Things I have coded, authored or built over the years.

Remarkably Accurate Quartz Clock

A scratch-built timepiece with ±10 second/year accuracy using an ATMega microcontroller and a regular quartz crystal. Details on Hackaday and Github.

The Remarkably Accurate Quartz Clock

RSS Parrot

An ActivityPub service that notifies Mastodon accounts about new posts in the RSS feeds they follow. I gave a talk about it at the GDG Berlin Golang meetup.


Chirpy TX/RX

A modified Casio watch with a headset microphone over it.

A protocol and implementation for transferring data out of an airgapped device over a piezo buzzer. It is included in the Activity Face of Joey Castillo's Sensor Watch.

Browser-based decoder: Chirpy RX receiver

CHDICT Chinese-Hungarian dictionary

Link: CHDICT kínai-magyar szótár

An open-source, community-edited Chinese-Hungarian dictionary that I initially conceived in early 2015. It took a bit over 2 years to seed the dictionary with its first 11k entries, which I translated from the English and German in CC-CEDICT and HanDeDict.

Back in late 2015 HanDeDict became an orphan, and since I had already made a lot of progress with the website software, I re-published it at

HanziLookupJS and a bunch of texts right here are also offshoots of this project. I wouldn't advise anyone to embark on a similar adventure: Chinese lexicography has a way of sucking you in ;-)

Related Github repositories:


Free, open-source Chinese handwriting recognition in Javascript.

HanziLookupJS demo

HanziLookupJS is a library based on Jordan Kiang's original HanziLookup from 2006. It contains data derived from Shaunak Kishore's Make Me a Hanzi, and an improved character recognition algorithm.

Check out the online demo at, or the code itself. Going by the number of stars and forks, this is my most popular repository on Github :)

A German vocabulary test inspired by Unfortuntely I lost the domain name for my own test, and TestYourVocab appears to have been swallowed by a marketplace for language tutors.

I basically just wanted to find out about my own vocabulary, but eventually went down the rabbit hole and dug deeper into vocabulary stuff than any sane person would ever want to. Your German vocabulary on a curve is the text where I analyze the results that were collected over the 2+ years while the test was online.