A Call Recording System's Design and Implementation

The system is designed for recording telephone call information including the call time,the call number and audio information on a computer hard disk.A device is designed to transfer the information from the telephone line to the computer.This device's principle and system architecture are introduced.The device is based on 51 serial MCU,FSK decoder HT9032C and DTMF decoder MT8870.It transfers audio signals to the computer sound card and other control signals to the computer's USB port.A software parses the data stream to control the recording actions and saves compacted audio files on computer hard disk.The system costs low and can be widely applied to police,call monitoring and company's customer service system.