Ok, I checked, ordet was roll, pitch yaw. I changed to pitch-roll-yaw, but this did not help.
I will make video.

I see that it is gimbal camera-PITCH-YAW configuration. If its application is to work in the "Follow" mode, to just repeat the rotation and tilt of a plain, then you have to enable PITCH and YAW motors and set the "Euler order" = Cam-PITCH-ROLL-YAW. I really surprised, why is does not initialize properly in this configuration, because it should work fine and start from any position: PITCH angle is properly defined in full 360 range.

If target is to lock camera to a point on a ground, for this configuration it is better to use Euler order Cam-YAW-ROLL-PITCH. It perfectly fits for such kind of gimbal and application - you control it in ROLL and PITCH global axes and does not depend how plane is oriented.

"Would like a toggle button (5pcs) for quick switch to profile on the board during setup. " - ok, I will add it in the nearest 2.65b6 beta release.

Thank you again. If you like I will make another video to show you the settings, I changed to pitch roll yaw and same problem at startup.
It seems to want to keep the camera not to flip picture..

"If target is to lock camera to a point on a ground, for this configuration it is better to use Euler order Cam-YAW-ROLL-PITCH. It perfectly fits for such kind of gimbal and application - you control it in ROLL and PITCH global axes and does not depend how plane is oriented."

This part I don't understand. We use both follow mode and tarheting mode. We change within rc switch.
What I don't understand is what you are saying about controlling in roll. There is no roll axis motor in the setup. How can do you want me to control roll? Maybe I misunderstood something.

Ok, but do you have any solution for our problem? I tried what you said and it did not help. Again as you see in the video, the problem is (not just start up, but also if I move with RC receiver) that if the camera pitch more than 89-90 degrees down, then the yaw tries to turn automatically 180 degree (I guess to try to make picture not to be upside down). However in our case the yaw CANNOT turn 180, but only 110 to each side. So we need to disable this weird auto functions.
So problem is not just start up, but anytime.
I tried to change Euler order, but that did not fix the problem.

I am trying to make PITCH-YAW gimbal without any encoder. I am using 2.63b0. Is there a way to look at one point by compensating roll of a frame. It is multi copter application. I want that if I am looking down and vehicle rolls, gimbal should yaw and pitch to keep looking down.

If encoder is needed, what will be setup and parameters for that. I am using extended board with CAN IMU.

I don't understand clearly. Even, For PITCH-ROLL gimbal, suppose gimbal is looking at (ROLL-0 and PITCH-0) and frame yaw by small angle, ROLL motor have to rotate 90 deg and PITCH motor have to change accordingly to maintain Line of Sight(LoS) on same point.

Only issue I see is that, in PITCH-YAW case, PITCH and ROLL axes will be swapped after 90 deg yaw.

Camera rotating about POV axis is acceptable for our application. I have come across off the shelf two axis gimbals which can handle fixed LoS in both CAM-PITCH-ROLL and CAM-PITCH-YAW configuration. Though I am not able to find any controllers separately. I only found SimpleBGC and thought it can handle fixed LoS for PITCH-YAW and PITCH-ROLL configuration.

Is there any chance of inclusion of this functionality in SimpleBGC in near future? If no, Do you know any controllers which can handle PITCH-YAW fixed LoS application? I was unsuccessful with Storm32.

Thanks for the reply.

Sorry as I was not clear in explaining our application. We are building ISR payload. We are looking for gimbal with continuous 360 pan and -15 to 90 tilt. Payload is belly mounted on UAV.

We have three modes of operation as outer loop for user. Loops are running at 400 Hz.(We don't know the inner loop frequency of SimpleBGC) We have implemented this algorithms in ArduCopter.
1. Point to Coordinate - In this mode, user will give LAT, LON. FCS will calculate PAN and TILT based on the UAV location and attitude.
2. Target Tracking - In this mode, Image processing algorithm will tell the location of target in the image. According to the pixel location we will command rates to the gimbal.
3. Euler Lock (Fixed LoS) - This is default mode. In this mode, user can give rate commands, but the moment user release stick, we want that LoS (Vector in NED) should be maintained compensating vehicle attitudes including ROLL.

We are facing issue only for third case. We hoped that Euler lock is available in Gimbal and we don't have to implement outer loop as outer loop will lag significantally because it is implemented outside Gimbal controller.

Due to weight constraints we wish to build the two axis gimbal rather than three axis gimbal. And I believe PITCH-YAW gimbal is the only way to achieve our objectives.

We are currently controlling through RC and not Serial.

My GUI is not showing Cam-ROLL-YAW-PITCH order of hardware axis. I am using 2.63b0 GUI.