Electronics, Radio & antennas

Cheap single-component RF filters

Low, Band, and High – pass filters are major components when working with RF. Depending on the application, filters can reduce output noise and unwanted signals or limit a transmit signal to a pre-specified frequency band to prevent interference with other signals. Here I want to describe how to build simple and cheap single-component (ceramic) filters for your DIY projects.

Linux kernel, Linux system development, Software

C++ in Linux kernel

Linux kernel is written in C (and in Assembly in platform-specific portions) language. C language is the only allowed language to write kernel modules. And there is no problem, in most of the cases. But sometimes some stranger things may be required. Let’s see how to use C++ for the Linux kernel modules.

Electronics, Networking, Software

RS-485 practice and theory

I just built two RS-485 adapters (version 2) and decided to write a little note about the RS-485 bus (and differential line) theory, plus perform some testing of the devices. This material mostly interesting for newbies. At the end of this article, you can find a funny way to test these devices 🙂


Hello HTTPS!

From this point, my site is also available via HTTPS.   It was not mandatory, but in modern browsers HTTP sites may be marked as ‘unsecured’ and ‘untrusted’. It may happen that in the nearest future all sites without encryptions will be blocked by default in every popular web browser. I don’t want to be badged as ‘untrusted’ or be…

Continue Reading


Isolated USB to RS485 adapter version 2

This is a second version of the USB to RS485 adapter. Please read this article about the first version. The new device is built with ISO3082 and requires fewer components. Also, this device can provide more reliability in some situations.