Appendix

Troubleshooting

Q: Device Busy (ERROR_BUSY)?

Terminate the existing driver process first:

pkill -f wujihand_driver_node
pkill -f robot_state_publisher
ros2 launch wujihand_bringup wujihand.launch.py

Q: Incomplete Topic or Service List?

The ROS2 daemon may have cached old node information:

# Restart daemon
ros2 daemon stop
ros2 daemon start
sleep 2

# Check again
ros2 topic list
ros2 service list

Or use the --no-daemon option for direct query:

ros2 service list --no-daemon | grep -E "set_enabled|reset_error"

Q: RViz Model Not Displaying?

Confirm Fixed Frame is set to {hand_name}/palm_link (e.g., hand_0/palm_link)
Confirm RobotModel's Description Topic is set to /{hand_name}/robot_description
Check if joint states are normal:

ros2 topic echo /hand_0/joint_states --once

Error Code	Meaning	Solution
0	Normal	-
1	Over-temperature protection	Wait for cooling and retry
2	Over-current protection	Check load, call reset_error service
3	Communication timeout	Check USB connection, restart driver