Arch Linux

otherbob

Member

Registered: 2012-02-22

Posts: 12

hwinfo display device file (/dev/ttyACM0), but it doens't exist

I'm trying to upload to my arduino over a usb serial connection but the serial port won't show up in /dev/
However when I run hwinfo I do get these 2 devices:

09: USB 00.0: 10200 Modem
  [Created at usb.122]
  Unique ID: KRJj.ncK5r6pDae7
  Parent ID: uIhY.gkSaZmjGyhD
  SysFS ID: /devices/pci0000:00/0000:00:1d.1/usb3/3-1/3-1:1.0
  SysFS BusID: 3-1:1.0
  Hardware Class: modem
  Model: "Arduino (www.arduino.cc) Modem"
  Hotplug: USB
  Vendor: usb 0x2341 "Arduino (www.arduino.cc)"
  Device: usb 0x0043
  Revision: "0.01"
  Serial ID: "74937303836351D03192"
  Device File: /dev/ttyACM0
  Speed: 12 Mbps
  Module Alias: "usb:v2341p0043d0001dc02dsc00dp00ic02isc02ip01"
  Config Status: cfg=new, avail=yes, need=no, active=unknown
  Attached to: #4 (Hub)

10: USB 00.1: 0000 Unclassified device
  [Created at usb.122]
  Unique ID: ncZn.UzMpz9F6bOD
  Parent ID: uIhY.gkSaZmjGyhD
  SysFS ID: /devices/pci0000:00/0000:00:1d.1/usb3/3-1/3-1:1.1
  SysFS BusID: 3-1:1.1
  Hardware Class: unknown
  Model: "Arduino (www.arduino.cc) Unclassified device"
  Hotplug: USB
  Vendor: usb 0x2341 "Arduino (www.arduino.cc)"
  Device: usb 0x0043
  Revision: "0.01"
  Serial ID: "74937303836351D03192"
  Speed: 12 Mbps
  Module Alias: "usb:v2341p0043d0001dc02dsc00dp00ic0Aisc00ip00"
  Config Status: cfg=new, avail=yes, need=no, active=unknown
  Attached to: #4 (Hub)

And the first one specifies the device file:   Device File: /dev/ttyACM0
But this file doesn't exist.

I tried to google around but I'm somewhat stumped, so any pointers or info is appreceated.

Thanks!

vwyodajl

Member

Registered: 2012-01-21

Posts: 183

Re: hwinfo display device file (/dev/ttyACM0), but it doens't exist

Did you install Arduino through AUR? If so did you add yourself to group uucp? Have you loged out and back in since adding yourself to the group?
There is an Arduino entry in the wiki, here is the serial part
https://wiki.archlinux.org/index.php/Ar … ing_serial
HTH

otherbob

Member

Registered: 2012-02-22

Posts: 12

Re: hwinfo display device file (/dev/ttyACM0), but it doens't exist

Thanks for the reply!
I think it's installed properly:
# pacman -Qs arduino
local/arduino 1:1.0-2
    Arduino SDK (includes patched avrdude and librxtx)

Yes I'm quite certain both root and myself are added to uucp:
# groups root
root bin daemon sys adm disk wheel uucp log
#groups bob
lp wheel uucp games video audio optical storage scanner power users

Yes and rebooted.
I read the wiki, the arch wiki is amazing by the way, I have been able to find a wiki for practically anything.

Perhaps related and I'm sorry for not mentioning it in an earlier post, I compiled my own kernel from source because I needed the latest version to get my GMA500 graphics to work properly, I'm currently using linux 3.3 RC4
So I might have broken the API for librxtx?

Also if the only problem is that the ttyACM0 isn't showing up, can I use mknod?
How do I find out the major and minor device number to give as arguments?

Thanks for the effort!

EDIT:
I went trough my kernel options again and noticed this wasn't enabled:
USB Modem (CDC ACM) support
So yea, I'm recompiling again and I'll see what happens, apologies.

Last edited by otherbob (2012-02-25 08:47:05)

vwyodajl

Member

Registered: 2012-01-21

Posts: 183

Re: hwinfo display device file (/dev/ttyACM0), but it doens't exist

Have you tried with the Arch kernel to see if the issue is still present or is the Arch Kernel not bootable for you? Just to test if you have the same issue, maybe go into run level 3 to avoid the graphics issues you had.
The rest I will leave to some other real expert been a while since I have done anything with Arduino. But I would think trying the orig kernel would be a good starting point, it is what I do with my custom kernel, or maybe seeing if there is anyone posting patches that relate to the RC kernel you are running. Sorry I could not be of more use

otherbob

Member

Registered: 2012-02-22

Posts: 12

Re: hwinfo display device file (/dev/ttyACM0), but it doens't exist

So yea, I feel kind of silly, it was the disabled kernel option(Device drivers->USB devices->USB Modem (CDC ACM) support).
It works like a charm now, sorry for wasting your time...

vwyodajl

Member

Registered: 2012-01-21

Posts: 183

Re: hwinfo display device file (/dev/ttyACM0), but it doens't exist

No time wasted Sometimes you just need to talk it out to figure it out. Do not forget to mark it Solved. Glad was just the kernel, was my guess once you said custom Kernel