Friday, 21 December 2012

Dell Charger vs "Dell" Charger

Not all chargers are created equal.
--- A drinking cat

My 3-year old Dell charger had cable issues for a while now. The inner wires of the cable that goes from the charger to the laptop are exposed. The cable from the mains to the charger also broke once, but that part is easy and cheap to replace.
Exposed wires on the charger.

I did not worry too much about it until, one day, I had to fiddle the wires to get my laptop to charge... I got afraid that it would stop working without warning, leaving me with 1 hour of battery life, and then, no computer to work (and play, and blog ,-)).

Sunday, 16 December 2012

Simple remote trigger for Panasonic Lumix

In this post I show how to build a simple remote trigger for a Panasonic camera (Lumix DMC-GX1).

A remote trigger is a cable, connected to the camera on one side, with with a button on the other side. The button allows you to take pictures without touching the body of the camera. This is especially useful at night, when taking pictures with a tripod: pressing the camera trigger will invariably shake the camera, leading to blurry pictures. Also, having a remote interface is interesting to automate picture taking (triggering from a laser sensor, timelapse, motion sensor, etc...), but more on that in future posts.

The "official" Panasonic remote trigger is fairly expensive (~50 USD). You can find much cheaper alternatives on ebay, but, isn't more fun to build it yourself?

The design I choose here consists of 2 parts: a cable, and a stripboard. The cable has a 2.5mm jack on one side, that will fit into the camera connector, and a simple 2-pin header on the other side, that is connected to the stripboard. The stripboard has 2 buttons: One allows to pre-focus (identical to a half-press of the camera trigger button), while the other triggers the camera to take a picture (full-press).

The completed remote trigger.

Monday, 10 December 2012

Playing Galileo

Galileo first observed 4 moons of Jupiter in 1609, using his telescope. There was some sort of controversy at the time, and Simon Marius may have discovered them at the same time, or, more probably, slightly later. Anyway, Marius still got to name the moons, according to 4 lovers of Zeus: Io, Europa, Ganymede, and Callisto. For those who did not have the privilege of learning Greek mythology in school, Zeus is a Greek god (actually, the father of gods), and Jupiter is its equivalent in the Roman religion. Zeus had countless lovers (and children), but Europa seems to have quite a successful career as namesake, since she also gave her name to a continent. Not bad, huh?

Back to the topic...

These 4 moons can easily be seen with a pair of binoculars. Actually, they could even be seen with the naked eye, were it not for their close proximity to the bright Jupiter. Anyway, the other night, I saw a bright spot in the sky, figured out, using Stellarium, that it was the planet, and started wondering if I could take pictures of it, with its 4 largest moons.

Friday, 7 December 2012

Migrating from Gentoo to Archlinux (part 3/3)

In the first part, I explained why I decided to switch away from Gentoo. In the second, I explained how to install Archlinux in a chroot, and install packages identical to those on your Gentoo installation.

In this last post, I give a few hints on how to configure Archlinux, and how to switch to your new system.

Tuesday, 4 December 2012

Migrating from Gentoo to Archlinux (part 2/3)


In the previous post, I explain how I got tired of Gentoo. The obvious distribution to switch to, for a Linux "geek" like me, is Archlinux: A flexible distribution that gives a lot of power to the user, bleeding edge packages, without the hassle of having to recompile everything.

I found several pages on how to migrate from Gentoo to Archlinux, but nothing that fits my requirements:
  • Minimum downtime. I only have one computer, so I want to be able to use Gentoo up to the point where Archlinux is ready to boot, fully functional (or almost), with all the packages I need.
  • No reformatting: I want to keep my Gentoo install in case something goes wrong
  • No installing on another partition: First, I don't have any free partition, and resizing partitions requires some downtime.
The official Archlinux wiki page (Install from Existing Linux) doesn't explain fully how to switch to the new system. This guy apparently installed Archlinux on top on Gentoo, replacing files as needed, but that doesn't meet my requirement of being able to roll back if things go wrong, and it seems a bit messy.

Saturday, 1 December 2012

Migrating from Gentoo to Archlinux (part 1/3)

Alright. I've been a Gentoo user for close to 10 years. 2 months ago, I decided to do a system upgrade, and I got something like this (actually, not my own output, I copied it from there, but I got very similar output, every time I upgraded for the past few months):
# emerge -auDNvt world
Total: 198 packages (115 upgrades, 1 downgrade, 71 new, 7 in new slots, 4 reinstalls, 2 uninstalls), Size of downloads: 243,450 kB
Conflict: 9 blocks (2 unsatisfied)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

  (sys-libs/ldb-1.1.4::gentoo, ebuild scheduled for merge) pulled in by
    sys-libs/ldb required by (net-fs/samba-3.6.7::gentoo, ebuild scheduled for merge)
The following keyword changes are necessary to proceed:
The following USE changes are necessary to proceed:
#required by net-fs/samba-3.6.7[client,ads], required by net-analyzer/nagios-plugins-1.4.16-r2[samba], required by net-analyzer/nrpe-2.13-r2, required by @selected, required by @world (argument)
=net-fs/cifs-utils-5.4 ads
Use --autounmask-write to write changes to config files (honoring CONFIG_PROTECT).

!!! The following updates are masked by LICENSE changes:
- dev-java/sun-jdk- (masked by: Oracle-BCLA-JavaSE license(s))
A copy of the 'Oracle-BCLA-JavaSE' license is located at '/usr/portage/licenses/Oracle-BCLA-JavaSE'.
You get the idea. 200 packages, probably a full night of compilation (on a decent dual-core laptop).