Mavlink gimbal control issue on Cube Orange

We are facing some strange issue on gimbal control over Mavlink with Cube orange.

We have 2 systems that are 100% identical ( Arducopter 4.0.3, Basecam controller tiny with FW 2.69 b7, same wiring, same configuration files ) with only 1 exception:

System 1 is using cube black
System 2 is using cube Orange

To control the gimbal we read analogue signal from joystick ( just pitch ) we than convert in digital using an ADC. Digital signal is than elaborate by our GCS into DO_MOUNT_CONTROL ( 205 ) and DO_MOUNT_CONFIGURE ( 204 ) . Both messages are than send to Arcopter over telemetry serial. Of course se use serial 1 for communication between GCS and Pixhawk, serial 2 for communication between Pixhawk and Basecam controller.

We already tried to change all SR1 and SR2 parameters to 0 ( zero ) on both systems. Same behaviour.

We have also tested mavlink messages between GCS and pixhawk using an arduino to read mavlink data in between and we agree that GCS to Pixhawk is perfect.

We suppose that on Cube Orange we have an excess of messages or much lower rate of messages 204 and 205 that affect our gimbal control.

Our SR2 parameters are configured as per Basecam suggestion

  • MNT_TYPE to 4 / “Mount Type (None, Servo or MavLink)”
  • SERIAL2_PROTOCOL to 1 / “MavLink” (Notee “SERIAL2” should be “SERIAL1” if using Telem1 port, SERIAL4 if using Serial4/5, etc)
  • SR2_EXTRA1 to 20
  • SR2_POSITION to 10
  • SR2_RC_CHAN to 20 and all other SR2_* variables to 0.

Cube black system react almost instantly with very smooth control, Cube orange instead has lot of delay ( up to 3-5 sec ) and control is not smooth.

Please let me know if we need to provide more informations

After lots of testing we work around changing some parameters on pixhawk and basecam:

We mainly remove all RC_chan bringing the parameter to 0, Disable RC request on Basecam and increase serial speed to 265000.

Can someone confirm that cube orange has a sort of filter of fewer bandwidth on serial2?