Copter-3.6.12 has been released as the official default software for MultiCopters and Helicopters.
For those flying 3.6.10 (or earlier) the upgrade is Critical to avoid possible lockups due to I2C storms. These situations are rare but we have seen enough of them that we strongly recommend upgrading.
For those flying 3.6.11, your vehicle is probably safe but we still recommend upgrading to 3.6.12 because it includes a fix to another rare case of I2C storm lockups caused by extreme interference on the bus. We have one reported case which involved a serial port inadvertently connected to an I2C port.
The upgrade from earlier versions of 3.6.x should be relatively painless with no re-calibrations required unless you see pre-arm checks prompting you to do so.
The two new changes in 3.6.12 are in the ReleaseNotes and copied below.
- Fix ChibiOS I2C DMA error
- COMPASS_SCALE param to allow manual correction of compass scaling
The second issue allows users to work around a compass scaling issue with the Hex Here2 GPS/compass unit. The Here2 compass unit’s scaling is off by about 17% meaning setting COMPASS_SCALING = 1.17 should improve accuracy. The accuracy can be checked before and after this change by:
- fly the vehicle in any mode but ensure the flight includes chaning the vehicle’s heading
- download the dataflash log and check the NKF4.SM values which are the compass’s “innovations” (the difference between the expected values and actual values). Lower is better so hopefully Here2 users will see lower values after setting the COMPASS_SCALE value to 1.17.
Note: beta testing of Copter-4.0.0-rc3 will resume next monday (Dec 16th).