The FireFader: Simple, Open-Source, and Reconfigurable Haptic Force Feedback for Musicians

Abstract

The FireFader is a simple haptic force-feedback device that is optimized for introducing musicians to haptics. It is based upon a single-degree-of-freedom potentiometer fader coupled to a DC motor, also known as a "motorized fader." A light is connected in parallel with the motor to help communicate the force's strength visually. The FireFader consists of only open-source hardware and open-source software elements. Consequently, it is relatively easy for users to repurpose it into new projects involving varying kinds and numbers of motors and sensors.

An open-source device driver for the FireFader allows it to be linked to a computer via USB so that the computer can perform the feedback control calculations. For example, the computer can simulate the acoustics of a virtual musical instrument to concurrently synthesize sound and calculate the motor force as a function of the fader position. The serial connection over USB increases the latency of the control signal compared to embedded implementations, but the serial connection facilitates easier programming via the computer, and the force feedback can be automatically disabled when the user is not touching the fader. Some new devices derived from the FireFader design are presented.