if all you want to do is play a mp3 file via the door bell press,
there are more appropriate devices that can be used. For starters:

<http://www.macklabs.com/minimacds.pdf>
<http://www.makezine.com/daisy/>
<http://www.pricom.com/Trains/DreamPlayer.shtml>
<https://www.gilderfluke.com/index.php?main_page=product_info&cPath=1_3&products\
_id=33
>
<http://www.cfsound.com/index_CFSound.asp>

HTH

On Apr 18, 2009, at 5:25 PM, Michael Klinosky wrote:

> Hello from Hummelstown, PA! (It's near Harrisburg.)
>
> I've been researching the notion of hacking together an mp3 doorbell,
> and a websearch hit on the PJRC website. Btw, yes, I noticed the bit
> about not being available anymore. Frankly, I can't see that the mp3
> player industry drove sales _that_ low - aren't there enough hackers
> out
> there to keep things going somewhat?
>
> Thus, I might be interested in buying a used unit.
>
> I need to know exactly what these units can do. E.g. can it be
> triggered
> it to play 1 file and stop (as opposed to continuous)?
>
> Does it merely play files from a list, or can it be set to randomly
> pick
> a file?
>
> Can I adapt USB hardware to it (to use a flash drive - just to make it
> easier when I want to add files)?
>
> I'm sure that there are other concerns to see if it's practical for my
> application.