Thanks that looks great. However the 5V you highlight is not connected to the barrel. It actually has a 220ohm resistor in series, which has the advantage of being able to short it to ground without damaging the board, however is not ideal to power 5V devices that draw more than a few mA. The 5V from the BBB's internal regulator (current-lmiited) are available on P9-7/8 (two rows above the 3.3.V), while the unregulated 5V from the barrel connector are available on P9-5/6 (the row just above 3.3V).