Fix fraying shoelaces with heat shrink tubing

Normally the ends of shoelaces are protected with plastic caps to prevent them from fraying, but they sometimes break and get loose. Once the ends of shoelaces start fraying, it is very hard to put them through the tiny holes of your shoes.  This is an easy fix:

  1. Get some glue, the right size of heat shrink tubing and a heat gun (or a lighter)
  2. Put a little amount of glue on your finger and wet the ends of the fraying shoelaces with it.
  3. Cut a suitable length of heat shrink tubing and shove it over the end of the fraying shoelace.
  4. Apply heat with a heat gun and you are done!

Booting the Asus R556LA laptop from USB

UEFI makes it harder, but not impossible to boot your PC or laptop from USB:

  • Shut down Windows and wait until all status lights on the laptop are out.
  • Press the power button and press f2 (without the fn button depressed) to get into the BIOS (Aptio Setup Utility)
  • If the laptop keeps on booting Windows and does not want to go into BIOS, try shutting it down with a long press (5 seconds) on the power button to shut it down and then power it up and press f2
  • Boot > Fast Boot: Disabled
  • Boot > Lauch CSM: Enabled
  • Security: Secure Boot menu > Secure Boot Control: Disabled
  • Save & Exit > Save Changes and Exit
  • Press f2 again
  • Boot > Boot Option Priorities > Boot Option : Generic Flash Disk
  • optional: Boot > Boot Option Priorities > Boot Option #2: Disabled
  • Save & Exit > Save Changes and Exit
  • The laptop should now boot from USB

20 Watt Class A Power Amplifier

In the nineties I built a class A power amplifier based on an article in the November 1985 edition of the Dutch electronics magazine Radio Bulletin. In 2000 I reproduced the article on my web site and added photos and extra schematics for a stabilized power supply for the preamp stage. Although some of the components are probably not available and the original website is long gone (archived on the WayBackMachine), I found it useful to repost the Dutch article: Klasse A-versterker van 20 Watt

Adding the SomaFM XBMC Plugin to OpenELEC

I am a huge fan of SomaFM. I Have been listening to this listener-supported, commercial-free Internet-only streaming music station for years.

I do no only use my xbmc on Raspberry Pi (OpenElec) to watch movies, I regularly listen to music as well. So how can we add the wonderful ambient, jazz, loungy or indie tunes of SomaFM to xbmc? A quick search pointed to, but my OpenELEC lacked the git command.

Reluctant to install git on OpenELEC just for this, I performed this workaround

  • I first installed git with the default package manager on my Linux Destop (Synaptic on Debian)
  • Following the instruction in, I downloaded the plugin with git to my desktop:
    git clone
  • I then archived and compressed the folder:
    tar cvzf
  • Transfered the .tgz file to the OpenELEC:
    scp root@openelec:/storage/.xbmc/addons/
  • Then logged in with ssh to the OpenELEC, and extracted the .tgz:
    cd /storage/.xbmc/addons/
    tar xvzf
    chown -R root:root
  • After rebooting your OpenELEC you can find SomaFM under Music > Add-ons

Happy listening!

VirtualBox fixed after a new Linux kernel

Every time Ubuntu updates installs a new Linux kernel, your VirtualBox is likely to be broken. I got these error when starting my virtual machine:

The virtual machine 'xxx' has terminated unexpectedly during startup with exit code 1.


Kernel driver not installed (rc=-1908)
The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please reinstall the kernel module by executing
'/etc/init.d/vboxdrv setup'
as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.

This is how I can solve it:

sudo apt-get remove virtualbox-dkms
sudo apt-get install linux-headers-`uname -r`
sudo apt-get install virtualbox-dkms

Tested on Ubuntu 13.04 with VirtualBox 4.2.10. Hope this keeps on working!

Seeed Studio EL Shield Review

Seeed Studio’s give-away

I am one of the lucky five who have received an EL shield from Seeed Studio’s first monthly give-away. I applied for the give-away because I have never worked with EL lighting before and I wanted to test if I could illuminate my bicycle with it. This post has a small introduction on EL lighting, how I used it to light my bicycle and finally a review of the Seeed Studio EL shield. Continue reading Seeed Studio EL Shield Review

A heat shield for the Atten 858D hot air rework station

The Atten 858D Hot Air Rework Station is a very handy tool. Until now I have only used it for removing some SMT components and for heat shrink tubing. Check the EEVblog for an in depth review of the Atten 858D.

Like any cheap Chinese gear, you should open it before turning it on to make sure it is electrically safe. My unit did have a grounded heat element, but the case was not grounded. This was easily remedied by sanding down the paint on the inside of the case around the mounting holes of the transformer and then making an additional connection between the ground pin of the mains input and one of the mounting screws of the transformer. A quick continuity check confirmed this hack was a success.

This Atten hot air rework station has a very nice feature: when you put the element in the stand, the heating element turns off and the nozzle keeps blowing until the temperature drops below 100°C. Although I regularly knocked the handset down because my rework station was on the front of my desk, I hesitated to put it more in the back. The backdrop of my workspace is a wooden panel and it would not withstand the initial heat escaping from the rework station… Continue reading A heat shield for the Atten 858D hot air rework station