This project was designed and implemented an electronic phone directory which has a built-in automatic dialer. The electronic directory allows user to Dial, Enter, Search and Delete entries. When dialing, the Atmel 8515 microcontroller will generate the Dual Tone Multi Frequency (DTMF) signals corresponding to the phone number being dialed. To avoid building the phone circuit for the dialer, a DTMF decoder was used to detect what number is dialed by the user.
May 5th, 2008