Yaw control not working and receiver not being recognized

#1

So I am working with a custom build of PX4 where I added a new vtol airframe and mixer, but did not change anything else. The issue im running into is that my yaw control is not working correctly. When I power everything on, everything centers. Roll and pitch work as expected, but yaw does not center when the sticks are centered. So if I yaw right on my transmitter, my servo will yaw right very slowly and then stay there. It will not reset back to center when the stick goes back to center. It will only move left if I push the stick all the way left, and then the yaw stops responding. Thinking this was a tricopter control issue (I was using the eflite convergence model to start) I switched to a regular quad copter config and experienced the same issue but with motor differential. Regardless of airframe this issue still happens.
Thinking this is an issue with the custom build because I flew this same fc on a quad a few months ago, I flashed the stable build through qgroundcontrol. Now the receiver is no longer recognized, which again is a new issue. I then tried flashing arducopter which gave me a px4.io error and refused to connect to qgroundcontrol. Fc is a hkpilot32 by the way.
Does anyone know what could be causing this issue or how I can get back to a standard working firmware? I can upload a log from the flight showing yaw being unresponsive if needed.

#2

I am getting this issue aswell with my custom build.

Especially this part:

Roll and pitch work as expected, but yaw does not center when the sticks are centered. So if I yaw right on my transmitter, my servo will yaw right very slowly and then stay there. It will not reset back to center when the stick goes back to center. It will only move left if I push the stick all the way left, and then the yaw stops responding.

#3

Hi, yaw stick is different with Roll and Pitch sticks. It is normal the yaw stops when yaw stick goes back to center. Yaw stick means angular rate though Roll and Pitch stick mean angles.

The reason why yaw moving is slow may be because the default control gains or maximum yaw rate is too small. So they should be changed bigger.

#4

Thanks for the recommendation, I will give that a try if I can get px4 to recognize my receiver. Unfortunately, I updated my custom code to the newest version (1.8) and now that also no longer recognizes my receiver. I have gotten arducopter to properly flash and work as normal after having to manually force the px4.io update on it, so maybe I will try flashing px4 back on to see if that issue is resolved. Anyone know how I can flash older versions of px4?

#5

I’m not sure but in QGroundControl ‘Firmware’ window there is ‘Custom firmware file…’ in ‘Advanced settings’ in ‘Firmware Setup’ for PX4 users.

#6

The older version of PX4 binary .px4 files can be found ‘Assets’ in the PX4 release page.

I’d like to know if this works or not.

#7

My usb port on my fc broke right off the board, taking the pads with it, so at the moment i am stuck with arducopter which is thankfully working well, but when my new fc comes in I will give it a try, hopefully some time next week.

#8

Well I have some update, I managed to borrow another controller (that I believe was purchased after mine) and uploaded px4 and have no issues running either standard 1.7.3 or modified 1.8.0. So I am gonna chock this up to a hardware issue.

#9

Hi @thisistins, I have similar issue. I’m using Pixhawk on tricopter and when I arm and try to fly, the drone simply rotates in the clockwise direction. I don’t know why. I’ve searched online and it says to reverse the servo channel which I have done via the RC4_REV parameter.

I also noticed that if I take the props off, then arm and put the throttle up a bit; when I push the yaw stick to the left, the servo tilts right (as expected looking from the back of the drone), and when I release the yaw stick, the servo still stays at the right position. Similar thing happens if I push the yaw stick to the right, the servo tilts left and stays there. Please any help or suggestions will be appreciated.

Thank you.

#10

hello,
I have the same problem that yaw is uncontrollable, have you fixed the error, please help me