Ik heb nieuwe theedoeken nodig, maar ik vind de theedoeken van de HEMA e.d. wat te gewoontjes. Ik ben gaan knutselen en heb nu een Rijkstheedoek gemaakt, geschikt voor elke Rijksafwas. In de toekomst wil ik allicht ook een Rijkshanddoek :-) Meer ludieke ideeën zijn welkom!

People that attend SIGBOVIK on average tend to have more smiles per minute than those who do not, so don't miss it - you might see me as well :-)

Ik heb reactie gehad van het Ministerie van Defensie waarom ze een "senior vibe coder" zochten. Ze waren eigenlijk op zoek naar iemand die kan onderzoeken of lokale AI/LLMs het ontwikkelen van OSINT-modellen kunnen versnellen. Het volledige verhaal is hier te lezen: blog.koenvh.nl/waarom-het-m...

Sommige organisaties accepteren woo-verzoeken alleen maar per post en dat leidt soms tot komische situaties. Vorige week heb ik nog een e-mail gestuurd naar een woo-contactpersoon met de vraag "is deze brief aangekomen?", met een PDF van de verstuurde brief als bijlage :-)

My submission to SIGBOVIK this year, titled "Too Long; Dye't Red: Doubling the Effective Number of Pages Using Stereoscopic 3D Printing". For those without a pair of 3D glasses, here are some pictures to help you read this tremendous advancement in information density.

Greetings! I was thinking: what if we can use the DNS for more than just questions and answers, but also for conversations? That's why I started working on ircns (ircns.koenvh.nl) to combine the best of DNS and DNS tooling like `dig`, `kdig`, and `drill`, with the modern chat protocol IRC.

I have been playing around with time and watch faces lately (like the one where it's always 11 AM and the one which shows historic facts). In case you missed it, I decided to do a small write-up on my blog: blog.koenvh.nl/weird-clocks...

Naar aanleiding van de gemeenteraadsverkiezingen gisteren kwam de vraag in me op: over een jaar zijn er weer waterschapsverkiezingen, weet je nog wat je drie jaar geleden gestemd hebt, en ben je tevreden met wat ze tot dusver voor het waterschap hebben gedaan?

I just managed to make another watchface, this time (pun intended) it's always 11 AM, but the timezone changes every hour to where it's 11 AM in the world.

Oh hey, that's a surprise: OverTake wrote an article about Pacenote Pal! www.overtake.gg/news/customi...

Twee weken terug zei het Ministerie van Defensie dat "een woo-functionaris binnenkort contact op zou nemen". Ik heb gistermiddag de woo-contactpersoon proberen te bellen, maar dat telefoonnummer verbindt door naar de persvoorlichting (die vervolgens logischerwijs niks kan betekenen).

Ondertussen heb ik met 21 organisaties contact opgenomen om te vragen hoe het staat met hun blockchainpilot. Mocht je op de hoogte zijn van nog een blockchainpilot van een Nederlandse publieke organisatie die in deze lijst ontbreekt, laat het me dan weten: blog.koenvh.nl/wat-is-er-me...

Tien jaar geleden was de blockchain een enorme rage. Veel publieke organisaties zijn in die tijd een blockchainpilot gestart. Ik heb bij twaalf van die organisaties nu gevraagd hoe het daarmee staat. Hier is een kleine greep uit de pilots die tien jaar geleden gestart zijn:

A couple of days ago I released a new version of Pacenote Pal, which now has greatly improved pacenote timings. There are still one or two small things I want to do, but by and large I'm happy with how it works so far :-) github.com/Koenvh1/Pace...

In further annoyances, my watch face for Wear OS was again rejected by Google Play. Why a very limited XML file needs a privacy policy, statement that it does not offer mortgages, an "app" icon, and more in the first place is beyond me - the WFF spec makes it impossible to do anything like that.

I spent the last couple of hours trying to figure out why every time I would redeploy my blog a stale version of my latest blog post would pop up until it reached the TTL, after which it would work fine. Turns out it's a Vercel bug. The temptation to rewrite everything in plain HTML is high.

Ik heb ondertussen ontvangstbevestiging van het Ministerie van Defensie gekregen. Ik heb de blogpost daarop aangepast: blog.koenvh.nl/vibe-coding-... (En zoals deze dingen lopen ben ik nu al een paar uur bezig om de caching van mijn blog beter te begrijpen en te optimaliseren...)

The paper I wrote together with @jvdham.nl and Roland is now available: "Your Disclosure Is Important To Us: An Analysis of Coordinated Vulnerability Disclosure Responses Using a Real Security Issue", get it now whilst it still has the "Just Accepted" watermark: dl.acm.org/doi/10.1145/...

De opdrachttekst voor een "Senior Vibe/AI developer" bij Defensie heeft bij mij nogal wat vragen opgeroepen, en die vraag bleef genoeg hangen om er een WOO-verzoek over te sturen: blog.koenvh.nl/vibe-coding-...

De Atom feed van het Rijkspodcastregister is nu ook van de afhankelijkheid van Spotify af. Als bonus is de feed nu ook zelf als podcastfeed te gebruiken: rijkspodcast.koenvh.nl/feed.xml

In addition to the €206 I spent on blueberries at Albert Heijn in 2025, I spent another €42 on blueberries at Lidl in 2025. That boils down to €248 on blueberries, or about €0.68 per day.

After playing around with the Albert Heijn GraphQL API yesterday, I now know I spent ~€206 on blueberries in 2025. I really like blueberries.

Sinds afgelopen weekend gebruikt het Rijkspodcastregister geen Spotify meer als speler, maar direct de bron van de podcast. Helaas zijn daardoor 35 podcasts niet meer direct te beluisteren, omdat die exclusief bij Spotify beschikbaar zijn. rijkspodcast.koenvh.nl

Mijn smartwatch is aangekomen en: het werkt. Ik kan nu elke minuut (voor 20:26) een gebeurtenis zien uit dat jaar. Staat nog niet in de Play Store, maar de code is hier te vinden: github.com/Koenvh1/Hist...

Spotify heeft aangekondigd dat hun API vanaf maart alleen nog zal werken met premium [1]. Dit heeft ook effect op het Rijkspodcastregister, dat niet meer zal werken. Als iemand nog een API key overheeft hoor ik het graag. [1] tweakers.net/nieuws/24449... [2] rijkspodcast.koenvh.nl

In de categorie impulsaankopen heb ik nu een tweedehands Samsung Galaxy Watch 4 gekocht zodat ik m'n wijzerplaat ook in het echt kan testen. Vanwege de manier waarop het Watch Face Format (WFF) werkt, heb ik een keten van ternaire selectieoperators van 899 KB groot (4941 mogelijkheden).

Ik ben bezig met mijn historische klok [1] om te vormen naar een wijzerplaat voor Wear OS [2]. Het lijkt te werken, maar de ironie is dat ik zelf geen horloge heb waarmee ik het kan testen. [1] koenvh.nl/playground/h... [2] github.com/Koenvh1/Hist...

Nine years ago I made a website to play Lingo, with the last commit seven years ago. GitHub told me that four days ago someone forked it and is now continuing development. The fact someone found it let alone forked it surprised me greatly. It's still online and can be found here: lingo.koenvh.nl

Continuing from yesterday: here is one of the problems I run into. The zone starts at that sign, but if you exit at the bottom right, the zone never ends. My algorithm subsequently considers everything as part of the no parking zone. Some signs that are there IRL are missing form the DB.

I have been trying to use the national traffic sign database to map where street parking is allowed. I thought my algorithm was wrong at first, but it turns out quite a few no parking zones never technically end because the signs are missing (both in the database and in real life).

Fun fact: Dutch traffic sign F16 (end of carriageway or lane reserved exclusively for trams) appears a grand total of 1 times in the Netherlands. Specifically here: www.openstreetmap.org?mlat=52.3601... / www.google.com/maps/search/... This makes it the least commonly used road sign in the country.

I updated my website to make it better reflect what I'm currently up to, as well as get the styling a bit more consistent. One problem: my current website is now ~10 years old, and getting the build tooling working (or just finding the docs) is becoming difficult. Hurray for web dev. koenvh.nl

A new update for ScreenDeck is now available on the Elgato Marketplace, now featuring support for local streams and volume control: marketplace.elgato.com/product/scre...

I played a "game" called TR-49 this weekend. It's an interactive story where you enter four character codes into a machine to discover books to slowly untangle the story behind it all. It stays interesting pretty much the whole way through and does not overstay its welcome. Can highly recommend.

I finally got around to making a quick write-up of my DVDgotchi project, where I made a Tamagotchi clone out of DVD menus. You can read it here: blog.koenvh.nl/dvd-menus-an...

I just updated my blog to make it slightly more obvious that there is an RSS feed that contains the blog posts in full, in case you don't want to leave your RSS feed reader. It can be found here: blog.koenvh.nl/rss.xml

I've been trying to find out how realistic it would be to make my own 300 baud* dial-up software. Step one: generating audio and reading it back in (with added background noise). So far it seems to work, surprisingly. DFT feels like magic. * 300 bps should be enough for everyone :-)

I know far more about rsync know than I reasonably should, so I figured I would make a write-up on all the things you technically could do with rsync, but you probably shouldn't. blog.koenvh.nl/what-you-can...

I use Hashnode for my blog, and recently they changed the styling which wasn't to my liking. Luckily they also offer a way to make your own front-end (using Vercel), and after a bit of tinkering it is now working: blog.koenvh.nl Frankly I think it's an improvement over what it was like before.

Happy New Year to everyone: to those now catching their breath after a time of fun festivities, as well as to those who - like me - are glad things are going back to normal again.

DVDgotchi is now available on DVD. Ironically I did not have any writeable DVDs left over in a cupboard, so I had to order new ones, along with some DVD labels and sleeves. I think this basically completes what I wanted to do with DVDgotchi :-)

With my newfound of DVD programming I had to create something, and it now actually works: Introducing the DVDgotchi. A tamagotchi clone implemented entirely using DVD menus. Works on any DVD player (and VLC). Source code and ISO available on github.com/Koenvh1/DVDg...

Since 2019 I have made custom Christmas cards. This year was no exception. I decided to "write" a blog about them: blog.koenvh.nl/christmas-ca...

Recently I've been looking into how DVD menus actually work, it's quite fascinating. A DVD player effectively runs a small VM where there are 16 16-bit registers that can hold variables. Buttons can set/read those variables. The standard library consists of only random number generator.

One of the things rsync does filter out are all the control characters before 0x20 except for \n and \r (when they appear at the end). This sadly means I can't use ANSI escape sequences to clear the screen. I did manage to play an ASCII version of Bad Apple!!, albeit slightly flickery at times.

In further toying around with the rsync protocol, I have now managed to make it display more or less arbitrary text. Of course I quickly had to recreate the famous scene from The Matrix. (And for the DNS people, this means I can likely make the DNS over rsync output compatible with dig)

Because I felt bad for all the DNS people having to miss out on the joy of working with rsync, I started on a DNS resolver over rsync. It should be mostly functional already. Feel free to try it out. The records appear as files, and the time is set to when the TTL will expire.

I published a new blog post about my Stream Deck adventures and how I turned it into a video streaming device. It now also has volume controls! (It also contains some lovely AVIF animations that took far too long to render.) blog.koenvh.nl/streaming-on...

Assetto Corsa Rally Pacenote Pal has now been published for about ten days, and already five people have made or are making custom co-driver voices for it. That's awesome. It's quickly turning into an advanced custom pacenote system :-)

Woohoo! ScreenDeck is now available on the Elgato Marketplace. Now you can easily use your Stream Deck as a video player: marketplace.elgato.com/product/scre...