Linux on cat /dev/snapshot

Raspberry Pi

Sat, 30 Jun 2012 12:26:00 +0200

My Raspberry Pi finally arrived after 4 months:

The stable Debian distribution “Squeeze” does not contain support for all of the Raspberry Pi features. That means there is no way around the the latest Debian “Wheezy” image: http://www.raspberrypi.org/archives/1435

But even with the latest image version there is still some configuration effort left…

WLAN Stick

For network connectivity I have chosen the Conrad WLAN Stick N150 Nano, which is based on the following chipset: USB: 0BDA:8176 Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter.
Unfortunately this chipset has some issues with the current drivers from both Debian Linux images as discussed in the forum thread Automatic setup for RTL8188CUS based wifi adapters. By executing the script install-rtl8188cus-latest.sh from the forum thread, the adapter started working immediately after the script was finished.
The general WLAN configuration is described in detail in the Debian Wiki: http://wiki.debian.org/WiFi/HowToUse#Command_Line

Wake On LAN

Sat, 03 Mar 2012 22:50:00 +0100

Under Ubuntu I chose the following way to activate wake on LAN on the eth0 device:

# Install ethtool
sudo apt-get install ethtool
# Create init script to set the wol bit on the device
sudo vi /etc/init.d/wakeonlan
#!/bin/sh
ethtool -s eth0 wol g
exit
# Make the script executable
sudo chmod a+x /etc/init.d/wakeonlan
# Create the init links
sudo update-rc.d wakeonlan defaults

Under Debian the following approach has been chosen:

Building a TP-Link TL-WR1043ND OpenWRT 10.03 image

Sun, 31 Jul 2011 23:48:00 +0200

This article gives a step-by-step description on how to get the m3ddity-player working on the TP-Link TL-WR1043ND device, using the stable version of OpenWRT 10.03 (backfire).

First you need to checkout the OpenWRT 10.03 (backfire) branch:

svn co svn://svn.openwrt.org/openwrt/branches/backfire
cd backfire

Then the feed for the m3ddity-player must be added:

cp feeds.conf.default feeds.conf
echo "src-svn jcoderz http://www.jcoderz.org/svn/m3dditiez/branches/openwrt-10.3/packages" >> feeds.conf
./scripts/feeds update ./scripts/feeds install -a

Now run menuconfig and select the necessary modules:

make menuconfig

The following list shows only menuconfig entries where settings have been changed. Settings not shown here are left untouched.

Music player fully integrated into the OpenWRT build process

Mon, 25 Jul 2011 00:44:00 +0200

The m3ddity-player and the GUPnP libraries, on which the player depends upon, can now easily be build for OpenWRT, just follow the steps below:

1. Checkout the trunk version of OpenWRT

svn co svn://svn.openwrt.org/openwrt/trunk
cd trunk

Add the jCoderZ package repository to the list of feeds

cp feeds.conf.default feeds.conf
echo "src-svn jcoderz " \ 
     "http://www.jcoderz.org/svn/m3dditiez/trunk/" \ 
"openwrt/packages" >> feeds.conf
./scripts/feeds update 
./scripts/feeds install -a

3. Run menuconfig and select the packages as described here

Building an OpenWRT image optimized for MP3 audio playback

Wed, 13 Jul 2011 20:36:00 +0200

For the audio-renderer, see revious posts, I decided to switch to the trunk version of OpenWRT.
I experienced some issues with the USB audio hardware and the trunk version should prove that there are no issues with the USB audio drivers which are already fixed.
The following configuration is for the bleeding-edge version, some module names have changed so it cannot be applied to the Kamikaze (10.3) version without modification (e.g. block-mount contains the overlay functionality and kmod-fs-ext4 has support for all ext file-system versions).
NOTE: This configuration has stripped all modules which are not necessary for USB audio and Wireless LAN.

Low-budget WiFi Music Player

Sun, 12 Jun 2011 13:17:00 +0200

After searching the net for quite a while I could not find a pure wireless music player for small money. In case you want to equip multiple rooms in your house with a music player it will cost you a lot of money. All products on the market come with a lot of features, of which most are not necessary. The following links show interesting hacks on how to build your own WiFi music player based on OpenWRT:

GUPNP: Failed to get SCPD: Cannot resolve hostname ((null))

Sun, 05 Jun 2011 18:23:00 +0200

The following message occurs when the <urlbase></urlbase> tag of the root device description is empty when trying to autoconnect actions:

** (process:25888): WARNING **: Failed to get SCPD: Cannot resolve hostname ((null))

Changing it to http://localhost fixes the issue.

<?xml version="1.0"?>
<root xmlns="urn:schemas-upnp-org:device-1-0">
  <specVersion>
    <major>1</major>
    <minor>0</minor>
  </specVersion>
<URLBase>http://localhost</URLBase>
  <device>
    <!-- ... -->
  </device>
</root>

The message is a bit misleading. I was first trying to find an issue with my DNS configuration.

Compiling GUPnP on Ubuntu 11.04

Fri, 03 Jun 2011 15:55:00 +0200

Because the GUPnP stack is lacking some documentation I describe my experiences with getting it complied under Ubuntu 11.04.
The commands will setup an environment that does not interfere with the Ubuntu provided packages, which are older than the ones compiled here. The library files will be installed under the location: ~/workspaces/openwrt/upnp

Download:

mkdir -p ~/workspaces/openwrt/upnp
cd ~/workspaces/openwrt/upnp
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-igd-0.1.11.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-0.16.1.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-igd-0.1.10.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-tools-0.8.3.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-dlna-0.6.1.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-av-0.8.0.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gssdp-0.10.0.tar.gz | tar xvfz -
wget -O - http://gupnp.org/sites/all/files/sources/gupnp-vala-0.8.0.tar.gz | tar xvfz -

Prerequisites:

VirtualBox 4.0.2 on Ubuntu 11.04

Sun, 29 May 2011 13:55:00 +0200

After an update to Ubuntu 11.04 VirtualBox was not running anymore. Startup fails with a hint that the kernel modules exited in error and that I should use DKMS to reconfigure the kernel module.

Running the vboxdrv setup command also led to an error:

$ sudo /etc/init.d/vboxdrv setup
[sudo] password for desktop: 
 * Stopping VirtualBox kernel modules                                  *  done.
 * Uninstalling old VirtualBox DKMS kernel modules                     *  done.
 * Trying to register the VirtualBox kernel modules using DKMS                  
Error! Bad return status for module build on kernel: 2.6.38-8-generic (x86_64)
Consult the make.log in the build directory
/var/lib/dkms/vboxhost/4.0.2/build/ for more information.
 * Failed, trying without DKMS
 * Recompiling VirtualBox kernel modules                                        
 * Look at /var/log/vbox-install.log to find out what went wrong

The log file indicates that a header file was missing:

New version of smpppd-web

Thu, 12 Jan 2006 05:46:00 +0100

The original versions of smppd-web by Christopher Hofmann neither support adding and removing links on the fly nor do they support dial-on-demand ISDN interfaces. That is the reason why I extended the original codebase by these features.
Further more the users for which I developed the software are german speaking only so that gettext support was also an important feature. Initially I added support for german and english languages.

As I’m not a SuSE user in general, the new version probably does not follow the SuSE directory guidelines and it does not come packaged as a RPM. Therefore it would be great if someone with SuSE RPM packaging know-how would create a successor RPM package out of Christopher’s original version. Or even better Christopher packages a new version for OpenSuSE ;)

Creating an ISDN Gateway with SuSE 9.3

Wed, 19 Oct 2005 07:31:00 +0200

In Germany flatrates are available for DSL only, so people, living in areas where DSL is not available, have to pay expensive time based fees for slowly connecting to the Internet. The problem is that M$ Windows and many of the installed tools are known for initiating internet connections although the user did not ask them to do so. Therefore it is crucial to reliably disconnect the ISDN line so that those unwanted connection attempts will not succeed. ISDN routers, which might be of help here, are hard to find nowadays and do not offer the comfort as new DSL routers do.

Linux support for TFA Klima-Logger

Sat, 02 Jul 2005 00:23:00 +0200

Update 2012-03-01:
I just ordered 2 outdoor sensors and the plan is to connect the Klima-Logger to a Raspberry Pi Board to make the data available via browser on my home network. Here are some resources I found

Outdated:

I recently bought a hygrometer from TFA-Dostmann, called Klima-Logger. It is the cheapest thermometer and hygrometer with PC connectivity I could find on the market. Unfortunately only a Windows software is provided to get the recorded values for temperature and humidity. I thought a Linux driver would be cool and started searching for resources on the net. Usually the Linux community is very fast in supporting new gadgets of any kind, but nothing could be found.