stellaris LM4F232 eval kit----reading from sd card

I see no need for further definition of the project.

I feel that I could program that by lunchtime -- simply from your initial description. Is that help enough?

Oh wait! -- You left out the schematic with an op-amp in it...Could you supply that before we make suggestions as to changes in the circuit?

I hope you understand what I am trying to say...

PRATEEK ARORA1 said:

reading the mp3 file, sending it to DAC ... is it a viable aproach??

No.

You can't just send MP3 data to a DAC.

A_W_Neil_elegance ++;

(and surely - if we may borrow your Xtal Ball - in steps N, N+1, etc...)

Perhaps we should give a teeny-weeny hint..

Such as the link to this device: www.mikroe.com/add-on-boards/audio-voice/smartmp3/

You can also go to the TI store and type in MP3 -- see what shows up...

You can also look on the main TI site -- and use the search term MP3 or perhaps even 430BOOST ???

Now, answer this question: Why do all these MP3 devices use a DSP type chip?  (and have a CODEC for same...)

That may well provide the revelation/miracle...

I'd have thought that a Cortex-M4 should be able to cope with MP3 decoding  without the aid of a DSP?

But, of course, that does not mean that it's trivial - not least due to the licensing questions...

(Note subtle hint of a key google search term...)

Is not the, "Elephant in the room" the realization that project should (in some small way) "match" the background/skills of the developer?

cb1- said:

that project should (in some small way) "match" the background/skills of the developer

Absolutely!

PRATEEK ARORA1 said:

i am working on a project in which I am required to...

So, PRATEEK ARORA1: do you not think that the person who "required" you to do this project had the expectation that you had the necessary skills/experience to do it?

Rather than try to blag it or bluff it, would it not be better to go back to that person and seek clarification and/or assistance?

sir,

whatever you are saying is right....i do not have the required skills to do it

and that is the reason i asked u guys to help me out

i really do not need a solution....i just need a direction as to exactly how to start learning for the thing i want to develop........and that's all i asked for

if someone can just help me with this ill be happy to work hard and learn something(even i am not able to complete the project)

thnx for the replies

So why did you say that you are "required" to do this project?

Who is requiring that you do this? Why are you not asking them to provide the help/guidance that you need?

Prateek:

Excellent attitude to have.

If skills really were required "in advance" my desk would be empty of projects.

Note that you have been given several lines of investigation above -- indeed some links exist.

Projects are not always what they seem... I realized that one project in university could not be done "as required" -- I re-wrote the specs to a project that could actually be accomplished (by me). It was actually intended that nobody be able to complete the task as it was "impossible" -- NP style problem. So, subsequently I was invited in for an interview and reminded that what I completed would be fine for a doctoral thesis -- or perhaps a masters paper -- but not for an undergrad project -- so they were considering failing me -- as I had not even attempted the project actually assigned... After I reminded them how silly that would look, since I had solved the general problems -- as opposed to the specific case,  they gave me the top mark on the course -- it was perhaps the most difficult course offered on the computer science / engineering menu.

The spec is not always the last word -- in this case the project is difficult but can be completed -- if this is an undergrad project perhaps it is intended that you fail -- but learn something.I know some engineers that would have difficulty with that assignment -- just because they have never looked at the problem before...

Or, like me, you can re-write the spec... as long as you accept the risk.

Now start looking...  you have a starting point.

You should certainly discuss with whoever assigned you the project before you proceed any further - you may have misunderstood and/or be overcomplicating it...

@ Prateek/others new to ARM - possibly new to MCUs programming/electronics in general..

Our (Andy, Dave, my) objective has not been to be harsh - but to perhaps further, "open your eyes" to the reality of the task you're embarking upon.  We three have been seriously, professionally involved in this field for past 15-20 years each, minimum.  I cannot recall - say 20 years past - such large number of people launching tasks which so far exceed their background and competence.  (perhaps "you-tube," the web, vendor ads - build expectations which are unlikely to be realized...)

These ARM MCUs are complex - in NO WAY should these be the first MCUs employed by a novice.  Frustration, delay, discouragement - lurk @ each/every corner. Many new users are unable to, "Set or Clear" a single GPIO bit - which is trivial for most all, simpler MCUs.  (I must have answered/advised in 100+ instances - just on this forum) 

I've long thought that along with MCU, IDE, task objective - each poster should "brief" the forum as to their past experience - core competency - and any/all related equipment at their disposal.  Minus this knowledge - responders necessarily "seize" upon the breadth & depth of poster's presentation - to craft a response.  While you're certainly entitled to, "request comment/assistance" - the very fundamental questions you posed are, "tip of the iceberg" - at best.

Should this be a school project - it is far too advanced, too demanding - IMHO.  If a boss asked - I'd follow responder Andy's instruction to the T.  If a hobby - I'd question whether you're prepared to devote hundreds of hours (perhaps thousands) to , "reinvent an already invented wheel!)  There are far simpler - hobby based boards (i.e. Arduino) which are far more suited for new users - and do not require great attention to a 1400+ pg. datasheet...

Wish you the best...

What might be worse than this though...

You should certainly discuss with whoever assigned you the project before you proceed any further - you may have misunderstood and/or be over complicating it...

Unless it is a really evil professor that is setting you up for a "too difficult" project. Nah... Couldn't happen...

Another approach for those wanting to make some "Quick Sketches" -- "Arduino Style" don't forget about the Energia Launchpad Software: See here:

http://www.energia.nu/download/

It is referenced on the TI Launchpad page etc. It includes compilers for the MSP430 and the LM4F.

I suggest that all students doing LM4F projects review the launchpad pages -- all of them -- and the associated Wiki and training pages. The resources there might cut a lot of work out of your projects.

Also -- loading the Energia software just might allow you to test ideas quickly -- and working functions can be moved into the "real" compiler.

i would like to thank you very much for ur active involvement in this forum

seeing that so many people are there to help you encourages me

well, coming to the point......its not a project given to me by any teacher...its a project that i proposed (didn't know the challenges involved then) in Texas Instruments Analog Design Contest.......

and now that i have taken the project without knowing the req. skills involved....i want to take the best from this opportunity to learn.....

as i already said, i never ask for solutions.....only direction....

i searched for the problem and found out that WAV files are much easier to read and there is a arduino project also......taking that as my starting point, i am now trying to accomplish the task....

thnx guys

PRATEEK ARORA1 said:

without knowing the req. skills involved

The skills that you are lacking at the moment are the ability to analyse a problem, and break it down into manageable parts, and the ability  to search & study the available materials relevant to those parts.

PRATEEK ARORA1 said:

found out that WAV files are much easier to read

Not so.

A file is a file - there is no difference between reading a WAV file from an SD Card and reading an MP3 file from an SD Card.

The difference comes in interpreting the content of those files once you have read them...

Andy:

I think we should give in gracefully -- perhaps we can just quietly update our definition of the word requirement. It seems easiest if we modify our dictionary -- since it is apparently outdated...

It's not like some of the other students who post here are doing much better on the investigation and research angles...

Dave Robinson said:

give in gracefully

Dave Robinson said:

just quietly update

Ha!  (will believe when (really if) we see this...)

Appreciate your humoring me by working in, "investigate"...  (never - at best rarely "research"...)