Category Archives: Uncategorized

KNX with Raspberry Pi – Install Raspbian Part 1

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  • Download Raspbian Stretch from https://www.raspberrypi.org
  • Find required device name
    df -h
    /dev/mmcblk0p1 29G 32K 29G 1% /media/marc/1FAB-7

  • Umount device
    sudo umount /dev/mmcblk0p1

  • Copy image to SD card
    dd bs=4M if=2017-09-07-raspbian-stretch-lite.img of=/dev/mmcblk0p1
    sync

  • Mount image to activate ssh
    mount /dev/mmcblk0 /mnt
    touch /mnt/ssh

  • Connect raspberry to network and power up; Find IP address of Raspberry
    nmap -sP 192.168.178.0/24
    Nmap scan report for raspberrypi.fritz.box (192.168.178.42)

  • Enlarge filesystem by logging into pi with username pi and password raspbian
    ssh pi@192.168.178.42
    sudo raspi-config

  • Select 7) advanced options
  • Select a1) expand filesystem

    • Bouldering in Tenerife

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    We have been searching for good place for bouldering in autumn/winter and decided to travel to Tenerife. Tenerife has a couple of spots that are well suited for bouldering.

    Logistics

    • Car: Renting a car in Tenerife is very cheap.
    • Crashpad: It is possible to rent a crashpad at Tenerife Outdoor. More information is provided on their Roxtar page.

    Boulder Spots

    Arico Nuevo

    Provides a lot of boulder possibilites. A guidebook with detailed information about all boulders can be obtained from the Tenerife Outdoor shop. They provide you with a link to the pdf guide that can be viewed on your smartphone/tablet. Since the pdf file is of very high quality I would recommend you to visit the shop and buy something there to support them.

    We spent four days in the barranco of Arico Nuevo.

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    Arico Viejo

    The famous climbing spot of Arico Viejo provides also many boulder problems. As far as I know, there is no guidebook available.

    Personally, I liked Arico Viejo very much. The baranco is very nice.

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    Teide

    The Teide national park provides also some bouldering possibilities. There is the so called Tortuga. This is a pretty high boulder, I would estimate it on 5 meters.

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    Links

     

    Code Evasion

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    Gerard Holzmann recently published an article on “Code Evasion” in IEEE Software. He showed a couple of examples how error handling increases the complexity of reading and understand code, but also the increased potential for bugs. This does not mean to remove all error handling, but to give an extra thought.

    In my opinion he is perfectly right. Writing proper error handling code is a big challenge. Ignoring it at all and let program crash is not always an option.

    Using exceptions instead of return values can increase the readability. It does not mitigate the complexity of error handling and proper reactions. IMHO one of the advantages of exceptions – at least in programming languages like C++ and C# – is that they can bubble up and you can catch them some where very different. Probably at a place where you can react properly.

    SonarQube – Managing Code Quality

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    SonarQube is a very powerful open source platform for managing code quality. Among others, you can collect code metrics, identify issues in our source code (i.e. display results from static code analysis) and visualize results from unit tests.

    A very powerful feature of SonarQube is its extensibility. You can add plugins to our installation and adapt the platform according to your needs. It is also very nice that you develop our own plugins. Developing own plugins requires a bit of understanding how the platform works, but it is not very difficult.

    Jorge Hidalgo has written a very nice introduction how to develop plugins. His tutorial complements the introduction provided by SonarQube.

    My first attempt to write a plugin was a simple widget that allows to embed an iframe into the SonarQube dashboard. With this dashboard I’m in the position to display external data.