Servo *only* works if RC transmitter is off?

ArduCopter Copter 3.5
1

Servo stops working when RC is connected.
Hey everyone, I’ve got a weird, persistent problem that I’m having. The short version: Our Aux1 servo doesn’t work when our RC transmitter (Taranis X9D) is connected to our drone. We can control the servo with the RC manually, but we can’t control it via the servo panel or via Auto missions…… if the RC transmitter is connected. (For financial reasons, I don’t want to run Auto missions without an RC. :smiley: ) This is on a clean install of MP, Pixhawk 2.1 with APMcopter 3.5, TaranisX9D RC, and FRSkyX4 receiver.

Longer version/ more detail: I’ve got a pump (we spray pesticides) on a drone. It has it’s own power source, runs off the Aux1 port, and works fine when I manually control the pump from the RC (using the Servo9 Function = RCxIn parameter.)

Our goal is to have the pump operate with the Do_Set_Servo command during Auto mode flights. When the flight plan is set up, with Channel 9 as the servo, and the proper PWM values (as verified working via the “servo” panel in the “Flight Data” screen) …nothing happens. Turn the RC off and the servo panel can control the pump again.

I’ve verified that Servo Function 9 (Aux 1) is set to 0 (disabled), as recommended in documentation:
http://ardupilot.org/plane/docs/common-servo.html

actually a typo on that page, as Aux 1 = Servo 9, Aux 2 = Servo 10
Either way, (in case I’m confused) neither servo fires when our RC is connected, we’ve tried this on both ports in case it was a hardware problem. I’ve tried a handful of different parameters, reinstalling firmware… and now we have a completely clean install of everything with default parameters, and this issue persists.

Would be extremely grateful for any help.

2

Have you tried setting it up as a camera shutter? Bit of a hack, but it’s one way to get both mission control and rc control over a servo, if you are happy with only having 2 servo positions.

3

A log of what your doing would be helpful as we can see that the inputs look like and also the outputs. In addition we can see how you have it configured and can assist in make some changes.

I have a switch set on my radio that when I flip it it turns on some LED’s on the copter. That should be similar to what you are trying to do except you what to be able to control it with a mission which I can also do.

Mike