I got a Sparkfun 5V Breakout (NCP1402), some JR servo lead extensions from HobbyKing, and a right angle mini USB cable from Amazon and made the rig shown in the attached photo (USB cable not shown). I also installed CHDK and the 3DR script on the S100. I can apply 1.5 volts(C cell) to the input of the breakout and get a clean 5 volts out and it will trigger the camera just fine. BUT, I can't seem to get anything out of PIXHAWK! I have configured the Ch7 switch on the TX to "Trigger Camera" and have TRIED to configure PIXHAWK to output to either relay 1 (Aux. out 5) or servo 11 (Aux. out 3)[I THINK, since the gimbal tilt (servo 9) is attached to Aux. out 1] I find most of the documentation very confusing since it refers almost entirely to APM with little reference to PIXHAWK!!!