ACRO bug (fixed in 2.9.1b): while doing flips in ACRO mode, if you switch to Stabilize while inverted your throttle will go to minimum. To regain throttle control you need to switch back to ACRO then back to Stabilize again (i.e. switch to stabilize twice). You never lose control of roll/pitch/yaw.
Loiter/AltHold/Auto/RTL bug: if you switch into these modes with throttle at zero motors will go to minimum until you raise the throttle.
Auto mode altitude bug (fixed in 2.9.1b): setting a waypoint altitude greater than 320m over home altitude may wrap around and instead be interpreted as a low altitude.
ArduCopter 2.9 is now in the mission planner and the downloads area!
The major improvement is we use inertial navigation to improve altitude hold. This increased reliance on the accelerometers means you must do some additional set-up before flying:
3. If upgrading from 2.8.1, modify the throttle and altitude PID values:
Here is the list of major changes (a more detailed list can be found in the release notes):
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.
Special thanks to our testing team lead Marco and the dedicated bunch on the 2.8.1 release thread who put their copters at risk while testing the pre-release version. Some of their videos are here: 1 2 3 4 5 6 7 8
Please feel free to report issues you find in the discussion below and/or add them to the issues list.
We've somewhat changed the autotrim method between 2.8.1 and 2.9. There are two methods:
Method #1: In flight auto-trim which can be engaged as in 2.8.1 by holding throttle down, and rudder right for about 15 seconds. Then you have 25 seconds in which you should try and fly a stable hover. Land, put your throttle to zero and it should fly level from then on.
Method #2: Set-up channel 7 to be "Save Trim", then fly in stabilize mode and use the trims on your radio to get your copter level. Then land, put your throttle to zero, don't touch your roll and pitch sticks and then flick the CH7 switch for a second or so (doesn't matter if it's longer than 1 second). remove the trims from your radio and fly again and it should be level now. Marco's done a video demonstration here.
P.S. I will update the wiki shortly. I didn't want to do it before the 2.9 release 'cuz it would have confused the 2.8.1 people
Not much has changed with the optical flow sensor and OF_LOITER so I expect it works the same as with 2.8.1. We have plans to properly incorporate it into the regular loiter mode by combining the velocity provided by the sensor into the 3rd order complementary filter we've started using (although we currently only use this filter for althold). I'm not sure if we will do that for 2.9.1 or the release afterwards.
There's a discussion here re updating the GPS mediatek firmware. We will write up a wiki page to make it official in the near-ish future.
Remember 42 and 0 will be the same for arducopter (0 = default which is 42hz) so "0" vs "20" is probably what you'll want to try. You can even try 5 or 10 if you'd like. Leonard is actually our real filter expert but my understanding is that lower numbers are more resistant to vibration but eventually it becomes less responsive. So we're looking for the lowest number that doesn't feel laggy or sloppy.
Anecdotal evidence so far seems to point towards 20.
Oh, ok, good to know. Thanks
Yes. With the new mediatek 1.9 firmware it's performance is getting closer to the ublox but I think the ublox is still slightly better. It just not quite a huge a difference anymore i think.
Hi Chris, I had the same problem as dudz, with it dropping to the ground as soon as I put it in alt hold. Disabling the sonar did the trick, and now alt hold works fantastic!
Any advice on troubleshooting the sonar though? I have the MB1200 unit that came pre-installed on my quad from the udrones store. I have verified that V+ and GND are correctly connected, and that pin 3 (AN) is connected to the signal side of AO as described in the wiki.
100% Thumbs up !!!
It really doesn't sound like a ppm encoder issue. I think Chris is right that your board isn't being detected properly by the mission planner. Have you ever been able to successfully load the code through the mission planner? CoolComponents is on the list of 3dr dealers so it should be the real thing instead of a copy.
I've just retested both an APM1 and an APM2 and they're loading fine so it seems to be specific to your board.
You know, I once had trouble uploading to a board and it was because I had one of the little jumpers. I think the problem jumper was JP2, JP3 or JP4 which are right near the radio input pins. If you have a jumper on one of those pins could you try remove it?
If that doesn't work, I'm not sure what to say, I guess the easiest solution is to load the code through arduino (the official 2.9 release is in the downloads area although it's the same as rc5 anyway).