Ein schnelles Projekt, das während dem 29C3 im Wiesbadener CCC entstanden ist: Die schwebenden Tropfen. Ein Magnetventil lässt getaktet (alle 50ms) eine kleine Menge Wasser durch. Seitlich angebrachte LEDs blitzen synchronisiert in die Röhre. Es entsteht der Eindruck als würden die Tropfen in der Luft schweben.
Schwebende Tropfen
Posted by Claudius Coenen on December 30th, 2012 | Comments Off on Schwebende Tropfen
Filed under Keine Kategorie, Technik | Tags: Arduino, Projekt, Wasser
Kamera-Steuerung per Arduino
Posted by Claudius Coenen on December 27th, 2012 | Comments Off on Kamera-Steuerung per Arduino
Für ein anderes Projekt brauche ich eine möglichst präzise Steuerung meiner Kamera. Fernsteuerung per Arduino war deswegen das Mittel der Wahl. Fast jede Kamera hat die Möglichkeit, einen Fernauslöser anzuschließen. Ich habe meinen Fernauslöser nur um zwei drähte und einen Optokoppler erweitert.
Im vorherigen Bild kann man den Optokoppler gut sehen, es ist das kleine Bauteil mit den vier Beinchen. Ich habe einen SFH6156 benutzt – hauptsächlich, weil ich den greifbar hatte. Es würde wahrscheinlich auch jeder Andere gehen.
Der Optokoppler trennt die beiden Stromkreise, so kann ich ziemlich sicher sein, dass ich mir nicht die Kamera zerstöre, wenn ich auf der anderen Seite Mist baue.
Filed under Fotografie, Technik
Setting up a Ubuntu 12.04 Guest as HVM, Converting it to PV
Posted by Claudius Coenen on October 11th, 2012 | Comments Off on Setting up a Ubuntu 12.04 Guest as HVM, Converting it to PV
With Ubuntu 12.04 it’s remarkably simple to convert a HVM guest to PV. This will probably work in much the same way with Ubuntu 12.10 as well. Here’s what i did:
Requirements
- VM Host running Xen 4.1 or later (mine is running the default packages provided by debian 6 / squeeze)
- A spare drive (will also work with a disk-image-file)
- Ubuntu Server installation ISO
Installation Phase
In the installation phase, i am running this machine as a HVM machine. The config can be found below. I basically give it a hard disc and the CD-ISO as disks and tell it to boot from CD. Everything else is pretty much default.
# Hostname name = 'machine' # HVM-Loader. kernel = '/usr/lib/xen-4.0/boot/hvmloader' device_model='/usr/lib/xen-4.0/bin/qemu-dm' builder = 'hvm' memory = 2048 shadow_memory = 8 vcpus = 2 disk = [ 'phy:/dev/sdc,ioemu:hda,w', 'phy:/dev/loop21,ioemu:hdc:cdrom,r' # i need to loop CD-Isos, not sure, why. ] # Networking vif = [ 'mac=11:22:33:44:55:66,bridge=br0' ] boot='d' vnc=1 vncpasswd = 'setup-something-nice'
Fire up your machine with xm create machine.cfg
and connect to it via VNC. Install Ubuntu the way you like.
Converting to PV
After the setup, i usually turn the machine off and mount the hard-disk on the VM host. I alter two things: I add a /etc/init/hvc0.conf (which is a copy from /etc/init/tty1.conf with slight alterations) and i put some static settings into /etc/network/interfaces.
I then reboot the machine with this Xen-Config:
name = 'machine' kernel = '/boot/vmlinuz-3.2.0-31-generic' ramdisk = '/boot/initrd.img-3.2.0-31-generic' root = '/dev/xvda1 ro,console=hvc0' memory = '2048' vcpus = '2' disk = [ 'phy:/dev/sdc,xvda,w' ] vif = [ 'mac=11:22:33:44:55:66,bridge=br0' ] on_poweroff = 'destroy' on_reboot = 'restart' on_crash = 'restart'
Filed under Keine Kategorie | Tags: HowTo, Ubuntu, Xen
Mobile Browsers and Multi-Touch Behaviour Compared
Posted by Claudius Coenen on June 24th, 2012 | Comments Off on Mobile Browsers and Multi-Touch Behaviour Compared
I recently came across a link to a MSDN-Blogpost that claimed to solve Multitouch-Interaction Cross-Platform in the browser. I was intrigued and started to experiment with it. The first step was to gather some data on the promised cross-platform-aspect.
I basically asked everyone i knew to fire up their cellphones and try the link themselves. Here’s what we found.
OS | Device | Browser | Points | Remark |
---|---|---|---|---|
Android 2.2.1 | htc Magic | Stock-Browser (Webkit) | 1 | 2 fingers zoom |
Android 2.2.2 | Motorola Atrix | Opera 12 Android | 2 | |
Android 2.2.2 | Motorola Atrix | Stock-Browser (Webkit) | 1 | 2 fingers zoom |
Android 2.3.7 | htc Desire Z | Opera 12 Android | 4 | device-max |
Android 2.3.7 | htc Desire Z | Stock-Browser (Webkit) | 1 | 2 fingers zoom |
Android 4.0.3 | Samsung Galaxy Note | Chrome Beta (0.18) | 8 | |
Android 4.0.3 | Samsung Galaxy Note | Firefox 12 | 1 | 2 fingers zoom |
Android 4.0.3 | Samsung Galaxy Note | Opera Mini | 0 | single touch scrolls |
Android 4.0.3 | Samsung Galaxy Note | Stock-Browser (Webkit) | 10 | |
Android 4.0.3 | Samsung Galaxy S2 | Chrome Beta (0.18) | 8 | possibly more |
Android 4.0.3 | Samsung Galaxy S2 | Dolphin HD (8.2.1) | 4 | |
Android 4.0.3 | Samsung Galaxy S2 | Firefox 12 | 1 | 2 fingers zoom |
Android 4.0.3 | Samsung Galaxy S2 | Opera 12 Android | 8 | possibly more |
Android 4.0.3 | Samsung Galaxy S2 | Stock-Browser (Webkit) | 4+ | |
iOS 4.2.1 | Apple iPod Touch | Safari | 5 | |
iOS 5.1 | Apple iPod Touch (3rd Gen) | Safari | 5 | |
iOS 5.1.1 | Apple iPhone 4 | Safari | 5 | |
webOS | hp pre 3 | Stock-Browser | 0 | did not work |
Windows Phone 7.5 | Nokia Lumia 800 | Internet Explorer 9 Mobile | 0 | did not work |
Windows Phone 7.5 | Samsung Focus (SGH-i917) | Internet Explorer 9 Mobile | 0 | did not work |
Learnings
Apple supports multi-touch in the browser far enogh back that it won’t be an issue.
Android’s stock browser gains multi-touch capability in Android 4. Other broswers support it at 2.2 already. Firefox for Android doesn’t support multi-touch at the moment.
What i find puzzling is the fact that Microsoft’s own demo doesn’t run on the two Windows Phone 7.5 devices i could find. If anyone can successfully draw in that demo, please drop me a line.
Also, too few people own webOS-Devices.
Thanks to everyone who contributed! If you try it yourself, please send your findings to me, i’ll add them to the list.
Filed under Keine Kategorie
WordPress Themes: Menu instead of Pagelist
Posted by Claudius Coenen on April 24th, 2011 | Comments Off on WordPress Themes: Menu instead of Pagelist
So you found this nice theme that really works well for your blog? That’s great. But sometimes Themes are not updated by their authors to use the latest features in WordPress. In my Case, i am using Simple Green by Flavius Matis, but it hasn’t been modified for quite some time. The Plugin doesn’t yet feature WordPress Menus, which were introduced recently.
Filed under Webdesign | Tags: Code, PHP, WordPress Theme
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