Tuesday, May 21, 2013

USB Serial Device With Unknown IDs

I got a new USB serial widget, but although it uses a regular FTDI chip, the manufacturer thought it wise to change the IDs, so that the Linux system doesn't recognize it.  Yes, I am glaring at you SerialComm...

One can work around that by forcing the vendor and device IDs when the driver is loaded.

For example:
Plug the offending USB serial adaptor in.
$ dmesg

Note the Vendor and Device IDs:
[452076.573062] usb 2-1.2: New USB device found, idVendor=0403, idProduct=6001

Now load the module:
# modprobe usbserial vendor=0x0403 product=0x6001

and now it should show up in /dev:
$ ls /dev/ttyU*

Turn that into a little script in /usr/local/bin for next time and la voila!


  1. When I did that, showed up two new /dev:
    /dev/ttyUSB0 and

  2. Yes, sometimes the old name remains in /dev for a while and the next number gets used. When you reboot, the dud device will disappear.


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