ES 52 - The Joy of Electronics Final Project

The purpose of this project was to design and build a wireless communications system capable of sending data over frequency modulated Infrared light in order to create a method by which students in office hours can request help from a Teaching Fellow in office hours.

The transmitter uses an Arduino and a LM555 astable circuit to encode and transmit the data. A divide-by-9 counter clocks a display to show the student a question number and to generate a 4-bit question number for transmission.

The receiver uses analog circuitry to condition the IR signal, which is passed through a phase locked loop to demodulate the signal. After further processing, this is read by a microcontroller, which provides visual and audio indication of a received signal on two seven segment displays and a speaker.