Hi Basel, thanks for your rapid reply.
I upload the connection diagram, the IMU output graph for about 900 samples and some photos of my quad and board on it. (one of the pictures is an + config but I cahnged it to x config. I put the picture for UNO view.)
I put a kind of foam under the IMU but maybe I need to try a softer one. This one could be a bit hard.
I use a small breadboard for wiring. The breadboard power and ground lines are connected the power and ground of UNO. All the other ESC ground to the breadboard ground (indirectly UNO ground). I supply UNO by 4s lipo which also supplies the motors.
Receiver is supplied from UNO (via breadboard power and ground lines).
I am not sure the IMU graph is the last version output but it could give you an idea how it is bad. If you look closer at the beginning of the IMU graph you can see the smooth “0” value. This is because I did not run the motors. When I run the motors all values goes crazy. After some trying I put a kind of averaging but then the measurement slowed down.
I could not find a receiver output I will send the receiver sample as soon as I can. (I crahsed my quad so it maybe takes a while