Wireless Liquid Level Sensing for Restaurant Applications

Since restaurants often make much of their profits on drinks, it is critical for servers to offer refills in a timely fashion. We propose wireless liquid level sensing glassware to aid in this task. Specially instrumented glassware detects fluid levels via a high-resolution capacitance measurement. A coil embedded in the table inductively couples power to the glasses, and provides a path for data exchange. Our prototype glass uses a standard microprocessor and a small number of passive components, making it extremely inexpensive. A version of this paper was submitted to IEEE Sensors 2002. This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Information Technology Center America; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Information Technology Center America. All rights reserved. Copyright c ©Mitsubishi Electric Information Technology Center America, 2002 201 Broadway, Cambridge, Massachusetts 02139 Publication History: 1. First printing, TR-2002-21, April 2002 Wireless Liquid Level Sensing for Restaurant Applications Paul H. Dietz dietz@merl.com Darren Leigh leigh@merl.com Mitsubishi Electric Research Labs Cambridge, MA, USA William S. Yerazunis yerazunis@merl.com