This bash command will remove the left over config files from old packages that were removed with “apt-get remove”.
dpkg -l | awk '/^rc/ {print $2}' | xargs sudo dpkg --purge
See the source article for an explanation of how it works.
May 26, 2009
Ubuntu - Purge configuration files for removed packages
March 29, 2009
Remote control car speedometer V2
After my semi successful prototype of my remote control car speedometer project using a reed switch, I’m back with version 2, this time using a hall effect sensor.
March 23, 2009
Stripboard Arduino & SD Card
I love my Arduino development board and have done some interesting experiments with it, and now I am at the stage of wanting to make some of my circuits a bit more independent and permanent, mainly so I can continue to use development board for tinkering with while leaving my other projects in a working state. The mind, body and soul of the Arduino is the ATmega168 chip, which contains all the memory, processor, analogue to digital converters and pretty much everything else. As these chips can be picked up for only a couple of pounds I thought I would have a go at making a stand alone unit to log data to an SD card…
March 9, 2009
Laser Show Prototype
I’ve recently acquired a laser pen, and of course, instantly dismantled it! I bypassed the push button and soldered on a couple of wines replacing the batteries, allowing it to be powered and controlled by the Arduino.
March 7, 2009
Transistor h-bridge VS driver IC chip (L293D)
As mentioned in an earlier post, I suggested the motor driver IC would be preferable over four transistors and lots of wire due to it’s small and neat package! However I have just realised something that may sway me in the other direction…
March 6, 2009
Convert to Plain Text (With HTML Entities)
I work a lot with user submitted data, and it usually comes in the form of a Microsoft Word document, either as a .doc or copied and pasted from Word into forms or emails. The problem is Microsoft Word likes to change some of the characters in your document to smart characters, most noticeably the double quotation marks, apostrophes, elongated hyphens and triple dots. Although this possibly makes the document look nicer (does it?), it is most annoying as it does not display properly in HTML, resulting in funny question marks and random characters.
I have created this simple form to strip out all of the Microsoft Word smart quotes and other weird or invisible characters that show up wrong in HTML, and replace them with the standard ASCII equivalents. At the same time you can also optionally encode the HTML entities. The results can be displayed or downloaded.
February 26, 2009
Hall Effect and Motor Driver Interference
My motor driver IC (L293D) arrived the other day, and before I put it to real use I thought I would just have a quick go at driving two motors at once…
February 23, 2009
Eyebrow Mishap
A couple of months ago I had a bit of an accident when cycling home from the pub, I thought it would be clever to cycle straight over a roundabout. Unfortunately my face was abruptly stopped by the pavement. Here are the results…
Warning: Don’t like blood? Don’t look 
(more…)
Hack-a-mouse!
My mates mouse stopped working the other day, so I thought I would have a go at fixing it, assuming it was probably a damaged cable as is usually the case. After checking the continuity of the cable we decided this wasn’t the problem. So I had the mouse apart and started poking around looking for bad connections or damaged components, and discovered something pretty weird.
February 17, 2009
Hall effect controlled CDROM draw
The next thing I wanted to try doing with my Aruino was driving some motors. I have got loads of old CD/DVD drives that I don’t use any more and thought this would be an ideal source of motors.
The motor on its own worked reasonably well connected straight between an output pin and ground, however it wasn’t particularly powerful as the output pin can only source a limited current, and I could also only turn it in one direction, without physically swapping the cables over. After a bit of research and discovered what was required to control the DC motor in both directions, and this is called a h-bridge.