Time flies so we always have to know it precisely. Plain old manually synchronized clocks are good but I’m tired of their inaccuracy and season based mandatory shift still not cleared EU wide. So I wanted to find a nice and handy wall clock without these drawbacks.

First, I went with DCF77 clocks but there is no strong enough signal inside the rooms here. I had a pet project to build an ESP controller based DCF77 transmitter just strong enough to cover my flat. Beyond the potential legal problems can be caused by a permanent 77.5 kHz radio transmitter, because of the lack of radio related knowledge this project was stopped after a while.

Finally, I found some nice internet based wall clocks on Ebay and Aliexpress so I bought a few. Later I noticed all of them were built on top of ESP microcontrollers. Great opportunities to customize. Right?

Nowadays everything is smart. Everything is connected to the Internet. Everything can be controlled remotely. But what about utility meters? I wanted to know how to gather data from electricity-, water- and gas meters as frequently as possible.

First, I decided to study electricity meters as they seem the easiest.

At the time of writing this article, I live in Hungary. I will try to emphesize all the time when I am writing about country specific things.

I had a Linux server with two physical network interfaces which were separated into two network namespaces. Security was set up like two machines with single network card in each connected to different physical networks.

At one day, someone found out, that a process runs in the ‘red’ network namespace needs to connect to a remote machine, reachable via the physical network interface connected to the other namespace we call as host namespace. How to do so?

I wanted to know how to use GPG keys securly in such a way like I already do with SSH keys: private key always kept on my local host while it is usable on remote hosts via SSH connection.

SSH client side

GPG Agent needs to be run. The agent is usually started on demand by gpg, gpgsm, gpgconf or gpg-connect-agent.

gpg-connect-agent /bye

The usual way to run the agent is from the ~/.xsession file:

Two weeks later then I ordered on banggood.com, my SonOff POW is arrived. I bought it to measure electricity consumption of my water heater and to control it remotely.

I started testing with my table lamp. I could start controlling it with eWeLink Android client in a couple of minutes. I could not just turn on and off my 230 V device in a single click on my phone but see current electricity consumption as well as scheduling future events.

Usually in corporate environment, or e.g in case of bigger schools., network administrators use application level proxies. A proxy can make internet access much faster as well as safer, however, these effects are getting more insignificant while secure connections are emerging. On the other hand, endpoint's proxy configuration not always trivial in a heterogeneous software environment. In some rare cases dealing with proxy configurations may became very time consuming while the existing of the proxy is absolutely a must have (the reason why is not important here).

More than seven years ago, when I published the first version of my "Who Wants to Be a Millionaire?" game, I started this site as a single-page plain HTML site. Later, it became a Wordpress blog, and then a Drupal site. It was useful to learn how a website was built up and how migration and maintenance processes were going. The last change was to introduce the English language content. In the last few days, my site has been in Drupal 8, thanks to my server upgrading "project" caused by a hardware failure. To be honest, the earlier site might have had security issues and anyway, it was time to update it. There are a complete new look & feel, fresh Drupal modules, a PHP engine, Ubuntu release and so on. So, actually, everything has been upgraded under the hood, too. There is a chance that some links don't work correctly. However, I did my best, so please feel free to contact me if you find any flaws.

Többször is írtam már a Marmalade SDK-val kapcsolatos tapasztalataimról, most is egy ilyen következik, de ezúttal már némi platformközi összehasonlítással együtt. Sőt, igazából ebben a bejegyzésemben pont hogy a két platform, egész pontosan a Windows Phone 8 és a BlackBerry Z10 összehasonlítása lenne a célom. Fontosnak tartom megjegyezni, hogy nem egy teljes elemzés következik, mint inkább egy szubjektív fejlesztői vélemény.

Lassan egy éve volt már talán, hogy sikerült hozzájutni egy BlackBerry Dev Alpha B telefonhoz (a Z10 fejlesztői változata), majd pár hónappal ezelőtt teljesen hasonló módon került hozzám egy Nokia Lumia 820-as Windows Phone 8 operációs rendszert futtató telefon is.

Pár héttel ezelőtt írtam a MySQL replikációról, majd most úgy tűnik egy PowerDNS alapokon nyugvó DNS kiszolgálóhoz szükség is van rá némi kiegészítéssel.

Ami miatt úgy tűnik használni kell, az a PowerDNS supermaster/superslave funkciójának egy hiányossága.

A domain név szervereket (DNS) elsősorban a megfelelő hibatűrés érdekében többszörözni szokás. Ilyenkor egy-egy zónához (például a halacs.hu vagy a .hu TLD) nem csak egy authoritatív (mérvadó) kiszolgálót tartunk számon, hanem legalább kettőt. Ezeket szokták legtöbbször elsődleges és másodlagos névszerverekként is említeni (feltéve, hogy csak kettő van).

A napokban felmerült az igény, hogy egy már meglévő Windows 7 Home operációs rendszert a már telepített alkalmazások újratelepítése nélkül Windows 7 Professional kiadású operációs rendszerre frissítsünk. Sajnos azonban ezt a múveletet a megvásárolt home és professional Windows 7 telepítőlemezek segítségével nem lehet közvetlenül végrehajtani. A kiadások közötti frissítésnek ez a módja ugyanis nem támogatott.

Fontosnak tartom megjegyezni, hogy az alább leírtakat csak valóban jogtisztán megvásárolt operációs rendszerek esetén tartom elfogadhatónak a nyilvánvaló jogsértések elkerülése érdekében.