I have run into a problem similar to Peter -
wherein the motors under 2.71 surge regularly just sitting in stable. Under 2.6, my quad runs beautifully, floats like a butterfly. Here is the motors graph (logs, params attached.) from a very nice 2.6 flight-
But installing 2.71, using 2.71 defaults, makes the motors pulse and they sound just like Peter's sound. It is obvious in the graph-
I too have done the Marco load old - reset - erase - reconfig, changed Rate P, Stab P to no avail. Just loading 2.6 back and it flies perfectly, 2.71 and the prob appears. Is anyone else having this prob? Are there any params I am missing?
On the good side, I love the new UBlox! I see a lot more accuracy even in 2.6, but even better getting a fix in 10 seconds rocks!
Are you saying the noise is during alt hold or all the time?
If you are saying alt hold:
The throttle_rate_P value can pump noise from the climb_rate calculation into the motors. It is higher in 2.7 than 2.6 by default since we have a new filtering mechanism. Use the 2.6 gains and let me know if it goes away. If not, I'll give you a patch that reverts to the 2.6 baro climb rate calculation.
Unfortunately it was bad in all modes - did ah, loiter and stable in above.
I have tried again, doing 2.71 with MP, reset, then erase to default params, then full config and still had very erratic results, lots of pulsing and twitching. I thought maybe params needed to get way different, so I lowered rate P down to .09, D to .001. It then flew sluggishly without as much twitching but still had kind of a rythmic surging / wobbling in in stable / AH / Loiter modes. Worse than that, several times it rolled to the left suddenly without any action from me and took quick stick to stop. (log attached- a big one is at the end of the loiter at 5580 - it pitched and I killed loiter not knowing why so erratic.). Do I need to play wih params I usually don't, like IMAX?
This is my fourth trip from 2.6 to 2.7x wherein 2.7 was very ragged and just loading 2.6 made it fly perfectly. The first time I was using Mtek gps and it was very twitchy and hard to fly - I assumed Mtek gps lag was a prob. Installing the UBlox did smooth some loiter twitching and it looks like it wants a tight loiter but it is still twitchy
The good news is that loading 2.6 with the UBlox really is a marked improvement over all before - my loiter and rtl are well within 2m almost all the time even with 2.6. It flies so well under 2.6 I am hard pressed to imagine much better, so I am hardly stressed. Anyway, THANKS again and have fun playing with your son!
I only just had chance to do a reasonable test:
UBlox first test
Loiter under sonar, and baro, GPS positioning amazing!
All modes work good, then got blown out to sea, lost orientation for a good while and it was getting tiny! Finally climbed to about 200 meters, switched to RTL, it worked flawlessly but took (what seemed to be) a long time to get back to shore against the wind, now that's not the way to test RTL...
Tried circle, it did circle, it did face the center, but seemed to circle in a very lazy way.
Motor surging is still there, maybe slightly less but still spoiling things, Its most obvious when in any sonar height mode, every little surge increases the height, as if it's floating over a series of bumps.
It happens still in all modes! I'd like to stick with v2.7 and get this problem located...