Microcontroller based handheld acoustic communication & power delivery through metallic barriers

Abstract

Acoustic communication solutions to this problem have been explored over the past 15 years but have not been widely deployed. The goal of this work was to develop a hand-held, battery operated system that is capable of wirelessly powering and communicating with electronics through a curved metallic barrier. Three systems were implemented using Digital Signal Processors (DSPs), Microcontroller Units (MCUs),or a combination of the two. An electronic system was developed on one side of the metallic barrier to excite vibrations at 1.25 MHz in a piezoelectric transducer attached to the barrier. Data was transmitted through the wall in both directions in half-duplex mode by amplitude modulating this carrier signal with Manchester encoded data. Energy from the carrier wave was harvested on the other side of the wall to power electronic systems.

The ability to reliably transmit data through metallic barriers without intrusive procedures like hole drilling is useful, and sometimes necessary, for the safety of personal and equipment in hazardous conditions. Examples include submarine hulls, space vehicles, and nuclear reactors. Traditional means of communication via conductive wires compromise the integrity of the metal vessels while traditional wireless communications solutions like WiFi are limited by Faraday shielding imposed by metallic barriers.

Successful acoustic communication at 10 kbps between MCUs separated by a metallic barrier was achieved, where one system was powered completely by the acoustic signal applied through the barrier.