I want to connect jetson as master to raspberry pi4 hat for Blueboat

I am working on project where I am integrating sterovision for object detection and obstacle avoidance with blueboat usv , where i need jetson nano on top of raspberry pi , to do this high level task , now i am facing difficulty to integrate it.

When i connecting Jetson to blue boat, system is getting corrupted and i had flash it and now system is working. Can you please guide me how to do, or how can i can access ardupilot, is it there any protocol or password..?