AVR-Chat

Do you really need to encode it ? Why not just store the raw samples ?
You can use the internal A/D for sampling, and playback with PWM.
A dual op-amp can be used as a microphone pre-amp.
Assuming a 8-kHz sample rate (you didn't say what quality you needed),
you'd only need to store 1 (or perhaps 2 if you use more that 8-bit 
resolution
from the internal A/D) per sample => 8000 bytes per second.
That like a walk in the park for an AVR.

For MP3 encoding/decoding, look at the Micronas MAS3587.

/Jesper

> I'm facing a new challenge that I haven't tried to solve before and I 
> would
> like some input if anyone has tried this before. I need to record and
> playback voice/sound from a microphone and store it on a Secure Digital 
> card
> with FAT16 file format, which is no problem, but what I would like some
> input on is what "front end" IC I could use to maybe do the MP3 encoding 
> so
> that I only have to "cheat" and store the pre encoded signal on the SD 
> card
> and be able to play it back again.
>
>
>
> I was thinking of using maybe a IC like this:
> http://www.analog.com/UploadedFiles/Data_Sheets/76229755AD73311L_a.pdf
> although it does not have the capacity to encode/decode MP3, I could use 
> it
> for both encoding and decoding my raw audio signal, but what I can't
> determine is if I'm able to store the data as fast as it samples with
> 64/32KHz onto the SD card.
>
>
>
> I know that Micronas makes some kind of MAS de/encoder for MP3 but have
> anyone had success with it?
>
>
>
> Best regards
>
> Lasse Madsen
>
>
>
> /My current knowledge doesn't enable me to use DSP processors as I've 
> never
> worked with them before and now is not the time to start unfortunately.
>
>