Sansa Clip+: noise when reading from micro SD card

[tempe]

hi everyone,

my clip+ always makes a noise comparable to a disturbance every time it accesses the sdhc card. any suggestions? i'm using the current release.

tempe

[bertrik]

Can you please state the *exact* version and build number?

How loud is the noise (approximately)?
Does it depend on the volume level? Like at what volume level is it very noticeable, and at what volume level is it neglible?

What kind of AMSv2 "variant" do you have? (see menu System / Debug / View HW info)

What kind (brand, speed class and capacity) uSDHC do you use?
Do you have another uSDHC card to test? Does it show the same problem?

Do you also hear it when accessing the internal storage?

What kind of headphones are you using?

[tempe]

hi bertrik,

1. 3.8.1, it's the release version. i dont know how i can find the build number.
2. hard to describe... it's well audible at low volumes (or with volume turned down completely). it does not depend on the volume level (it doesnt get louder if i increase the volume). from -45 db and up it's neglible.
3. AMSv2 variant 0
4. kingston micro sd hc 8gb, class 4
5. yes, also with a 2 gb micro sd where no brand is printed on. way less audible though.
6. yes, also with internal storage. way less audible though.
7. earplugs sennheiser mx-400 (i think)
btw: no noise with the original sansa firmware

tempe

[bertrik]

Can you try the latest patch in http://www.rockbox.org/tracker/task/11907 ?

[tempe]

first of all, this seems to be exactly the problem i'm having!

but... i'm sorry i'm no programmer and i've never applied a patch yet. afaik after looking in the simple guide to compiling, i have to install a compiler software and deal with the source code and put in patches there and compile them, which seems a difficult thing (at least for me). isn't there an easier way?

tempe

[tempe]

@ bertrik: i'm willing to look into the whole compiling procedure, but in the guide it says that it's badly outdated and should not be used until updated. so is there another way or should i wait?

[evilnick]

Which guide are you following?

[tempe]

this one:

http://www.rockbox.org/wiki/SimpleGuideToCompiling

is there another one (for beginners)?

[saratoga]

this one:

http://www.rockbox.org/wiki/SimpleGuideToCompiling

is there another one (for beginners)?

http://www.rockbox.org/wiki/DevelopmentGuide

[G4Oblivion]

SimpleGuideToCompiling is outdated, but still gives you a basic idea of what you need to do.

I suggest using a VM like VirtualBox instead of Cygwin. Cygwin is hell, imho.
If you've never used a linux distro, then I suggest using Ubuntu 10.04 LTS.

You're going to need to open the terminal (its under 'Applications -> Accessories -> Terminal')

Type this into the terminal:

sudo apt-get install subversion
sudo apt-get install texinfo

Once you have those installed you're going to need to checkout the rockbox source. From the terminal type this:

svn co svn://svn.rockbox.org/rockbox/trunk rockbox

This will download the rockbox source to '/home/NAME/rockbox'

Create a folder called 'build' in the rockbox source directory by typing this into the terminal:

cd rockbox
mkdir build

Now you're going to need to run rockboxdev.sh to install the eabi toolchain. From terminal type this:

cd build
../tools/rockboxdev.sh
e

(This step can take anywhere from 20min. to 3 hours. Sometimes longer)

Please see WorkingWithPatches in the wiki to see how to apply patches.

Now we need to build rockbox. Type this into the terminal (this needs to be run in the 'Build' directory):

../tools/configure
62
N

This creates the make file. Normal build.

To compile rockbox, type this into the terminal:

make
make zip

Most of these steps are explained in SimpleGuideToCompiling, so be sure to read that first.
I wrote this pretty fast and assume you are using Ubuntu, have read the wiki and want to compile rockbox for the Clip+

I believe you need to compile the bootloader, since the patch changes files in the 'firmware' directory.
That is a bit more complicated, and I don't feel like explaining it in this post.

[tempe]

thanks for your help guys! i'll try it outas soon as i have time. just one question: the patch does indeed alter a firmware file:

Code: [Select]

diff --git a/firmware/target/arm/as3525/sd-as3525v2.c b/firmware/target/arm/as3525/sd-as3525v2.c
index 8134869..26d2d6a 100644
--- a/firmware/target/arm/as3525/sd-as3525v2.c
+++ b/firmware/target/arm/as3525/sd-as3525v2.c

so what does that mean in the matter of compiling the boot loader? i haven't found anything in the guide for that.

[torne]

You don't really need to recompile the bootloader for this change, but that is a good rule of thumb nonetheless (many changes to firmware/ will affect the bootloader). If you do want to build a bootloader sometime, then this is simple: create a separate build directory (e.g. build-bootloader) and when running configure and it asks you what type of build, type b for a bootloader instead of n for a normal build.

[bertrik]

My suggestion to try the patch is a just an attempt to get a grip on this problem. I think there's a very small chance that it's actually going to completely solve the problem, it's just interesting to know if it makes any difference at all. We still don't know what exactly causes the interference problem.

Building the bootloader is totally unnecessary for this. I can supply a binary if needed, please ask me in #rockbox when I'm around.

I think we (the rockbox team) should order the uSD and SD extender boards from SparkFun and have someone with a scope take a look at the signals:
* compare sd signals between OF and rockbox
* check clock setting (speed)
* check if the OF stops the sd clock at all between transfers
* any other thing we can think of to diagnose on the sd port

[tempe]

thanks everyone, i managed to make my own build and it worked!! 

the noise is still there with the patch. i dont know if something went wrong in the patching/compiling process.

how can i find that out? can i compare the source code somehow?

the head of the patch code is included further up in this thread. i guess I have to look into as3525v2.c? but what do the +++ and --- mean and why does the path begin with a/... and then with b/... ?

tempe

[tempe]

ok, i made another build including the noise patch as well as the backlight-on-volume-change-off patch. since the latter one works smoothly, i guess that i made no mistakes.

so, my conclusion: the noise is still there with the patch in the same volume 
if i can contribute to the solution of the problem, let me know.

btw: i have a 16 gb kingston micro sdhc, class 4 (so basically the larger sister of the 8 gb), and this makes NO NOISE !!

thanks a lot to all of you, especially to all the developers of rockbox!!

tempe