I know that it sounds a bit “this can’t work”, but it works. Depends a bit what scanner you’re using though (I used a Canon).
But, it depends a lot on what scanner you’re using. And, you might need a special cable for it. I just happened to have all the bits needed for it, the cable ain’t that special but you might need it. It’s just a regular UBS OTG cable adapter but with add extra usb socket for USB power so you can connect any usb charger to it.
Why? so that you can offer the USB voltage that the scanner (or other devices) might need. This is for the scanners/etc that gets powered via the USB cable.
But, it worked for me with just a regular $1 USB OTG adapter cable as well. This with my Canon LIDE 50 scanner.
Ok, I got the cables needed. Then what?
Well, this is the most important part. You need to install an app for it. I need to stress that it might not work at ALL with the type of scanner you’ve got.
To get started it’s just to connect everything and start the app, you will get asked when you start it if you want to let it access USB devices. From there it’s just to press Scan, and off it goes. For me it was that simple, which I was a bit amazed over. And, it can save what you scanned to a PDF file that you can just mail or do whatever with.
And, that’s pretty much it. I’m pretty glad that this works since my scanner doesn’t have drivers for Windows 8 (which I use on my main computer).
It worked of course on my M7 as well I should mention. I think that it will work on any device that supports USB OTG, which might give my Nexus 7 some problems.