At a technical level
We catalog it as USB OTG, but we also call it USB Host, or USB On-The-Go. It is simply an extension of the UBS 2.0 standard that expands the possibilities of a USB connection. The USB standard without the OTG extension always uses a master / slave architecture. This means that there is a main device that is the master, and that is the one that controls the configuration and data transfer at all times. Instead, USB OTG compliant devices are capable of switching master / slave roles.
Basically, in a normal USB connection there is a device that is the one that commands the other. Suppose we connect a keyboard via USB to our mobile. We could not send the keystrokes to the mobile, because it is the mobile that controls the keyboard. When the connection uses USB OTG, then both the mobile and the keyboard can become controllers of the other, so that the keystrokes would also reach the smartphone.
Possible uses of USB OTG
Of course, the possibilities offered by having a smartphone that has USB OTG are immense. As we have already mentioned, we can connect a keyboard by USB. We may have a high-level keyboard that we want to use with our smartphone or tablet without having to replace it with one with Bluetooth technology. If the tablet or smartphone has OTG we can try to use it through the USB connection, without having to use Bluetooth connectivity.
On the other hand, we can also think about the world of video games. Connecting a DualShock controller or one from the Xbox, via Bluetooth, is not always easy, which often leads to complicating the process, having to install additional applications, etc. With a smartphone or tablet with USB OTG we can connect the controller through the UBS connection and control the terminal from the controller.
And finally, we could not forget the possibility of using an external memory through this type of connection. With an external hard drive, one with power supply, or simply with a USB memory, we can have an immediate memory extension on our smartphone. And it is not only a matter of expanding the external memory of the smartphone, but of being able to transfer the files quickly between devices. If we edit photos on the tablet, we can easily make a copy from a hard drive where we have them stored on the tablet just as we would with a computer, and with the transfer speeds of a connection of this type, without having to choose by the data connection.
What mobiles have USB OTG?
It is impossible to create a list of all the smartphones or tablets that have USB OTG, mainly because a large number of them are entry-level and from lesser-known manufacturers. In any case, the most normal thing is that the manual will show if it is compatible with this type of connection. To use the USB OTG connection, you need an adapter that usually has a very cheap price and that we can find in any electronics store. The most normal thing is that it is not necessary or to root the terminal.
Of course, we are aware that certain smartphones do have USB OTG and are from the best-known brands, being the Sony Xperia Z, Xperia ZL, Xperia Z Ultra, Xperia Z1, Samsung Galaxy S2, Galaxy S4, Galaxy S4, Galaxy Note, Galaxy Note 2, Galaxy Note 2, HTC One X, HTC One, HTC One mini, HTC One max, LG Optimus G, LG G2, and the Nexus 5. The Nexus 4 carries such a connection, but it was blocked by Google, and currently there are some systems to activate it, although later software updates made this connection impossible again.
Finally, there is an application that we can use to find out if our smartphone is compatible with USB OTG. It’s called USB Host Diagnostics, it’s free, and it’s available at Google play.