Repair the Syma X12S quadcopter by replacing the motors and rotor blades (and what to do if it does not lift off afterwards)

Syma X12S quadcopter with new motorsMy friend owns a Syma X12S quadcopter that was cheaply imported from China. It really is an amazing piece of hardware and the perfect entertainment when you spend an evening with friends. Piloting this miniature aircraft is quite easy – it only takes a few flying sessions until you acquired enough skills to handle it. However, I still managed to crash the quadcopter in a way that damaged two of its four motors. The beauty of this toy is its modular design: Even though it is a cheap product, most of the parts are LRUs, so you can simply order a replacement for the defect part and replace it yourself.
This short post shows how to replace the motors of a Syma X12S quadcopter and highlights some difficulties to look out for.

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Fixing Full-HD VGA support for the Epson EH-TW5200 Projector

If you happen to own an Epson EH-TW5200 projector, you might have experienced problems setting Full-HD (1920×1080) resolution using a VGA connection under linux. When I set the resolution to Full-HD, the whole screen would stay completely black. This is just a quick fix for the other 4 people that might have this problem.

The difference between the original modeline and the new one is the vertical refresh rate: The projector proposed 60.02 Hz via EDID, and the new modeline is just a tad slower, using 59.94 Hz. I was connecting a ThinkPad T60 to the projector, so the problem might also be the RAMDAC of the laptop, something about blank phases, who knows.


Homeserver Upgrade: Odroid XU3-Lite Setup on a SD-Card

I recently bought a new home server, the Odroid XU3-Lite to replace my poor man’s home server I called the thin-server, to run CherryMusic and the like.


That little ARM machine is a beast in the size of a cigarette pack, featuring a total of eight CPU cores, an ethernet port and most importantly an USB 3.0 port to connect an external hard drive. It also comes with a plastic case, with a small fan inside and a PSU that is strong enough to power external hard drives connected to the USB ports. I ordered the smaller “Lite” version, which has a slightly lower CPU clock rate, but costs a lot less than its bigger brother.

In this post I’ll guide you quickly through the installation process of the ubuntu image on a micro SD-Card, how to make use of all the space on the microSD card and how to secure this little fellow a little after the installation of the image.

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How to add USB Gamepad support for your Android phone or tablet


I was almost at the point to buy a playstation or xbox controller to use with my tablet, since they seem to be supported out-of-the-box. But actually I still have an old USB controller lying around, which would be more than good enough for playing some games. Interestingly my gamepad did in fact work partly, but only the left analog stick and one or two buttons, and the rest did not. My hacker spirit told me that this must be fixable somehow.

So I started hacking around and added support for my old USB gamepad for my android tablet. In this post, I’ll show you how I did it and how you can to add support for any gamepad to your phone or tablet as well!

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Samsung Galaxy S3 repair – Glass screen/digitizer replacement and why it is not recommended

Glass screen replacedA friend asked me to repair her friends Samsung Galaxy S3 mobile phone, that had a broken glass screen/digitizer, so I had a closer look at it. The process of replacing the glass screen/digitizer on a Samsung Galaxy S3 is straight forward and not many tools are needed. However, what you really need is patience… a lot of it.

This post shows how it is done and why I still would not recommend it anyway.

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Samsung SSD 840 EVO 2.5 Zoll SATA – Firmware update under GNU/Linux

I recently bought a Samsung SSD to replace my HDD in my Arch Linux notebook. It is a “Samsung SSD 840 EVO 2.5 Zoll SATA”. One of the first things I do when I get new hardware is to make sure the latest firmware is installed. Mine did not have the latest firmware update and – as it was to expect – Samsung SSD firmware updates under GNU/Linux are not (officially) supported. Samsung ships only Microsoft Windows software, called “Magician”, which can directly update the firmware or create a live USB-Stick to do the update. Additionally, they provide *.iso image files (one for Microsoft Windows systems and one for Apple computer, respectively) to update the firmware from a live CD. The *.iso image file intended for Microsoft Windows would also work under GNU/Linux, only that my notebook does not have a CD Drive anymore. Obvioulsy, the only option left was to create my own live USB-Stick under GNU/Linux – without using Microsoft Windows and that crappy Samsung “Magician” software. A simple “dd” comand to “burn” the *.iso file on an USB-Stick did not do the trick, as the Isolinux version Samsung uses is over 10 years (!) old.

This article shows how to update the firmware of a “Samsung SSD 840 EVO 2.5 Zoll SATA” under GNU/Linux using a bootable live USB-Stick.

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UEFI, GNU/Linux and HP notebooks – problems and how to get it working

There is a lot of confusion and wrong information in the internet about the Unified Extensible Firmware Interface (UEFI) and how to set it up correctly – especially under GNU/Linux. What makes things worse and also confused me a lot is that all vendors tend to implement this “standard” differently. So although UEFI is defined as a new industry standard replacing the BIOS, it can hardly be called “standard” at this time. Yet another problem of understanding UEFI is, that people seem to mix up words that have a special meaning.

My old notebook still uses the old BIOS-MBR setup, not capable of any UEFI fancy-ness. But it is dying, so I recently bought a new one. It is an “HP EliteBook 840 G1”. I used that opportunity to familiarize myself with UEFI and GNU/Linux.

This article explains two things (only taking GPT setups into account):

  • How is UEFI implemented in practice and set up with GNU/Linux?
  • How to set up UEFI and GNU/Linux on HP notebooks?

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Create a GNU/Linux multiboot USB-Stick (Live USB) with Syslinux chainloading

Since USB-Sticks, that are fast and have a high capacity, are finally affordable, I decided to buy a new one. I usually install a GNU/Linux live CD (more precisely live USB) distribution on my USB-Sticks: either SystemRescueCd or Kali Linux (former Backtrack). The left over space is used for the classical purpose of an USB-Stick – data exchange. Todays USB-Sticks have enough capacity to easily fit several GNU/Linux live distributions on them, while still leaving enough space for other data. So my plan was to create a multiboot USB-Stick, that would boot my favourite GNU/Linux live distributions mentioned above. Unfortunately, searching the internet for implementing this did not give me any satisfactory results. There are a ton of guides that explain how to create an USB-Stick that boots GNU/Linux, but there are almost no multiboot solutions. The few howto’s about multiboot USB-Sticks are either about booting *.iso files (which only works with some GNU/Linux distributions) with GRUB 2 (which is designed for static boot setups anyway) or require further customized modifications of the GNU/Linux live distributions. I wanted a simpler solution that – once created – allows for easy updating of the installed GNU/Linux live distributions.

This guide will explain how to create a multiboot USB-Stick that can boot several GNU/Linux live dirstibutions via Syslinux chainloading. It will have several partitions (one for each OS and one for the main Syslinux bootloader) and a separate data partition, that can be formated independently in any way you like, so that your data is seperated from the operation system data. This guide installs SystemRescueCD and Kali Linux on your multiboot USB-Stick, but any other GNU/Linux live distribution should work as well. Adding more than two OS should also be no problem.

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Raspberry Pi Case DIY

I finally got myself a Raspberry Pi and it obviously needs a case. (By the way, it runs the ARM version of Arch Linux, naturally.) Of course I wanted to build one myself, rather than buying one of those boring cases that almost cost more than the device itself. I already had a vague idea about the concept but nothing solid yet. The concept had to be simple (but solid), because besides a Dremel and an electric drill I only had standard tools at hand. (You do not even need a Dremel if you have a small saw instead.)

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RAID5-Server to hold all your data – the NAS alternative with software RAID

This was an old project of mine. A few years ago I had a huge load of data comming in (~4 TiB) and the amount of storage I needed suddenly more than dubbled. Until then I was using two 1.5 TB HDDs which I mirrored by hand using rsync, because I’m paranoid of loosing data. It was annoying to always copy all data to each disk to have redundancy – and certainly not a smart solution. Now that data wouldn’t fit onto the two disks anyway, so it was time to think of a new solution. I had enough of wasting my time with copying files from one hard drive to another.

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