In the context of home automation, many different sensors (with different communication channels, e.g. DECT, WLAN, Bluetooth, Zigbee, …) were combined on a Linux-based system (Raspberry PI). The open source platform “Home Assistant” was used as the base framework.

The following is an excerpt of the implemented components:
– Graphical design incl. 3D floorplan (dedicated day/night display and image-based integration of open windows)
– Window open detection (turn off the heating, warning if open too long at cold temperatures, reminder when leaving the apartment)
– Power sockets with integrated on and off switching according to daily and behavioral cycles
– Smoke detector with warning via messenger and correlation with temperature sensors
– Humidity monitoring/warning in all rooms
– Presence tracking via registered mobile devices on the local router (e.g. corresponding ECO mode for heating)
– Business calendar based home-office-mode (e.g. heating in the office)
– IR-pulse-based energy monitoring
– …

In 2016, I started with a low budget 3D printer assembly kit to dive into the 3D printing technology (Figure 1). After the assembly, the print quality and speed was in need of improvement (as expected in this price range). For this reason, I have developed, 3D designed, and printed improvements for the 3D printer. This includes a better print head (Figure 2), sensor mounts with integrated dowels, filament push heads, cable guide chains (Figure 3) etc. These improvements significantly increased the printing speed and quality. All these adjustments are made in close cooperation with the open-source community. In this context, I have made all developed parts available for free, open-source and parameterizable on Thinigverse. The parts have been viewed more than 0.9 million times and achieved more than 0.25 million downloads. More than 150 users also shared pictures of the components designed by me, integrated into their printing system.

In addition to improvements to  the printer itself, I also develop many other parts – mostly custom solutions when there are no commercially available products to solve a problem.

Figure 1: Assembly of the 3D printer.

Figure 2: Developed improved print head.

Figure 3: Developed print head cable chains.

In 2014 I started with android app development. Besides smaller projects, a fire department internal app was created. The app includes a digital accounting and payment system, mission documentation and statistical evaluation, scheduling and reporting, as well as e-learning, for example to familiarize users with road names in the area of operation.

The core of the application was developed in Java in 2014 and 2015 and has since been continuously adapted and expanded. In addition to new features, the ongoing adaptation to new Android versions is among the range of tasks. Also, the adaptation to new technical standards, such as the migration of the database to “Firebase” in 2022 are part of continuous improvement.

For private cellular alarms, I designed and built a dipole antenna with a spectrum analyzer, which ideally picks up the radio traffic of interest. Using a local secure server, the data was digitized and forwarded to the mobile device.

In the course of time (2019 and the following years), the analysis was extended by artificial intelligence in the context of speech recognition, keyword classification and routing. Additional information is integrated via web scraping.

On the mobile device, current conditions are analyzed and corresponding notification patterns are activated. For example, a discreet alarm pattern is triggered at a distant location, while prominent signals are sent in the event of stay in the vicinity.

In 2020, a Monkey C application for a Garmin watch was also developed, which can read out and display the information obtained.

In 2011, I designed, engineered and programmed a robotic arm in my spare time from scratch. The basic components are sawed wooden elements, servos and the high-precision bearing of a discarded hard drive as a base. The implementation of the motion control was done on a C-Control Unit Mega 128.

A short demo of the robotic arm can be seen in the following animation:

In 2010 I have been working on flashing Android operating systems to windows mobile devices. To make this process accessible to many people I have recorded and published tutorials on youtube. The videos have been well received at the time and have been viewed a total of 0.4 million times.