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!
Thanks Jonathan, Yes thats me!
I'm now very experienced at putting these things back together, I've had a lot of practice - I have about 8 different types of glue in my flight bag, so the DJI was airworthy again in less than 15 minutes.
And its glorious sunshine here, so I've skived off work to try and put together a video entitled 'how much fun can you have with an arducopter', it's going to involve fpv gear - and this will only be my fourth fpv flight ever!
Expect more carnage :)
looking good guys just waiting for all the new bits and pieces to arrive from all over the world....than i will hopefully be airborne again......without a flay away this time one hopes....
As I'm about to leave for the field to test 2.5 outside, just curious, is the ACCEL_ALT_HOLD operative? if so what's the difference between values 1 and 2? I understand 0 does nothing...
I don't think the accelerometer Z dampening stuff has been shown to work very well. Certainly it wasn't tested as part of the testing cycle leading up to the 2.5 release so can't make any promises about it.
From a quick look at the code ACCEL_ALT_HOLD = 1 is a simpler that uses the z access accelerometer value to apply a throttle dampener of up to 100 (i.e. 1/10th of your total throttle range).
ACCEL_ALT_HOLD = 2 is more complex and tries to use the accelerometer to do some dead reckoning. Apparently it can modfiy the throtlte by up to 300 points (i.e 1/3rd of your total throttle range).
Randy, even though firmware has Accel_Alt_Hold=0, can it still effect altitude hold? I was pilfering through code and found that it was not commented out from the copy I pulled from the official download wiki. I had been loading this firmware onto boards without noticing it. After almost pulling my hair out, due to aircraft falling out of the air when engaging alt_hold/loiter, I commented this out. No problems at all with altitude hold after i did this, or is this just happenstance?
What's more likely is that your THROTTLE_TRIM value was set too low. This is the base throttle that altitude hold will use and after a factory reset this is set to 350 which seems to be too low for many people. As you fly around in stabilize mode (and don't climb too much) it slowly adjusts this value to what your copter really needs. So the problem went away more because you spent more time hovering around.
Did the arming procedure change? gps is blinking, and before the red led used to stop flashing when gps had a lock even before you armed it. Now gps is blinking and never stops blinking until I arm it, it then immediately stops blinking. Is this a correct observation?
ArduCopter V2.5.1ß - Perfect Loiter (APM1 - Sonar - Light breeze):
I apologize for the poor video quality, not the usual which I have used, I had my fullhd cam available but I wanted to capture this loiter to make you see, after one hour of "ch6 tuning".
The small shifts are only due to error of the gps.
Inside the zip: parameters, log and tlog.
Maybe you could take your hand and drag it away from the spot and see how well it returns... Also, I wonder if this would hold up in more aggressive winds with your low loiter_p gain.
Yes Adam, he returned in the exact position, but i've in one hand the tx and in the other the phone... :P