Re: [uCsimm] MP3's

From: David Williams (davidwilliams@ozemail.com.au)
Date: Wed May 03 2000 - 20:10:23 EDT


Hi,

I am using PWM to play uncompressed sounds (inc voice). It seems to work quite well. I
have my own hardware running my own operating system. My problem is that I need to
produce the audio with a very small diameter speaker or other sound element such as a
peizo. My current solution is to use a peizo glued to the case to get max sound. I only
have a about 2cm diameter available and would like to be able to hear the sound from
1-2 meters away at reasonable volume - similar to a mobile phone ringer.

It would be nice to add some compression to reduce the size of the audio files! As
mentioned by others 68EZ328 is not powerful enough to do MP3 decoding by itself. Maybe
some sort of simpler compression would be helpful. Any ideas?

Dave.

Micah Dowty wrote:

> MP3s would be nice, but I am curious to see how many have found a use for
> the EZ328's sound. I had connected the PWM output (not of a ucSimm but of
> my Kiwi) to a buffer chip to increase the current. The output from the
> buffer chip connected through a 100uf capacitor (to remove the DC) to
> headphones. It plays 32khz audio nicely, and I can fit a good portion of
> a song in my 8MB DRAM uncompressed.
>
> All this was 'bare metal' programming though, and I suppose the first step
> would be making a /dev/dsp driver for the sound. I would enjoy doing this
> but I need to research linux driver programming a bit.
>
> After a driver is implemented, should be trivial to port sound apps.
>
> Micah Dowty
> www.homesoftware.com
>
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> On Wed, 3 May 2000, Keith Christopher wrote:
>
> > Has anyone tried running mp3's on a ucSimm ?
> >
> >
> >
> > This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/
> >
>
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