K3A

Since MacOS version 10.7 Lion, it has not been possible to use the ServerName option in the CUPS client.conf configuration to add a remote CUPS and skip the local CUPS server. Instead, printers are expected to be added via the Settings app. However, for some reason, adding the printer there did not work for me. The printer was added successfully and looked fine, but when selecting the printer to print a document, it would display as “Offline” and it would say “Looking for printer” in the Jobs dialog. The fix is easy!

For many years I have been using RT2870/RT3070 USB WiFi dongles and I was happy with them. They have great Linux support thanks to the ath9k_htc driver.

But as number of IoT devices increased, one day one of them couldn’t connect and hostapd was reporting errors like these:

Could not set STA to kernel driver
nl80211: NL80211_CMD_SET_STATION result: -105 (No buffer space available)

We all got Android devices without a proper manual so here are some basics I have learned over time…

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During my attempt to program an Atmel micro-controller to act as a remote controller sending RC5 commands, the original remote suddenly stopped sending the correct Standby code to the device and I noticed device ID part of the RC5 frame has changed from 0x10 into 0x11. I accidentally switched the original remote to a mode for a different type of appliance! I realized that after I found a nice PDF from Freescale semiconductor showing a table with common device IDs and command IDs.

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Facebook prý spojuje lidi a umožňuje být neustále s přáteli, aniž bych vystrčil nohu z baráku či postele. Facebook se tváří jako nejlepší kamarád a pomocník, že dělá pro nás to nejlepší. Ale je tomu opravdu tak? Read more…

Sending Referer header to the target site after every click on a link is basically revealing URL of the referring site. Several sites mention it as a potential privacy concern but as far as I know there is no UI option in common browsers. Firefox since 28 added “hidden” options for this.
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From what I have seen, many people use weak passwords. But it’s actually easy to make them strong. Let’s see. Read more…

SQL je nejběžnější jazyk používaný pro práci s RDBMs (relační databázové systémy). Protože je užitečné umět pracovat s databází, septal jsem stručný přehled operací, které se pomocí SQL dají dělat na jednoduchých konkrétních příkladech, s odkazy na další zdroje.

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Aby se předešlo překlepům a nechtěné platbě na cizí účet, využívají číšla účtů v ČR formát podle vyhášky č. 62/2004. V tomto článku je odkaz na generátor validních čísel.

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I bought a cheap solar power bank from China to power my temperature sensor. Unfortunately it was shutting itself down once fully charged, requiring me to power on manually again. In this post I will show you my reverse-engineering notes, images and what I did to make it always powered on.

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