udev_rules

A whole set of useful udev rules for different devices I use

Creating udev Rules

Identifying the Device

In order to create the udev rules, we need to know how Linux can identify it. To work out the properties of the USB device use

udevadm info -a -p /sys/class/tty/(PORT)

In our case, this will (PORT) will most likely be something like ttyACM0

Non-serial devices (such as cameras) use the video4linux driver

udevadm info -a -p /sys/class/video4linux/(VIDEO)

where (VIDEO) will most likely be something like video0

Notes

• Have to use subsystem tty if you want to talk to it as a tty
• Can use product or vendor or something to identify the device
• Can check the existing permissions with << stat --format '%a' /dev/(PORT) >>

Reload the udev rules

We can either get the new rules to apply by unplugging and replugging our device in, or simply by reloading the rules

sudo udevadm control --reload-rules
sudo udevadm trigger

You can then check it worked by

ls /dev/tty*

Linking git udev rules to System udev Rules

Done through a symbolic link. Run the following command from the git udev rules directory. WARNING: Make sure nothing is in the udev rules folder before doing this...

sudo rm -r /etc/udev/rules.d/
sudo ln -s ~/Documents/udev_rules/ /etc/udev/rules.d