What makes this USB device tick?

Bounty · Post by **Bounty** » 2007-12-14 02:14pm

I got my hands on a very, very cheap photo keychain. It's a no-brand thingy ("Digital Photo Keychain", Panda-looking logo on the software disc, made in China) with a simple Windows app ("Photo Viewer") to covert and transfer files. Got it for free with a pack of CD-R's.

When I connect the USB cable under Windows, the keychain shows up as an unformatted drive and I can't do anything with it - double-clicking it just brings up the floppy format utility. The included application can synchronize with it just fine.

Connecting it under Linux does precisely dick.

So how does this work? Is it just a simple flash drive with a screen that doesn't show up properly? Is there any way to store files on it without the utility? Is there any way to find out?

General Zod · Post by **General Zod** » 2007-12-14 02:15pm

Perhaps you're lacking a driver? It could be old enough or off-brand enough that it needs one.

General Deathdealer · Post by **General Deathdealer** » 2007-12-14 02:17pm

You use the Photo Viewer to put the pictures on the key chain. You start the Photo Viewer, pick which photos you want to put on the Key Chain and then click synchronize. You cannot put things on there like you would a thumb drive. I have one myself and this is how mine works.

Bounty · Post by **Bounty** » 2007-12-14 02:18pm

General Zod wrote:Perhaps you're lacking a driver? It could be old enough or off-brand enough that it needs one.

I'm assuming the synchronization software has a driver, or some way of reading/writing to it, because it can get to the photos just fine. It's just that neither OS can access it directly, which is what I'd ideally want.

I have one myself and this is how mine works.

Yes, I know, I read the excuse for a manual. What I'd like to know is how I can get around that shitty sync app and use it with anything other than Windows.

General Zod · Post by **General Zod** » 2007-12-14 02:24pm

Sounds like it could just be a firmware issue on the USB keychain's part. Reallly does sound like a crappy model though.

General Deathdealer · Post by **General Deathdealer** » 2007-12-14 02:26pm

It is kind of a cheap key chain, but the Photo Viewer is the way to load the pictures onto it. Plus the only way to charge the batteries is to plug it into a USB port for a couple of hours.

Bounty · Post by **Bounty** » 2007-12-14 03:01pm

If it does use another filesystem, is there any way to find out which? Can something like, say, Gpart figure it out?

Bounty · Post by **Bounty** » 2007-12-14 03:13pm

I tried mount /dev/sda:

mount: you must specify the filesystem type

...which is a problem for obvious reasons. There's nothing in dmesg except bits about the swap file and wireless connection which I think are from booting.

ETA: Gpart guesses four blank partitions partitions. I don't think Linux is actually seeing the device.

Bounty · Post by **Bounty** » 2007-12-14 03:19pm

Mounting to /mnt/sda1 gives the same result. Mounting /dev/sda1 -

mount: special device /dev/sda1 does not exist

Google isn't helping either, it must be too generic.

Bounty · Post by **Bounty** » 2007-12-14 03:42pm

lsusb can see it, I think; it gives a vendor and product ID for an unidentified USB device that isn't my mouse or wireless adaptor. Googling the number tells me that the hardware in this thing is apparently used a *lot* of bargain photo keychains and at least one person is trying to figure out how to access it.

I keep digging.

ETA: it might be a variant of the DPF018 from a company like Yong Sheng, or it at least uses the same hardware and synchronisation application. The shell is different though.

ETA2: lsscsi says it's from Sitronix, who make LCD device drivers.

ETA3: it's times like these when I wish I knew something about computers. Looking into this is fun but I just don't have the knowledge or expertise to do anything useful.

RThurmont · Post by **RThurmont** » 2007-12-17 12:08pm

It should be noted that /dev/sda and /dev/sda1, on systems with Linux 2.6.19 or newer, would refer to the first HD on your IDE, Sata or SCSI bus, and the first partition thereof, respectively (if you're box is a multiboot rig, then sda1 will most likely be Windows).

On my box, due to the peculiarities of my setup, USB disks get mounted under sdc or higher, but the actual location of the special device files under GRUB itself is /dev/bus/usb. However, if you plug in a typical USB key and type mount, you'll see the path to the device file you'll want to use in attempting to mount that device.

Realistically, your best bet is to attempt to install the device's software in Wine (hoping, of course, that Wine's USB support is reasonable).

Bounty · Post by **Bounty** » 2007-12-17 12:10pm

Won't work under Wine. My hard disk is under /dev/hda1 as far as I can tell (that's what it says in fstab, anyway; but after a partition table wiping mishap, everything's not quite mounted right).

RThurmont · Post by **RThurmont** » 2007-12-17 11:50pm

If your HD is PATA, and you're running on 2.6.18 or earlier, your HD will be listed as "hda" or somesuch, else, it will be sda or somesuch. That probably means though that /dev/sda and /dev/sda1 are the correct addressses for it. Interesting problem, though...

Bounty · Post by **Bounty** » 2007-12-18 05:17am

I'm on 2.6.22

And I just double-checked, my swap file, Linux partition and data partition are all under /hda. I'm not sure about my Windows partition; it's automounted somehow but I can't find it in fstab, which doesn't really seem possible. I think it's got something to do with me having to retrieve the partition table with Parted.

RThurmont · Post by **RThurmont** » 2007-12-18 05:24pm

Wtf? That's bizarre. It don't make no sense!

Perhaps they changed the disk addressing scheme in 2.6.22 after the howls of protest from people who were annoyed that what had been "hda" was now "sda". I'll look into that a bit more and get back to you.