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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              • about minimOSD firmware: flash the r800 firmware found here:  http://diydrones.com/forum/topics/adding-extra-functions-to-minimos...

                just flash the char flasher first, than charset itself and only than the copter firmware. 

                • Oh, I did that (FW r800).  That's what led me to more than five hours of screwing around with the MinimOSD.

                  I did the Character Flash first, then the Copter Firmware.  That led to issues with my SR0 and SR1 settings in the Pix.  The OSD worked fine with my original Pix settings, but for whatever reason, I was getting the dreaded No Mavlink Data.  Why the heck would it work, then not work?  I got it figured-out (from here: https://code.google.com/p/minimosd-extra/wiki/APM).

                  Then, sometimes the panels would update with the "OSD text" location change I would make, then sometimes it would not.  On my particular OSD (genuine 3DR), I have to power-up both the analog and digital side (and even in the right order), and then there's only a 10% chance the any change will take place).  Then other times, the OSD would just be blank (extremely frustrating to say the least).  And yes, I am using Panel 1, Panel 2, and no panel via a three-way switch on my TX.  Seems to be working nicely, but it sure took a long time to get from Point A to Point B...

                  • oh, SR0/SR1.... those are erroneously zeroed out in the 3.2+ been this way since the RC1.  honestly, minimosd needs a better wiki to explain the process. I kind of figured it out faster, since I never new about r800 and used whatever firmware was in the wiki downloads and there is a guide on how to set up those.  it took me about 10min to setup everything, however I "discovered" the r800 only about a month ago. just flashed that one and am using that one since than on all copters.

            • Developer

              Joe, your statement needs a bit of clarification

              I think you guys are confusing cases where the sensors detect a problem with the setup in the vehicle with the case where sensors themselves failing.  In both cases we report the problem.

              It is really important that you guys understand that you can have gyro / inertial nav problems with any version of the firmware.

              We have learned how to detect problems and provide warnings rather than just having people arm and then have crashes. When you see the warning messages that means the sensors and the autopilot are dutifully doing their job and detecting and reporting errors.  That means you should fix something with your setup, not question the messager and say the autopilot is not working correctly.

              If you are getting a message about bad gyro health then you have some issue where the gyro drift is too high.  It might be voltage related. It might be temperature related. It might be caused by bad GPS. There are many possibilities.  The autopilot is doing it's job to tell you something is wrong.  It is up to you to look at the logs and figure out what is wrong.

              If you get a message about a sensor failing, that is different kind of problem but again the autopilot will tell you there you about it.

              • Craig - I am going to PM you as my post below you is actually to Artem, yours just came in sooner.  Sorry about that.

  • Well I said earlier I couldn't get rid of bad compass error on my hexa, Went into mission planner do I another compass cali and no I can not do anything with it. I just get error 99 in the compass cali. This error is affecting so many people and personally is getting right up my nose. I have had 2 pixhawks and now both of them have let me down! I thought DJI was a joke seems 3DR is now becoming a joke!

    • I had an issue where no matter what I did the compass would not calibrate right. One of the devs [ Bill ] suggested I do 'reset to defaults' in the full param list. Might want to save all your current setting first like RTL alt , failsafe settings , PIDS, etc... but anyway after I reset to defaults  I was able to calibrate the compass and save the offsets no problem. I also did the motor offsets and it's been flying perfect ever since. I did have to enter my settings again but not that big of deal.  I have no idea if that will fix your issue but its worth a try at this point I would think. 

      • I'm going to try this when 3.2.1 is out. If I save my settings can I not just reload them after "reset to defaults"? I think reset to defaults wipes the flash memory. I was primarily going to do this because I did "set home location" which I believe is bad on 3.2, but if its resolves my compass issues as well I will be very happy.

        • re - If I save my settings can I not just reload them after "reset to defaults"?

          I believe so yes.  You can get 3.2.1 already that's what I've been flying. 

          • Developer

            That will just defeat the purpose of resetting them back to defaults.

            You can select only a few key tuning items to re-load

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