Demo abstract: AudioDAQ: Turning the mobile phone's headset port into a universal data acquisition interface

Abstract

Smartphone peripherals like the Square card reader, Red-Eye mini, and HiJack platform suggest a growing interest in using the headset port for more than just headsets. How-ever, these peripherals only support sporadic activities in an efficient manner. Continuous sensing applications - like monitoring EKG signals - is possible but remains too inefficient for many realistic usage scenarios. We present Au-dioDAQ, a new sensor data acquisition platform. In contrast with prior work, AudioDAQ requires no hardware or software modifications on the phone, uses significantly less power, and allows continuous data capture over extended periods of time. The design is efficient because we draw all necessary power from the microphone bias voltage, and it is general because this voltage is present in every headset port. Data is modulated within the audible range, captured with the built-in voice recording app, and sent to a server for processing and storage. We show the viability of this approach by demonstrating an EKG monitor that can capture data continuously for hours.