László Monda's Blog » Hacking

3D printing service providers

Laci — Wed, 12 May 2010 23:01:34 +0000

I'm collecting the ones that alow you to upload STLs and give you a quote:

I'd love to see contributions to this list.

Making a helping hand that actually helps

Laci — Wed, 31 Mar 2010 02:03:12 +0000

I've seen some helping hands offered by various shops and I'm not impressed at all. Their price is usually dirt cheap and I can say from experience that you get what you pay for. The only viable solution is to build a kickass helping hand for yourself. Fortunately, Instructables has some really great tutorials:

I've been trying to get the parts for a while but it's very challenging to source the hoses. If I won't be able to get them from Hungary then I'll order them from a foreign country.

Open Hardware Revolution

Laci — Sun, 14 Feb 2010 20:24:05 +0000

I'm very passionate about open hardware. I'm into FOSS software for a long time since about 2000 when I completely switched to Linux, but I've only recently became conscious that it's possible to create hardware by individuals or small groups.

Hardware is not that fascinating to me in itself. Sure, lots of big companies create well-designed and quality hardware, Apple being one of the most well known amongst them, but I'll never buy their products because these devices are locked and not designed to be exploited to reach their full potential. Putting OpenWrt into my ASUS WL500GPV2 is the best example I can think of how one can make his/her device a thousand times more powerful and customizable by replacing the stock firmware. Unfortunately, it's necessary to buy closed hardware in most cases because there are not many open alternatives but this situation can change in the future and whenever I can I choose open hardware.

In the Next Industrial Revolution, Atoms Are the New Bits is a fascinating read for anyone interested in the open hardware revolution. Atoms Are Not Bits; Wired Is Not A Business Magazine has lots of though provoking arguments and Are atoms the new bits? discusses the mentioned issues even further. I don't really think that open hardware will ever take over the world and will replace closed hardware. The big manufacturers fiercely protect their intellectual property and most consumers couldn't care less whether they can hack a given piece of hardware because they just wanna use the damn thing (with all its shortcomings, being unaware of its full potential).

Hackers are a different breed. There are a several hundred open source projects out there, the most relevant ones being present on Harkopen, Open Innovation Projects and Open Manufacturing. Reprap is the flagship project of the revolution and rightly so because it's very rare for the open hardware community to create something this complex and well working, even if the quality of the created models lags way behind the commercial alternatives. I think open hardware is not so widespread because 1) most of the projects are technical minded and aren't practical for the average Joe, 2) most creators are only interested in implementing, not distributing the projects, 3) these teams don't have any marketing / business experience and 4) the economies of scale are against us (until we conquer the world).

I definitely have to work on 3) but the Ultimate Keyboard is gonna be ready in the not too distant future. I don't mind learning non-technical stuff to make it happen.

Installing cx_Oracle on Ubuntu Karmic Koala, 64 bit

Laci — Fri, 29 Jan 2010 02:48:03 +0000

I'm using Oracle 10g, but you're free to download any other versions that you want.

wget http://prdownloads.sourceforge.net/cx-oracle/cx_Oracle-5.0.2-10g-py26-1.x86_64.rpm?download
# We should use alien but it didn't work for me.
rpm2cpio cx_Oracle-5.0.2-10g-py26-1.x86_64.rpm | cpio -id
sudo cp usr/lib64/python2.6/site-packages/cx_Oracle.so /usr/lib/python2.6
# Go to the Oracle Instant Client download page and accept their fucking license, then download Instant Client Package - Basic for version 10.2.0.3, that is instantclient-basic-linux-x86-64-10.2.0.3-20070103.zip
unzip instantclient-basic-linux-x86-64-10.2.0.3-20070103.zip
sudo cp instantclient_10_2/{libclntsh.so.10.1,libnnz10.so} /usr/local/lib
sudo ldconfig

Installing such proprietary shit like Oracle (related software) is a bad experience too many times.

Lock your laptop and turn off display with the touch of a keystroke in Ubuntu Karmic

Laci — Tue, 12 Jan 2010 14:33:06 +0000

I think this feature will soon be standard in Ubuntu as many users requested it. It's absolutely mandatory for me because every time I leave my laptop I carry out this action, even at home. Yeah, call me paranoid...

I've written a simple script to deal with the issue:

#!/bin/bash gnome-screensaver-command -l sleep 3 xset -display :0.0 dpms force off

You're encouraged to bind it to any key combo. It should work perfectly out of the box but a gnome-power-manager related bug enables the display some seconds or minutes later randomly, so we have to

killall gnome-power-manager

and it should be pretty fine. For those who can't afford to live without gnome-power-manager an alternative (and in my opinion suboptimal) workaround exists.

Joe Grand is my hero

Laci — Sat, 19 Dec 2009 18:57:01 +0000

About a year ago I became involved in electronics. This was because the development of the Ultimate Keyboard requires strong electronics knowledge and not only I couldn't hire anybody (without the resources doing so), but I also wanted to understand electronics and over time as I read the articles on Hack a Day I realized how cool electronics really is.

I've been doing software development for a few years and it's always fun, but doing purely software development in itself is not that interesting for me as it used to be. We have a keyboard, a mouse and a monitor, that's mildly interesting. We also have the Internet for several years which is much more interesting. What if create a propeller clock, a line following robot or all kinds of ultra-crazy stuff, both the hardware and software? That sounds to me like the ultimate fun.

Joe Grand is probably the most well-known hardware hacker who became famous as one of the hosts of Prototype This. He is a really cool guy and has tons of interesting materials on his site. I'm grateful for every piece of knowledge that I can learn from guys like him.

nitehawk rocks the house

Laci — Sat, 19 Dec 2009 18:11:33 +0000

Finally, I got my first laptop a week ago which I named nitehawk because of it's color. It's an Acer Aspire 8935G-874G100BN and I think it pretty much represents the level of hardware integration that can be achieved in 2009. With its 18.4-inch LED LCD screen and its load of impressive features it's almost more like a desktop than a laptop and it's exactly what I wanted because I change my location of a two weekly basis and I don't need much mobility other than that.

The first thing I did when nitehawk arrived is I sent it back to Acer so they could remove Windows 7 and give me back its price. When all things summed including the traversing costs I haven't earned almost any money, but I didn't do it for the money. This was my gentle gesture to show Redmond that they're welcomed to taste my middle finger.

nitehawk's keyboard is as crappy as most laptop keyboards from a typewriting point of view, but I do truly appreciate its power efficiency in overall and suspend, hibernate especially. I carry it in a Targus TCB001EU XL notebook backpack because I couldn't get any other backpacks in Hungary that was big enough to hold this beast. :)

Moving my Linode in 3 hours from Dallas to London with one click

Laci — Sat, 19 Dec 2009 00:40:33 +0000

Oh yeah, Linode has just reached Europe. Moving from Dallas to London made my ping go from 150ms to 50ms looking from Szeged and the migration couldn't have been easier or smoother.

Thank you Linode staff, you rock!

Fix your mouse as it were new for $3

Laci — Fri, 18 Dec 2009 22:58:42 +0000

I've just replaced the microswitches of my Logitech MouseMan Optical dual sensor mouse. I bought it about 6 years ago for about $80 and I was extremely satisfied with it until the switches broke.

Today I managed to get some Omron D2F-01 switches. The original switches are Omron D2FC-F-7N parts but they have been obsoleted. The new switches have a crisp tactile feel which I love, altough they are a little bit harder to press than the old ones.

Being able to replace the switches is one of the "secrets" that manufacturers don't want you to know because chances are you wouldn't have to buy any other mouse ever again. There are other temporary fixes to solve the issue, but replacing the switches with new ones is stongly advised.

How to measure the actual memory usage of Linux processes

Laci — Tue, 01 Dec 2009 10:56:55 +0000

This is a much harder question than one might think as VSZ and RSS are not accurate. /proc/{PID}/smaps provides the most accurate information as of Linux 2.6.16.

ps_mem.py is a nice script that summarizes smaps information on a per application basis and gracefully falls back to measure VSZ when no smaps support is found.