Related power question. My board has a 4 pin female header which reads/looks like: POWER5V Gnd 9V x x x xI've read the admonitions about not using too high a voltage or reversing polarity--so just want to be 100% sure this means I can use, for instance, a 9V battery to power the whole board. I've looked at the schematic for the board, which shows a VIN but doesn't specify a voltage. So, a related question for my general education is am I missing something on the schematic? Should I be able to definitively answer this question for myself?Thanks!