Gimbal tilt control doesn't work when using PPM input from RX

[tensafefrogs]

I was just trying to set up gimbal tilt control via channel 6 on my TX but couldn't get it to work. I suspect that the issue was because I'm using PPM input from my RX to the APM (2.6).

APM versions: 3.1 and 3.1.2 (I tried upgrading just in case it was a recently fixed issue)

My setup is as follows:

• Using PPM from the RX (openLRSng) to APM via CH5, with PPM jumper set on APM
• Checking radio calibration does show that CH6 (and 7 and 8) all work when moving knobs or whatever on the TX
• Connecting the A10 and A11 outputs to a brushless gimbal controller (in this case a HobbyKing Martinez/Brugi clone) should allow gimbal tilt control via the PWM output from A10/A11. I just wanted tilt control so used A11 as output and selected "RC6" as the input on the Gimbal page of APM. When changing the min/max values on the gimbal screen I would see the gimbal move, but moving the CH6 knob on my TX would not move the gimbal.

As a workaround (and so I know the gimbal does work), I've connected my RX directly to the gimbal tilt control input, bypassing APM altogether. But if there is better ROI support in the future (or just for cleanliness) it would be nice to connect it all up through APM.

Let me know if you have any q's or need me to try some other config. I'll see if I can verify that it all works when not using PPM if I have some time this week to tinker with it.

[jason4short]

I use this all the time. Can you post your params? Also verify you are actually connected to A11 and A10. The labeling is sometimes skewed. There are two rows of pins, then A11... You can also connect a servo to test. Just use the power and ground from your servo rail and put the signal wire to A11. Don't power directly off of the aux pins. You can brown out the APM by drawing too much power with a servo.

[tensafefrogs]

Hmm, ok, lets go through it:

• Wire connected from A11 (double checked it just now, it's correct) to A1 on the Martinez board - I also know this is correct because when I change the min/max in APM planner, the gimbal moves
• Another wire from the ground of A11 to the ground next to the A1 pin of the Martinez board - I tried with and without this as I saw some mention of needing a common ground. I'm not using the 3rd power wire at all (I also tried without this wire, makes no difference)
• Under Radio calibration I can move my CH6 knob on the TX and see it update [1]
• Under Optional setup > Gimbal, I have it set to use "RC11" (which I understand to be A11 output) and "RC6" as input [2]
• Under PIDs, I have "Ch6 Opt" set to "CH6_NONE" - the min/max under this are set to 0.0 and 1.5 (I couldn't find anything any that talks about these two numbers, have tried a few diff values) [3]

[1] Radio Calibration:

[2] Gimbal setup

[3] PIDs

And I believe that's all it should take, right? Again, it works if I connect the gimbal directly to my RX and move the CH6 knob on my TX, and I can also see the gimbal move if I change the min/max values on the gimbal page of APM Planner, which suggests that that A11 output is correct, there just seems to be a problem between the RX PPM input and converting that to PWM output on the A11 pin.

Let me know if you see anything wrong here or have ideas to try out.

[ofishel]

Any updates on this? I running into the same issue with APM 2.5 with 3.1.5 firmware and a Tarot T-2D gimbal.

[rmackay9]

I've updated the instructions for setting up the Tarot 2D gimbal just yesterday. It should all work. http://copter.ardupilot.com/wiki/common-tarot-gimbal/

The bit that was unclear was what to set the Servo Limits and Servo Angles to. There are instructions there now on what those mean.

[ofishel]

Will these steps work for an APM 2? I noticed the change from CH11 to CH9 for what looks like just Pixhawk. I tried to switch it anyway, but the gimbal didn't get any signal (solid blue light).

I switched it back to CH11 and tried to control the gimbal through my TX again without success. However, when I start the gimbal, it sets itself to 0 degrees. If the click the "Reverse" box in the Tilt options, the gimbal moves to -90 deg. It's clearly getting a signal from the APM, but it isn't picking up the readings from CH6 from my TX

[ofishel]

Update: For some reason, I was able to work via CH10 in the Windows Mission Control application. I also reversed the settings so that the pot at min settings puts the gimbal at 0 deg. So odd.

[rmackay9]

I'm going to close this because I don't think the above was all just configuration issues. Please holler if I got it wrong.

[jgeragi]

I have exact same issue as tensafefrogs. Same setup as well. I notice that stabalize does not seem to be working on the roll axis servo as well? If I change the servo limits the servos move. I used to be able to pick up while disarmed and see servos moving to stabilize camera but this is not happening. I too am unable to control via CH 6 but I suspect it will work if I connect as tensafefrogs did, but what about stabilize??