Note: just as the release was going out an issue was found re support for the all Camera Gimbals on the APM1s (it doesn't work) and with 3 axis gimbals on the APM2 (2-axis works ok but not 3). If you're one of these people, please wait for 2.7.3 which will be out shortly.
UPDATE: 2.7.3 is now in the Mission Planner
Functional Improvements over 2.7.1:
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.
There is still some question on whether the default Roll/Pitch Rate P (0.175) is high enough (it was 0.185 in 2.7.1) and also some people feel the Throttle Rate should be higher (currently 0.300 but some say 0.330 or even much higher would be better).
Please feel free to report issues you find in the discussion below and/or add them to the issues list.
Thanks and enjoy!
Found my problem. the servo cable from the Rx to the APM for CH-6 was backwards.
so, Dani - which parameters should I tune first to match your ALT-hole performance?
Also check your compass calibration/declination. If these are off it is always heading in slightly the wrong direction and this can end up in a diverging circle.
as stated in the wiki FAQ: "My copter increasingly swings up and down in alt hold. It eventually get's down to the ground: Your THROTTLE_P is too high or low. You don't need a lot of P to do alt hold. Think of how much you move the throttle to hold alt perfectly. Not much! That's what you need P to do. I will ramp up as your battery goes lower to make up the difference."
In my case I lowered the THROTTLE_P.
Just play with it.
Thanks Dani. I really do appreciate your assistance and advice.
I did use the Wiki for reference, but there is no "THROTTLE_P" in any of the MP screens.
I did set CH6 to "CH6_THR_HOLD_KP". The CH6 knob changed the "Altitude Hold P" in the ArduCopter Config Screen. It also presented as "Altitude Error" in the "ArduCopter Pids" screen. And in the "Parameters List" screen it is the "THR_ALT_P" parameter.
Can you see why this is confusing to someone not intimate with the software?
On the ALt-Hold mode, I was able to tweak the above parameter (CH6_THR_HOLD_KP, Altitude Hold P, Altitude Error,or THR_ALT_P. Pick one as they all appear to be the same parameter), and I got the ALT-Hold mode where I am happy.
I am not afraid to tweak other parameters, but figuring out which parameter name to tweak is not trivial when they all go by different labels.
Guys need help over here: http://diydrones.com/forum/topics/apm-2-5-level-gets-corrupted-logs...
looks like a bug or defect on APM 2.5 on the auto trim. please read and check the logs.
Need to know if this needs to be RMA or just waiting for code fix.
What should the LAND flight mode do? Should it just descend and land wherever the Quad is? Is it at all tied to GPS?
Good question, Ive only tried it when included in an autopilot mission plan. I went to look it up in wiki, but its not listed in the flight modes which is strange.
I would assume that because its an auto pilot functions it would be using the GPS and probably in combination with the barometer. Just my guess though.
You could probably test if by turning off the GPS and then see if "Land" will make it land using the barometer only.
I've played with the land mode a few times - It slowly drops the copter until it's on the ground. I've got a hexa and have had it hop after touching the ground 2-3 times before settling, so I haven't played with adjusting it yet.
I have a sonar installed, and have been told in the past that it uses the mix of baro and sonar (if available)
I would happily update the wiki if we can get some more info about its' function..
That's what I expected it to do. Maybe I have something set incorrectly, but while it usually does what you describe, sometimes, it actually seems to send the quad upward. Very weird.
Have you had it hovering when switching to land? If it doesn't start from hover, it wont know what throttle value to start reducing from..
In the code of do_land function, there is a call:
so as I understand it makes loiter with descent.