Listening to candlelight

I remembered reading once that manufacturers of electric candles had been using melody-card chips as LED drivers, causing these candles unseeingly to emit music. In order to ‘audify’ this optical sounds, I connected a BPW34 diode (with large Silicon cell, so it actually generates a voltage) to a jack chassis and hooked it up toRead more

Portable room acoustics

I’m currently living in an apartment without the possibilities of building a permanent recording studio. (In one of the previous houses I lived in I had a room specially modified for recording and practicing) I still want to be able now and then to record instruments without the sound of my concrete square room, withoutRead more


I came across the drawdio at and Again a wonderfully simple idea, but very imaginary and creative! I made one as Sinterklaas-present for my mother. I didn’t have time to buy a kit, so I had to use parts that were lying around. Using the schematic Limor posted on her site I madeRead more

Tchibo Cleaner Robot Mod-chip

Today I managed to kill (what could definitely be.. sure…) the last bugs in the design of the Tchibo Cleaner Robot mod-chip. In fact, it is not only a chip.. it is a tiny PCB that slots in the place of the original ATmega8 controller. On this PCB an ATmega32, 16MHz crystal and Max3232 areRead more

PCB lamp shade

How to turn a major cockup into something nice? The first batch of PCB’s for the feet of the soccer humanoid were flawed. I have used the wrong footprint (mind the pun) for the microcontroller (NXP LPC2148.. wonderful controller by the way). So eight PCB’s in a slight trapezoid form were rendered utterly useless… IRead more


While making a dynamixel library for Processing, I started fiddling around with a simple humanoid head that I constructed earlier (as temporary setup for the soccer Humanoid). This head consists of three AX-12+ types dynamixel servo’s by Robotis, and two Logitech Webcam’s (currently only one used). The control software in Processing controls the head (basicRead more

Relaxed evening viewing film on ceiling

Ok, I know that there is a wide community building DIY beamers using screens and overhead projectors (or even custom ordered sets of Fresnel lenses).. but that does not prevent me from putting my own together.. in less than 10 minutes (the time it took to remove the top mirror of the overhead – theRead more

Interfacing Paper with Phone: reading book on mobile phone

My phone doesn’t support reading of txt files or pdf. Upgrade to an i-phone would be the most sensible thing to do. However, my phone does have a 320×240 screen, capable of displaying images… How to make something out of that? I found a simple solution on this weblog, converting a text file using LatexRead more

RFID hackerscamp @PICNIC08

At the hackerscamp organized by mediamatic I have been working on a mobile massage couch, together with Ralph Meijer and Fabienne ‘fbz’ Serriere. It was an exhausting week full of pizza, cola, junkfood, stabbing needles, programming arduino’s, getting ‘marktplaats’ parts by train, hacking massage mats, soldering LED matrixes, debugging circuits and disentangling wires, so allRead more

Arduino bootloader for ATmega32

The Arduino boards mainly use Atmega8 or ATmega168 controllers. For most of the projects and boards I have been working with in the last years, I have been using mega32 (more memory, more IO). In order to make use of the excellent Arduino resources, making my boards Arduino Compatible seems a logical choice. First thingRead more