Cell Phone Audio Controlled Point of Sale

A Cell Phone Audio Controlled Point of Sale system was designed and built for an undergraduate electrical and computer engineering senior design project. The system was designed to enable a user to transfer data from any cell phone to a point of sale device using audio tones. The project involved researching the frequency limitations of cellular phone networks and designing and building a point of sale device capable of decoding audio signals. The end result was a functioning prototype which was demonstrated at the 2009 Engineering Expo. This document describes the design process, implementation, and testing results of the project