The latest AC2 code is posted. This is the last code before the big switchover to APM2 codebase.
What you should expect: More stability and better handling, especially if your CG is not centered.
Heres the update list from the downloads section:
Most stable flying version yet. Includes new stability patch by default and a new DCM gain and clamp value that should reduce drift due to linear acceleration in missions or long flights.
Switched rate gain calculation to use raw IMU rather than the DCM's omega. This crisps up the response a lot.
1280 has lost local flash logging, sorry, but it's just not supportable any longer.
some older tests have returned now the program memory is freed.
Remember, to use the new logging format on the 2560, you need to erase it at least once to format it.
He're the video showing just the control loop patch. The DCM patch was added later and improved the handling some more.
Yes that is strange that the copter should be already in good overing situation for the Halt-Hold to work properly.
Is there a missing initialasation?
Or maybe a Integration reset missing ?
Maybe it's just a PID setting problem. I would say that the ALT_HOLD_I component should compensate for bad throttle starting points, probably having big I and Imax will fix it... but that's just a guess
...I still couldn't make mine work decently.
I am not sure to take the next step. I opened up a ESC on my quad custom build in hope to do a firmware update. It has a
C8051F310 on a Turnigy Plush 40. This Silicon Labs processor is also used with the what Turnigy calls the super brain ESC.
This hardware has not failed so far and is reliable. However I may need to purchase the ESC's from DIY drones store.
Any additional tuning (except one descriped in the manual) should be applied after burning IMU? I've uploaded 2.0.55, had 2 normal flights with no significant stability increase and one - between those two - when the copter flipped like it has not been leveled.
P.S. Thanks for fixing "Missing RC Rev param" bug:)
Hi, another question.
Can you still load this firmware out of Arduino?
(From a VERY windy Cape Town, grr....)
I did load the 2.0.55 firmware with Arduino on my Atmega2560 with no problems.
Ok, today I'm really negative about my copter :-( ...if anyone feels like helping or encouraging me...
I'm facing different problems with altitude hold and the magnetometer.
For alt hold, it seems to work with sonar (although pids are not good at all) but when I load the log there's no valid data (just zero). In the CLI the test works fine. Anyway, when I get barometer alt hold it gets pulsing and if I donwload the log I can see that the baro outputs zero height once in a while for no reason. With the tests on CLI it looks like it's working fine (no spikes)... obviously here you have no motor running, vibrations, etc. But why? How can I fix it?
Also a couple of times the alt_hold was working fine with sonar and suddenly started decreasing throttle until it touched down when I switched to manual (the throttle stick was centered, I think). Does anyone saw this problem too?
The other problem is the magnetometer. When it points east, I get 90 as output in the CLI which is perfect then I point it south and I get around 230 which is 50 degrees off... then pointing west I get around 300 and north is fine again like east...
Third problem is that my copter lean to a random side after minutes of not even too aggressive flying. I tried playing with the pids unsuccessfully. If I land and take off again, the copter is centered again. I already soldered the filtering pads and the APM is mounted on a plastic support with a some (small) kind of vibration absorbing proprierties.
And let's keep going with troubles: I did some tests about motor redundancy (keep the copter leveled even if a motor fails) and realize that if the copter goes beyond 90 degrees of pitch, it will start flipping and not recovering. Like, even if I stop the motors, wait for the copter to stop oscillating, wait some seconds and start again the copter will move to vertical position and flip again and again. Is this normal?
The stabilize_I didn't improved the recovery speed from one motor turning off while I saw that RATE_I does a great job in this... I can share some videos if someone wants them...
Last one is yaw... it always drift slowly in one random direction... Like one full turn in 60 seconds or less.
For your convenience other problems will be discussed in another post :-P
Hehe, sorry for this but today I feel powerless on my hexa.
Thanks for the reply on using Arduino.
I'm using a quad, standard, 1280 board.
The wind is too bad to fly outside, and the house too small to try position hold :-)
In stabilize mode it is very stable, the best I've seen so far.
I don't have the yaw drift that some previous versions had.
If I connect usb in Mission Planner, my compass shows the correct direction.
You don't perhaps have some power wires near the compass?
Obviously on the quad I can't test one motor out!.
I'm using a DX8, so I'm going have to live with the RTL failsafe, if it works :-(
Thanks for the reply,
I do have power cables right under the APM, like 3 cm away from the magnetometer but the problem exists even when the apm is the only thing powered (through USB) so it has not to be related with power lines. I still didn't use loiter, auto or RTL so this is not a big issue for now but it is an issue.
The most annoying thing now is the leaning to one side thing... It might be vibration (my cheap motors and props vibrate like hell) but it never did it so bad...
I don't know, I think I'll to sleep on that and will see on the weekend...
Ok I just found a reason for the baro problem...
as most of the time, it is my fault. I was reading the logs with mission planner 1.0.98 and a column was missing so in the sonar altitude column there was shown the yaw input and in baro altitude there was the sonar altitude so baro works fine!
The sonar have all those spikes but some filtering and shielding should fix it or I could disable it.
Magnetometer is still not working properly, though
Have you tried to adjust declination in setup? For some unknown reason had my compass completely wrong view, I installed the latest (from.50 to .55) version of apm and everything was in ok