I have soldered together an Adafruit Motor Shield (Version 2) following these instructions for standard headers (non-stacking headers). The end result looks similar to the image below:
I'm hooking the shield to an Arduino Uno and I want to hook up some sensors to this shield as well. Unfortunately, the standard headers that I've soldered on don't allow me to do this. I see two rows of holes next to the ones I've already soldered, numbered 0-13 on the digital I/O and 0-5 on the analog I/O. Can I solder female headers onto these holes in order to enable them? Are there any pins that I can't/shouldn't use? I've heard a rumor that the motors use up some of the pins, but I can't find any information as to which pins to avoid, specifically.
Any help would be greatly appreciated.