Pixhawk BAD ACCEL HEALTH APM 3.2 - collecting data

A few users, myself included, appear to be having issues calibrating accels and/or arming when using APM 3.2 on a Pixhawk.  I see posts here and there, but thought it may be best if those having the issue could all 'check in' to one post so that the developers can see how widespread the issue is and gather data.

My Pixhawk will arm occasionally, and will even fly successfully.  Occasionally however it will not arm and I will receive the pre-arm error "Accels not healthy".  A few days ago I was able to arm and fly thorugh one lipo, then after landing and swapping batteries I could not arm due to this reason.  I have attached the logs from the successful flight, as well as the failed pre-arm logs, to this post.

As you can see from these images there is something amiss with IMU2.  This is a snippit from the good flight, showing values for AccX on IMU1 and IMU2:

3691166950?profile=original

and here are the same values on the second attempt, pre-arm.

3691167027?profile=original

In the 3.2 release thread a few users had mentioned the issue and Randy advised to set the log_bitmask to "131070" so that it will log everything including the pre-arm checks.  I encourage others having the issue to do the same and share the logs and experiences here so that we can find out what is going on here - is there a bad batch of Pixhawks in the wild that only now show the hardware errors due to something new in 3.2, or is there an issue in the APM software?

goodlog.bin

badlog.bin

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        • Hi, yes, that's why You can not arm. Prearm check is enbled.

          I got different accel health errors when upgrading from 3.2 to 3.2.1 in February.

          Then I downgraded and no problems.

          Have You tried to recalibrating accelerometer?

          (And I am also not sure, if this FC is genuine one :) Mine was purchased from 3DR ~300EUR without telemetry)

          Hope You will find out the problem.

          • Eva..I see you mentioned price of Pixhawk in Euros so I guess you are from EU...so,original Pixhawk can be bought here http://www.uav-store.de/autopilot/pixhawk/#cc-m-product-8496353793

            and the price will be better than ordering from USA and pay for post and tax....

            uav-store.de - This website is for sale! - uav store Resources and Information.
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          • Sure, it is a cheap clone...

            but there are so many users here complaining about the same issue, that i thought, maybe someone actually fixed it!

            i tried recalibrating acc and compas. without any success. The strange thing is, that with disabled pre_arm checks, the machine flies insanely good! 

            So what now? just not caring about the safety checks?!

            Thanks

            • Somewhere in this thread there is answer for you...I cant find it ..something like;try shortcut power wires(black and red)  ..of course,without ANY lipo connected

              • yes, ive read this, but i thought this is only for the original 3dr pixhawks?

                • I would say you have RTFHawk....

                • lol,,,, read better it says NON-3dr boards :) 

                  • not the pixhawk, but the whole copter WITHOUT lipo plugged in.... in old school terms it is called draining the capacitors... never hurts been doing it since early February on my basher copter. btw if you are looking for a budget friendly pixhawk equivalent with great quality google "arsov uav x2" it is a pin to pin compatible pixhawk shrunk about 2 times in size... 

                  • ohh.. my english is not the best... 

                    But is this an option? shortcutting the pixhawk everytime i have used it?! Hmmm

  • Hi, Im not sure if my pixhawk has this problem;

    I have an original 3DR Pixhawk with the DJI e300 kit and the drone only flew well few times, before with AC 3.2 i got a lot of prearm warnings, althought with AC 3.2.1 the number of warnings got reduced, but the drone never flew well. Reviewing the logs in Mission Planner i never found reasons for the crashes, until a review my logs with the "APM File Log Analysis" and i saw some errors in the accX, accY and accZ graphs, when this happens the drone falls. I attached some images of the graphs, log and video. I hope that someone with more experience read my log and help me :)

    Thanks.

    Mechanical Failure (MP)

    3701964069?profile=originalFrom APM Flight Log Analysis

    3701964124?profile=original

    Imu Consistency, MP doesn't show the "gaps" and the "jumps" of the Acc values.

    3701964088?profile=original

    This is the video from the flight

    7.BIN

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