The Area Code Finder captures a number and looks it up in a table containing every known area code. The hardware uses a ZiLOG Z8F0822 MCU along with a 2 × 16 LCD module and a 16K × 8 I²C EEPROM to store the data tables. An optically isolated RS-232 interface allows the area code data to be downloaded from a computer. A low-power op-amp interfaces with the telephone line. A 9-V battery powers the system, with a low-power voltage regulator supplying 3.3 V for the MCU. A switchable 5-V regulator supplies power to the LCD module. The software consists mainly of the DTMF decoding and phone number parsing routines. New data is downloaded through the serial port using the Xmodem file transfer protocol. Area code and country code information, which is available on several web sites, can be used to generate the file to be downloaded. The EEPROM can store all possible area codes from 200 to 999 and up to 512 international country codes.

Richard Wotiz
U.S.
dick601@mystics.org

Abstract | Entry

Grand Prize | First Prize | Second Prize |
Third Prize | Honorable Mention