Mikkel L. Ellertson wrote:
Jeffrey Ross wrote:
How does Fedora assign which USB to serial adapter is assigned
/dev/ttyUSB0, /dev/ttyUSB1 etc through a reboot?
I basically want to make sure that one specific USB adapter remains at
one location throughout a reload and unfortunately the on board serial
port doesn't work (hardware problem)
Thanks..Jeff
I believe it assigns them in the order it finds them when scanning
the bus. Changing where the adapter is plugged in, ro plugging in
another serial device can change that. You may want to consider
creating a udev rule that creates a symlink to that serial adapter
with a meaningful name. I do this with the serial adapter for my
GPS. (Actually, this is my old rule. I am working on having it tell
gpsd that it was added/removed, and supporting more then one
device.) If you have more then one device with the same vender and
product ID, you can also test the serial number.
KERNEL=="ttyUSB*", SYSFS{idVendor}=="067b",
SYSFS{idProduct}=="aaa0", SYMLINK+="gps"
Mikkel
Since I have two of these USB to serial adapters made by the same
manufacture
I guess the serial number is going to be the way to go, and I like the
symlink
idea, makes sense and is easy enough to implement in my scripts.
The device according to "lsusb -v" shows the following (among a lot of
other stuff):
idVendor 0x050d Belkin Components
idProduct 0x0109 F5U109/F5U409 PDA Adapter
bcdDevice 1.02
iManufacturer 1 Belkin USB PDA Adapter
iProduct 2
iSerial 3 799020
If I understand correctly I would create a file in /etc/udev/rules.d say
/etc/udev/rules.d/serialusb an put the following lines:
KERNEL=="ttyUSB*", SYSFS{idSerial}=="799020",
SYSFS{idProduct}=="0109", SYMLINK+="serial"
The next time the device was inserted into the USB port udev would create
the mapping so that /dev/serial was always this adapter.
Did I get it right?
Thanks!
Jeff
