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MP3 board


Anyone have much experience with the MP3 decoder? I was going to do a “Chumby like” project that had a built in alarm clock. Instead of hooking up a buzzer, I was thinking it might be easier to just get an MP3 board and patch it into my computer speakers.

Anybody have any thoughts or ideas?


Hi Chris,

everything you need is here

There is a MP3 Decoder Extension from Olimex. Just connect to the UEXT connector and start the sample.

Or what do you mean??


Hi Cypher,

I was just curious if anyone here had some first hand experience with it and could tell a bit about their experiences.


I have tried out and it works fine.

Only with higher baudrates I got some dropouts. But for normal files it should runs smoothly

I think it depends on which crystal oscillator you used(In my case the crystal frequency was around 12 MHz. But maximum frequency can be up to 24 MHz. Maybe that was the reason for dropouts.

Here is another discussion in the other GHI board,3256.0.html

I used the driver from GHI and changes some lines of code for running on an Embedded Master Dev System.


Ok, thanks. I’ll probably pick one up with my (next) cobra then.


By the way, we have a shoutcast internet radio working on cobra and other devices! You will need the MP3 decoder to play internet radio.


Hmm… Maybe I can integrate that into my alarm clock then. Maybe I’ll make it so that you can configure it via WebUI to play an internet radio station for the alarm.


One more thing: In the photo, the two jacks on the board appear to be mounted slightly off center. I was going to mount this in the Cobra’s case by drilling two holes for the jacks, then using the nuts to tighten the jacks down the side of the case, so I cannot afford for these to be off center. Is this just the picture, or are htye really slightly off?

…And another question, what do the two jacks do? Obviously, one is audio out, but is the other mic in or something?


Hi Chris,

the other jack is an audio input. So you can connect a microphone and record some audio.

I took two picture where you can see both jacks and they are not slightly off.

Take a look here

The board is from olimex. There were also the schematics and a description of the board and look for MOD-MP3


Thanks Cypher, my next question is probably only going to be able to answered by someone with a FEZ Cobra enclosure and one of these boards…

I am looking at this board, and I am starting to wonder whether it really will fit inside the FEZ Cobra enclosure. There is an AA battery holder, so I used an AA battery for scale as the maximum height of the board.

Can anyone actually confirm as to whether the board will fit in the enclosure somehow? I was hoping to mount it so it was facing the oppisite direction of the Cobra ports, so the two jacks stick out on the right side. It doesn’t matter where on the right side since it looks like it is going to be a really tight fit.


It will surely fit! This is the first board we looked at when we made the design. Note that you are mounting the the MP3 board on the side panel and so it can be higher than the FEZ Cobra board, which mens they can overlap.

Your weather station will now have ShoutCast internet radio and can play music right off a thumb drive :wink:


What about you add a relay and then control the lights too?

Be careful when using high voltage power sources…do not die now, we need your project completed :smiley: just kidding.


Hi Chris again :smiley:

I don’t have the enclosure but I took some pictures of both board for reference

But I think Gus is right , it will fit.

Or you use the breakout board from Sparkfun. There were no battery holder. So it is more flat than the MOD-MP3 board from Olimex


Hi Gus and Cypher,

Yeah, that looks like it should fit now that I see that.

I might add a relay or something to control the lights, but I think I have a better idea. They (Billy Mays lol) sells a remote controlled light switch, so you can switch an electrical outlet on remotely. It doesn’t looks like it would be too hard to hack the remote to be controlled by an MCU instead of the physical switch.