Prerequisites:
- Guruplug connected to your network via ethernet and a JTAG module to allow serial console access to the device
- Computer connected to your network (probably also the computer you want to use to access your Guruplug via the serial console)

Part 1: setting up the TFTP-server and putting the images in the right place

- Download pre-compiled U-boot binary here (direct link) into a directory (e.g. /root/guruplug)
- Download pre-compiled binary kernel here (direct link) into a directory (e.g. also /root/guruplug)
- Install a tftp-server (under Ubuntu Linux) and check whether it is running:

sudo apt-get install tftpd-hpa
service tftpd-hpa status

- Go to your work directory (/root/guruplug) and extract the u-boot and the kernel archive:

tar xvzf guruplug-u-boot-flipflip-20101111.tar.gz
tar xjvf UImage_linux_kernel_2_6_33_7.tar.bz2

- Copy of the extracted contents the following two files to the folder where tftpboot resides, in my case /var/lib/tftpboot:

mv /root/guruplug/u-boot.kwb /var/lib/tftpboot
mv /root/guruplug/uImage /var/lib/tftpboot

Part 2: The serial console / JTAG setup and ‘burning’ the images

- Connect via the serial console to the Guruplug, see this page. This
allows you to see what is going on on the device, including the boot process (U-boot).
- Turn on the Guruplug and see the device booting, when you see a message which allows you to interrupt the boot process by pressing a key, do so, this will show you the U-boot prompt
- Set some environment variables to prepare for ‘downloading’ the images from your TFTP-server (= serverip variable) to your Guruplug (= ipaddr variable). The IP addresses used here might be different for your network. The serverip is the computer running the TFTP-server. The ipaddr is the IP address you give to your Guruplug. It might be handy to save the environment variables so they are there everytime you boot.

setenv serverip=192.168.0.100
setenv ipaddr=192.168.0.110
saveenv


- Download the U-boot image from the TFTP-server into the memory of your Guruplug, erase the old U-boot image and write the new U-boot image into the memory of the plug. Finally reset the device. If everything went fine, you will see your updated U-boot prompt.

tftp 0x6400000 u-boot.kwb
nand erase 0x00000000 0x0100000
nand write 0x6400000 0x0000000 0x80000
reset

- Now install the new kernel image from the TFTP-server into the memory of the Guruplug and set the environment variables and save them.

tftp 0x6400000 uImage
nand erase 0x100000 0x400000
nand write.e 0x6400000 0x100000 0x400000

setenv x_bootcmd_kernel 'nand read.e 0x6400000 0x100000 0x400000'
setenv x_bootargs_root 'ubi.mtd=2 root=ubi0:rootfs rootfstype=ubifs'
setenv x_bootargs 'console=ttyS0,115200'
setenv x_bootcmd '$(x_bootcmd_kernel); setenv bootargs $(x_bootargs) $(x_bootargs_root) ;bootm 0x6400000;'
setenv bootcmd 'run x_bootcmd'
saveenv


Now you should be able to boot up your Guruplug with a new U-boot and kernel installed by entering the following command:

reset

Useful links:
http://www.denx.de/wiki/bin/view/DULG/Manual
http://www.plugcomputer.org/plugwiki/index.php/U-Boot_Quick_Reference
http://www.plugcomputer.org/plugwiki/index.php/Re-building_the_kernel_and_U-Boot

Another issue is that my computer cannot manage to play the HD files, so I also need to buy a faster computer. Which probably will be required if I want to really start editing movies, my laptop is not fast enough.

Now comes the important thing, find your Mediatomb config.xml file. In my case it was located at /ffp/var/mediatomb/config.xml. To edit the file, open it with vi:

In the config file search for the variable named protocolInfo and change it from no to yes:

<protocolInfo extend=”yes”/><!– For PS3 support change to “yes” –>

Enable the custom-http-headers section by removing the <!– and –> tags and enter the following lines, which are essential for the Samsung television to recognize your media files:

<custom-http-headers>
<add header=”transferMode.dlna.org: Streaming”/>
<add header=”contentFeatures.dlna.org: DLNA.ORG_OP=01;DLNA.ORG_CI=0;DLNA.ORG_FLAGS=0170000000000000000
</custom-http-headers>

Change the mapping in the extensions section:

<map from=”avi” to=”video/mpeg”/>

Somehow the Samsung LED tv will only play files if they are mapped as .MPEG files, even though they can be divx/mpeg/whatever. Not sure why/how, but it seems to be the solution.

Restart Mediatomb, click here for information about daemons. Be sure to clear your Mediatomb database and reindex all media files, this can be done via the Mediatomb web interface which is by default accessible via the IP of your NAS-device, port 49152. When you’ve finished all the steps, your Samsung LED television should play most of your media files flawlessly from your CH3SNAS via DLNA.

AutoPager

Yesterday I stumbled upon an interesting plugin for Firefox called AutoPager. Normally I don’t pay too much attention to all those plugins because I am happy with what I have – if you don’t know what you miss … – and the only plugins I used were blockers or webdevelopment-related ones.

But the AutoPager plugin is a really handy one. It automatically tries to detect when a site has multiple pages, like Google for example. Normally when you have reached the end of a page you click on a link to go to the next page, this goes on and on. With the AutoPager plugin you only have to scroll down to the bottom of your page and it automatically adds the next page below your current page. So the only thing you now have to do is just scroll down and the upcoming pages will all appear below each other. So less clicking.

Grails logo

Since June this year I started at work developing in the open source web application framework Grails . In the past I developed some websites in object oriented PHP in combination with templates in Smarty. Gained experience in handling quite common things like forms/JS, uploads, usermanagement, simple fancy stuff, user friendly URL’s via mod_rewrite et cetera. Actually in my last project (WTC) everything was very nice and clean, no more than 50 lines of code for handling a page, everything beneath was done by OO-classes interfacing with the database. But still it was not a real framework and I have never used one in PHP, although there are plenty of PHP frameworks out there. I think my expertise was more on the building of stand-alone applications with Java Swing/AWT.

But, everything has changed for now. I started building a new prototype of the data support platform for my work in Grails, which is a concatenation of Groovy on Rails. Groovy being a superset of Java – 100% compatible with normal Java, so easily integrate existing libraries – allowed me to pick up things quite fast. Furthermore what I mentioned about my personal PHP experience in the above paragraph, is already covered completely by the Grails framework. Everything works nicely via the Model-View-Controller concept. Beneath the hood Hibernate and Spring are doing their work for persistency/database stuff. The only thing you have to do is write your domain classes which describe your database tables, constraints, fields and relations. Then with a single command you can generate the whole application with CRUD-interface, which means the controllers and views for your domains are generated. To start your webapplication you only have to type ‘grails run-app’ and that’s it. One final thing to mention is that there are many plugins available to give your application a lot of nice features and that Netbeans has a plugin to support Grails.

Of course most effort is then going into customizing your views and controllers and testing. But I am quite convinced that for the upcoming time Grails has become my favorite webdevelopment environment. I am currently even busy to port all existing WTC code to Grails and within a short time it was already up and running. I’d recommend anyone to give it a look/try.

Two weeks ago we decided that we should look for a new television, besides looking for new houses. I did some research and found out that the Samsung UE32B7000 32″ LED LCD television seems to be what we needed. We didn’t want a 37 or 40 inch screen, because it’d be too much an eye-catcher in the living room. This television is only 3 cm. thin, not too power-hungry (I measured ~75 watts – see also this comparison of HD-TV’s) because it is illuminated by LED-lights instead of CCFL‘s (TL-like tubes) and last but not least it has quite some nice technological features. You can use widgets – and even develop them, somehow Yahoo is involved in this technology. Some default installed widgets are from Flickr (photos from internet) and a weather-channel. There is even a Twitter-widget which you can use and there also seems to be a Youtube-widget, which I haven’t found yet.

The television has many, many inputs. One useful input is the network connection which we now have connected to our router, which itself is connected to our network attached storage (NAS) device. This is just a little box with harddisks in it and some mini-operating system running. The television supports DLNA, which means that it can stream video/audio/photos from that little NAS, which works flawlessly.

So we now have an up to date multimedia living room.

• Full Adlib, Sound Blaster, Covox Speech Thing and Disney Sound Source compatible
• 11 FM Music Synthesizer
• Digitized Audio Playback
• Analog Digital Recording
• Manual and Software Volume Control
• Configuration Setting via Software Control
• Dynamic Filtering
• Built-in MIDI-interface
• CD-ROM interface
• Built-in amplifier
• Microphone Automatic Gain Control Amplifier
• Game port
• Complies with Microsoft Multimedia Level I
• 6 Bundled Software

  

This device is elegant, small, low power (only several watts) and very functional. It contains a vacuum fluorescent display with a 320×20 resolution which can display the songname, RSS-feeds or a VU-meter for example. Furthermore it contains a Wifi-receiver for the internet audiostreams and several audio outputs (analog RCA, digital optical, digital coax and headphone mini jack). The nice thing about the device for me is that there is a big open source community behind it (Wiki, forums). The company (SlimDevices) is really open about the design and what components are in it. Furthermore you can also get plugins for custom visualizations.

Finally you can also control the device (volume, change radiostation, add RSS-feeds) via internet or via the remote that comes with it. Anyway, I/we am/are very happy with it. The old radio is now stored somewhere upstairs.

While I was looking around for portable/smaller solar panel based chargers, I stumbled upon a so called Solar Mobile Charger. This device allows you to recharge your mobile phone, mp3-player or other device, by converting solar energy to electricity, which is really handy. My plan is to recharge my mobile phone as much as possible with this new device. I immediately ordered the device via a Dutch website and I hope to get it this week. You have to start somewhere with solar energy.