Blinkies: Open Source Sound-to-Light Conversion Sensors for Large-Scale Acoustic Sensing and Applications

Abstract

We propose an open source hardware platform called Blinky, a sound-to-light conversion sensor that harvests sound power at low-rate and conveniently. Blinkies are made up of a central processing unit connected to two microphones and a few light-emitting devices, are powered by a battery, and protected by a robust enclosure. Distributed in space and combined with a conventional video camera, they allow to practically sense sound power over a very large area without hassle. We give a comprehensive overview of the proposed system and its potential applications. We describe the hardware design and trade-offs made. We provide a model for the channel between sound power measurements and signal acquired by the video camera. Because each sensor is potentially affected by a different attenuation due to the channel, we propose a calibration procedure to restore the scale of the measurements. The effectiveness of the calibration is validated in an experiment. Finally, we demonstrate sound source localization using a hundred-and-one actual Blinkies in highly reverberent environment.INDEX TERMS Blinkies, acoustic power sensors, distributed sensing, sound source localization, soundto-light conversion.