read mp3 sound with chipkit max32

Created Thu, 12 Jul 2012 11:40:38 +0000 by snaida09

snaida09

Thu, 12 Jul 2012 11:40:38 +0000

Hello,

I have chip kit max32 and i want to read mp3 sound from Sd card. I can read and write text file from Sd card but i don't know how i can read sound from sd card and send it for my speaker (i can send tone for my speaker but not sound).

thanks for any hint.

nik999389

Thu, 12 Jul 2012 15:09:58 +0000

The reason why this happens is that when you read the data for a sound file you get what is called "raw" sound data. This data needs to go through a decoder so it can make it into the sound that comes out of the speakers.

You need an MP3 decoder. The most commons ones are the VLSI decoders. You can get to the website here:

[url]http://vlsi.fi/[/url]

Sparkfun also uses their products and they have made a couple break out boards for them. You might want to start off with the MP3 player shield. This will help you get a hang of how to use the MP3 decoder and how it works:

[url]http://www.sparkfun.com/products/10628[/url]

If you want to go more embedded and don't want to use a shield and such they sell another breakout board that is even smaller:

[url]http://www.sparkfun.com/products/8953[/url]

They also sell the IC by itself. Just keep in mind that all of these chips are interacted using SPI so make sure you have a good understanding of how that works. If you don't then you'll have to learn it when trying to interface with the decoders.

I hope this helps! :D

Jacob Christ

Fri, 13 Jul 2012 05:07:52 +0000

A quick search on google for mp3 decoder software reviled this:

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2680&dDocName=en554171

Jacob

nik999389

Fri, 13 Jul 2012 14:21:17 +0000

This is great Jocob! That library is a great find, it seems that I have underestimated the pic32 processor once again!

I am so used to working with the Arduino that I forget all the power that this little processor actually has! Thanks for sharing that.

Jacob Christ

Sat, 14 Jul 2012 19:15:20 +0000

As with all mp3 decoding you should be aware of this note:

It should be noted that even though the Helix MP3 decoder is free to use and is open source, the MP3 algorithm itself is not free and has royalties associated with it. These royalties must be paid in order to use the algorithm. For more details, visit http://www.mp3licensing.com

When you buy a chip, you pay for the license... If your just building something for yourself your probably don't need to worry about the license, but if your plan on selling anything you make, then be prepared to be served if your not paying licensing.

Jacob