== Hiro's Stuff ==
Valentin Boettcher's Site


This is the web presence of Valentin Boettcher a.k.a. Hiro98.


  • currently studies physics in Dresden.
  • codes stuff.
  • is a science-fiction junky and space enthusiast.
  • loves jamming with the saxophone.
  • is hooked on LISP and Clojure.
  • appreciates C++.
  • likes his Kyria.

You can check out my Github, Gitlab and KDE Invent profiles for most of my projects as I publish the source to most things I produce.

I’ve got a CV in German.


Converting a Kawai KSP-30 to pure MIDI

My Kawai KSP-30 digital piano has been on its last leg for some time now. To get it to work at all, I had to unplug the amplification circuit whose interface on the main PCB was burnt out. Of course is wasn’t of much use by itself after that bit of crude surgery but worked fine as a midi keyboard. Figure 1: The main PCB. There must have been some creeping currents because the piano got more and more unreliable requiring hectic powercycling to boot and finally not booting at all. Read more...

KDE GSOC: Thanks and Work Product

First of all: A big thanks to my mentor Jasem Mutlaq and the KStars Team. Jasem, you were extremely helpful whilst leaving me a lot of freedom. With patience you have endured my mood swings and occasional panics :P. It has always been a pleasure working with you and I am certain that this will continue to be the case. Furthermore, the rest of the KStars Team, especially Akarsh Simha, Wolfgang Reissenberger and Robert Lancaster who have found bugs, helped me to debug them and suggested improvements1. Read more...

KDE GSOC: Wrapping it up…

Well, we all know that the work on open source projects is never truly finished, but all of the core goals have been achieved and the time is up :). In this post I’ll briefly summarize my GSOC work and then talk about one last small but user-facing feature that I’ve implemented. I’ve successfully implemented a new DSO backend and smoothed out most of the bugs. The python framework does work satisfactory and all existing catalogs have been ported. Read more...

KDE GSOC: Second Coding Period; Some Notes on the Catalog Repo.

TL;DR DSO catalogs in KStars are now generated reproducibly in the CI. A list of available catalogs and documentation can be found here. As promised last time I’ll now go a little into the Catalogs Repository. Usually DSO catalogs are pretty static and rarely change due to the nature of their contents. But although galaxies do not tend to jump around in the sky, catalogs still get updates to correct typos or update coordinates with more precise measurement. Read more...

Neuseeland Restauration

TL;DR Die Neuseeland-Blogposts sind nun wieder da und korrekt datiert. Zwar lagen mir die Neuseeland-Blog posts als markdown quelle vor, jedoch hatte ich den Erstellungszeitpunk unvorteilhafter Weise aus den Dateisystem-Metadaten1 ausgelesen. Nach der Neuinstallation meines servers vor ein paar Jahren waren diese Metadaten vollends verloren. Meine erste Idee war zu versuchen die Zeitpunkte anhand der Email Newsletter zu rekonstruieren. Auf diesem Wege versprach ich mir jedoch keinen baldigen Erfolg da mein eigenes Email Archiv nicht soweit zurueckreicht. Read more...

KDE GSOC: Community Bonding and First Coding Period (May 17 - July 11)

Of course the task I described in the last post looks and is quite monumental. That is why I laid some of the groundwork for my GSOC beforehand (in the actual German semester breaks). This work continued in the community bonding and first coding period and will therefore be described here. But first I want to thank my mentor Jasem Mutlaq for his support, his patience with me and his nerves of steel. Read more...


Hi folks, talking to you over the interwebs is Valentin Boettcher who is overhauling the Deep Sky Object (DSO) system in the KStars Desktop Planetarium for the Google Summer of Code anno domini 2021. This is the first post in a series and rather late in the coming, so let’s get right to it. I’m currently studying for a master’s degree in physics at the TU-Dresden in, you’ve guessed it correctly, the beautiful city of Dresden (Germany). Read more...

Installing without Fear

Note to self: If you want to make sure some nice GNU/Linux installer does not touch certain drives just run echo 1 > /sys/block/sdX/device/delete in a root shell and the drive will vanish from the system. Shamelessly stolen from: https://askubuntu.com/questions/554398/how-do-i-permanently-disable-hard-drives

Fixing Linux Dualboot: Reinstalling the Windows EFI Bootloader Files

Note to my future self :). Reloading my Linux install after a pretty radical ‘nuke and pave’ I had to get my Windows dualboot back to work. There are a thousand guides on how to do that, but I’ll add another one in case your setup is similar to mine. I have installed windows on a separate drive and Linux on my main drive, along with the efi partition. Don’t follow this guide blindly. Read more...

How to use the Systemd userspace DBus API on Traivis-CI

I am currently working on a project which involves talking to the systemd userspace session via the session dbus instance. After some fiddling around and enabling debug mode on travis via the excellent user support, I came up with the following. Travis uses VMs that run ubuntu which comes with systemd. To enable the userspace dbus session, one has to install the dbus-user-session package. After the installation, it has to be activated through systemctl --user start dbus. Read more...
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