Roland's homepage

My random knot in the Web


This is my home in the virtual world, where I write about things that I want to share. The freely available software that I've written as well as some of the photographs I've taken over the years can also be found here. Please use the navigation links on the right if you are looking for something.

Recent articles

  1. Automating package updates on FreeBSD

    When updating my ports, I prefer to use packages when I have not changed the options of a port. This describes how I do that.


    Compiling large programs like firefox can take a long time. Therefore I like to use packages when updating my ports. But I don’t …

  2. Installing Pelican 4

    Pelican is the static site generator that I use for my website. This allows me to write my website posts in almost plain text (actually a light-weight markup language named reStructuredText), which are then translated into HTML. As someone who has written his webpages in HTML by hand, I can …

  3. Creating a nomogram with Python and Postscript

    At work I needed a suitable way to check the calibration of gelcoat spray equipment. Gelcoat requires an initiator (often called “catalyst”) in the form of a peroxide to cure. The peroxide/gelcoat ratio is important, so it is checked regularly by spraying the separate components into suitable containers and …

  4. TeXLive 2018 update

    Today I updated my TeXLive install to 2018. Although the install went fine, there was a problem with the binaries.

    Both asymptote and xetex were linked to different versions of some libraries than those that are supplied by ports. So I had to rebuild them.


    Some might wonder why …

  5. Measuring particulate matter with the PMS5003

    This article details how I used the Plantower PMS5003 particulate matter (“PM”) sensor on a PC or laptop, using an FT232H breakout board to make the connection.


    My reasons for buying this device are so that I can measure airborne particulate matter at home and at work. So I …

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