Having Issues with A10 & A11

My Hexa-C came preassembled from 3D Robotics and my first discussion (No Connection/No Hearbeat) was finally corrected but now I have a new problem.

The copter was ordered with a pitch controlled servo platform and the the intermediate cable (red, white, & black) was connected to the following pins:

  - White to A11

  - Black to Output ground pin 7

  - Red to Output positive pin 7

When I connect the Turney TGY-90s servo cable (brown to black, red to red, & yellow to white) the APM's GPS and UART1 leds go blank and the APM appears to dropped dead.  Unplug the cable's white plug from A11 and the APM come back to life.

At this point I reversed the servo cable with no ill affect.  I also put a volt meter on A10 & A11 and noted they both have a 5 volt consistent output.  Is this normal?

At this point, I think the APM is faulty or it's not setup from the factory correctly.  Anyone out there help figure this one out?


Doug W.

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  • CORRECTION:  APM's GPS and UART1 leds go blank was stated earlier.  In fact those LEDs were NOT the leds that went blank.  It was the Red and Blue leds.

  • Ok, to round two of testing.  I direct connected the servo cable to S (3rd from left) connection and it started working.  Ok Servo is functional.  Yes I did notice after turning RC (channel 6) potentiometer full range that brownout did occur.  But when I plugged in the intermediate cable to output side positive and negative and the the 3rd pin from the left (S) pin, I did not get any indication that the servo was receiving power.  The red and back cables were tested with an ohm meter and it indicated no breaks in the wires, so I mettered the output side and noted no power was observed.  Where do I go from here?  Is the APM the issue, do I need a BEC or something else?  

  • acording to the order you describe above white(signal), black(neg), red(pos) on the connections

    and your servo brown(Neg), red(pos), yellow(signal)


    you are reversing the power if thats the case


    a11 should be signal

    black and red should be power

  • Here is the wiki entry for how to hook up a camera gimbal:


    Scroll down until you see the section on servo output channels.

  • Developer

    Are you sure you are connecting to A11 and not SPI connector which is the first 2 rows of 6 pins at that end of the APM A connectors. The labelling is a bit off.

    see http://copter.ardupilot.com/wiki/ground-station-setup/ to see a clear picture

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