Measuring DC current with Hall Effect sensor over PIC on the same circuit
The device measures the current flowing between the screw terminals, which are isolated from everything else. the pins are to power the hall effect sensor only, however, there's no reason you couldn't have power going through the screw terminals and then going to anything you want, those screw terminals are isolated from the pins so measuring itself is fine. Although those hall sensors aren't known for having amazingly good sensitivity, if you've got a 5A sensor, you'd be hard pressed to measure with an accuracy (or resolution) of much better than 50mA.