Syntacts: Open-Source Software and Hardware for Audio-Controlled Haptics

As vibrotactile feedback systems become increasingly commonplace, their application scenarios are becoming more complex. In this article, we present a method of vibrotactor control that accommodates emerging design requirements, namely large vibrotactor arrays that are capable of displaying complex waveforms. Our approach is based on control through digital audio interfaces. We describe a new open-source software and hardware package, Syntacts, that lowers the technical barrier to rendering vibrations with audio. We also present a tutorial on common control schemes with a discussion of their advantages and shortcomings. Our software is purpose-built to control arrays of vibrotactors with extremely low latency. In addition, Syntacts includes means to synthesize and sequence cues, and spatialize them on tactile arrays. The Syntacts Amplifier integrates with the audio hardware to provide high-quality analog signals to the tactors without adding excess noise to the system. Finally, we present results from a benchmarking study with Syntacts compared to commercially available systems.