I want to make sure I'm not doing anything stupid. I have a 9 volt battery going into the raw Vin on the board, then I'm using the board's Gnd and pins to power a servo and ping. It runs great when powered by USB but acts funny when only running off of the 9 volt. The correct action, if I'm not mistaken, is to break the servo off and run it from a 5v power source and continue to power the arduino with a 9 volt? Or should I max the arduino's Vin with a 12v battery and see if that fixes it? Just want to ask before I fry it.
Well, a 9v battery is not the best choice for running anything that takes more than just the Arduino and a couple LED's, they simply just don't have the same current as alot of the other batteries.
The 5v supply from your USB supply can supply 500ma safely. Testing with smaller servos should be okay, I've tested 2 at a time. (microservos, only taking 120 ma each)
But a 12v battery will work. Just make sure you're checking the bottom of the board, it gets really warm when working with more than 9v. (When I say really warm, I mean you can almost burn yourself)
But yes, you've got the right idea, generally people will use a separate battery for powering their servos vs their boards, just make sure you've got the grounds connected together if you go that route.
Thanks for the quick response! That sounds good