Serial Port Access Confirmed | Generated by AI

Home 2026.07

✅ Confirmed — everything is working

Check Result
User in dialout group ✅ Yes (via sg dialout)
/dev/ttyUSB0 device ✅ Present, CH340 active
Port permissions ✅ rw-rw----, owned by root:dialout (20)
Read/write access ✅ Success — port opened with O_RDWR

The usermod -aG dialout xiaoxin was applied correctly. Your current shell just hadn’t picked up the new group yet. Running commands via sg dialout (or newgrp dialout) activates it immediately.

Two ways to make this permanent for new terminals

  1. Log out and log back in (or reboot) — every new terminal will have dialout automatically.

  2. Or just run this once in any new terminal you open:

    exec su - $USER

    (it’ll prompt for your password, then start a fresh login shell)

Either way, the Arduino IDE and any serial tool (screen, minicom, arduino-cli) will now be able to connect to /dev/ttyUSB0 without issues.

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