Persistent USB Device Names on Linux


It’s common when you unplug and plugin a usb device on linux for the device name to change.  i.e. from /dev/ttyUSB1 to /dev/USB2.  This poses a problem when you want to programmatically access these devices.  You can however use udev rules to ensure the device always has a familiar name as a link to the underlying changing name.

After you’ve identified your device look for unique information about it.  Use this udevadm command to identify one or more unique attributes.

udevadm info --name=/dev/ttyACM0 --attribute-walk

In my case I’m using a Teensy 3.2 connected as /dev/ttyACM0 which has a unique serial number.

Create a udev rule file.

sudo vi /etc/udev/rules.d/99-usb.rules

Add the unique attributes you discovered and the alias you want to use.

SUBSYSTEM=="tty", ATTRS{idProduct}=="0483", ATTRS{serial}=="301110", SYMLINK+="lidar"

Load the new udev rule

sudo udevadm trigger

Now my program can access my lidar consistently by referencing /dev/lidar

 

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