Warning #1: PX4/Pixhawk users upgrading from AC3.1.5 (or earlier) may need to re-do their compass and accelerometer calibration because AC3.2 also uses the backup compass and accels. Pre-arm checks have been added to ensure this has been done.
Warning #2: on the APM2.x the logs must be downloaded using MAVlink instead of the terminal.
AC3.2-rc14 is now available for BetaTesters through the mission planner’s Beta Firmwares link. The full release notes can be found in ReleaseNotes.txt and changes from -rc13 can be seen below.
Feel free to raise issues found during testing on this discussion or in the new support section in the APM Forum.
It’s a big release with “the onion” restructure and a bunch of new features (including these 57 closed items) so we need to re-test almost everything including all flight modes, all mission commands and all the new features. Marco and I will be maintaining (and adding to) this testing list. Issues reported will first be checked by Jonathan, Marco and I and then confirmed bugs/issues will be put on the github issues list (and then hopefully fixed).
Thanks especially to the beta testers who put their copters at risk testing each release. Enjoy!
Changes from 3.2-rc13
1) Safety Features:
a) fail to arm if second gyro calibration fails (can be disabled with ARMING_CHECK)
2) Bug fixes:
a) DCM-check to require one continuous second of bad heading before triggering LAND
b) I2C bug that could lead to Pixhawk freezing up if I2C bus is noisy
c) reset DCM and EKF gyro bias estimates after gyro calibration (DCM heading could drift after takeoff due to sudden change in gyro values)
d) use primary GPS for LED status (instead of always using first GPS)
Well, you can also just dump the screws and just tape the case together, or use brass screws, or stainless, or aluminum.
Take a normal magnetic compass, move it closely around the electronics and wiring in you quad/plane, see if there any major deviations on the needle.
Both with power on, and off.
If that remains pretty stable, you have some other problem.
I replaced the steel screws in the Pixhawk and GPS with brass screws. That way even my own screwdrivers, which have become magnetized over time, will have no affect on the screws.
Big offsets of compass is caused by residual magnetization of compass IC. I haved same problem with onboard pixhawk compass (high offsets values around 600-800). I rid of that by demagnetizing chip with modified AC 50Hz transformer, after that offsets are very low around 10 to 30.Hope it helps .
@Randy, Sven, Bartek,
This is VERY interesting and probably worth adding to the wiki. Miraculously I found my tape head demagnetizer and held it to the mag chip and made it much worse the first time, The second time I waived the wand around over the chip and voila! the offsets are now very good (101, 18, -4) and the compass is working perfectly. Thank you so much Bartek.
Could the compass becoming magnetized be one cause of flyaways? I didn't know this was possible so it's worth some thought and testing. In my case, having the GPS wires running over the magnetometer must have caused the residual magnetism and this could happen over time with less obvious causes and unbeknownst to the pilot.
Thank you Bartek, I'll give that a try. Somewhere I have a tape head demagnetizer (if I can find it) and I also have a big tool demagnetzer. I'll let you know how it works.
I think you demagnetized the chip to the point where it doesn't care where north is anymore.
Micheal does raise a valid point.
I would be very weary of waving a high power de-magnetizer around sensitive electronics.
Unless you have stuck a very strong magnet onto your APM, there is hardly any way to build up a strong magnetic bias.
Just google "hall effect devices", see if you can really "de magnetize" them, or should have too ?
@Randy. Thank you.
I did update to the latest Mission Planner. 184.108.40.206 build 1.1.5434.14510 (c8e0f3e1)
The new "compass live calibration" changed somehow.
The previous offset on this quad (done with "speedy live calibration") were: -65 23 36
After updating mission planner and re doing the same procedure at the same location, the new offsets were:
Test 1 : -52 19 47
Test 2: -53 7 47
Test 3: -57 21 38
Should I continue or just leave it at the last one? I did hope to get constant values.
But the first and last tests are not too far apart.. Which one to believe?
I think those compass offsets will be fine. Those offsets are all pretty small and compared to the overall field length (which is likely around 500) a 16pt change should be ok. I say "16pt change" because it looks to me like the Test #2's Y axis offset shows the largest change and it's 16pts from it's previous value.