Troubleshooting

4.1 Port Access Permission

If you can't find the port when launching the Ubuntu HMI:

• Method 1: Add the current user to the dialout group

  sudo usermod -a -G dialout $USER

  After execution, apply the permissions:

  • Current terminal only: newgrp dialout
  • System-wide: sudo reboot

• Method 2: Launch the HMI with sudo

  sudo wuji-hand-hmi

4.2 Display Scaling Warning

If a display scaling warning appears during startup, the system display scaling ratio is greater than 100%. Adjust the display scaling to 100% (1:1) in your system settings, then restart the HMI.