with the offset / gain in place, and a tweak of the horizontal velocity PIDs, I finally can see drift control working. It’s still there, but so much better than ever before.
It also confirmed I need to do some temperature trend-lining for accelerometer offsets and gains – I did the offset / gains indoors at about 20°C. Outside it’s only 10°C and that definitely had a significant effect on vertical velocity, and to a lesser extent horizontal too.
I almost daren’t say it, but it really does now feel I’m on the downhill run and the finish line is finally in sight – still in the distance – but visible at last. Phew!