Interesting article about converting an old android phone or tablet into a gaming system. It requires your phone to support USB OTG (On The Go). What is that? Basically it means your phone can act as a USB host (like a computer) instead of a target (like a thumb drive). I would think most phones could do this since I think OTG spec came out…gee early 2000’s. But I guess that is not always the case.
http://lifehacker.com/turn-your-android-phone-into-a-diy-portable-game-consol-1677171264
http://lifehacker.com/5849961/how-to-turn-your-android-or-iphone-into-a-portable-retro-game-arcade