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.


i've finished another controller using the great avr-usb from obdev. this version has 16 pushbuttons, 1 switch, 1 light sensor, 4 pots and 1 slider. just like the previous redKontroll it shows up like a standard HID devices and i have coded some simple max patches and supercollider classes to parse the data.

of the 16 buttons, 12 are arranged as a full octave on a piano (black&grey instead of white&black), divided into 2 groups (cde/fgab). the remaining 4 as additional buttons on top of each group to form small pyramids. all this to later make it easier to remember what functions i assigned to which button.

schematics, firmware, partslist and helper classes are available here.

the total cost is about €45 and the major part of that is the buttons and the pots (see partslist).


soldering is such a nice relief from coding. for years i've had an old pc-joystick laying around (thank you abe). i knew i wanted to build something from it - something that would produce lovely noise - and yesterday i finally got around to hack it. the joystick now contains a slightly modified micro_noise synth circuit (based on a design by SGMK mechatronicart.ch). it also holds a 9v battery and the pc-connection cable now serves as sound output cable with standard 1/4 jack.

micro_noise_joy from redFrik on Vimeo.

i used the switches and potentiometers that the joystick had and it was very quick to build and cost me virtually nothing. i just cut some cables and soldered them onto a tiny circuit board together with a few components. see the schematics below. the only visible change is the jack output and a the led i mounted in the case.


this is a tiny project from about 1 year ago. i wanted to add extra ir-light for my dvcamera's nightshot mode. very useful when playing in dark and smoky clubs.
i bought 10 osram high power ir leds (SFH4550) and found 5 small resistors (47ohm). i run it off two 1,5v batteries
below a picture and the schematics.


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