ACRO bug (fixed in 2.9.1b): while doing flips in ACRO mode, if you switch to Stabilize while inverted your throttle will go to minimum. To regain throttle control you need to switch back to ACRO then back to Stabilize again (i.e. switch to stabilize twice). You never lose control of roll/pitch/yaw.
Loiter/AltHold/Auto/RTL bug: if you switch into these modes with throttle at zero motors will go to minimum until you raise the throttle.
Auto mode altitude bug (fixed in 2.9.1b): setting a waypoint altitude greater than 320m over home altitude may wrap around and instead be interpreted as a low altitude.
ArduCopter 2.9 is now in the mission planner and the downloads area!
The major improvement is we use inertial navigation to improve altitude hold. This increased reliance on the accelerometers means you must do some additional set-up before flying:
3. If upgrading from 2.8.1, modify the throttle and altitude PID values:
Here is the list of major changes (a more detailed list can be found in the release notes):
As per usual PIDs are optimised for the 3DR/jDrones quad with 850 motors and 10" props. If you're using more powerful motors/props and are seeing bad flight behaviour in stabilize, start by turning down Rate Roll P in 25% steps.
Special thanks to our testing team lead Marco and the dedicated bunch on the 2.8.1 release thread who put their copters at risk while testing the pre-release version. Some of their videos are here: 1 2 3 4 5 6 7 8
Please feel free to report issues you find in the discussion below and/or add them to the issues list.
@Andreas: motors too powerful for the total weight of the quad, or propellers wrong for that motors (too large or with a lot of pitch).
When the quad as weight is perfectly balanced must stay in hover to 50% of stick, the optimal rpm for all the motors.
You can remove the "click" in the throttle stick of your tx (you have to open it to do), a linear control is better for rc quad\heli.
However it's normal that it is difficult to manually find the perfect hover point, experience helps.
I get a minimum of 9 all the time, even indoors. When reviewing my post-flight logs, I see it climb to 12 along the way. It seems to go up and down during the flight, perhaps due to altitude, although I haven't gone higher than 30m and I'm usually around 7m. Doesn't seem to vary with cloud cover. I'm using ubox and I'm in Ohio, USA.
Looks like 8 or 9 is the norm on this animation for 45N.
PS: I also use a 5.5V BEC on the inputs, but I have been disconnecting it when connecting USB because if its not powered the output impedance of the regulator is very low (short) so it just causes the APM to reset.
Also you should be able to connect using an FTDI cable see this link for info
Thanks for your reply's guys.
I dont acctually have the rachet in place, I just wanted to use that to explain my problem.
My Quad has very large props for its size and still I hover at +- 50% throttle. I will change the props from 12 inch down to 10 inch and see what it dose. I also have some 11 inch to try.
Leonard, thanks for the offer, I'd like to get the code. I'll PM you my email address.
Stop and consider why the TS5A23157 MUX chip gets fried and not the other components and why it doesn't happen to others who only apply a 5V BEC to the input headers of APM 2.5 - the reason is a 5V BEC outputs 5V +/- 5% so the maximum voltage is 5.25V whereas a 5.5V BEC can output more than 5.5V and that is what causes the mux to fry in that case.
If you examine the TS5A23157 datasheet you can see why, red arrows
The advice that it is safe to apply 6V supply via APM 2.5 Input headers is simply WRONG!! absolute MAXIMUM voltage on Input headers is 5.5V. A 5.5V BEC assuming it is rated at 5.5 +/- 5% can exceed that when it outputs 5.775V
I'm wondering if the props (especially carbon fiber) can cause multi-paths for the GPS signals and thus bad mathematics to happen?
RTH tuning question.
I have RTH tuned fairly well but I get a slight wobble on the descent at the end. What is the main gain parameter for RTH? Or do just have the basic rate gains slightly too high?
RTH descends very much vertically, which demands a lot from your tuning. I'd probably start by increasing Roll and Pitch Rate_P by 10%. Using RTH and waiting for the descent to see if it wobbles might take a while; if you can manage to get vertical descent wobbles in stab mode, you can tune it a lot faster that way.