Neural head gear...
I really enjoyed Chappie. The story line does have a fair few holes and some of the human acting is a bit dodgy but Chappie was fantastic to watch.
The biggest problem for me was the neural head gear seemed written in to the movie for the express purpose Chappie uses it for. It appears to me that it's not used at all to control the obvious doppelganger of ED-209. So when Hugh was wearing the neural thingy what was he using it for when it looks to me like the screens were showing him what he needed to see and the joysticks controlled the robot.