Unable to open serial port/dev/ttyusb0

Ubuntu12.04 insufficient permissions when using USB to serial port, as shown below:

Unable to open serial port/dev/ttyusb0

Insufficient Permissions

 

Solution:

Add udev rules. The procedure is as follows:
Create a file/etc/udev/rules. d/70-ttyusb.rules
Add a line to the file
Kernel = "ttyusb [0-9] *", mode = "0666"
After you re-insert the USB to the serial port device, the common user has the permission to access the device.

 

The 70-ttyusb.rules file also has another method. Use lsusb to check the idvendor and idproduct of the USB-to-serial chip.
# Lsusb
This row is displayed in the result.
Bus 005 device 007: Id 0403: 6001 future technology devices International, Ltd ftbench USB-serial (UART) IC
Id 0403: 6001 indicates idvendor = 0403, idproduct = 6001
The content of 70-ttyusb.rules is as follows:
Subsystem = "tty", attrs {idvendor} = "0403", attrs {idproduct} = "6001", mode = "0666"
Re-insert the USB-to-serial port device, which can be accessed by common users.