Copter-4.1.2-rc1 has been released for beta testing and can be downloaded from the various ground stations (e.g. Mission Planner, QGC) or downloaded directly from firmware.ardupilot.org.
The changes vs 4.1.1 are in the release notes and copied below
Changes from 4.1.1
- CAN_Dn_UC_OPTION param added to help resolve DroneCAN DNA conflicts
- Durandal with alternative ICM-20602 IMU
- OBAL autopilot support (Open Board Architecture for Linux)
- FETtec One ESC protocol support
- Bug Fixes
a) ADSB vertical velocity reporting fix
b) APM/LOGS directory creation fixed on some boards
c) AutoTune fix to disable SMAX limits that could interfere with tune
d) EKF3 fix to switch to non-zero primary core when disarmed
e) Notch filter update rate fix
f) Surface tracking fix if rangefinder glitches
g) TradHeli rename of H_COLL_HOVER to H_COL_HOVER
Most of these fixes are relatively minor but “5f) Surface tracking fix if rangefinder glitches” is dangerous because it could cause the vehicle to climb or descend a few meters each time the rangefinder glitches.
If all goes well we hope to release these changes as the stable version in about a week.
Any and all testing is greatly appreciated!