Overview

The project was to build a robotically actuated violin, playable by an external midi keyboard. It was for the project course APSC 459 and was sponsored by Bernhard Zender. The project was done in a group of three and was completed in the 8 months that the course ran for. The project consisted of four main components: the fingers on the neck of the violin, the bow mechanism near the bridge, the circuitry and the keyboard. The fingers operated by solenoids pulling strings that were attached to arms that were nominally held upward with elastic bands. When the solenoid was engaged the finger would press on the neck and when released the fingers would naturally return to their original position and the string would be free of contact. The bow mechanism was done using a circular wheel that was wound in horse hair to simulate a full length bow. The bow was rotated and caused the string to vibrate and emulated the sound a violin normally makes. The circuitry involved many quarter h-bridge circuits that turned on the motors and solenoids when a small voltage was applied to the gate of a MOSFET. The keyboard sent out MIDI signals that were translated into a serial signal and into a Wiring microcontroller board. The Wiring board then decided what the signal meant and turned on solenoids and motors to cause the violin neck to be pressed at a specific point and also to spin the circular bow on one of the strings. At the end of the project a large technical report was handed in.

Results

Converted MIDI signals to microcontroller signals

Controlled solenoids and motors via microcontroller

Gained experience in writing large technical reports

Emulated a few notes of the violin using our circular bow design and fingering mechanism

Project is used as a demo for students taking the course in future years