One of my friend still using NuttX on 2018 manufactured black cube.
So far, there was no problem at all…
except one case = Dataflash : stuck thread(write)
recently… getting nervous about using NuttX
bottom line is … shifting to Chibios is mandatory? or choice?
Mandatory. Arducopter/Ardupilot/Ardurover on NuttX is no longer being developed nor supported. There are also some critical safety bug fixes to the handling of multi-IMU failover that occurred after the transition to ChibiOS which were not back ported to NuttX.
Tl;dr - Its mandatory.
highly recommended.
First of all the older Ardu firmware does have some undesirable behaviour around the IMU redundancy in failure that was recently resolved.
Further to this under NuttX you can’t enable all three EKF for full sensor redundancy .
Basics are it’s strongly advised to update to latest with the specific Cube Black Firmware, then enable all three EKF.
Also if you do update make sure you download the latest Mission planner and specifically the drivers from the MP downloads page as you may need them to connect after updating.
Highly recommended.
The next update, Ardupilot 4.0 is a big one, once that’s out of beta, we will be strongly suggesting everyone move to it.