things to do with an ipod case... instead of throwing it away, i took some spare parts and built a new synth based on my monijonsyn2. the new synth has a push-button and one can now step through a few different programs. and the 2-way switch set different 'modes'. in this 1.0 version there is only 3 programs and 2 modes.
the programs basically just maps the 3 analog inputs differently, and the modes switches left/right output channels.

it's very cheap and easy to build. 2 aa-batteris provide power, the inputs are 3 touch points, 2 potentiometers, 1 button and a combined on/off/mode switch. all the sound generation (2 pwm pins) and program logic happens inside the 8bit avr mega8 chip and the code is easy to hack (see main.c in the zip below).

todo: add more fun programs to the firmware

Package icon monijonsyn3.zip13.97 KB


my latest controller. i'll premiere it this friday (23july, 2010) at the bring-your-own-laptop event at staalplaat. it inlcludes a light sensor, 2 touch sensors, some big switches and lots of knobs for control. it is also wireless and runs off either a 9v battery or a 9-14v wall adapter. the controller data is picked up by redWirelessMaster and is then read by the computer via a serial port.

firmware, partslist and schematics attached below. a supercollider class for interpreting the data is also included. (101109: minor updates)

photostream from the build process. i took out most of this beautiful old electronics and replaced it with my own circuit board. only kept the front end interface with the nice knobs.

update 130122: supercollider gui class updated and new helpfiles and midi control (via a nanoKontroll).

ipod touch microphone

i bought the klinkenstecker 3,5mm 4pol for €2,40 from segor.de. the capsule microphone i had laying around. sorry no data or idea where i got it. the whole thing is very simple to build and the sound is totally allright. now i can record into the ipod thouch and run apps like rjdj and supercollider with audio input.


for our recent installation at iscm world new music days in växjö (www.musicalfieldsforever.com/searching_voices_conc.html), i built a circuit for controlling 9x5m el-wire (electroluminescence). there are 9 channels in total and 3 inverters that are powering three 5meter cables each. tic201d triacs are used for switching the 110v ac on/off, 9 led+ldr pairs (aka vactrol) generates the control voltage for the triacs and wireless control for the whole thing is obtained with an atmega8 and a pair of nordic transceivers. supercollider is generating the control data.

el-wire_9ch_triacs from redFrik on Vimeo.

Image icon el-wire_9ch_triacs.png39.79 KB
Binary Data el-wire_9ch_triacs.sch95.41 KB


more custom electronics. a wireless system for our flute/video duo kretslopp (together with flutist anna svensdotter).
3 knobs and 3 buttons on the right hand arm, 1 accelerometer (3d) on the left hand arm.
anna made the leather bracelets.

attached is schematics, avr firmware and a max/msp patch for testing.

update 090823: also attached supercollider classes

wireless slave and usb master...

overview. controllers, master, slave and 'bracelet'.


a cheap little circuit that reads 10 analog controllers (8 knobs and 1 joystick). i built it for my neighbour jens' portable keyboard project. it's using an atmega88 and a 4051 multiplexer to get 10 analog-to-digital converters. a standard max232 with some caps lets the atmega88 talk to the serial port of the computer.
attached is schematics, avr firmware and a max/msp patch for testing.

Package icon jensKeyboard.zip65.23 KB


custom wireless system built for craftwife. the leds are to be sewn into real ties (update 090428: now done - http://www.youtube.com/watch?v=QUGKfC0SYck). there are 6 red leds per slave and each led can be dynamically controlled (pwm 0-255). all slaves run on battery (AA 3.6v lithium) and keep in contact with the master using 2.4ghz wireless transceivers (nordic nRF24L01+). the maximum working distance is about ~80m (line of sight).
the master talks to supercollider via the RedTieMaster and RedTieSlave classes (usb-serial 115200 baud).

schematics, firmware, partlist and sc classes attached below (gnu gpl v2)



master and slaves...

leds on ribbon cable...

total cable length: 135cm
distance between leds: 4cm

redTie-hardwareWireless from redFrik on Vimeo.

Package icon redTie.zip76.62 KB


update100721: rewrote the firmware and changed a few things. also renamed the project. it was previously called redUniform2-master
update100724: added supercollider classes to the zip archive

this is my all-round master for wireless controllers like redUniform and redThermoKontroll. it's a rebuild of my previous redUniform-master. i generalised it, added some buttons, switches and leds and put it into a proper box. i also removed the on-chip ceramic antenna on the mirf transceiver and replaced it with a socket + a 4inch duck antenna. now the range of the system is much greater.
the buttons i will use either as additional controllers or as backup controllers if the slave fails during performance. the 4 leds are independently controlled and i imagine using them for visual feedback. usually i perform with the laptop hidden in the back and the laptop screen turned off. the leds will help to discretely show the status of the piece (form, section, sensor activity etc).

version3 firmware and schematics attached.


Subscribe to RSS - electronics