Experiments with USB-OTG

[HarryT]

The announcement of the Nexus 7 was the first I'd heard about "USB-OTG", so I thought I'd do some experiments with it on my Samsung Galaxy Tab 2 7.0. I bought the cheapest Samsung USB-OTG adaptor I could find on Amazon UK. Although it said it was for the original 10" Galaxy Tab, it looked the same as the connector on my 7", so I bought it hoping it would work, and, thankfully, it does!

It's a short cable, with a Samsung connector on one end, and a USB socket on the other end. if I plug a USB memory stick into the socket, a few seconds later the tablet says "USB Mass Storage Connected", and automatically opens my file explorer app (the Samsung "My Files" app) to show the contents of the USB stick (which mounts as "/Root/UsbDriveA"). I can copy files from or to it, or open media files (music, photos, videos) on it from the normal apps. An item in the notifications area lets the memory stick be safely dismounted.

Interestingly, I can also plug a USB mouse in. When I do this, the tablet says "Mouse Connected", and a small mouse pointer appears on the screen. I can't really see much practical use for this, but perhaps it might be useful in something like a picture editing app?

A keyboard also works, and I can use it anywhere that the normal soft keyboard generally appears. I imagine this could be of genuine use for something like a word processing app.

It all works extremely well - rather impressive, in fact. It's a real shame that the Nexus apparently won't support USB sticks, because I think that's where this facility is most useful. Probably good for Samsung (and other manufacturers who do support them) that it doesn't!

[Jabby]

Originally Posted by HarryT

It all works extremely well - rather impressive, in fact. It's a real shame that the Nexus apparently won't support USB sticks, because I think that's where this facility is most useful. Probably good for Samsung (and other manufacturers who do support them) that it doesn't!

OTG has been around since Android v2.2 and I can't see why Google would disable it in v4.1. The Nexus 7 Guidebook says that keyboards, mice and other devices are supported with the addition of a USB adapter.

Of course it is possible that OTG has been partially disabled, but for the life of me I can't see why. I don't think I would put too much credence in a single blogger to have the final word on the matter. None of the first tier reviewers have mention it.

I have a Nexus 7 on order so I guess we will know, with certainty, in a couple of weeks.

Regards - John

P.S. I got this USB adapter for my Galaxy Tab 2 7.0:

http://www.amazon.com/Samsung-EPL-1P...ng+usb+adapter

[HarryT]

Originally Posted by Jabby

Of course it is possible that OTG has been partially disabled, but for the life of me I can't see why.

I don't think it's a matter of OTG having been disabled, but rather that the o/s doesn't have FAT filesystem support built it. As you say, we'll know one way or the other when people get their hands on a Nexus.

P.S. I got this USB adapter for my Galaxy Tab 2 7.0:

http://www.amazon.com/Samsung-EPL-1P...ng+usb+adapter

I got this one:

http://www.amazon.co.uk/Black-Female.../dp/B00751EV7K

[HansTWN]

Originally Posted by Jabby

OTG has been around since Android v2.2 and I can't see why Google would disable it in v4.1. The Nexus 7 Guidebook says that keyboards, mice and other devices are supported with the addition of a USB adapter.

Of course it is possible that OTG has been partially disabled, but for the life of me I can't see why. I don't think I would put too much credence in a single blogger to have the final word on the matter. None of the first tier reviewers have mention it.

I have a Nexus 7 on order so I guess we will know, with certainty, in a couple of weeks.

Regards - John

P.S. I got this USB adapter for my Galaxy Tab 2 7.0:

http://www.amazon.com/Samsung-EPL-1P...ng+usb+adapter

I had USB OTG on my Windows Mobile 6.+ O2 Flame in 2006. I quite often used a flexible keyboard with that device to do some extended typing. And thumb drives also worked. Not exactly new technology.

[DebbyS]

Thanks for all the tips! I back up things to thumbdrives and external drives, now I may be able to access them directly with my Tab rather than going through my computer.

[HarryT]

Originally Posted by DebbyS

Thanks for all the tips! I back up things to thumbdrives and external drives, now I may be able to access them directly with my Tab rather than going through my computer.

USB-OTG only works with "low power" devices, so it won't work with an external drive unless it has its own power supply.

[ghostyjack]

I wonder if it would work with this:

Samsung Introduces Tablet-ready DVD-drive with Android Compatibility/

[Jabby]

Originally Posted by HarryT

I don't think it's a matter of OTG having been disabled, but rather that the o/s doesn't have FAT file system support built it. As you say, we'll know one way or the other when people get their hands on a Nexus.

I think the Android internal file structure must be FAT32 for two reasons:

1- If I format a micro sd card as FAT32 on my PC and insert it into any of my tablet Android has no problem using the files.

2- When connected to a PC via the USB, Windows Explorer can create, delete or do anything of the things it can do on its own files.

Time will tell.

I would have bought one like your OTG cable if I had seen it. My other OTG cables look like yours except for the mini/micro usb replacing the Samsung connector.

Regards - John

[ilovejedd]

Originally Posted by Jabby

OTG has been around since Android v2.2 and I can't see why Google would disable it in v4.1. The Nexus 7 Guidebook says that keyboards, mice and other devices are supported with the addition of a USB adapter.

Of course it is possible that OTG has been partially disabled, but for the life of me I can't see why. I don't think I would put too much credence in a single blogger to have the final word on the matter. None of the first tier reviewers have mention it.

It's not partially disabled. Google just chose not to include drivers for USB mass storage.

[HarryT]

Originally Posted by ilovejedd

It's not partially disabled. Google just chose not to include drivers for USB mass storage.

Does that mean that adding USB mass storage support would involve no more than downloading a driver file?

[=X=]

Originally Posted by HarryT

...

It all works extremely well - rather impressive, in fact. It's a real shame that the Nexus apparently won't support USB sticks, because I think that's where this facility is most useful. Probably good for Samsung (and other manufacturers who do support them) that it doesn't!

Great post Harry!

Originally Posted by Jabby

I think the Android internal file structure must be FAT32 for two reasons:

It can be Linux(Android) has the ability to run on FAT32 or ext(2/3/4), but stating that all Android devices run FAT is incorrect. Format your SD card to NTFS and you will see Android/Linux can read that format just fine.. My samsung phone was installed with FAT32. The problem with FAT however is Linux runs slower on it than ext. So some manufactures chose FAT while some perfer ext.

Originally Posted by HarryT

Does that mean that adding USB mass storage support would involve no more than downloading a driver file?

Yes and no. You'll have to root your device and update the kernel/module. Chances are somebody will have a hack for this shortly after the Nexus is released.

However be warned Google disables the ability to rent movies from their store if they detect a device has been rooted.

=X=

[ilovejedd]

StickMount already kinda works with root. However, you need to copy files from USB mass storage to internal storage. No doubt custom ROMs will pop up that include USB mass storage support.

[BobC]

Originally Posted by HarryT

Interestingly, I can also plug a USB mouse in. When I do this, the tablet says "Mouse Connected", and a small mouse pointer appears on the screen. I can't really see much practical use for this, but perhaps it might be useful in something like a picture editing app?

A keyboard also works, and I can use it anywhere that the normal soft keyboard generally appears. I imagine this could be of genuine use for something like a word processing app.

I've been playing with a 10" Android tablet for a few weeks now - this also has an OTG port. Not only can you use a keyboard or mouse but if you get a suitable wireless keyboard & mouse combo (not bluetooth) you can have both at once. The mouse can be very handy for selecting text for editing (much easier than messing with a touchscreen) and for selecting when links are tightly packed on a page. Another advantage of the wireless version is that the keyboard ond mouse are locally powered from AAA cells rather than sucking power from the USB port which only has to power the wireless adaptor.

BobC

[DebbyS]

Originally Posted by HarryT

USB-OTG only works with "low power" devices, so it won't work with an external drive unless it has its own power supply.

I did wonder about that, as the external drives require either being plugged into a computer or into a powered usb hub. Still, if I get the USB-OTG device, I could use it to see my thumbdrives and larger SC cards, etc. Hmm, a toy for my toy.