Here is what i use in one of my top down game.
Controller, joypad and emptyjoypad are at the same position at the left of the screen and its for moving the player.
Controller2, joypad2 and emptyjoypad2 are at the same position at the right of the screen and its for the players angle.
Emptyjoypad is exist so user if they drag the controller small distance the player dont move,so you can remove it if you want the player start moving immediately.