In Android 4.2, the Developer Options menu and USB Debugging option have been hidden. If you need to enable USB Debugging, you can access the Developer Options menu with a quick trick.
The developer options aren’t just used by developers. USB Debugging is required by adb, which is used for rooting an Android device, backing it up, installing a custom ROM, taking screenshots from a computer, or doing many other things.
Accessing the Developer Options Menu
To enable Developer Options, open the Settings screen, scroll down to the bottom, and tap About phone or About tablet.
Scroll down to the bottom of the About screen and locate the Build number field.
Tap the Build number field seven times to enable Developer Options. Tap a few times and you’ll see a countdown that reads “You are now 4 steps way from being a developer.”
When you’re done, you’ll see the message “You are now a developer!”.
Tap the Back button and you’ll see the Developer options menu under System on your Settings screen. This menu is now enabled on your device – you won’t have to repeat this process when you want to access the menu again.
Enabling USB Debugging
To actually enable USB Debugging, you’ll need to enter the Developer options menu, scroll down to the Debugging section, and tap the USB debugging checkbox.
Note that USB debugging should only be enabled when you need it. It’s a security risk to leave it enabled all the time. For example, if you connect your Android phone to a USB charging port in a public location, the port could use the USB access to your phone to access data on your phone or install malware. This is only possible if USB debugging is enabled. If USB debugging is disabled, computers you connect your Android to won’t receive such low-level access to it.
To disable USB debugging and other developer options when you don’t need them, slide the switch at the top of the screen to Off.
Other Developer Options
This screen also contains other options, although most of them will be useful only for Android app developers. You shouldn’t touch any of these options unless you know you need them for some reason.
In Android 4.2, the most interesting new option for non-developers is probably the “Force 4x MSAA” option under Drawing. Like the same option in graphics driver software on a PC, this will force 4x multisample anti-aliasing. This forces your Android device’s graphics hardware to render 3D scenes at a higher resolution than the screen can display, downsampling them before outputting in your screen’s lower resolution. This takes a lot of extra graphics power – and many devices may not be able to handle it – but it’s a way of reducing aliasing (jagged edges) in games if your Android has powerful enough graphics hardware.
Accessing the Developer Options may be a bit confusing the first time you update to Android 4.2, but it’s easy once you know the trick. This prevents average users from stumbling across the Developer Options and being confused.