BlueROV2 Heavy gripper causes down thrust

I have a BlueROV2 Heavy with an attached gripper. I use the mav.manual_control_send() function to control the gripper. Specifically, to close the gripper I call:
mav.manual_control_send(target_system,0,0,0,0,0x200)
and to open it I call:
mav.manual_control_send(target_system,0,0,0,0,0x400)

These two calls reliably close and open the gripper. However, they also cause the ROV2 move downward for a few seconds.

What am I missing or doing incorrectly?

Hello @billmania,

If you look closely at the MANUAL_CONTROL example, you will see that, non-intuitevely, the z value should be 500 instead of 0.

Try mav.manual_control_send(target_system,0,0,500,0,0x200)

Edit: I see our example for buttons is sending 0 for throttle, I’ll get that fixed.

I made that modification to my code and that stopped the diving. However, now there is a different issue.
If I put the ROV in MANUAL mode, I seem to be able to open and close the gripper repeatedly, without noticing any side-effect. If I instead put the ROV in DEPTH_HOLD mode, submerge, and then work the gripper (either open or close) the gripper does as commanded but then the thrusters lift the ROV back to the surface. The thrusters continue to spin at a high rate.

Hi @billmania,

That is odd. Can you share a minimum code to replicate that?