I have seen many wave/audio/mp3 shields, but I still don't know how to do this.
What is a good audio shield which is also able to record sound ?
The input can be a electret mic or a line-in.
The next step is using it together with the Ethernet Shield.
I would like to send a (small) audio file to the Arduino, and also to retrieve a (small) recorded file from the Arduino.
Using a PWM output would stop the Ethernet handling, so I need some kind of shield that is able to do that.
That shield should be able to use a compressed audio format, like mp3, because I want to send and receive it over the internet.
I would like to do this with the Arduino, because getting to know the Raspberry Pi would take a lot of time.
This is what I found so far:
The Adafruit Wave Shield can be adapted to record audio, http://www.adafruit.com/blog/2009/07/07/waverp-an-arduino-library-for-recording-and-playing-wave-files-on-the-adafruit-wave-shield/
But it is used with wave files, not compressed audio.
The Voice Shield, http://www.spikenzielabs.com/SpikenzieLabs/VoiceShield.html
They provide a program to upload sounds, but I'm not sure if that can be done from Arduino (to be able to receive and send it sounds via ethernet).
The Rugged Audio Shield, http://ruggedcircuits.com/html/rugged_audio_shield.html
But it seems it can only do wave files, not a compressed audio file.