When connecting the pixhawk with the motors also in the circuit there is an arc of current at the connector (scary) and the motors beep then twitch to a beep every 1-2 seconds as the PIXHAWK powers up and continues to twitch and beep indefinately.
My OCTO with PIXHAWK is talking to the Mission Planner, I was able to get my Futaba 14SG to talk with the TFR8SB, I have calibrated the RC inputs for H4X on my OCTO. The compass is also done.
I have a foldable landing gear for my OCTO but only manually. I would like to buy a servo to drive the gear up and down. Naturally it needs to be light and it should not need to be very powerful as the landing gear is quite light as well.