Yearly Archives: 2017


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: https://developers.google.com/android/images#instructions Problem I called the following command as recommended in the instructions: ./flash-all.sh Result (quite […]


Dodge Ram MegaCab brake caliper replacement

Problem The front right caliper of our truck clamped every time I applied the brake so the front right brake was braking all the time. I recognized it because the truck does not start to roll on after releasing the brake even when standing downhill and while driving she pulled sideways to the right. When I stopped I could already smell where the problem was located. I waited until the brake was cooled down and drove home really slow and used only the transmission and the parking brake to slow down. Result I replaced the caliper of the right brake which solved the problem. […]


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@192.168.2.106:~/photos/handy-samsung-s7/ 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 […]


Complete rack mounted and painted.

Pickup Rack

This weekend I build a rack for our pickup truck which reaches over the complete cab to the beginning of the windshield. At the beginning I was concerned about the long overhang because we own a 2007 Dodge Ram Megacab but it turned out that my concerns have been unneeded. On the picture above you can see a styrofoam roll I installed to avoid damage if the rack is hitting the roof of the cab. Luckily there is no contact after the first hundred miles. The rack is made out of 25 millimeters square tube with 1.5 millimeters thick walls. I need approximately […]


2017 Cultivation plan

2017 Cultivation plan for our raised bed

This week we prepared our raised bed for the 2017 season. In the first step we removed the old strawberry plants. We kept the chive some of the branches of the strawberries which they produced last year. Everything from the last year can be seen in the picture on the left side (areas one and four). The new planted two, three and five are planted with loose leaf lettuce (two), Wasabi Arugula (three) and Rainbow Carrots Purple Sun (five). Between the five areas we planted radish to create a visible separation between the five areas. I created the cultivation plan with LibreOffice Draw. Cultivation […]


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 Germany.map 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. […]