I used the piece of code to print a line to a matrix printer from PostgreSQL. The matrix printer was connected to the database server and supplied with endless paper. I used a matrix printer, because you can print directly to the device.

With the method, described below, it’s possible to print with a SQL query or print something initiated by a trigger. Using this method you can log specific data ‘offline’.

The print_line method consists of three files; print_line.c which contains the code to address the printer, a Makefile to compile the print_line.c file and a print_line.sql file which creates the function in SQL.

print_line.c

Makefile
MODULES = printhash
PGXS := $(shell pg_config --pgxs)
include $(PGXS)

print_line.sql
CREATE FUNCTION print_line(text) RETURNS integer
AS '/usr/local/libexec/print_line.so', 'print_line'
LANGUAGE C STRICT;

Installation:
mkdir /home/user/print_line
cd /home/user/print_line
unzip print_line.zip
make
cp print_line.so /usr/local/libexec/
// open postgresql command line client and execute:
# \i /home/user/print_line/print_line.sql

Usage:
SELECT print_line('Hello World!');

Download:
Download print_line.zip

More information on Synology NAS systems can be found at www.synology.com

Packages

Download and install the following packages and it’s dependencies:

• Code::Blocks
• libwxgtku2.8
• libwxgtku2.8-devel
• wxGTK2.8

wxFormBuilder

Download the wxFormBuilder 3.0 linux source including the pre-generated Makefiles. Now unpack the tarball, build and install wxFormBuilder:

• cd /usr/local/src/
• wget or fetch wxformbuilder-3.0.57.tar.gz
• tar -zxvf wxformbuilder-3.0.57.tar.gz
• cd wxformbuilder_3.0.57
• make CONFIG=Release
• ./install/linux/wxfb_export.sh /usr

Code::Blocks

• Start Code::Blocks and open the menu Tools -> Configure tools…
• Click on Add.
• The following picture shows how to setup the tool:

• Save the settings and open the menu File -> New -> Project
• Choose wxWidgets project
• Walk trough the wizard
• Use wxWidgets 2.8.x
• Preferred GUI Builder: wxFormBuilder
• Application type: Frame Based
• Use the default widgets configuration

When you would like to modify your GUI you can open the following menu: Tools -> wxFB. Which will launch wxFormBuilder with your GUI. When it asks for conversion, click yes.

Don’t forget to generate the code (press F8) before you switch back to Code::Blocks. Otherwise you changes won’t be visible. You also need to build your project in Code::Blocks before your changes are visible.

In certain versions and combinations of the software the following compile error could occur: “wxMessageBox was not declared in this scope”. There are two solutions to this problem:

1) I noticed wxFormBuilder changed a bit. All headers where included in the generated code, even when the headers were not necessary. Now not all the headers are included. When you use other wxWidgets methods just add the proper header. In this case you can use the following include:

#include <wx/msgdlg.h>

2) Do not use the Code::Blocks wxWidgets template and just setup a clean C::B project. Then also setup a clean wxFormBuilder project by using the inherited class tutorial (*). Finally add the code manually to the project.

Links

• Code::Blocks
• wxFormBuilder
• Inherited class tutorial (*)

The TMP421, TMP422 and TMP423 are the industry’s smallest remote junction temperature sensors with a built-in local temperature sensor. The single remote channel TMP421, dual remote channel TMP422 and triple remote channel TMP423 provide a remote sensor accuracy of +/-1C (maximum) and a local temperature sensor range of +/-1.5C (maximum). Both sensors are RoHS compliant and can be used in numerous applications including LCD/DLP®/LCOS projectors, servers, central office telecom equipment, and laptop computers. They are also suitable for industrial controllers, processor/FPGA temperature monitoring and storage area networks.

The TMP421, TMP422 and TMP423 feature a two-wire/SMBus serial interface as well as multiple addresses. The remote temperature sensor diode-connected transistors are typically low-cost NPN- or PNP-type transistors or diodes that are an integral part of microprocessors, microcontrollers and FPGAs. The TMP421, TMP422 and TMP423 also include series resistance cancellation, programmable non-ideality factor and diode fault detection.

The sensors operate on a standard I2C/SMBus compatible, two-wire interface over a temperature range of -40°C to 125°C, with a remote temperature range of up to 150C. For maximum power savings, the device circuitry (other than the serial interface) can be shut down, thereby reducing current consumption to typically less than 3uA.

More information can be found on the following URL: http://www.ti.com/tmp421-pr

Driver pre-release download (no warranties!): tmp421-src.tar.gz

That’s the very same question I asked myself a few years ago. I think, that’s is the most difficult step in the process of learning. How should I start? Where should I start? With what should I start?

First of all you need to ask the following question: Can I start? The most simple answer is: yes you can! Everyone can start with game development, but on what time frame? Perhaps you need to learn a bit more of other topics before you actually can begin, because you can’t really program for example.

When developing games, a good knowledge of programming is a real advantage. It will be a lot easier to understand what’s going on. So when you are reading my post and you can’t even program, I would suggest to begin with learning C, C++ or PHP for example. You can take the course on your own by reading books and playing around a bit with simple console based applications or by taking the proper education in a school.

If you can program, then it’s a lot easier to start with game programming. Now we come to the answers on the questions how, where and with what to start. I think it’s the best to cover something I have experience with. When I tried to learn game programming, I personally started with a purchase of a GP2X game console.

The GP2X is a portable device running a modified version of Linux. At the time I started to program for the GP2X, it was possible to create games with C or C++ combined with SDL for the graphics, controls and sounds. I started with loads of projects, but actually I never really finished a project yet. I learned a lot of it though. So when you are really up to a challange, buy a GP2X and start to create games! /* Will post sample code, IDE and games in near future. */

A few months later I started with a project on the Rijswijk university of professional technical education. The goal was to design and create a game from scratch. However, for the university it was important to have an insight on the process of designing and creating a game, because they wanted to start a new programming theme: “Game development”. The game programming theme will cover the most important aspects of game development. So there where a few extra requirements. An opensource engine should be used for example. This is important, because then the university is allowed to change some things “under the hood”, there is no problem with licensing costs and games can easily be published by students. Also, our projectteam was required to make use of physics simulation. Which, by the way, makes games really more interesting.

One of the steps in the process was picking the best game engine. We decided to make our own “package” which consisted of the following parts:

• Ogre3D (render engine)
• PhysX (physics engine)
• NxOgre (wrapper between Ogre3D and PhysX)
• FMOD (sound manager)

I started learning developing games by following the tutorials for Ogre3D. I also played around with the Ogre3D samples by modifying code and playing around with it. After we had setup a test environment with the help of a NxOgre tutorial named ‘Cake’. “Cake is a small sandbox type application to quickly prototype or play with any feature of NxOgre. It’s designed to work within two functions; createScene and onFrame, so that all of the Ogre, GUI and Input code is hidden away from direct view and the developer can concentrate on the NxOgre code only.” (Source: cake)

After we played around a lot with cake we decided to start on the game development of the real game. Phyzle, our concept, is an open source puzzle game using physics as its main game play element. The goal is to bring a ball from point A to B as fast as possible using physics elements like magnets, springs and more.

In a level your goal consists of bringing your ball from A to B as fast as possible, without losing or destroying your ball. The faster you finish, the more points you will earn. The ball can be destroyed by elements like fire, hammers or explosions. Besides the destroying elements there are also helping elements. You can use these elements to improve your finishing time. For example you can make use of elements like fans or magnets.

Making a game concept

/* Will post this topic in the near future */

In general, I can’t cover every topic about game development. However, the internet does cover almost every topic. Please make use of it! _{And, of course, make use of the following URLs:}

• http://www.gamedev.net/
• http://www.gamasutra.com/
• http://www.gdmag.com
• http://www.devmaster.net/

/* Disclaimer: This post is still a draft. More topics will be added in the near future. When you need specific information, please ask for it by replying to this post! */

Requirements

• FreeBSD (jail) installation
• Port/package linux_base-fc4 installed
• Enabled linux emulation
• COD4 DVD

Creating your server release

• First of all you need a MS windows installation or emulation to install/unpack your COD4 DVD. For example you could install/unpack to ‘C:\Games\cod4\’. The reason that you need to do this on windows is because Activision/Infinity Ward doesn’t provide a serverpackage or unix installation of cod4.
• Now patch your installation to the latest version (current version is: 1.7568)
• Create a directory ‘C:\Games\cod4srv\’.
• Copy the all the files and directories from cod4 to cod4srv.
• Go to ‘C:\Games\cod4srv\’ and delete the following files as this will save some space on your server:
  • Docs\
  • main\videos\* (all but keep zakhaev_escape.bik)
  • players\
• Get the cod4 linux binaries from the following URL: http://treefort.icculus.org/cod/ (most recent: cod4-linux-server-06282008.tar.bz2)
• Unpack cod4-linux-server-06282008.tar.bz2 to ‘C:\Games\cod4srv\’.
• Now pack ‘C:\Games\cod4srv\’
• Transfer the pack to your server
• Unpack (to the directory ‘/home/cod4/cod4srv’ for example)
• Keep your original (C:\Games\cod4\) directory for future patching

Running your COD4 server

• Create a server.cfg file (an example server.cfg file can be found here)
• Put the server.cfg file in the ‘/home/cod4/cod4srv/main’ directory
• Now we can run the server:

cod4srv# cd /home/cod4/cod4srv
cod4srv# ./cod4_lnxded +set dedicated 2 +set net_port 28960 sv_maxclients 20 +exec server.cfg +map_rotate &

This command will start a dedicated server on port 28960 with 20 slots, map rotation enabled and will load the options from the server.cfg file. The server will run in the background. Optionally you can run the server in a screen session and detach from it.

Patching your server release

/* Coming soon */

Installing anti-cheat mechanisms

PunkBuster

First shutdown or kill your running cod4 server. Now run the following commands:

cod4srv# cd /home/cod4/cod4srv
cod4srv# ./pbsetup.run -e
cod4srv# ./pbsetup.run --add-game=cod4 --add-game-path=/home/cod4/cod4srv/
cod4srv# ./pbsetup.run -u

While running the PunkBuster setup it will ask you to agree to a license and possibly ask you a few other questions. The PB setup will download and install the most recent files. Now you can run your server again!

Dmw Pro

/* Coming soon */

FAQ

Why don’t you play cod4? Oh, I forgot to tell… I don’t really play cod4, I just installed a cod4 server for a couple of friends. And yes, I have an official license key.

Hacking at Random

International technology & security conference. Four days of
technology, ideological debates and hands-on tinkering.

On August 13-16, 2009 the 20th anniversary event edition of the
four-yearly Dutch outdoor technology-conference will take place near
Vierhouten, NL.

What is HAR?

Since 1989 the international community that builds the internet has
been getting together on a series of conferences to discuss the state
of contemporary technology, the future of it and the sociological and
political consequences of their work. The participants vary from
students and people with personal interests to researchers, scientists
and entrepreneurs who are widely recognized as the best in their field.

The atmosphere is friendly and relaxed, the average level of knowledge
is high and outside of the official lectures the site is buzzing with
energy, ideas and projects. The New York Times likened the 1997 edition
to a “Woodstock for Hackers”. We do our best to keep that atmosphere.

When these conferences first happened twenty years ago, the internet
was like the Wild West, a new frontier to explore. That has changed,
virtually every household in the Western world has access to the
internet and, just as happened in the Wild West, new questions have
risen. Questions of governance, sustainability, integration with
existing power structures, shortage of IP space and energy, censorship,
security, etc. The notion of hacking, to use a system in a creative way
that was not thought of when it was invented, has also shown to be
applicable to fields outside of ICT technology.

Where is HAR?

The location (+52 19′ 50.02″, +5 49′ 27.98″) is near Vierhouten, a
small settlement in the beautiful Veluwe area renowned for its culinary
industry. The former socialist youth-camp [1]de Paasheuvel provides
some good old-fashioned Dutch [2]gezelligheid. A variety of camping
areas will cater to our broad range of camping and non-camping
audience: varying from secluded spots in the foliage to larger fields
for those of you who want to cluster together to form a village.

There is a train-station nearby, in Nunspeet. From there it is a
10-minute drive to the festival terrain. Some form of transport from
the station to the terrain will be arranged, but the truly adventurous
among you may choose to take a hike: it is definetely within walking
distance and the surroundings will not disappoint.

Who is HAR?

You, me and some hundreds (if not thousands) of other like-minded
folks. In true spirit, there will be no visitors but only volunteers.
In order to keep costs low, expect to lend a hand here and there. You
might be operating the A/V-equipment in one of the lecture tents, sweep
the floor in the bar tent, check in visitors at the entrance or pour
drinks at the bar. A great way to discover new talents, or develop
those hidden ones you never suspected you had!

Of course, there is a somewhat smaller group of madmen and women that
will lay (and have been laying) the groundwork for another great
edition in the year leading up to the event. This event could easily be
dubbed “the next generation”. Because, yes, the original crew that has
been working hard on these conferences have earned a relaxing holiday
by organising the four preceeding events. A new generation is eager to
take over, and continue their legacy. Not to say that the old farts are
not interested, au contraire my friends. There is a healthy mix of new
blood and experienced hands currently working on the necesarry
preparations.

In fact, this is reflected nicely in the foundation that was set up to
handle all the paperwork and other legal requirements: [3]the Hxx
foundation. Its board is a 50/50 mix of old and new: Aldert Hazenberg
and Mischa Peters have been involved to a great extent in all past
events, Koen Martens made his organising debut 3 years ago on WTH and
Mathijs Schmittmann is our new kid on the block.

In case you are wondering “but where is Rop Gonggrijp”, no fears: he is
right around the corner and [4]believes we “pesky new-generation
event-hackers” are going to do just fine. He will help out where
possible, but more on that below.

Of course, HAR will not be happen without huge sums of money. We have
tried to keep ticket prices low, even in these times of financial
crisis, so we are attracting a number of sponsors and donors. But don’t
worry, HAR will not be called “Yoyodyne Inc. HAR2009″ even if Yoyodyne
coughs up millions of euro’s.

And more..

As this is being written, the last work is undertaken on the
ticket-webshop, which we hope to have online early december. At the
same time, the program committee, led by the more than qualified Rop
Gonggrijp, is preparing the call for papers and otherwise developing a
solid lecture program that’ll make your mouth water (even if you have
visited every single conference between WTH and now and seen em all).

Of course, planning has started on an in-promptu power infrastructure
and intranet, with uplink to the interwebs. And naturally, there will
be various foods and beverages.

Subscribe

If you want to receive the latest news on HAR2009 as it happens, be
sure to subscribe to the relatively low-volume announcement list. Send
an email to [5]announce-subscribe@har2009.org or visit
[6]www.har2009.org and enter your email in the subscribe form.

Perhaps you’re thinking “hey, I want to help!”. If you have some time
in the next months and are prepared to make a commitment, send an email
to [7]help@har2009.org.

The wiki is available at [8]http://wiki.har2009.org/.

Potential sponsors can mail directly to [9]sponsoring@har2009.org.

Press inquiries can be sent to [10]press@har2009.org.

References

1. http://www.paasheuvel.nl/
2. http://en.wikipedia.org/wiki/Gezelligheid
3. http://www.stichtinghxx.nl/
4. http://har2009.org/index.php?p=66
5. announce-subscribe@har2009.org
6. http://www.har2009.org/
7. help@har2009.org
8. http://wiki.har2009.org/
9. sponsoring@har2009.org
10. press@har2009.org

Het weersysteem werkt erg goed, maar een desktop PC slurpt 24/7 natuurlijk veel energie, dus hebben we besloten om het weerstation op een Linksys NSLU2 te installeren. Een desktop trekt idle al snel 100 watt, de NSLU2 trekt volledig actief niet meer dan 10 watt.

Qua stroomverbruik levert de NSLU2 een hoop besparing op. Daarnaast kan ik de NSLU2 meteen inrichten als webserver en het weerstation zijn resultaten op het internet laten publiceren. Verder is het apparaat fanless en dus ook erg stil ten opzichte van een desktop. Op het moment ben ik bezig met het inrichten van de NSLU2 met een speciale Linux distributie, namelijk: NSLU2-Linux. De software die ik voor het weerstation gebruik is wview weather. Daarnaast een MySQL database en een apache webserver voor de publicatie van de resultaten.

Op het moment verloopt de installatie vlekkeloos. Wanneer ik tegen problemen aanloop zal ik deze zeker bloggen. Daarnaast zal ik de algehele voortgang bloggen.

Daarnaast zijn er nog een aantal andere zaken die spelen. Zo is er bijvoorbeeld door SUN een sponsoring van servers gedaan aan het twiki open source project, maar omdat twiki.org geen legal entity heeft zijn deze op naam van twiki.net komen te staan. Dan komen er bij mij de volgende vragen naar boven: Zal twiki.net ethisch handelen en de servers overdragen aan de fork? En hoe zal SUN hier tegenover staan?