Re: ttyUSB0 not appearing - SOLVED

[Dave Smith <dave@nobodynet.net>]

Problem eventually solved.  The cause appears to be that the RS232 end was 
plugged in to the temperature sensor I'm using, which was powered up, at 
the time when the adaptor was connected at the USB end.  This possibly 
means that one of the RS232 control lines is asserted at that time
(ref. http://osdir.com/ml/hardware.gps.gpsd.user/2006-02/msg00010.html ) 
and confuses things (I had rebooted with the sensor powered/connected 
before without problems, so not sure why it caused grief this time).

Now that it's working, the entry in /proc/bus/usb/devices looks very 
different:

T:  Bus=02 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 10 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=16 #Cfgs=  1
P:  Vendor=0711 ProdID=0230 Rev= 1.03
S:  Manufacturer=USB-RS232 Interface Converter
S:  Product=USB Ver1.2 Device
S:  SerialNumber=005248
C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr= 50mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=mct_u232
E:  Ad=81(I) Atr=03(Int.) MxPS=   2 Ivl=2ms
E:  Ad=82(I) Atr=03(Int.) MxPS=  64 Ivl=1ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=  16 Ivl=0ms

...it's clearly now an RS232 "converter", and is no longer using the 
usbhid driver.

--Dave



On Fri, 8 Feb 2008, Dave Smith wrote:

> Hi all,
>
> Since an unplanned reboot yesterday, my USB<->RS232 adaptor is no longer 
> appearing as /dev/ttyUSB0.
>
> dmesg shows the following when it's plugged in:
>
> usb 2-2.1: USB disconnect, address 4
> usb 2-2.1: new full speed USB device using uhci_hcd and address 5
> usb 2-2.1: configuration #1 chosen from 1 choice
> input: MCT Corp. Serial Mouse Adaptor as /class/input/input9
> input: USB HID v1.10 Mouse [MCT Corp. Serial Mouse Adaptor] on 
> usb-0000:00:1f.4-2.1
>
> Similarly, it's entry in /proc/bus/usb/devices appears to be:
>
> T:  Bus=02 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#=  5 Spd=12  MxCh= 0
> D:  Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=16 #Cfgs=  1
> P:  Vendor=0711 ProdID=0231 Rev= 1.03
> S:  Manufacturer=MCT Corp.
> S:  Product=Serial Mouse Adaptor
> C:* #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr= 50mA
> I:  If#= 0 Alt= 0 #EPs= 1 Cls=03(HID  ) Sub=01 Prot=02 Driver=usbhid
> E:  Ad=81(I) Atr=03(Int.) MxPS=   8 Ivl=8ms
>
> Sadly, I don't know what it used to appear as, whether it's always been 
> treated as a "Serial Mouse Adaptor".  In any case, I'm not using it for a 
> mouse, I'm using it to talk to a temperature sensor module, and so I need to 
> access it through ttyUSB0.
>
> I haven't been able to find anything specific on google.  Some posts relating 
> to other distributions have pointed to it maybe appearing under /dev/tts/ but 
> I don't have any such directory myself.
>
> I'm using a fairly up to date install of Etch.
>
> Many thanks in advance for any help,
>
> --Dave