Switch access is now available in the new version of Android Lollipop version 5. This feature is design for people with limited access to the touch screen. Using externally connected switches a user can navigate around the home screen of the tablet, open apps, and navigate between clickable objects on the screen. Within the accessibility settings you can choose options to use a single switch with auto scanning or two switches with step scanning. There are also new features to improve the contrast of text and options to assist people who are colour blind.
A number of blue tooth switches and keyboards that can be used such as the Blue2 switch from AbleNet. Keys or switches can be assigned to actions such as start auto scan, click, long click, home, back etc. To get switch access started you need to first pair a bluetooth switch or keyboard and also enable Switch Access under accessibility.
A useful guide for setting up your new Android tablet is available from AbleNet.