I have a UDOO quad running Ubuntu 12.04 and am trying to get a USB to Serial cable to recognize as /dev/ttyUSB0. When I do a lsusb I get this additional line: Bus 002 Device 003: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port I have tried using the modprobe command (modprobe usbserial vendor=0x067b product=0x2303) but notice no changes to my /dev directory. While searching the forum I found someone with a similar issue trying to set up a GPS device (roadancer @ viewtopic.php?f=17&t=136&p=1347&hilit=gps#p1347) but did not see a solution for my problem. My usb to serial console port on the UDOO is working fine but I need to connect to equipment with a 9 pin rs-232 port. Any help would be greatly appreciated.