Implementation Of A Joint Power Harvesting And Communication Technology On A Smartphone'S 3.5mm Audio Interface

With the popularization of smartphones, various smartphone-centric applications have emerged, which use a smartphone in conjunction with microcontrollers and sensors for data acquisition, processing, display, communication, and storage. Because smartphones do not have a universal data interface, many applications use the 3.5mm audio interface for data communications so that they can work with various types of smartphones, but the problem on the power supply is unsolved. In this paper, we have combined the Frequency Shift Keying (FSK) modulation scheme with Audio Track Streaming mode into an app to establish joint data and power transmission on both left and right audio channels so that the smartphone can provide up to 36.3mW power and 1.6kbps data rate to the microcontroller. Furthermore, we have implemented digital data filter, power detector, timingerror detector/corrector and differential Manchester coder and decoder in the same app and achieved up to 7.35kbps data rate from the microcontroller to the smartphone.