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!
You can now use Ch7 to access Auto-Trim. So take off and fly as normal, flip Ch7 high, do the auto-trim routine, and then flip Ch7 off.
Yeah, but my Copter flys away, so i cant do Auto-Trim without Stick Inputs.
As far as I know, auto trim is supposed to be used WITH stick inputs. The objective during the auto trim time is to have the quad hovering as stable and still as possible with the help of the sticks, this way, the gyros and accel will get an idea of how much do they have to compensate for you to have a steady hover and those values will be used as new offsets. The next time you fly in normal mode, the previous tuned offsets will be used as a neutral hover point. That's why you should use this mode in a windless environment, or you will be compensating not only the quad balance but the wind inffluence also, wich will turn agains you when you fly windless or wind comming from other direction.
Using a switch from the radio on ch7 does not do any good since Ch7 is always High
>800 whatever is the switch position (1 or 0 ) at least on APM2 with a DX8.
From what I understand, the CH7 Auto-trim allows you to manually modify the accelerometer offsets in real time while flying, so you will be using stick inputs.
1. Take off in a windless environment (indoors if available)
2. Switch into Auto-Trim mode
3. Use the stick to NUDGE the copter until it is hovering as motionless (horizontally) as possible, i.e. minimal accelerated drift.
4. Switch out of Auto-Trim without touching the sticks for a couple seconds.
What you are doing is actually using the stick to adjust the offsets, not necessarily to merely control the attitude of the vehicle. The way I learned what was happening was by plugging my quad into Mission Planner and engaging Auto-Trim mode. With the quad on the bench (motionless), as I moved the stick I could see the artificial horizon being adjusted, which is the result of the "level" offsets being adjusted by the stick!
I personally have had some problems using Auto-Trim, so i just level it on a good surface for now. I hope all of that helps. I'm no expert but I think I have a reasonable handle on the theory, anyway!
That is exactly as I understand it too Eric.
During auto-trim you are trying to keep the quad as still as possible in the air, using the sticks.
If you are having to hold left roll to keep the quad still the APM will see this and add in some left roll trim for you until the quad does not roll left any more, at mid stick, same thing with pitch.
As you say Eric the stick inputs tell the APM how much the quad is off-level and adds in small amounts of trim until its level (motionless in hover).
It's very useful, I've even sort of got it to work in light winds as well, as long as i do it quickly and from 3 different orientations (nose in to wind, side into wind, diagonal into wind) you can still get a better level than on the bench. Obviously in strong winds it's not much use at all.
Thx a lot ppl. Last Info, that i had was, that i dont use the sticks. Only starting and the copter will level, then land and thats it. So i did it wrong.
Have to test. ;)
Marco.... know if you can work with ultra pwm speed as they work from 200 to 1200.and be able to change the code to use? ... I'm asking because I have a plate alsomultiwii and that some codes were changed and you can use that speed, thanks
At the moment is useless because the code of AC does not turn more than a few hundred Hz, and then would serve no purpose to have a pwm signal over the frequency loop of the code.
Anyway you can force the output rate at "490" adding this line to the config:
#define RC_FAST_SPEED 490
Do you use "simonk" firmware?
My second APM1 board is missing a diode that some how got knocked off. Is it possible to just power the APM1 via USB together with the power hack?
My APM2 came in this week. :-)
Today I had some time to test.
I used an DIY frame 50 cm with KDA 20-22L and APC 10x4,7props powered by a 5000mAh 30C batt
It flew very nicely with default pid's
One thing I'm battling with is the fact as soon as I swith to Alt Hold, lets say from about 1,5m, the quad goes up to 3 meters. Retried from 1m and again it goes up to 3 m. Above the 3 meter it stays at the desired height.
Its like the 3 m is the minimum.
I have no sonar attached.
Could this be a parameter??
Attached is the log
What firmware version are you using?
That sounds like you have the throttle rate P to high since it seems to be overcompensating. I would recommend CH6 tuning to dial it in. Try lowering it a bit first