What I am thinking is a 5-wire connector with symmetric pins say 5V-out-gnd-out-5V so even if you plug in wrong it will still work 
Just a thought, like apple's new connector.
What I am thinking is a 5-wire connector with symmetric pins say 5V-out-gnd-out-5V so even if you plug in wrong it will still work Just a thought, like apple's new connector.