We've just released ArduPlane 2.34
This release includes one very important update for APM2 users, and a few other minor updates.
The main reason for the release is to fix a bug in the scaling of the MPU6000 accelerometers. We discovered that the MPU6000 on the most recently shipped APM2 boards had different accelerometer scaling than earlier boards. This resulted in bad attitude calculations which would get worse during flight (as the DCM code interpreted the conflicting information between the gyroscope and accelerometers as gyro drift). We now query the product ID of the MPU6000 on startup, and fix the scaling according to whether it is a RevC or RevD version of the chip.
If you use an APM2 with ArduPlane then it is strongly recommended that you update to the 2.34 release.
Other less critical changes in this release include:
Great work Tridge!
Shameless feature request: Could you add a firmware update via telemetry option?
It's a pain to pull my APM and the oddball connector they used is always getting lost anyways. Hopefully APM3 uses a standard mini-B USB connector.
I don't think it's possible to do update over Telemetry - the APM2 isn't wired that way as far as I know.
What I suggest you do instead is get a micro to mini-B adapter (maybe 15cm long) off ebay and leave it in place. You can then put the socket in a more convenient place in the plane.
That's a great idea! I was a little grumpy because I thought I left the micro-B at my shop (too late to go get it tonight). Low and behold I actually found a micro-B cable sitting on my coffee table! Guess the GF had a few scattered around for her Android phone.
After the update I notice the az value shows the proper +/- 1000. So was the scaling actually fixed or did you do a workaround to rescale in the firmware?
I mentioned in another thread a few odd behaviors I noticed. Maybe I can list them here as feature requests...
When the plane is inverted it seems like it's trying to use the elevator to loop back upright. This isn't the best way to recover from being upside down. It would be better to roll out of the inverted position.
It also thrashes the rudder one way or another and/or back and forth when inverted.
I didn't have the wing on when I discovered this, so maybe I'm off-base here.
I agree that recovery from inverted flight isn't great. It does use roll, but I think the main problem is the wrap of the roll at 180 degrees however. As the roll passes through the 180 degree mark the sign changes, and the plane can change which way it wants to right itself. That usually works fine, but it is possible for it to get into an oscillation and take a couple of tries to recover.
I'm not sure when I'll get to this, but I have noticed it, and was planning on adding some "stickyness" to the roll direction.
Hi Tridgell !
There was a critical bug in the previous version (2.33), that when landing option is selected for a particular waypoint which is say close to home, the Arduplane will move toward this waypoint unpowered irrespective of wether the plane reached the home, or still behnd that or even have crossed that landing waypoing by several hundered meters.
I observed this many many times. If the plane is yet to reach the landing waypoint and if the altitude it has came down to is low then the plane will land there, not bothered about that he has not reached the landing waypoint.
And if the plane is heading unpowered, toward a landing waypoint and while the waypoint reached its altitude was still high, the Arduplane 2.33 will still not bother and continue to move ahead, and may go several hundred meters away from that landing waypoint.
Has this been taken care in 2.34 ?
Nothing in the landing code has changed.
I'm guessing what you are seeing is the "land_complete" code activating. That activates when the waypoint is a "landing" waypoint and the plane is either within 2 seconds of the landing position (according to the GPS speed) or within 3 meters of the landing altitude.
Once either of those two conditions is met "land_complete" is set, and the throttle is forced to zero. This is done to ensure that we don't keep spinning the prop when we are landing (which is important in many planes which belly land, and a good safety feature in all planes).
The surprising thing is that you are triggering this so far from the landing point, How much higher is the previous waypoint?
Have there been any updates to the camera mount code in this release? I know work was being done on it to potentially be released in this version.
Is APM aware of the wind speed and direction?
Does it compensate it somehow? (Not crosstrack.)
Can someone provide a short description with a photo (if possible) of how I should configure the solder bridge on APM2 (V2.4.1) to use UART2 for telemetry? Also if one does so do you lose telemetry on the UART0/2 port when the USB cable is disconnected?
Since firmware 2.34 I cannot connect to my APM2 through APC220.
I get a "Connection timeout" and there seems to be one frame of data being sent. The status info (attitude, gps etc) of that single communications burst is being displayed in APM planner (both 1.1.52 and 1.1.88) and then there is no refresh anymore. I had good communication with fw 2.33.
Please help me out.
Also got a question! :)
Is it possible to make APM mix a little rudder to throttle?
It is very important!