[PLUG] USB Serial Port Adapters

Jackman kd7nyq at gmail.com
Fri Jun 17 19:20:31 PDT 2011


Why can't udev rules be applied here?

On Fri, Jun 17, 2011 at 6:48 PM, Fred James <fredjame at fredjame.cnc.net> wrote:
> Tim Wescott wrote:
>> (omissions for brevity)
>>   I did an experiment: I started with my Fax
>> modem and the board I'm developing plugged in.  I did ls /dev/ttyU*.
>> Then I unplugged the development board and did ls again.  Then I plugged
>> in a debugger that has its own USB serial port adapter, and did ls
>> again.  Here's my results:
>>
>> tim at servo:~$ ls /dev/ttyU*
>> /dev/ttyUSB0  /dev/ttyUSB1
>> tim at servo:~$ ls /dev/ttyU*
>> /dev/ttyUSB0
>> tim at servo:~$ ls /dev/ttyU*
>> /dev/ttyUSB0  /dev/ttyUSB1
>>
>> What _did_ happen is that at different times the same device -- ttyUSB1
>> -- got mapped to different physical devices.  That is what I _do not_
>> want to happen.  What I want to happen is to plug in the development
>> board and have /dev/ttyUSBdevelop appear, and to plug in the debugger
>> and have /dev/ttyUSBdebug appear (or some similar me-defined mapping).
>> Different devices.  Different, _unique_, identifiers.
>>
>> Otherwise, every time I plug a bunch of stuff in to the machine, I'm
>> going to have to do a bunch of hand work to figure out what ports map to
>> what devices at the moment.
>>
> Tim Wescott
> Thought 1:  If you can use CLI (command line interface) to determine
> what you need to know, then a (BASH) script can be written to do that.
> Thought 2:  If a device can be identified (example: ttyUSB1 is the
> debugger), then it can be mounted to a directory (example: ~/debugger)
> Thought 3:  If 1 and if 2, then the two can be written together in a script.
> Does any of that help?
> Regards
> Fred James
>
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-- 
Andrew Jackman
kd7nyq at gmail.com



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