Quote:
Originally Posted by rcheshire
Does this type of hardware require a special udev rule or is it likely to be covered under the generic usb stuff?
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Hi Rowland,
In the following I am talking generic Linux here. I am not familiar with
the kernel these guys might be using with their Raspberry PI boards.
But given it is likely to be a reasonably up to date version of the kernel,
the following should hopefully still hold true.
Firstly, you would need to check if
CONFIG_USB_SERIAL_FTDI_SIO=y
is in the running kernel.
You can do that from within a running system -
# zcat /proc/config.gz | grep CONFIG_USB_SERIAL_FTDI_SIO
If it were not set, you would need to set it in the .config file of the
kernel source, do a make, go drink coffee for a while and
when the image is ready, load the new kernel.
When you insert the FTDI USB Serial device and type
# dmesg
somewhere toward the bottom you should see a message of the type -
[ 60.123920] usb 1-1.1: Detected FT232RL
[ 60.127866] usb 1-1.1: Number of endpoints 2
[ 60.132156] usb 1-1.1: Endpoint 1 MaxPacketSize 64
[ 60.136982] usb 1-1.1: Endpoint 2 MaxPacketSize 64
[ 60.141823] usb 1-1.1: Setting MaxPacketSize 64
[ 60.150705] usb 1-1.1: FTDI USB Serial Device converter now attached to ttyUSB0
If you do a
# ls /dev/ttyUSB*
you should also see the device instantiated there.
Now, if that was the only USB Serial device you ever used, you
could always access it via /dev/ttyUSB0.
If you had more than one and sometimes the various ttyUSBn's got
mixed around, you might then want to add a udev rule to create
a persistent name.
Here is a link on how to do that -
http://hintshop.ludvig.co.nz/show/pe...erial-devices/
In the example on that web page, the author exploits the unique
identification number of each adapter. As long as you kept the same
adapter coupled to the same telescope port or whatever, then you
can then address your peripherals using your own symbolic names.
All the above is probably of help to Neil, assuming he is using a FTDI
device and assuming whatever kernel he was running didn't have
FTDI support compiled in.
Best Regards
Gary