Circuit Lake

This ATmega32-based project describes the implementation of a phone line audio and event recorder originally devised for technical support call center quality assurance purposes. However, it is a reasonably generic telephony platform that can be easily adapted for other applications, such as an answering machine/interactive voice response system; or, doing away with the LCD and SD/MMC card, it could become a low speed modem; or, adding a few relays, it could be made into a remote home automation system. The project is designed by Marco Carnut.

Project Features

• Works both as a standalone device or in conjunction with a PC
• Records up to 230 calls or 17 hours of audio with a 512MB MMC/SD card
• DTMF detection for European-style incoming caller ID and outgoing number detection
• Allows listening to calls in real time or replaying them later
• Allows simultaneous record and playback
• Transmits audio over the serial port either in real time or replaying from the memory card
• LCD for call progress monitoring and timing
• Optional “mini-UPS” battery backup allows operation even in case of power failures