veckonr is a Chromium extension that shows the current ISO 8601 week number right in your browser toolbar. Never wonder which week it is again. Install it for free:

Get it for Microsoft Edge · Get it for Chrome

• OpenFlight: open-source golf launch monitor. I'm a collaborator on the project.
• Golf tagging in OSM: I help improve how golf is mapped in OpenStreetMap. I'm one of the authors of the proposal Relation:Sport for golf courses, which defines how to map facilities with more than one course, the tees each course is played from, and scorecard values that differ by tee. I also help with FairwayMapper, a tool that gets golfers mapping their own courses.
• golfTiles: free, open-source vector tiles and a MapLibre GL style for golf courses, built from OpenStreetMap data. Most golf apps show plain raster OSM maps that can't display everything mapped on a course, so golfTiles defines a vector tile schema for zoom 14+ and scripts (osmium + tilemaker) to generate your own PMTiles. Demo
• OpenYardage: create a yardage book with distances, hazards and elevation change hole by hole from OpenStreetMap, and print it for free. Please check it out, it's awesome! I've helped by proposing improvements and by recording LiDAR scans of greens with my phone to validate the green slope maps it generates from DEM sources with international coverage.

I contribute to FTW, a local-first home energy management system (EMS):

• srcfl/ftw: the EMS itself, coordinating solar, batteries, grid and EV charging.

negative-price-calc shows how negative electricity prices affect your solar export. I improved it so it runs entirely in the browser, meaning your file never leaves your computer, and added more metrics to the results. Try it

• export-mermaid-to-svg-vs-code: VS Code extension that exports Mermaid diagrams to SVG with one click, from .mmd files or every diagram in a Markdown file. It also fixes blank labels and missing shapes when the SVGs are opened in Word or Inkscape.

I sent fixes to PINGMapper (side-scan sonar to benthic habitat maps), claude-from-here and buzz.

• klattorp.se: digitised photo albums from the village of Klättorp in Vissefjärda, so the old pictures are kept and anyone in the village can browse them. With this project I focused on learning about EXIF metadata: each picture carries its own description in its metadata, which the website renders as the caption and which follows the picture when you download it. Built with Hugo. (source)

• tornfvof.se: website of Törn och Törngöls fiskevårdsområdesförening (FVOF), which manages fishing in the lakes Törn and Törngöl in Emmaboda. It collects fishing permits, rules, maps of the water areas and old depth charts, plus an archive of the association's documents, statutes and court rulings. The interactive map loads MapLibre only when it scrolls into view and waits for a tap on Data Saver connections. (source)

  For other fiskevårdsområdesföreningar: the repository also contains the QGIS project behind the map, and step-by-step instructions (in Swedish) for making your own vattenområdeskarta from Lantmäteriet's open property data.

• beskattningFVOF: a Jupyter notebook about taxation in a medlemsbeskattad rättsamfällighetsförening, such as a FiskeVårdsOmrådesFörening. The association isn't taxed itself: each member declares their andel of the yearly result, but only above Skatteverket's exception of 1,500 kr (this year's amount, subject to change). Given every property's andel in a CSV file, the notebook simulates each possible result. It plots how many members must declare and the total they declare, and prints the breakpoints: the result to stay under before more members have to declare. Name, exception and range are set at the top of the notebook.

• hugge.se: my personal website, built with Hugo.
• rikstelefon: decode the rotary dial of a 1924 Ericsson BC 310 telephone with an ESP32-C6, using the ESP-IDF pulse counter (PCNT).