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About the Project

Project Description

Materials Use & Total Cost

Schematic Diagram

The PCB

Application

Task to our project

Shout Box

   

 

 

 

The Digital Voice Message Recorder

 

 

 

 

 

 

 

 

 

CIRCUIT DESCRIPTION

The main component of the circuit is the DSI0242 IC. This chip is a high-quality, single-chip answer to short-duration messaging applications. Internally, the IC includes an on-chip oscillator, microphone preamplifier, automatic gain control, anti-aliasing filter, smoothing filter, and speaker amplifier.

Actually, a minimum record/playback system may be configured with the addition of a microphone, a speaker, a push button switch, a toggle switch, and some passive components. However, the version featured here is equipped with its own power amplifier for much louder sound.

Recorded sound is stored inside the IC’s non-volatile memory cells, which require no power for message storage. Voice and audio signals are stored directly into memory in their natural form. This provides high-quality, solid-state voice reproduction.

How the IC operates?

To initiate a record sequence, the IC’s pin 27 (REC) is toggled down. The recording will start when the pin 23 (START) is pushed down and continues until the message space is filled. Recording stops when the message space is filled. The IC automatically powers down and gives a sound.

The playback cycle is initiated when pins 26 toggled up. Pushing down the pin 23 (START) the IC will start and continue to play back the recorded signal. The IC automatically powers down when the EOM (end of message) marker is reached. A new playback sequence is initiated at the subsequent falling edge of the voltage at this pin.

Toggling down the pin 27 (REC) and pushing down the pin 23 (START) also initiates a play cycle for as long as the message space is not filled. The stops playing the recorded message and enters the power down mode when the IC detects a rising voltage at this pin or the EOM is reached.

The REC signal takes precedence over other operations. Any low-going transition on REC initiates a new record operation from the beginning of the start address or at a selected location, regardless of any current operation in progress.