Pixhawk: Powering servos

I got a BEC and a servo to hook to my Iris. A fellow Facebook user showed me how he hooked his up. He sent pictures showing the output of the BEC hooked into one of the main outputs on the back of the PH, and his servo hooked to AUX2.

I did the same thing, hooking (temporarily) the inputs of the BEC to the appropriate leads on the balance plug to power it. The BEC became very hot, and a volt meter showed that there is no voltage on any of the AUX power pins. I’ve seen numerous diagrams showing a BEC plugged into the AUX ports (such as this one: planner.ardupilot.com/wp-content … ixhawk.jpg), but plugging it in that way gave me the same result.

What I finally ended up doing was connecting the +/- leads to the corresponding leads on the servo, and running a separate signal wire from the PH AUX port to the signal input on the servo. Then, at least, I could get it to work. (Bonus: The BEC is no longer hot enough to fry an egg.)

The fellow Facebook user I mentioned says his setup is working the way he has it hooked up, so I’m puzzled as to why mine isn’t. I’m using the same parts he is. My Pixhawk was one that I got from 3DR last December. Has there been a revision to it since then that works differently in some way?


You don’t need a BEC to power servos. The Power Module will do that fine.

You mean, like this one?

store.3drobotics.com/products/a … connectors