housing is laser-cut MDF with pressure-inserted columns. Features current "starving," capacitor "drain" switch, an opto-isolation strobe, and diode mixing.


Polyrhythmic synthesizer utilizing CD40106, CD4040, CD4093, and CD4017. Diode mixing option, polyrhythmic clock input to step sequencer, opto-isolator gated quadrophonic output, and two external modulation inputs.

Beat Extractor

Beat extractor, distortion box, and visualizer. Uses a CD4049 inverter responsive to audio input, creating a pulse wave counted by a CD4040 binary divider. Rotary switches allow selection of divider outputs. Output from the CD4040 also reaches a CD4046 phase-locked loop that attempts to track the pitch of the signal. Three external modulation outputs. Excellent for gating/crushing drum and bass lines, and for visualization of audio signals.

Cigar Box Instruments

These instruments are built into the Darice 8.375" x 8.125" x 1.75" craft box. The surface is thin enough to allow pots and toggles to be screwed in, but sturdy enough for strong hand pressure and performance. I recommend this enclosure to the students in my hardware courses. The two instruments displayed here are a matrix mixer and a touch-sensitive sequencer with breakout pins for an external resistor matrix.

Hacked Toys

Circuit-bent "groovy tunes" with substituted clock resistor, circuit-bent toy guitar, spring monoverb built from a toy "echo" microphone and an old radio enclosure, and a hacked resistor matrix used to control the clock rate of a homemade sequencer.