Creating Named Devices Using udev

Many devices use USB to serial bridge ICs like the FT232, CH340 or CP2102. Not only micro-controller developer boards like the Arduino, but 3D printers or RC remotes and some flight controllers as well. Some µCs have even integrated USB interfaces and don’t need these chips at all. All these devices use a serial interface…

Multiple OctoPrint Instances using systemd

Note, that there is a newer version of this article available. This is a “work in progress”, which I have tested for a few months. It workes fine, but there could be issues not yet found. Especially when installing or removing additional Python packages. This article is based on my other article about setting up…

OctoPrint on Ubuntu with systemd

Note, that there is a newer version of this article available. Most OctoPrint installations out there, will, most likely, run with an ready baked OctoPi image file for the Raspberry Pi. This is obviously the most straight forward approach to get OctoPrint up and running. Still, there are good reasons to run it on a…

Sonoff S26 EEPROM Upgrade

The Sonoff S26 WiFi-Plug/Switch uses a ESP8266 micro-controller and 1 MB of memory for its firmware. It is possible to replace the default EEPROM IC with a bigger one. This comes in handy, when using Tasmota and OTA-upgrades, since the upgrade needs to be locally stored, before it can be installed. The 32 Mbit (4…

1000 oder 1024: (SI-)Präfixe für die Einheit Byte

Warum ist das eigentlich nicht so einfach wie bei Gramm und Kilogramm? Früher oder später wird man mit der Tatsache konfrontiert, dass es bei der Angabe von Bytes nicht so einfach zugeht, wie bei anderen Maßeinheiten. Insbesondere bei großen Datenträgern wundert sich der eine oder andere, warum die Angaben des Betriebssystem auf den ersten Blick…

Self-signed SSL certificates

This article describes, how to use OpenSSL to create a self-signed certificate authority and sign certificates with it.

avr-gcc/avr-libc Tutorial

avr-libc is the standard library for AVR micro-controllers. It already contains many functions and header files that are optimised for the target platform.

Dimmable keyboard LED light

Some time ago, I decided to build simple but decent LED stripes, to put them under my PC’s displays and illuminate the keyboard and the working space directly beneath. I used 5 V LED strips, since plugging the light into a free USB port, seemed to the be easiest way to power the light.

Virtual Box host and internet access without bridge mode

This short tip explains, how to connect the host system to the guest VM and allows Internet access for the guest at the same time, without using the bridged network mode. This setup makes sense, if you don’t want to expose the VM to the rest of the host’s local network, but still want the guest to…