I am looking at the manual for the tiny osd 3 and I see a reset button. Is this for resetting the home position, or does the unit do that whan it is turned on a finds the satellites? Or is it for resetting the calibration? i just want to know if the reset has to be pushe d each time you fly to reset home, as that would be very ackward. Also how is the voltage meter. Does it really tell you when your battery is low and you should finish your flight?