Connecting Gremsy Pixy U Gimbal to Rpi4 and Pixhawk4

I have connected my PixHawk4 Telemetry 2 to a RPi4 /dev/ttyAMA0 and have MavProxy working correctly. I have a Telemetry RF unit to the Telemetry 1 port on the PixHawk4. I want to connect a Gremsy Pixy U gimbal. I want to control the gimbal from the Rpi4 based on telemetry data. I am interested in how I should connect the serial port on the gimbal to the RPi4/PixHawk4.

Send mavlink gimball commands to Pixhawk, and Pixhawk will forward those to the gimbal.

Thank you. As I understand I should connect the PixHawk directly to the gimbal. I am currently using both Telemetry ports on the PixHawk (one for the RF Telemetry unit and one for the companion computer). Is it possible to reprogram the Pixhawk for a third Telemetry port?

You can configure every single serial port to ba a telemetry port. Two is not a limit. Serial 3, 4, or/and 5 can also be telemetry. Just set them with SERIALx_PROTOCOL = MAVLINK.

Just follow https://ardupilot.org/copter/docs/common-gremsy-pixyu-gimbal.html and replace SERIAL2 in the instructions with the serial port you want to use

Thank you, I did this, I used Serial 4

Almost there. I followed your recommendations. I was able to control the gimbal remotely using my MissionPlanner at the ground station. It worked perfectly. However, when I ssh’ed into the onboard Rpi4 rennin raspberian and ran mavproxy in the usual way that I did before connecting the gimbal, I get a continuous stream of messages under MAV>. I get the following:
"
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
Got COMMAND_ACK: DO_MOUNT_CONTROL: ACCEPTED
.
.
.
"
Is there something I am missing. I want to point the gimbal using mavproxy commands from the Rpi4.

Ignore those messages.