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Showing posts from 2013

Oracle SQLDeveloper 4 on Debian/Ubuntu/Mint

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Oracle SQLDeveloper is one of those tools you just kind of need around, but with its slew of bugs around so once its setup, you try not to touch it. Occasionally, Oracle releases a new version (or an early preview) with some of the bugs fixed and this appears to be the case with version 4 Early Preview.



Unfortunately, these early previews are no longer distributed as general gzip archives to work on any Linux/Mac distro, there's only a RedHat RPM installer for the Linux platform. Thankfully, this is easy to fix using the utility we known and love as Alien. Conversion of RPM to DEB Start by ensuring you have the Alien utility installed.

~$ sudo apt-get install alien
Then after downloading the RPM package from Oracle, run it through the alien utility.

~$ sudo alien sqldeveloper-4.0.0.12.84-1.noarch.rpm Warning: Skipping conversion of scripts in package sqldeveloper: postinst Warning: Use the --scripts parameter to include the scripts. sqldeveloper_4.0.0.12.84-2_all.deb ge…

Fixing a Toyota remote car key

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So I recently purchased a used car. It's in pretty good condition, but the master key with it's remote lock/unlock functionality, had seen better days - in fact, it could only unlock, not lock.


Apparently these keys can't just be cloned so the car dealers have to install an entirely new key system which will cost in excess of US$500. Not having anything to loose, I set out to try and fix the key instead.




The key looked like it had been chewed on by a dog or something, and then attempted fixed by melting the plastic and adding some epoxy. I took it apart and located a small plastic container housing the electronics and battery.



The lithium battery seemed in fine condition, considering it was some 8 years old.


With a scalpel, I cut open the rubber membrane around the button to get to what was underneath. To my surprise, there was a little button loose in there - so it was pretty obvious why it did not work!



Obviously I would not be able to solder anything this tiny, with the…

How to pimp a greenhouse

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My wife got a luxury greenhouse this spring and while I certainly enjoy the crops coming out of it, it's not exactly aligned with my own geeky hobbies. While unfortunately it's not in the cards for me to invest in a solar system generating green electricity for my entire household, I *can* at least construct a system for a 14m2 greenhouse. The goal is to build an off-grid system for lighting the greenhouse at night using energy provided by the sun in the day, as cheaply as possible. Sourcing components There are many small solar system packages complete with panel, charger and battery; but the price typically starts up around US$200 and that's without the light. For me, part of the fun in something like this, is doing it yourself with cheap COTS components. After some browsing around, ordering and waiting for things to arrive, I ended up with the following:

2x 5W amorph solar panels from local hardware store (US$45).


No-name Chinese 10A MPPT charge controller from ebay (U…

Talking to a Kamstrup 685-382 electricity meter

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My utility company provides me with ways to see historic consumption of electricity up to a few days ago. However, by that time I have long forgotten when, what and why I did to consume as I did. In order to save power and money on the utility bill, one needs to have some way of monitoring and discovering usage patterns *immediately* as they take place! When I saw you could buy cheap US$50 used industrial strength electricity meters in the form of the Kamstrup 685-382, I decided to buy a few of those. The idea was to have it installed as a secondary meter in my house and try to hook up some sort of communication interface, connected to a low power computer responsible for data acquisition, analysis and presentation.

It has to be said up front, that I am far from the only one looking into this. On a Danish engineering discussion forum, I came by other people experimenting with the Kamstrup 382, except that none of the info I came by there seemed to apply to my version of the meter. S…

Installing Linux Mint on a Macbook Air

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In late 2011 I bought the Apple Macbook Air 13" (model 4,2 with 128GB SSD) to replace my aging road-warrior Dell 420. As much as I was impressed by Apple's hardware and the Macbook Air in particular, I was never taken by their software or the OSX that comes with the Macbook Air when you buy it. So within a week or so, I started experimenting putting Ubuntu (my then favorite OS) onto it. Things may have improved by then, but it was quite a task to get Ubuntu installed and set up properly - much more difficult than setting up Linux on a non-Apple laptop. The end result was a functioning but fragile setup, where each update to Ubuntu (new kernel in particular) would require me to reboot into safe mode and manually edit various files. As chef Ramsay would say, what a f...... nightmare.

After 1 1/2 year and a dangerously outdated system (so many Java vulnerabilities), I decided it was time for a re-install. This time around however, I chose to try out the new favorite kid on the …

Rikomagic MK802IIIS (4'th gen Android-on-a-stick)

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I am a bit of tinkerer... I like taking things apart, understanding how they work (to some degree) and come up with new combinations of what can be done. So when I saw the $54 MK802IIIS "Android on a stick" device with 4'th generation specs, I had to own one. Think of it as a tablet, without a display or battery, that you hook up to the TV instead.



What makes the MK802IIIS so interesting? First and foremost, the device is obviously readily usable as a media player. It makes it possible to upgrade any TV with HDMI input, to a "smart TV". This is especially interesting these days, where TV-on-demand services like NetFlix, Hulu, HBO etc. are delivered via custom applications on a limited subset of TV's or via proprietary boxes. Since this stick is based on the popular Android platform, all you really need to do is visit the Google Play store and install the appropriate application from the content provider. Why Google hasn't pushed this cheap and simple…