In my spare time I like working on all kinds of projects, which are often programming related. In alphabetical order, I've been working on:
Arbitrage | Brainfuck | Furbie | Lego cat | PSP | .rc | Scripts | Sites
"In economics and finance, arbitrage (IPA: /ˈɑrbɨtrɑːʒ/) is the practice of taking advantage of a price difference between two or more markets" [Wikipedia].
The arbitrage script takes as input the bid and ask for different commodoties (e.g. currencies) and displays any loop holes found. It then also displays an adjusted solution that does not have any loop holes.
There are also some sample inputs available.
Back in 2002 I wrote a tutorial for this esoteric programming language. Also check out Brainfuck quines.
Furbie is a Dutch chat bot that can tell you the local weather, make simple calculations, keep track of a to-do list, remind you of upcoming events (user-defined) and much more. To find out more, contact Furbie on IRCNet.
Furbie's source is available.
For my then girlfriend's (now wife ;) birthday I made a Lego model of our cat:
You can also download the LEGO Digital Designer source or check out how the final result looks.
Around 2007-2008 I spent some time improving Map This!, a homebrew GPS program for the Sony PSP. Since Go!Explore hadn't come out yet, Map This! was the only proper option available. Some of the improvements I made include: GPS trail recording, smart zooming and auto map selection (based on current position).
MP3 streaming tutorial (RSS)
The PSP allows you to stream music from a web server to your PSP using RSS.
Since the order of RSS feeds cannot be changed on the PSP itself, you can use the PSP RSS Sort script instead. Source available.
PSP Guitar is a guitar synthesizer that supports notes from octave 2 till 6 (inclusive), with support for flat (♭) and sharp (♯) notes. The key bindings are as follows:
- Left trigger: decrease octave;
- Left trigger+note: hold for flat note (♭);
- Right trigger: increase octave;
- Right trigger+note: hold for sharp note (♯);
- Right: note C;
- Left: note D;
- Up: note E;
- Cross: note F;
- Circle: note G;
- Square: note A;
- Triangle: note B.
It also shows a visualization of the sound waves.
PSP Tone Generator
PSP Tone Generator v0.1 can create up till five simultaneous tones ranging from 20Hz to 10kHz. It also shows a visualization of the sound waves.
Version 0.2 supports only three tones, but has a higher range (20Hz to 20kHz) and tighter timing, resulting in better quality at high frequency ranges.
Version 0.3 supports different frequencies for the left and right output channel and includes support for fine-tuning the frequency by holding the square button.
Video converter script
I used to regularly watch movies/series on the TV through my PSP. For that I used a converter script to convert any file ffmpeg can read, to the one and only proper format the PSP will read: H.264/MPEG-4 AVC video (level 2.1), AAC audio. The script requires ffmpeg and Perl to work.
There is also an iPhone version, an FLV (Flash) version and an HTML5 version available.
I'm an avid user of mutt, vim, screen and bash. Each link goes to my .rc file.
The barcode generator generates barcodes from numbers from a wide range of formats. Source available.
Explore vs. exploit
Find out if you should explore something new, or exploit a known favorite (e.g. food, jogging route, TV show, etc.) using the Explore vs. exploit script, which minimalizes regret. (See also my blog post.)
iTunesExport.js is a Windows-only script to export in one go all of iTunes's playlists into M3U8 format (M3U with UTF-8 encoding). Instructions are in the file itself, but in short: save it to disk and run it. (See also my blog post.)
MooTabs 1.3 is the updated version of MooTabs. It works with MooTools 1.3. (See also my blog post.)
Russian sentence generator
Practice Russian verbs of motion, translations are in Dutch. Source available (SQL).
Small toolkit for often-used web functions.
I made the following websites, mainly for family members:
- DianaMaatjes.nl, personal website of Diana Maatjes;
- EdwardMaatjes.nl, personal website of Edward Maatjes;
- MicroGasWash.com, a technology for filtering emissions;
- Rymotec.nl, a company offering services related to environmental issues and business administration.