sudo apt install ros-foxy-usb-cam
default to /dev/video0, change it in /config/cam_param.yaml. Run colcon build again after changing to make sure it's loaded
# create workspace etc...
colcon build --symlink-install --packages-select vh_image
source install/local_setup.zsh
ros2 launch vh_image ros2_cam.launch.py
default to /dev/video2 in terminal 1
./script/usb_cam.sh
in termainl 2
ros2 run vh_image vh_image