In playing with the APM 2.0 I wanted to try out the GPS. Under usb power sitting on the window sil it never locks. Hooked up a battery, went outside and after a bit I did get a solid blue led. Walked back into the house and set the APM back in the window and the lock stayed. Un plugged the battery, plugged back in the usb. No lock.
Question, if have the unit powered up via the battery and hook up the usb at the same time, will this cause any power problems (smoke!). I know my AT Mega board can do this fine. Want to check before I ruin an expensive goodie!