Car stereo and Android

**sdguy67** · 11-12-2009, 01:48 PM

My car stereo (Sony Xplod) has a USB port and says it works with iPod and other USB media players. But when I plugged in my Droid, I got an error on my stereo saying it wasn't supported. Any idea if I just need to set it up differently, or if maybe it truly isn't compatible. I had the same issue with my old Blackberry and never found a solution

**extorian** · 11-12-2009, 04:51 PM

When you connect your phone, does the phone come up with a USB Connected message in the notification bar? And if so, have you clicked it and clicked Mount?

**sdguy67** · 11-12-2009, 04:57 PM

Originally Posted by extorian

When you connect your phone, does the phone come up with a USB Connected message in the notification bar? And if so, have you clicked it and clicked Mount?

Yes, I clicked mount and the phone shows that it is connected, but the radio just doesn't recognize the media. I wonder if it is a file format issue or something

**sdguy67** · 11-12-2009, 05:01 PM

Just found a post on a different forum discussing a similar issue, it said his Sony head unit only recognizes Fat32 file format. Any idea what the Droid uses?

**extorian** · 11-12-2009, 05:03 PM

It's probably that the likes of both of your phones are composite USB devices, and your Sony head unit can only connect to normal USB devices.

A composite USB device is basically several USB devices in one - in the case of your phone it's a USB Android Debug Bridge (used for debugging, etc), and a Mass Storage Device (the USB drive bit), and probably a simple USB hub as well to allow connection to both at once, if it allows that... not tried that... anyway you get the idea... A composite device often needs more drivers to work, and Windows comes with thousands, whereas a USB Mass Storage Device just needs that one driver.

If you plug a normal USB Flash drive into it with some MP3s on it, does it work?

**extorian** · 11-12-2009, 05:04 PM

Originally Posted by sdguy67

Just found a post on a different forum discussing a similar issue, it said his Sony head unit only recognizes Fat32 file format. Any idea what the Droid uses?

It's not what the phone uses, it's what the SD Card is formatted as. It's FAT32 yes, unless you've either partitioned it yourself or installed a custom OS like Cyanogens that does it for you. In which case the Sony head unit might not recognise multiple partitions too... but I suspect it's the composite device issue.

**sdguy67** · 11-12-2009, 05:17 PM

Originally Posted by extorian

It's probably that the likes of both of your phones are composite USB devices, and your Sony head unit can only connect to normal USB devices.

A composite USB device is basically several USB devices in one - in the case of your phone it's a USB Android Debug Bridge (used for debugging, etc), and a Mass Storage Device (the USB drive bit), and probably a simple USB hub as well to allow connection to both at once, if it allows that... not tried that... anyway you get the idea... A composite device often needs more drivers to work, and Windows comes with thousands, whereas a USB Mass Storage Device just needs that one driver.

If you plug a normal USB Flash drive into it with some MP3s on it, does it work?

From what I have read, it should work with items that are mass storage capable. So I don't know.

Also, wouldn't an iPhone and/or iPod use composite USB also? Why would they work but the Droid not?

**extorian** · 11-12-2009, 05:19 PM

I would have imagined the iPod and iPhone are composite devices, but at the same time they're so popular that Sony may well have included USB drivers specifically for them.