der nulleffekt

This is the Open Hard- and Software Wiki by Berlin based light and sound artist Wolfgang Spahn.
If not mentioned otherwise, all boards, codes and designs are made by Wolfgang Spahn. They are mainly developed for his art installations, performances and his workshops.

Except where otherwise noted, content is licensed under the following license: CC Attribution-Noncommercial-Share Alike 4.0 International.



- Spahn Feistkorn
- U.F.O. Yashas Shetty & Wolfgang Spahn
- Maailmankaikkeus D.Eggermann, A.Pussinen and W.Spahn, 2018
- Symbolic Grounding Ch.Faubel and W.Spahn, 2018
- Beats per Machine collective work lead by W.Spahn, 2017
- Embedded Artist M.Steiner and W.Spahn, 2014-16
- Monitored Artwork M.Steiner and W.Spahn, 2015
- Die Fröhliche Wissenschaft
T.Henninger and A.Anklam in cooperation with W.Spahn, 2014
- Liquid State Machine M.Howse and W.Spahn, 2011-12
- Molecule J.Hoffman and W.Spahn, 2010
- Spiel-Tisch T.Gerwin and W.Spahn 2010
- augen-auf-schlag T.Gerwin and W.Spahn 2008



Border Pixel

Pi Zero always On-The-Go

07. June 2021
Pi Zero always On-The-Go, a USB-OTG Hack

Paspberry Pi Pico - Programmable I/Os

10. May 2021
A manual for the Programmable I/O's of the Paspberry Pi Pico

Serial Wire Debug (SWD) and Raspberry PI

30.January 2021

A workaround for OpenOCD & Raspberry Pi.

USB Soundcard Oscilloscope

16.November 2020

A simple USB sound card hack for an Linux Oscilloscope.

Voltage Controlled Oscillator

6.November 2020
voltage controlled oscillator

A basic Voltage Controlled Oscillator for learning, experiments and development. It's designed to plug it directly in a breadboard.

Handmade Electronic Music

30.June 2020
Handmade Electronic Music - The Art of Hardware Hacking
by Nicolas Collins, Routledge 2020

includes an article of my Confetti Neuron

copyright of the cover by routledge, 2020

Raspberry Pi HQ Camera Protection

12.May 2020
Frame for the Raspberry Pi HQ Camera

A 3D printed frame for the latest HQ Raspi Cam.

Analog Computation #01 - Chua's Circuit

09.May 2020
Analog Computation #01 - Chua's Circuit

This is the first lesson about analog computation, it's about the implementation of a Chua's Circuit in the analog computer Confetti to gain a chaotic oscillation.

Arduino Bootloader

23.Mar 2020
Burning the Bootloader

An update on burning an Arduino bootloader with all kind of AVR programming boards in the Arduino IDE and in command line.


04.Mar 2020

A Raspberry Pi Audio Hat with two Line In and two Line Out.

Raspi-PD Control Hat

22.Feb 2020
Raspi-PD Control Hat
A Raspberry Pi Hat for analog and digital inputs in Pure Data.

Pure Data on the Raspberry Pi

06.Feb 2020
Here are some workarounds for Pure Data, GPIO, Arduino and some sound cards on the Raspberry Pi 4: Pure Data on Raspberry Pi

Experimental VGA Processor

11. December 2019
A new new all signal mixer (incl. VGA): the Experimental VGA Processor

For mixing and experimenting with analog video signals.

Lenovo Rectangular Power Adapter

2. October 2019
Lenovo Rectangular Power Adapter to 5.5mm Round Jack
To use a Lenovo power supply for a T12-942 solder station.

Electric Intonarumori

31. July 2019
Electric Intonarumori - a noise-synth with beautiful feedback.

Symbiotic Synth

10. Apr. 2019
Symbiotic Synth - a low voltage oscillator that is powered as well as controlled by the human body.

PB202 MIDI to CV Update

15.Jan. 2019
I updated the Paper Bit 202 Midi to CV board. It has now 4 CV outputs and gives out the clock signal as a trigger sinal.

PB705 VCCC Voltage Controlled Chua Circuit

23.Jan. 2019
Chua's Oscillator for Paper Bits! PB705 VCCC Voltage Controlled Chua Circuit

VGA & Sound Blender

10.Dec 2018
The all purpose signal to VGA mixer: VGA & Sound Blender

RS232 Control

19. Oct 2018
A RS232 Controller for two Waveplayer8: RS232 Controller

PB808 Kick Drum

09. Oct 2018
ThePB808 Kick Drum for the Paper Bits is online!

Pop Neuron 2

1.Sept 2018
New version the Pop Neurons:
Exitatory Pop Neuron 2
Inhibitory Pop Neuron 2

Pop Neuron

12.Jan 2018
the Paper PCBs: Pop Neuron
the exhibition: Symbolic Grounding

Confetti - An Analog Computer

15.Sep 2017
Confetti is a modular analog computing system.


12.Sept 2017
Keyboard-compatiblility for the Paper Bit: the PB702 MIDI Synthesizer.

A simple Hat

12.Sept 2017
Raspberry Basic Hat
That simple Hat for an Raspberry Pi helps if one just needs some buttons and LEDs.

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Credits & Contact


If not other mentioned all software, boards, web-sides and manuals are written, designed and developed by Wolfgang Spahn 2008-21.

Except where otherwise noted, content is licensed under the following license: CC Attribution-Noncommercial-Share Alike 4.0 International.

Creative Commons License