Getting the HP 2400c Scanner working in Linux Ubuntu Karmic

I had a tough day working on Ubuntu to get a HP 2400c Scanner working today.

A list of problems included the drivers not being included in the Sane package – and after an upgrade to karmic a normal user couldn’t access the USB device.

Here’s a quick rundown of what I did to get it working.

1 – Download the HP scanner drivers from Elcot
2 – Install the drivers as root. The instructions are in the readme file.
3 – Create a new udev rule by creating the file /lib/udev/rules.d/71-scanner.rules
4 – In the rules file, paste in the following code:

#HP ScanJet 2400c
ACTION=="add", ATTRS{idVendor}=="03f0", ATTRS{idProduct}=="0a01", GROUP="scanner"

5 – Add the user to the scanners group.
6 – Run Sane or Xsane and be happy!

There was a bit of groping around as I hadn’t created my own udev file before without following the instructions or howtos for specific hardware.

The key point to know is that there are some very useful commands:
lsusb – lists info about the usb devices plugged in
udevadm monitor – outputs udev events and shows you the device paths for any devices plugged in / removed
udevadm info –query=all –path /devpath – Shows the udev properties of a specific device
udevadm info –attribute-walk –path /devpath – Shows the udev properties of a device and its parents
* devpath is the path output from udevadm monitor

Once I’d worked my head around these, I could put together the .rules file that I needed. This basically checks the vendor and device ID match, and that it is an ‘ADD’ action. Once confirmed, udev adds the group membership of the device to ‘scanner’ so that the users you want to use the scanner can actually use it!


Prevent Windows from Reinstalling Group Policy Programs

While Group Policy software distribution is a quick and easy way to get software around a network, it isn’t without its problems. One such problem is when a computer is attached to a new domain. If your software distribution is the same, Windows will still reinstall the MSI packages.

The simplest way is to join export a registry key from a computer that is currently joined to the new domain, and then import it into the new system.

And here it is:

<code>HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\AppMgmt</code>

Simple Linux DHCP / DNS Server

I’ve just completed the first DNS and DHCP server that I’ve built for a while. This was using Ubuntu Linux 8.04.

The nice thing about the process this time around as opposed to when I set one up a couple of years ago is that I was a little more au fait with the process. The DHCP successfully updated the DNS records, and everything ticked along nicely.

It’s going into production tomorrow, so I’m hopeful that it will fix a number of network problems that a client has been having with the RM DHCP Server service that runs in Windows XP.

If it would be easy to tie the upcoming Samba 4 into the mix, then I think that you have the perfect open source server! I have another server to put together soon, so I plan to write a ‘howto’ and post it here.