Trouble Shooting

This pages contains some of the common problems and the known solutions to them.

Communication

Problem: incompatible CH340 driver of some types of models. Unable to establish connection, and the device does not show up under \dev.

Solution: run sudo apt-get autoremove brltty. brytty sometimes interfere the functionality of certain drivers for CH340.

Problem: want to use multiple USB2CAN devices, but the naming for the device is not fixed.

Solution: If you are using a Canable device, you can use the slcan related command. If you are using a device with CandleLight firmware, you should checkout this section of the Canable Documentation and see how you can set udev rules properly.

All the socketcan devices should be under /sys/class/net. You can check the properties of the device using sudo udevadm info -ap <device_path>. udev file should be created at /etc/udev/rules.d/99-candlelight.rules.

Considering writing udev so that it can be deteremined using solely idVendor, idProduct, serial. If not possible, use KERNELS property to assign name based on physical port locations of its parent usb device. Below is an example udev file.

SUBSYSTEM=="net", ATTRS{idProduct}=="606f", ATTRS{idVendor}=="1d50", ATTRS{serial}=="004C00375646571520363132", NAME="can_bytewrek_0" # using serial number
SUBSYSTEM=="net", KERNELS=="3-1", ATTRS{product}=="XCAN-USB", ATTRS{idProduct}=="000c", ATTRS{idVendor}=="0c72", NAME="can_xcan_0" # using kernel

After creating udev file, run this command and unplug/replug to activate:

sudo udevadm control --reload-rules && sudo systemctl restart systemd-udevd && sudo udevadm trigger