Change the port name and execution authority of the microcomputer connected to Ubuntu and LiDAR

Execution authority (permission) and port name (/ dev/ttyACM0, etc.) will be required when connecting the microcomputer and URG via USB for serial communication.

When there are multiple serial devices in this way, the port names are assigned in the order in which they are connected, so the serial setting must be changed each time multiple devices are connected. In addition, it is necessary to grant execution authority for serial communication.

Since it is troublesome to set each time when connecting a device, we will deal with it.

Setting method

Microcomputer: STM Nucleo F446RE LiDAR : Hokuyo UTM-30lx

First, check the device information of the microcomputer. Execute the following command.

dmesg

Then, the product name of the connected device will appear at the bottom of the log, so record the three [idVendor] [idProduct] [Serial Number] above that device name.

【URG】 [Microcomputer]

Next, create a configuration file. Execute the following command to open the text with root privileges.

sudo vim /etc/udev/rules.d/99-serial.rules

If the three numbers you checked earlier, the port name you want to set, and the execution authority are as follows

Set as follows and save.

KERNEL=="ttyACM*", ATTRS{idVendor}=="15d1", ATTRS{idProduct}=="0000", SYMLINK+="ttyACM_URG", MODE="0666"
SUBSYSTEM=="tty", ATTRS{idVendor}=="0483", ATTRS{idProduct}=="374b", ATTRS{serial}=="**3**", SYMLINK+="ttyACM_STM", MODE="0666"

• The URG side does not use the serial number.

This completes the settings. There is a way to reload it, but please restart it for sure.

Verification

Connect the device and type the following command.

reo@reo-desktop:~$ ls -la /dev/ttyACM_STM 
lrwxrwxrwx 1 root root 7 January 9 18:36 /dev/ttyACM_STM -> ttyACM1

reo@reo-desktop:~$ ls -la /dev/ttyACM_URG 
lrwxrwxrwx 1 root root 7 January 9 18:36 /dev/ttyACM_URG -> ttyACM0

If it is output like this, the setting is successful.