My digital voice recorder project

Discussion in 'General Electronics Chat' started by electron_prince, Dec 28, 2013.

  1. electron_prince

    Thread Starter Member

    Sep 19, 2012
    Hi, I want to make a digital voice recorder using microcontroller (AT89C51).

    This is what I have in my mind:

    A condenser microphone will convert sound into electrical signals, then I'll amplify these electrical signals using LM386 IC. Now I'll use an analog to digital converter IC to convert these amplified analog signals to digital signals and now my microcontroller will read these digital signals and store it to a storage device like micro sd card.
    To play the recorded sound, my microcontroller will read the digital signals from storage device and then using digital to analog converter I'll convert it back to analog signals and then amplify it and send it to speakers.

    Am I missing something in my model? Do you think it's going to work?
  2. MrChips


    Oct 2, 2009
    That is the classic way of designing a digital audio recorder, until you do the math.
    What is your sampling rate?
    How many seconds of sound do you wish to record?
    How much memory will you need to store the recording?

    There are other solutions available.
    Investigate delta modulation.
    Check out Winbond/Nuvoton ISD4002/3/4 chips.

    Various companies package ISDxxxx chips on gadget boards: