I'm trying to do a quadcopter with some friends and we have a problem. It goes forward instead of hovering in place. We made a video to explain it, you can see it here.
As you can see, the quadcopter flight and go forward when I don't touch the controller. I need to correct it to go backward and it goes forward again.
We use the kk2.1.5.
The HobbyKing KK2.1.5 Multi-Rotor controller is a flight control board for multi-rotor aircraft (Tricopters, Quadcopters, Hexcopters etc). Its purpose is to stabilize the aircraft during flight. To do this it takes the signal from the 6050MPU gyro/acc (roll, pitch and yaw) then passes the signal to the Atmega644PA IC. The Atmega644PA IC unit then processes these signals according the users selected firmware and passes control signals to the installed Electronic Speed Controllers (ESCs). These signals instruct the ESCs to make fine adjustments to the motors rotational speed which in turn stabilizes your multi-rotor craft.
We made some test. As you can see in the video, we placed the battery backward to be sure there is no weight against. When we check values in the debug mode, all values are at 0 when nothing is pressed.