I was wondering about this part of a circuit diagram. I believe the component marked as JP12 is a DC barrel connector, which I thought had three pins. One to detect input, one with V+ and one with ground.
However I thought this device was also receiving 5.0V from USB. The diagram shows pin 1 of the DC connector directly connected to the VBUS line, does this mean the DC connection is also powering the USB device. If so, what is pin 2 being used for.
Also, I have no idea which of the three pins in JP12 is supposed to be ground. Am I mistaken, and this DC connector does not supply ground?