Control surface servos won't work VTOL quadplane

Do you mean having the exact same signal on both thrust motors? Then you could just make a Y-cable to feed the PWM from AUX5 to both ESCs. If you think about controlling each motor individually then you would have to change the mixer: https://dev.px4.io/en/concept/mixing.html (eg enable yaw control over differential thrust instead of a rudder)

Great! once I get control of the forward thrust motor, I will give it a tryā€¦ Will keep you posted.

Hi Tim,
I am having the same problem on servo outputs. My firmware version and platform is the same as yours. There is no deflection of servos whatsoever. May you give me a guideline through which you succeeded?
Thanks in advance

Hi Bluespirit2
Sorry for not respondingā€¦ I switched to using kk2 boards for a while and wasnā€™t monitoring this chat group. Were you able to get everything working?

Tim

Hi sfuhrer
Iā€™m back with a new design of VTOL, this time a tailsitter with a similar layout as Openerā€™s Black Fly. I have it working with two KK2 boards linked in series, but want to put the Pixhawk 4 in it.

Iā€™m using the VTOL Quad Tailsitter frame as a starting point. I would like to use all 8 motor ports on the Power Distribution Board as actual motorsā€¦ I would like to control my flight control surfaces through the remaining 8 FMU/PWM outputs.

Iā€™m using QGround v3.5.6
Before when you were helping me the labeling of the PWM and AUX seem different from what Iā€™m seeing now.

I can seem to get my servo to activateā€¦ it is on the first pins of the FMU-PWM rail (which is powered by a BEC) and AUX 1 is mapped to Channel 1 (Ailerons).

Any thoughts? I tried all the steps you gave me last time, but the mavlink didnā€™t like this line (pwm info -d /dev/pwm_output1 or pwm test -d /dev/pwm_output1 -c 1234 -p 1200)

Summary: want to use the Main 1-8 as motors and FMU-PWM as control surface servos. Servos not activating. DX6 TX and Serial Receiver.

Hi again @Tim.Talon,

Do I understand it correct that you are using the Quadrotor X Tailsitter airframe, so with Autostart 13003? If you didnā€™t change the mixer then you need to connect the actuators as it is documented for this airframe:image

You could ofc make changes to the firmware (in the mixer) to create a new airframe that has the servos on the FMU. But the easier option would be to connect it with everything on MAIN. Why again is would you prefer to have the servos on the FMU? Do you have more than 8 actuators?