Version 2.5 of the ArduCopter code is now available in the AP Mission Planner and in the downloads area!
The default PIDs are optimized for a 3DR/Jdrones quad with 850 motors and 10" props. If you're using more powerful motors/props, start by turning down Rate Roll P in 25% steps.
While some testers have reported very good flights with the default PIDs, some have reported that this release is a little "sharper" due to the DCM improvements and have found they needed to:
reduce stabilize P by 10% (i.e. 4.5 -> 4.2)
reduce stabilize D by 30% (i.e. 0.15 -> 0.10)
increase rate D from 0 to 0.001
Tuning loiter can be tricky. Refer to the discussions which will appear below for more community feedback on what parameters work best.
Please post your feedback in this discussion. For enhancement requests and bug report, please add them to the arducopter issues list. When possible please include logs (tlog and/or dataflash) and tell us whether you're using APM1 or APM2 and what version of the software you're using (presumably 2.5 but tell us anyway!).
Thanks for this release go to the developers (both in the core team but also those who have provided bug fixes through the issues list) and also the community members who participated in the previous release thread and provided some great detailed information in the form of issue reports and logs which allowed us to nail some bugs!
Oliver, could you try a flight with the compass disabled? We're trying to figure out if magnetic interference is causing issues that we're not seeing on the dev team copters, perhaps because the compass code had changed and has more impact on flight performance than before.
Think it almost has to be a software issue.
How else can be explained that turning to previous software versions eliminates the problem entirely?
Think u4eake mentioned that in this thread some pages ago. Same hexacopter flying 2.5.3 = yaw problems, returning back to 2.0.49 = no yaw problems whatsoever.
Is the yaw problem actually also present on APM2 hardware?
Compass on last flight was working correctly. What I can't understood is why I had problem on only one quad and just for two flight, third flight was ok for the compass but not for the barometer.
For the second quad (same software version 2.5.6 beta) all was fine.
But if it can help I can do the test, in couple of day, it seems that we will have again bad weather (cold and rain) for some days.
Just 3 questions,
I just need to disable magnetometer in MP?
Does It will have bad effect on DCM regarding gyro accelerometer correction?
Do you need I activate special logs?
Oliver, do you want to enter in the "kamikaze testers team"? We really need active (expert) members, PM me or Chris for this, if you want to join.
Oliver take a look at this and consider if this might be partly contributing to this problem .
It may be your barometer is being affected by pressure variance with the centre cover you are using. Since this post and even before it some others have found this to be the case
Also check the mounting of the AMP board is firm and my thought in this on this post here. http://www.diydrones.com/forum/topics/arducopter-2-5-released?comme...
Thank you for the info.
In my case I'have the problem with or without the cover. And Barometer value move a lot also on the bench.
My propeller and motor have been balanced. An my APM is mount like this:
Apm is mount with plastic bolt on an epoxy plate, to avoid short. And the epoxy is fixed on the frame thru rubber stand to filter vibration.
The cover box have also some hole behind the epoxy plate and frame center plate to avoid air disturbation from propeller.
For info this config has flown very well since last tuesday.
Oliver I have just been spending some time looking at your photos to see if I can spot any hardware issues. This container you are using looks like it is air tight? I see you have an aerial sticking up out of the container in a tight fit hole, but I don't see any other vent holes.
If the container is air tight, when you are out in the sun the air pressure will increase as the air in the container heats up and try to expand and if it cant get out pressure will build up in the container. This will give the affect the baro will read this that the quad is going down so it will try compensate and try to make it go up. This might be why in test 1 it shows the negative altitude and started to climb when you switched into a mode?:
The cover should have the same opening holes in the top as the bottom to avoid pressure changes in the container and particularly when you are flying so the baro get the reading of the outside pressure.
Also I see your props are very close to the housing so this can also cause pressure zones that are different in pressure to the surrounding atmosphere that may affect the baro. Try to imagine the column of air being dragged down from the four props and if any of this affects the air near the center of the quad.. There will certainly be pressure variances surrounding the center of the quad if the props are very close and can posibly affect the baro.
Other things I spotted that may or may not be an issue is I see many wires running parallel and yet no shielding or chokes are fitted to the wires to reduce rf interference. The mag and and other sensors are very sensitive to RF noise. so best to put chokes on wires or at least twist them. Keep the Xbee and RX aerial and wires well way from the mag and sonar wire as well. Ive had lots of issues until I fixed this on my rigs with this same problem
About Hole, I've a 30 mm hole drilled under the box, but not on the cover. Wich has maybe enough during winter flight test (not so sunny and warm as tuesday). The reason why i've not made a hole on the top was to avoid air pressure due to speed. But it not explain why alt falls down so fast when quad is on the bench on the field without cover.
Regarding propeller, I know they are very close, but I've done a lot of hand test at home without motor or motor with propeller at high speed, and baro alt was good.
Rf noise will be the suspect (unfortunatly I have not bring with me my portale oscillo). I'had some kind of problem with xbee at 900Mhz, wich has been solved by changin for a 2.4 Ghz module.
I know also relative percentage of humidity can have an effect on RF noise. I definitively don't think this is a software issue (2 quads same APM bought at same time).
I've done a test à home this morning on the bench, Mag is ok and alt stay in +-50cm which is pretty good (with or without engine armed an running), I will became crazy;-). If open the window to get a gps lock baro start to move when i'm locked in 3D. Gps and xbee cable are twisted but maybe not enough.
I've somewhere some choke. I will try to put some choke and see what's happen.
Finally I've found my problem with Baro.
April 17th was a beautiful day (very sunny), we should pay attention on direct sunlight on Bosch baro. In my case this why I've problem only outside, and why it was working before during winter. All the test I've done before outside was on cloudy day's.
Netherless I've also put some choke.
The way I've found is funny, I've installed the choke and put the quad on my window to get a gps fix, it was ok until sun appears for some minutes, during this time baro fals for 12 meters... and I've remeber it's noticed somewhere in the wiki.
that's really interesting Oliver, I had no idea the sun would affect the baro.. thanks for the info and nice videos I saw you post as well.
@Oliver: Xbee on which frequency, 900 MHz?
If on 900 MHz you must absolutely put the module away from the APM, it bothers him that the barometer.
I've the new 3DR Radio 900 MHz version and i've same issue.
To solve the problem I had to twist the cables that connect the module to the APM, and put away 20 centimeters and with the antenna pointing down, not in line with APM.
Before doing this I had the height that varied from 0 to 5 meters continuously (measurements made on the ground of course).
I'm using a 2.4 ghz xbee, cause I've had an issue with 900Mhz module with baro.
Anotherthings to consider here in france 900Mhz is not allowed (used by mobile phone ).