CH340 dev ttyUSB not showing Linux, but detected in terminal

By admin Posted on August 2, 2022

如果usb驱动已安装好，lsusb 也能看到 usb 设备，但还是在 arduino 中无法选到所需的 usb 端口，尝试下面的修复方法。

Let’s fix this Error

Let’s fix this error by editing the configuration file “brltty-device.rules” of BRLTTY which is in “/usr/lib/udev/rules.d/”.

Each linux distro may have a different number, in this article my linux distro has a prefix of 85 which is “85-brltty.rules”.

Now, open a terminal and use the following command:

sudo gedit /usr/lib/udev/rules.d/85-brltty.rules 

Look for the row that has the id 1A86:7523 as shown in the following image:

# Device: 1A86:7523
# Baum [NLS eReader Zoomax (20 cells)]
ENV{PRODUCT}=="1a86/7523/*", ENV{BRLTTY_BRAILLE_DRIVER}="bm", GOTO="brltty_usb_run"

Then, comment (#) before *ENV{PRODUCT}==”1a86/7523/*”, ENV{BRLTTY_BRAILLE_DRIVER}=”bm”, GOTO=”brltty_usb_run”* , so it becomes like this:

# Device: 1A86:7523
# Baum [NLS eReader Zoomax (20 cells)]
# ENV{PRODUCT}=="1a86/7523/*", ENV{BRLTTY_BRAILLE_DRIVER}="bm", GOTO="brltty_usb_run"

The save the file.

The next is to find the system running brltty-udev.service. Please use this command:

systemctl list-units | grep brltty

And stop that service using this commands:

systemctl mask brltty-udev.service
systemctl stop brltty-udev.service

Replug Device

After that, replug the device. look at in the software. ttyUSB0 will appear. If it doesn’t appear, please logout/reboot your linux operating system.

Done. Hopefully this CH340 dev ttyUSB not showing, but detected in the terminal article is useful.