My volvo car cannot read from my n900 over usb
 

Hi,
my car (volvo v50) has a usb connector. With this connector, you can attach usb sticks and hard disks, to read music files from them.
This works fine for many devices, including my colleague's htc magic.
This device also just exports a vfat filesystem, and then in the car you can navigate through the directory structure and play songs.

However, with the n900 this doesn't work (obviously after selecting "mass storage mode" - with the htc you also need to confirm in a similar fashion)
I have no idea why the n900 would be any different, as it's also just a vfat filesystem over usb.

The problem happens with both with mine (3.2010.02-08) and another colleague who has a n900, running the more recent PR1.2

How can i make this work?
Thanks,
Dieter

Re: My volvo car cannot read from my n900 over usb
 

Just a guess but maybe your Volvo's stereos don't like the folders named .foldername @ root of the mass storage?

I don't have a sollution to offer though...

Re: My volvo car cannot read from my n900 over usb
 

Could also be because the n900 exposes 2 drives.

Re: My volvo car cannot read from my n900 over usb
 

My Volvo V50 has no such connector :´(

How exactly does it not work? Does it go like "no music found", "no device found", "incompatible device" or is there any blue smoke?

Correct me if I am wrong, but when you connect a N900 to a PC for the first time in mass storage mode, it will map up TWO removable disks, right? One for the SD card, and one for the internal memory card. Maybe your Volvo opens the wrong one, or maybe it gets confused.

Edit: too late. What he said.

Re: My volvo car cannot read from my n900 over usb
 

Indeed Aydan, what's up with that?
when I plug in the phone to my laptop, in dmesg I see I get a sdb and a sdc. Even though they have the same permissions, sdc cannot be opened (or listed) with fdisk. only sdb can. And because of this, only sdb can be mounted as fat filesystem. what is sdc? and can i get rid of it?

I will check the car manual to find out any limitations such as dotfiles/directories.
In the meanwhile, I wanted to share the (clean) output of an fsck:

edit: wow, many posts at the same time :)
@Volt:
i have the "two devicefiles" every time i attach my n900 to my pc, not just the first time.
the usb connector is an option. I'll write down the exact error message this evening.

Re: My volvo car cannot read from my n900 over usb
 

another difference with the htc magic: my colleague tells me the magic exports 1 blockdevice, but it has a partition table containing 3 partitions.

Re: My volvo car cannot read from my n900 over usb
 

So, what I am guessing is that the car stereo simply connects to the first drive. One possible solution could be to make a symlink from the first drive to the one containing your music.

The internal memory is 32 GB - I am guessing that is what you're looking at with your 28991619072 bytes. Do you keep your music on the SD card?

Re: My volvo car cannot read from my n900 over usb
 

Nope - it's FAT32 so no symlinks.

Re: My volvo car cannot read from my n900 over usb
 

Maybe editing /usr/sbin/usb-mass-storage-enable.sh and changing it so that only exports one LUN may work.

Re: My volvo car cannot read from my n900 over usb
 

Same issue with my car stereo - My n900 will give me an error message saying that it can't connect in mass storage mode because usb is already in use.

I just gave up and starting listening over bluetooth.

Re: My volvo car cannot read from my n900 over usb
 

@cfh11 that sounds like a completely different problem.
@qwerty12: i have no such file, however there is /usr/sbin/osso-mass-storage-enable.sh, I'll try to understand how it works and play around with it.
@volt: you mean the second. the first one is the one containing the vfat. the 2nd one is the one that is unusable. I think I don't even have a sd card. That is, i didn't add one myself after getting the phone.

the big question is: why does the phone expose a 2nd blockdevice which is not even usable because there is no device (sd card) for it?

Re: My volvo car cannot read from my n900 over usb
 

perhaps its related to the whole dumb/smart charging cable issue? cant say i know too much about it so forgive my ignorance if i'm completely in the wrong area!

Re: My volvo car cannot read from my n900 over usb
 

As a workaround, use FM transmitter or bluetooth, while waiting for a working solution to this. I myself like to be cable-free, but I also understand your PoV. There is even a nifty application for xferring mp3 tags over RDS in the repositories.

Re: My volvo car cannot read from my n900 over usb
 

Okay, we did some experimenting:
- the error message is "onleesbaar" (unreadable)
- by playing with /usr/sbin/osso-usb-mass-storage-enable.sh and especially with the g_file_storage module and it's options (rmmod and modprobe are our friend), we managed to present the following over usb:
1) 2 devicefiles, one for the sdcard (doing nothing) and one for the vfat partition (this is the default way) -> same error
2) 1 devicefile, one for the vfat partition -> same error
3) 1 devicefile, one for the complete flash storage with mbr (/dev/mmcblk0) -> same error
4) 2 devicefiles, one for the sdcard (doing nothing) and one for the complete flash storage with mbr (/dev/mmcblk0) -> same error

From the manual of the car we can read there are the following limitations:
max 500 directories
max 64000 files
min 256 MB of size
support for playback of mp3, wma, and wav files. other files will just be ignored.

We will do further experiments like copying the entire vfat contents to a usb stick, trying to clean up the special dotfiles, etc. *sigh*

Re: My volvo car cannot read from my n900 over usb
 

Update: we copied all files from the /home/user/MyDocs/ directory to a USB stick with rsync.
One file wasn't copied by rsync (/home/user/MyDocs/._?) - also tried to just cp it - but besides from that, all files and directories are the exact same on the USB stick as on the phone.
The car recognized the USB stick and immediately started playing the songs that are on it.
*puzzled*

Re: My volvo car cannot read from my n900 over usb
 

I think you are on to something here....

Re: My volvo car cannot read from my n900 over usb
 

this seems to be about charging or not charging?
http://talk.maemo.org/archive/index.php/t-38230.html

The phone doesn't charge in the car indeed, but it doesn't bother me that much.
Our real issue is that the car doesn't read the music from the n900, i don't think charging has much to do with that

Re: My volvo car cannot read from my n900 over usb
 

for that error you should check if the device is actually in use, and what is using it.

For me the issue was Easy debian, it would stay open and not allow use of the mass storage mode.
I just started using the "Close Debian" app after using debian, and this allows me to use mass storage mode once again

Re: My volvo car cannot read from my n900 over usb
 

No, I don't think it has something to do with the charging issues either.

"2) 1 devicefile, one for the vfat partition -> same error" - this sounds like the best setup for the car to find the right partition. I would have thought that would work. And you tried copying over the files to another device, and no problems with the files/structure... So it looks more like it has to do with the file system/partitioning. Which I guess was what you believed all along.

So I did a little offsite googling. This might be of interest:

"volvo_fox
11-24-2009, 05:09 PM
The drive is formatted with fat32 from the producer. <br>I have tried to format it in windows vista. But it is still unreadable.<br>I cannot delete the partition in windows either, so I had to use a third party software (active partition manager) to delete the partition on the usb. <p>I created a smaller partition, approx 8 GB and copied some music to it. My car was able to read it. " (...) "Repartitioned the usb drive and made it use all its space. Formatted it with fat32.<p>Copied 10 cd's to the drive and tested. My Volvo reads and plays the song wonderfully.<p>Guess the partition from the producer was not compatible with Volvo.<p>"

http://forums.swedespeed.com/archive.../t-129594.html

Re: My volvo car cannot read from my n900 over usb
 

Thanks Volt,
Maybe Nokia also used "unusual" tools to create the vfat filesystems.
If/when I find the time, I'll reformat the partition (or a microSD card) using mkfs.vfat and try it out.

Re: My volvo car cannot read from my n900 over usb
 

I am not sure if this is the problem but usually the problem relies to FAT/FAT32
most players which have USB connection need to have FAT or FAT32 devices.
even my home DVD player didn't read the USB NTFS hard drive.
After I formated it to FAT32 the problem solved

I hope I helped you

P.S. I wish my volvo S40 had a USB or Aux in too :mad:

Re: My volvo car cannot read from my n900 over usb
 

This might be OT, but my PS3 doesn't recognize my n900 as well.

Re: My volvo car cannot read from my n900 over usb
 

I backed up my data from Mydocs, umounted /dev/mmcblk0p1,
did an "mkfs.vfat -F32 -s64" (using the mkfs.vfat tool on my phone, I wonder if it's somehow patched by Nokia), remounted it, and am now restoring my data. (which goes much slower then backing it up, btw, about 4.8MB/s), and will try again in the volvo when it's done. *fingers crossed*

Oh and btw, as you can see in my filesystem info on page 1, the FS was already fat32, and fat32 works, we tried with an usb stick. So i make it fat32 again. It had 128 sectors/cluster, whereas it now has 64.

Re: My volvo car cannot read from my n900 over usb
 

ugh. it failed :@

I guess next things to try are using the mkfs.vfat of my regular pc ( I think nokia may have messed with it), and/or using a microSD card

Re: My volvo car cannot read from my n900 over usb
 

My colleague did the same experiment, formatting the Mydocs partition using mkdosfs (this is the same as mkfs.vfat, and he used it to write to the usb stick succesfully) on his Arch Linux pc, and the volvo still does not recognize it :((