Failed to update home location (2)

I built a tracker using the ReadymadeRC frame, a recent Pixhawk clone and some radios I’ve used before, calibrated everything and connect it like this:
Mission planner -< USB cable >- Tracker Pixhawk -< Radio link >- Copter on APM

Connection opens, I see both devices on the map, moving tracker manually changes the horizon as expected.
When I arm the tracker by hardware switch, MP says “armed” and then "Failed to update home location (2)"
Moving copter or Tracker correctly updates the position on the map, so what does this message mean? Is it even relevant?
The tracker does not move the servos at all.
While playing around I had two occasions where it seemed to go into the right end position and stop. Could not reproduce. Changing flight modes of the tracker is confirmed in the HUD but nothing changes in behavior.

Hello. I am with the same problem… anyone can help?

Seems that on AT with SITL - how to set up home pos there is a possible solution - but not for me: I have downgraded the firmware to 0.76 but it could not Arm, so no way to use it…

I suspected the clone radio or APM2.5 on the copter could be the an issue and got another Pixhawk + Radio but did not have the time to test it yet.
Thanks for the link, will test that as well.

If anybody has a working setup please post your hardware and firmware versions, thanks.

So I spent some more hours on this, still the same issue. At the moment I cannot recommend Antenna Tracker with the currently available Pixhawk clones, it definitely does not work as one would expect from the documentation.

I replaced the APM by a Pixhawk, the GPSes, the radios, the cables, flashed again the firmwares APM plane and antenna tracker and did all calibrations again. What I found is:

  • Waypoints reading or writing does not work when AT firmware was flashed. I guess this is expectd behaviour, but tried anyway as MOsborne mentioned something in that direction here:
  • When setting to manual it drives to more or less south, when setting to auto it goes to more or less north and stays there.
  • The positions get updated correctly on the map. The error appears even when the plane is still off and you connect to AT and just wait and arm.
  • The settings for Yaw and Pitch PID, IMAX, rate etc do not change anything. I have the battery loaded to the RMC wood frame so it is quite heavy and way too much for the servo to handle at this speed, but no matter how small I set the values I cannot see any change in behavior.

Hope this helps in circling down the issue. If anybody got a working setup please let us know the parts, I could not find any known to work configuration that you could still buy.