Me? I'm not.

This is my personal blog, where I write about things that interest me or that I'm currently working on.


I'm working as a Senior Developer for SAP SE in the S/4 HANA Source-toPay & Order-to-Cash. My main focus is the development of cloud products based on SAP Cloud Platform. I mostly do development in Java with the Spring Framework and SAPUI5 and JavaScript.

In my sparetime, I like to ride Mountain Bike and do some programming for macOS and iOS in Swift.

Terrarium light automation


In my last post, I mentioned that I would develop a homebridge plugin to control the terrarium light. In fact, this wasn't necessary. I developped a small script called terralight. With terralight, I'm able to control the light as I wish to do, e.g. automatically turn on or off the light on sunrise or sunset. Feel free to use it and give feedback! Instructions are available in the readme of terralight.

Leopard geckos and Terrarium automation


I recently build a terrarium where I'm keeping leopard geckos. The climate of the natural environment they live in is similar to teh one in house or a flat in western europe. To provide them a decent environment you need to have some light sources in the terrarium. I decided to control the lights using Apple HomeKit . The HomeKit apps already provide some good automation tools. When it comes to leopard geckos, you have to put them to winter rest. You have to start this process at the beginning of October by reducing the time where the lights are turned on by an hour each week, until the light stays off. This process is not possible with the HomeKit tools. Fortunately Homebridge exists: "Homebridge allows you to integrate with smart home devices that do not support the HomeKit protocol."

I'm going to develop a Homebridge plugin for a programmable soft switch which controls the light sources of my terrarium. Stay tuned for further articles, since I'm in an early planning stage for this plugin.

Powering Raspberry Pi on and off

It is possible to turn a Raspberry Pi on and off with a simple push-button switch and a small tool that is called pi-shutdown. The switch must be connected to the pins 5 (GPIO 3) und 6 (negative pole). If you push the button for about one second, the Raspberry Pi is shutting down and reboots. If you push the button for three to five seconds, the Pi is shutting down and turns itself off. If the Pi is turned off, you turn it on by pushing the switch.

The source code of pi-shutdown is available on GitHub. Instructions are available on the author's homepage.

Source: c't 25/2017, page 152

New Project: A Retro Console Emulator in a Retro Console Enclosure

On the last weekend, I've seen the documentary Atari: Game Over which "is a documentary film [...] about the North American video game crash of 1983, using the Atari video game burial excavation as a starting point".

In my opinion, the classic consoles and their games provide a more compelling gamer experience than the modern games. So I decided to roll my own Retro Console Emulator in an enclosure of a Retro Console.

Spring Boot eats the body of POST requests

I my current project, I had the task to integrate Apache Olingo into our Spring Boot based service. The goal was to levarage all feature that several Spring components provide. Unfortunaltey Spring Boot ate the request bodys of POST requests with a content type of multipart/mixed. In this article, I describe the background of the issue and how I solved it.