A Smartphone Compatible SONAR Ranging Attachment for 2-D Mapping

Abstract

The ability to attach external devices to smartphones has revolutionized the role of smartphones by extending their capabilities beyond the limitations of commodity hardware. Developing external attachments that allow smartphones to sense the depth of an area will facilitate the development of new immersive applications and technologies. In this paper, we propose a smartphone compatible SONAR ranging attachment and address the compatibility problem by proposing a hybrid hardware/software modulator that allows a digital sensor to communicate with a smartphone via the 3.5-mm headphone jack, found on most smartphones. We evaluate the proposed sensor using two metrics, accuracy and spatial resolution. We evaluate the accuracy of this system by measuring known distances with the sensor and comparing them. We measure the sensor’s spatial resolution by using ranging information from the SONAR module along with the phone’s gyroscope, accelerometer, and magnetometer to construct a two-dimensional map of a space.