[memz180]

This problem was occuring with me.

2 things I did to fix it.
1. Checked all motors that are exactly the same as shown on Librepilot with their order. 
2. Check your flight data to ensure that quad is moving the way your moving it. If you roll left ensure that the quad in the graphics is also. If not you'll have he instant roll.

I've been flying mine for a while now absolutely love it at the moment.

[TheOtherCliff]

It really really looks from video that stabilization is backwards / incorrect.

It starts a little unlevel say leaning left, so it tries to make it go right, but because it is backwards it goes farther left, so it tries even harder to go right which ... in human time it instantly flips.

Reading back, I see your first post you say

I can see that pitch and yaw are in reverse, that means, when i grab the copter in my hand and pitch it down, in the GCS flight data panel,  it looks like yaw right.

If it still does this than that is your problem, which says that either FC is not mounted normally or at least that RotateVirtual does not correctly match the way the FC is mounted.  This will definitely cause this instant flip.

Wiki has info about how to adjust RotateVirtual for different FC orientations.  If FC is mounted normally, RotateVirtual should be 0,0,0

I added some detail and suggest that you re-read my post about the things that cause flipping.
https://forum.librepilot.org/index.php?topic=3994.msg26880#msg26880

Good luck.

[TheOtherCliff]

I checked your prop picture and they look correct.  It still could be motor rotation wrong.  All motors should blow downward when spinning. 

It looks like you have the board mounted with 90 degree clockwise rotation and that you have that correctly configured in your settings (0,0,-90).

You have ZeroTheIntegral enabled as it should be.

There are things I cannot check that you will have to recheck.  First one that comes to mind is that ESCs are plugged in the correct location.  You can take props off, Output page -> Test Outputs to make sure of rotation direction and that ESCs are plugged in the correct place.

[sallyc]

This problem was occuring with me.

2 things I did to fix it.
1. Checked all motors that are exactly the same as shown on Librepilot with their order. 
2. Check your flight data to ensure that quad is moving the way your moving it. If you roll left ensure that the quad in the graphics is also. If not you'll have he instant roll.

I've been flying mine for a while now absolutely love it at the moment.

I checked this two but still failed

[AerialPerPlexity]

How about the transmitter is any channels reversed? maybe pitch or roll reversed?

[JardCrocker]

Hi...i am a new user here. As per my knowledge if a simple test of holding the quad in your hand and starting the motors to a very slow setting makes it try to violently twist out of your hand, then it is a setup problem.

[sallyc]

thank you everyone, problem solved, it is the motor channel reversed.
i have another question, when i connect cc3d to pi and read the telemetry data from controller, why the attitude state has value even my controller is still?

[sallyc]

I checked your prop picture and they look correct.  It still could be motor rotation wrong.  All motors should blow downward when spinning. 

It looks like you have the board mounted with 90 degree clockwise rotation and that you have that correctly configured in your settings (0,0,-90).

You have ZeroTheIntegral enabled as it should be.

There are things I cannot check that you will have to recheck.  First one that comes to mind is that ESCs are plugged in the correct location.  You can take props off, Output page -> Test Outputs to make sure of rotation direction and that ESCs are plugged in the correct place.

And by the way, if I want to know the velocity of X, Y, Z direction, which uav object should I read?

[f5soh]

VelocityState ?

[TheOtherCliff]

why the attitude state has value even my controller is still?

I don't understand.  Are you saying that Attitude State is changing even when controller is still?  How much does it change, some small amount is normal.  Maybe a picture of a Attitude State scope so we can see.

[sallyc]

VelocityState ?

VelocityState shows the velocity related to homelocation, so should I set homelacation first? And is that possible that when velocity in Z direction is zero, the velocity in X and Y are still existing?

[sallyc]

why the attitude state has value even my controller is still?

I don't understand.  Are you saying that Attitude State is changing even when controller is still?  How much does it change, some small amount is normal.  Maybe a picture of a Attitude State scope so we can see.

[f5soh]

VelocityState shows the velocity related to homelocation, so should I set homelacation first? And is that possible that when velocity in Z direction is zero, the velocity in X and Y are still existing?

VelocityState is NED :
- North and East velocity comes from GPS.
- Down velocity comes from Baro + Accelerometer correction

Assuming you are using a Revo/Sparky2 board, not a CC3D where VelocityState is not computed at all.

[TheOtherCliff]

Those attitudestate changes are down in the 1/1000th of a degree range and come from normal sensor noise.  It sounds like you need to ignore changes below some threshold.  Be careful to not just say I will look at changes in the 1/100ths place because a 0.0000001 change can change 0.1299999 to 0.1300000