Thanks for confirming that -rc3 does not fix the issue. Could you re-confirm that 4.0.0-rc1 does work? I’ve recompiled -rc1 on my machine and placed a binary here. https://www.dropbox.com/s/lm1p6grtxtv4eyj/arducopter-400-rc1.zip?dl=0
P.S. this version is actually not identical to what firmware.ardupilot.org would have produced but it’s very close and should act the same.
Thank you for the Feedback, I did try a test again with 4.0.0 RC1, last time it was in the bench. This time in the air and the issue did happen. So it was not fixed in this Version, sorry for the mistake. I will check your Version today and let you know.
Ok, txs for doing the test. In the coming days I’ll produce a version of 3.6.9 and 3.6.10 so you can confirm that one has the sync issue and the other doesn’t and then we can narrow down on which change between these two versions caused the issue.
I was wondering if you could provide a log using Copter-4.0.x? We discussed this on the dev call and it seems that 4.0.x has a new IOMC onboard log message that provides information about the IO processor’s health including errors and restarts.
I will also produce those test firmwares for you shortly.
Thank you again for your help! We tried the 4.0RC1 you provided, the problem is still there.
I can send you also a logfile, but it will take 2-3 days.
Sorry to keep asking you to testing various firmwares… but I think there’s a good chance we’ve got to the bottom of this finally so I’m wondering if you can test the binary from Tridge at the bottom of this thread. Here’s a direct link to the CubeBlack binary that has a fix. This is Copter-4.0.2-dev so it hasn’t gone through beta testing so please be careful.
@Jimmy_Oliver that sounds like a motor timing issue.
I would go through available data on the firmware/motor combination as a first step.
Definitely doesn’t sound like bearings.
I dialed back to v3.6.9 and the knocking stopped but I am still going to roll back firmware on ESC’s when KDE decides to get back to me on my service ticket.
If indeed the problem goes away when you load Copter-3.6.9, could you give the firmware linked above a try?
I am going to test a version from Tridge to see if the knocking returns. This exchange is cross pollinated with a Facebook thread. Still not convinced that KDE firmware update wasn’t responsible for a wild LOITER ride I took 2 days ago. Flew fine in STAB.
Here is a 4.0.2pre copter firmware with the fix that may help:
http://uav.tridgell.net/tmp/copter-4.0.2pre-CubeBlack.apj
Fantastic! Nice clear demonsration and it’s really really great that this seems to fix the issue. I’ll probably release Copter-4.0.2-rc1 tomorrow to start beta testing.
At the end of the video I think you said “no knocking”, is that right? I don’t hear knocking in the 4.0.2 version, but just want to make sure
I listened again when I was home and had proper audio, it is clearly good. Thanks again for this test!
I had the chance to test it today, but only on the ground, I tried both versions, the new 4.0.2 and the 4.0.2pre. The problem was still there, but I have to do some more tests tomorrow. I tested first 3.6.9, which works fine, updated to the new version, but than had an another problem were I received always a radio failsafe when I used full throttle.
If it helps, here are the logs, first one ist 3.6.9 and second one the new version
Thanks for the feedback. I checked the logs and it looks like the 2nd one (000005.BIN) is still running Copter-4.0.1. Can you retry with Copter-4.0.2-rc3?
I tried it today, double checked the firmware, all ground tests worked fine!
We checked also, why there was a Radio Failsafe, when we gave full throttle. It was a setting under MOT_PWM_TYPE, it was set to one, changed it to two and everything worked fine again.
I have the same problem with one of my copter when I update from 3.6.9 (chibios) to any greater firmware
When I press the safety switch, sometimes 2 ESC are ready, other times only one esc is ready.
20 seconds later the 3rd esc is ready and so on …
Today with with Copter-4.0.2-rc3 it worked.