I need to map one serial port converter to static usb port so after my raspberry gets restarted I still have the right mapping.
I bought this USB-> serial port RS485 converter http://www.dx.com/p/usb-to-rs485-adapter-black-green-296620#.VZ5TnPmvXco And it looks like it is using chip CH-340. I need to change the serial number of this chip to be able to give it the same /dev/ttyUSBx in Linux after reboot.
I tried to find unique attributes using udevadm info -a -n /dev/ttyUSB1 but nothing is unique there, I have 4 of these converters connected and they all show the same serial number and vendor. Is there any chance to change the serial number or map them staticaly?