"I am using a 4-in-1 25A ESC (http://www.hobbywing.com/product_show.asp?id=292). It has a 3A/5v Switch BEC. Does it mean that I am stealing 5v from the Pixhawk and running into the risk of a brownout?"

"Hi. So I tested Marco's circuit in flight and it worked perfectly. Interestingly, I also tested the circuit without providing 5V to the Aux rail.... and it still triggered my camera!? I don't really understand why. I thought maybe the 3.3V from the…"

"I have Marco's circuit working on a breadboard. Now looking into testing it in flight. What is the best way to power the 5 v ubec? Is it ok to steal power from the main flight battery or is it better to use a secondary battery?"