Thanks! I think you're right -- Mission Planner is the only app that has any meaningful information to share. At least it shows logs.
I tried to go to Compass Calibration in Mission Planner, and it surprised me by firing up the Motors without warning!
It also says the throttle is not zero.. like the midpoint is all wrong.
If I had to guess, the (Android) Mission Planner doesn't have a default template for Solo, or isn't interpreting the Parameters the same way?
I'm encouraged that it was able to spin the motors -- first time anything armed in weeks, and apparently in defiance of the controller saying it can't arm?
The IMU Calibration with OpenSolo4 *works* with the (old) stock Solo APK. It walks through the IMU orientations, seems to do its thing. I don't know if it's actually working, but it seems to make it through the process. Solex appears to be completely abandoned and the UI is so broken that IMU can't continue. The author hasn't been seen since 2021?
Yesterday I spent another whole afternoon with the Solos, going to a remote no-building no-metal field, stripping down to "Air Travel" no-metal on me, and still could not calibrate compass with Solo app, Mission Planner, or Solex.
most often, it would get exactly halfway in the progress bar and just stop there.
Sometimes it would complete the progress bar and then sad-buzz error.
Sometimes it would get halfway and then just stop blipping without anything but Cancel to do.
Can anyone share a calibrated parameter file? I'll take anything at this point.. Just want to get these Solos flying, don't care if the compass doesn't work at all and it's all manual.
(I've spent more time trying to "calibrate" this compass than I would to build a whole FPV drone from scratch. I don't know how anyone is getting this done with the tools available now in 2023. I wish I had never bought Solex or installed OpenSolo4, as I'm so sad these were both flying fine two weeks ago on stock firmware.

Is there any way to go all the way back to that, or is it hosed now that servers are down?)