I've been taking my quad out for testing lately and I've run into a few issues when trying to fly it.
Firstly, I'm finding it very difficult to keep the quad in roughly the same spot. Whenever I get it in the air it always seems to be drifting quite quickly in some random direction. The quad itself is stable and flying without oscillation, so I think I've got my PID control values tuned fairly well. I'm using fairly cheap ESCs (these ones: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=...), is it possible they're not all responding the same way to throttle commands? Or am I just a terrible pilot?
Similarly, I have trouble keeping it at a constant altitude. Even when I have Altitude Hold engaged the quad will sometimes rapidly descend when I haven't touched the throttle.
Another issue I've had is maintaining the quad's heading. Once in flight the quad will begin yawing rather quickly, which makes it quite difficult to control. I have the magnetometer, I've calibrated it's offsets in the CLI and verified that it's working in the Configurator.
GPS hold seemed to work for a little bit today. That is until I tried to alther the quad's heading, then it banked steeply and rapidly descended.
I've verified that my RX is trimmed correctly and the accelerometers are initialised properly.
I'm not sure what else to try. Any help/input would be greatly appreciated.
could your transmitter have been in altitude or GPS hold position when you activated motors?
This happened to me but luckily my hand was over the quad centre and was able to stop it!
I initially had problems wit the bullet connectors. Seems far away from the issue you seem to have however once hard wired together, I have had no problems with the stability (no more uncommanded death rolls!) I also mounted the boards between two layers of soft foam, maybe the vibrations were affecting the IMU's? Anyway, I think they helped.
However, I too have the heading hold issue, I thought it was heading lock enabled? Anyway, I set my rudder rate way down low (50%) so I need full stick to yaw it with authority. just small tweeks left and right keeps heading and gives me time to respond. Also, some "pool noodle" foam skids help me sighting the front and back:) I fly in X form as I want to make a plane like fusalage later. But for now, Im having fun getting stick time up, indoor flying helping out a lot. It helps with the confidence and now I use it to do parachue tests without the need of a plane or conventional heli. Just shoot it up high and release the chute and beat it to the ground for the next one. Small things amuse small minds:)