Maximilian Batz, Autor auf pi3g.com

Beamer Recherche

By Maximilian Batz | 2019-02-07

Beamer Recherche Technologien LCD Je Farbe ein LCD Panel, werden zusammen projiziert (Licht wird durch die LCD Paneele hindurchprojiziert) zweitbeste Kontrastwerte Gut für Helligkeit. Nachteile: · Fliegengitter-Effekt (“screen door effect”) · staubempfindlich · LCD-Memory-Effekt (Einbrennen) DLP nutzt kleine Spiegel auf einem Chip, um Licht an / aus zu modulieren. Meiste Modelle haben ein Farbrad um…

Vorteile von Android™ vs. Linux

By Maximilian Batz | 2019-02-06

Technische Grundlagen Android™ basiert auf dem Linux-Kernel, optimiert ihn aber besonders auf embedded Systeme & mobile Plattformen. Android nutzt den Linux Kernel mit einigen Anpassungen. Es unterscheidet sich jedoch grundlegend von üblichen Linux Distributionen, wie bspw. Debian / Raspbian / Alpine Linux. Üblicherweise nutzen Distributionen die GNU C Bibliothek (glibc), und einen X server (bspw.…

Building a persistent in-line editing experience with Crystal, MongoDB (datanoise / sam0x17)

By Maximilian Batz | 2019-02-05

As documentation is still sparse, I would like to add some. This is what I am building currently: The individual fields are going to be editable with an inline editor, which will automatically save to the backend – no need for reloading the whole page. The point of the whole is a backend for my…

Q&A LetsTrust TPM

By Maximilian Batz | 2019-02-04

This is a series of questions and answers for our LetsTrust TPM module. If you have an industrial project, and are looking at 100+ units, we’re happy to work with you to modify the product, if necessary. Contact us for details. Is there the possibility to support the TPM module on the Linux Kernel 3.1?…

WLAN password Anonymebox 3B+

By Maximilian Batz | 2019-02-02

Usually the WLAN password for the Anonymebox 3B+ is set to a random password during manufacturing. It is shipped to you with a silver label, carrying the WLAN password on it which is set. If you order the image, or upgrade from an earlier Anonymebox firmware, there is a default password which is set. The…

Alpine 3.9.0 initramfs init changes

By Maximilian Batz | 2019-02-02

Alpine 3.9.0 ships a new version of the init script in it’s initramfs. left: Alpine 3.9.0, right: Alpine 3.8.2 There are a number of interesting changes: better and earlier networking support for the boot process, with an additional kernel parameter for cmdline.txt: BOOTIF, allowing you to specify the device interface you want to use for…

Using nuitka compiler for python3 on Alpine Linux ARMHF (musl)

By Maximilian Batz | 2019-01-31

Motivation pidoctor is written in Python (as there was no easy way to get Crystal to work on ARMHF / musl). This means a dependency on Python – which adds overhead. I suspect that this overhead is the reason that pidoctor will not run on 256 MB Raspberry Pi’s – because the RAM is exhausted…

Debugging the Alpine boot process

By Maximilian Batz | 2019-01-22

As discussed in my previous post, Alpine Linux goes through several stages when it boots. Just after mounting the boot media, and scanning it for apkovl’s (with nlplug-findfs), there is an option for you to get a console, by setting $SINGLEMODE to yes. Setting SINGLEMODE to yes is easy, you simply add the word “single”…

kemal-session does not persist data

By Maximilian Batz | 2019-01-22

https://github.com/kemalcr/kemal-session Analyse what is happening with your session cookie. In my case, the session cookie was reset everytime I went to login. I realized, that my idea of cleaning up the old session as a first statement after successful login, before setting up the new session is not a good idea. I suspect, that the…

Using modules in crystal

By Maximilian Batz | 2019-01-22

As your application grows, you would like to move from one big .cr file to separating your code into smaller files. You can use require from your main .cr file to add code from other files: require “./tools/*” This statement will add code from the tools directory, relative to your main .cr file. This will…