Firstly, I've had some problem today when transitioning from loiter mode back to stabilize mode. So when I switched back to stabilize mode, it was as if the thrust command was frozen, and when I set the thrust at the maximum, my quad wouldn't take any altitude, but barely keep the same altitude.
I checked the log files and the MOD commands appear with the right mode...
After having grounded the quad, I could fly again without any problem, but when trying again this transition, I had the very same problem and this led to a more serious crash.
Did anybody encounter such behavior ?
Does the arducopter switch instantly from one mode to another ? Are there some kinds of transitions between modes that could explain that problem ?
Secondly, in loiter mode, my quad is drifting in light/medium wind and doesn't seem to make any efforts to keep its GPS position. I know the conditions were not ideal since there was some wind, but in Stabilize mode, I could easily compensate the drift manually, and the correction needed was light.
Finally, I wanted to test the RTL mode, so I waited for the GPS lock before arming the motor to properly set the RTL Home position. Hovering in stabilize mode 30m from the home position at about 3 meters high, I switched to the RTL mode. The Quad went almost to the right direction, but it was gradually and fastly losing altitude and finally crashed. I had cut off the thrust input on my radio but I heard that the motors were still trying to turn, even with the quad crashed upside down...
What is the proper behavior for the RTL mode ? Was it trying to land/ground ? In RTL mode, does the thrust input still function or is the quad completely autonomous ?
I think it would be a good idea to add some basic "flying mode" testing procedures to the wiki ?
What version were you flying?
It was the version I had flashed 1 month ago using the APM planner. I guess it was2.0.45 or 2.0.5?
I have now updated the APM planner and used it to upgrade the arducopter's firmware to the last "stable" version (v2.1 I guess).
Mode switches are checked 3 times per second. The copter switches to the selected mode immediately.
RTL is fully autonomous, thrust function won't work, but pitch/roll still work, so you can correct the heading of the copter.
Default setting is to return at current altitude.
OK, thanks for those details!
I guess I should set up the sonar before trying again the RTL mode.
Today, I could make my quad fly and I did try "stable", "loiter" and "simple" modes with the lastest stable firmware (2.1.0 Alpha) and everything went fine!