Cleaned my keyboard again

… six years later, I did it again – not as careful as last time six years ago but it feels wonderful to write on a well cleaned keyboard anyway. Cleaning and contact spray converted my writing from “thiiiiiiiiiiis” to “this” – haha, recently often the letter “a” did not work and “i” was doubling – now everything works fine.

Nexus 7 – install old android version 4

Our Nexus 7 (first version) was super slow since it was updated to android version 5.x so I decided to install version 4.4.4 which is the latest version before version 5. I tried to downgrade by the instructions supported by Google but it did not work and I have to call some additional commands. See solution section. Hopefully the tablet is a little bit faster with version 4.4.4. Before I started I have to enable USB-Debuging in the Developertools on my device. Link to the Google factory images: Problem I called the following command as recommended in the instructions: ./ Result (quite […]

Syncing images from android smartphone to raspberry pi

I was looking for a solution to backup the photos taken with my smartphone to our raspberry pi. Android side I searched for synchronization apps and ended up using rsync as backup tool. Therefore I installed the app ‘Rsync Wrapper‘ on my smartphone and configured it with the following parameters: Source: /storage/9C33-6BBD/DCIM/Camera/ Destination: martin@ Option: -r –ignore-existing –progress -e “ssh -l martin -i /data/user/0/net.letscorp.rsyncwrapper/files/06a73f67-6234-40e7-81de-7add8fa4c783.key -y” I removed the –verbose parameter and added the –ignore-existing parameter. The –ignore-existing parameter was added by me because the synchronization took up to twenty minutes where the most of the time was used to check which files are […]

Install OpenAndroMaps on OruxMaps via PC

I tried to install maps from OpenAndroMaps on OruxMaps on my SmartPhone (Samsung Galaxy S7). At first I tried the recommended way on the website of OpenAndroMaps and used the direct download and installation via my smart phone. I selected the “Install on Oruxmaps” option and the download started but it seemed that my phone could not unzip the downloaded archive within one day (8 hours). So I downloaded the map-file (zip) to my pc and unpacked it there which results in a file called which is approximately 2.7GB big. I copied the map-file to my phone connected to my pc via […]

Cleaned my keyboard

This week I had the strong desire to clean my keyboard because it was really dirty and disgusting. The cleaning results are okay but the plastic is still bleached out because this keyboard is at least ten years old. The keyboard is even not listed at the discontinued section at the producers website but it still works fine. It even has one of these half inch wide DIN connectors. Currently I use a adapter to connect it to my computer to the PS2 port. My brother connected his keyboard to his smartphone with the following adapters: DIN to PS2, PS2 to USB and USB […]

Create a gps track, follow it with your phone and track your way

Last weekend we made a small bike tour with our eBikes. To prepare the planned route I created it online an loaded it to my smartphone. I don’t use my smartphone to navigate but I like it to use it like a map with the route painted on it. In this post I describe my solution to create a track and follow it with my phone. I recommend to read the documentation especially of GPSies and OruxMaps maybe you can find a better way than I. But currently I like the way it worked, especially the part with the QR code on GPSies which […]

Raised flower bed - 2017-02-07

How to deal with empty or missing fields in messages

In the following post I want to discuss how to deal with empty or missing fields in messages from the perspective of the receiver. I will try to explain the problem with the following scenario. Scenario There is a ‘sending system’ which sends data in messages to a ‘receiving system’. In my example the sending system sends demographic data of persons to the receiving system. The sending system may be a patient registration system in a hospital and the receiving system a statistics tool. How the messages are sent is not relevant in this scenario but we can assume that the messages are […]

Raised flower bed - 2017-01-29

CSV alternatives (JSON, XML, BSON) – Raised flower bed

Comma-separated values (CSV) I am working at the IT-Department of Universitätsklinikum Erlangen (University Hospital Erlangen) and this week I created a CSV file for a other project. The aim of this project is to migrate clinical findings into a new system. The clinical findings in the old system don’t have identifiers like a patient-id or a case number but some demographic data (name, surname, birthdate, zip code, …). The project manager and his developer who are responsible for the migration contacted me and asked for demographic data of our patients to implement a heuristic to assign the clinical findings to the correct patients. […]

Raised flower bed – 2017-01-22

Raised flower bed – 2017-01-22

Blog changes I changed the theme of this blog this week from Twenty Fifteen Theme by to the free Customizr Theme. When I started to search a new theme on the site it was overwhelming how much cool templates you can find there. My first thought was to look for a template which fits good to my ideas and adapt it a little bit.  But I realized soon that a new template is more than the installation and the assignment of some widgets. After I tried some templates I searched for a template which is highly customizable. My google searches directed my […]

Das Hochhaus von Katharina Greve – durcheinander

Unter von Katharina Greve entsteht gerade ein Hochhaus auf das, bis zum 5.9.2017, jede Woche Dienstags eine neue Etage hinzugefügt wird. Hier ein kleiner JavaScript Schnipsel zum einfügen in FireBug um die Etagen durcheinanderzubringen. (Wahrscheinlich geht das auch unter Chrome oder dem Microsoft IE mit deren Entwicklerwerkzeugen – das habe ich aber nicht getestet). Das jQuery-Plugin habe ich von und leicht angepasst. Die Anpassungen waren noetig, damit die Etagen korrekt geschichtet werden (setzen von CSS-Eigenschaft ‘z-index’) und damit das Erdgeschoß und der Keller immer unten sind (sieht sonst sehr komisch aus wenn der Rasen irgendwo zwischen drin ist). Vorraussetzung dafür, dass […]