Have a question about multimedia or audio? Ask our Expert, Ken Boyce

Hello Alex,

Unfortunately I do not have any product based experience with the BU9458 or BU9457 devices from Rohm.  Nor do I know of a commercial product on the market that uses them.

Also, it appears that the datasheets for those devices do not offer much info on any application circuit.  So I can't really judge very well a potential product design based on them.

However, the basic idea of the parts is good in that you have both SD card and USB (flash memory drive) as input sources for the formatted audio material.  Also, a key advantage is that the part can operate self contained as a decoder or can be controlled via an external processor/micro-controller.

My direct experience with an MP3 player design was one involving a PIC microcontroller + an MP3 decoder which in turn was controlled by a larger CPU running a complex system that happened to need audio at various operations.  That design used a standard SD card with very simple file naming structure which may not meet your needs.  If you want more info on this, let me know.

Ken

Definitely I should be politicians!

Later one I will send you source code.

     Best Regards Alex

!!!!!!!!!!!!!!!!!!!!!!!!

!  Alex for President  !

!                      !

Thank you for sharing your code ( and your schematic ), now I have a good ( and working ) starting point.

The project is an 'mp3 player for armchairs': a client of us produces relaxing/massaging armchairs, and he want to add this function to his armchairs.

The player should have an usb input ( so each one with an usb memory could listen to his favorite music ).

Two versions are planned: a 'dumb version' ( with no display ) and a 'smart version' ( with grafical display ) and bu9457/8 addresses both versions.

P.S. oddly enough rohm applications for bu9457/8 already knows of this strange use ( as an mp3 player for armchairs ), the image is from rohm site

Hello
Can you help me I'm not getting the folders view.

Leonardo,

I am sorry but I don't understand your question.

Ken

Sorry,
Can you help me?
How to access folders on BU9458 check the total amount of music.
Thanks

Hi Leonardo,

I could not find a data sheet for the BU9458 on the ROHM website.  However, I did find one here:

http://pdf1.alldatasheet.co.kr/datasheet-pdf/view/349375/ROHM/BU9458KV.html

As  usual with Rohm data sheets, there is very little information.    However, there is a statement that a FAT analysis function is contained   in the part.  What that means to me is that it can check that the SD   card that can be interfaced to it is in the FAT32 format or not.  But  the data sheet does not give any indication what the function does.  The  function  may be able to tell you used/available memory space, but the  data sheet  does not indicate such a thing.

My guess is that the part does not allow getting the information you want, although only Rohm can answer that question.

There is also information about a BU9458 demo system at the following URL:

http://krisbahar.com/online_work/demo_eval_code_rohm_bu9458_&_oki_ml610q412_v01_2010-08-11.pdf

The article has some info about Folder operations, but it is limited to   simply choosing the folder, and the song in the folder.  Nothing about   Folder space usage.  Look at pages 21, 22.

The source C code for the demo is at the end of the article.


Perhaps you could contact Rohm and pose the question to them.  Someone   else may have also asked the same question.  The author of the article   is Kristopher Bahar, and his website is:

http://krisbahar.com/  and his email address is krisbahar@gmail.com.

Sorry I cannot be of more help.
Ken

Can you help me?
I am not able to read data bu9458
It has something wrong with i2c but do not know.
my email leocranio1@hotmai.com
Thanks ...

Hello Leonardo,

I personally have not used the BU9458 part so cannot really advise about it.

However, Kristopher Bahar has an application note at the follow URL which may be helpful in case you haven't seen it.

http://krisbahar.com/online_work/demo_eval_code_rohm_bu9458_&_oki_ml610q412_v01_2010-08-11.pdf

He may be able to help you more than I can.   His email is not published on his website, but he has a contact form at : http://krisbahar.com/contact.html.   Please use that form to contact him directly.

Kind regards,
Ken

Hi Leonardo,

OOOPPS !   I see I directed you to Kris Bahar in an earlier reply.   Were you ever able to contact him?  If so, was he helpful?  If you have not contacted him, try again.   I will also try to send this message content to him.

Ken

Hi Leonardo,

OOOPPS !   I see I directed you to Kris Bahar in an earlier reply.   Were you ever able to contact him?  If so, was he helpful?  If you have not contacted him, try again.   I will also try to send this message content to him.

Ken