of_loiter is not working

My of_loiter mode position is not working.
I use APM2.5 board and 2.9.1b version,
the optflow value changed when I move my quadrotor.
But,the x/dx ,y/dy,squal value are very strange.
x y changed but dx dy always 0 or 1,and squal always 0 or 255
what’s the problem whit me?
(My english is pretty basic,please don’t mind.)

Sounds like a communication problem between the APM and the optical flow sensor. I’m sure you’ve seen the wiki page on it. If you don’t follow the instructions precisely you could have problems.

You may need to be careful because the non-3dr optical flow sensors sometimes have a different pin mapping.

Best of luck.

Okay,Maybe I should try more times.
If it still not working, I will take some pictures and post.
Please give a favor by then thx.