I am quite new to this, but I have tried to connect my InfintiyMR-S2 gimbal to a CubeOrange with both PX4 and ArduPilot and I just can’t figure it out.
Gimbal: Infinity MR-S2 (documentation)
SimpleBGC version: 2.70b0
ArudPilot version: 4.4
I followed this guide to configure ArduPilot:
https://ardupilot.org/copter/docs/common-simplebgc-gimbal.html
So my parameters are: (the gimbal is connected to telem1)
MNT1_TYPE 4
SERIAL1_PROTOCOL MAVLink1
SERIAL1_BAUD 115200
SR1_EXTRA1 20
SR1_POSITION 10
SR1_RC_CHAN 20
For configuring the SimpleBGC gimbal I also followed the previous guide and also consulted the official AlexMos documentation:
The configuration:
Finally, I connected the RC_PITCH/AUX3 pin to RX, the RC_YAW to TX and the GND to the GND pin.
I plugged these into the TELEM1 port as similarly suggested in the ArduPilot guide above.
The SimplBGC board (as seen in the documentation of the gimbal → link at the top):
With this configuration, I now see the 1Hz heartbeat of the gimbal in QGC:
And if I switch the RC_SERIAL and UART2 then the gimbal receives packets from the fc.
But I couldn’t manage to get any further than this 
Any help is highly appreciated