Abstract:

The FireFader is a simple haptic force-feedback device that is optimized for introducing musician to haptics. It has a single degree of freedom and is based upon a mass-produced linear potentiometer fader coupled to a DC motor, also known as a "motorized fader." Lights are connected in parallel with the motor to help visually communicate the strength of the force. Compatibile with OS X, Linux, and Windows, the FireFader consists of only open-source hardware and software elements. Consequently, it is also 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 laptop via USB, so that the computer can perform the feedback control calculations. For example, the laptop can simulate the acoustics of a virtual musical instrument to calculate the motor force as a function of the fader position. The serial interface over USB causes delay of the control signal, but it facilitates easy programming and less expensive control nevertheless using floating-point computation. Some new devices derived from the FireFader design are presented.