here is how i built a wireless isolated dmx controller that takes osc input. the box uses an esp8266 to create a wifi access point that one can connect to with a laptop (or phone or whatever). opensound control messages sent to the box are converted into standard dmx commands. multiple clients can be connected and send dmx commands at the same time.

f0dmx 1

f0dmx 2

below is arduino code for the esp8266, the kicad schematics and some supercollider test code.

//Generic ESP8266 Module, 80 MHz

#include <ESP8266WiFi.h>
#include <WiFiUdp.h>
#include <OSCMessage.h>
#include <OSCData.h>
#include <LXESP8266UARTDMX.h>

#define PORT 19999  //EDIT osc port
const char *ssid = "f0dmx"; //EDIT softAccessPoint network name
const char *password = "mypass";  //EDIT password
#define CHANNEL 3 //EDIT wifi channel

WiFiUDP Udp;

void setup() {
  WiFi.softAP(ssid, password, CHANNEL);

void dmx(OSCMessage &msg) {
  int chan, value;
  for (byte i = 0; i < msg.size(); i = i + 2) {
    chan = msg.getInt(i);
    value = msg.getInt(i + 1);
    ESP8266DMX.setSlot(chan, value);

void start(OSCMessage &msg) {

void stop(OSCMessage &msg) {

void loop() {
  OSCMessage oscMsg;
  int packetSize = Udp.parsePacket();
  if (packetSize) {
    while (packetSize--) {
    if (!oscMsg.hasError()) {
      oscMsg.dispatch("/dmx", dmx);
      oscMsg.dispatch("/start", start);
      oscMsg.dispatch("/stop", stop);

bill of material...

1       dcdc            ROE-0505S       reichelt
1       xlr female      XLR 3KU         reichelt
1       optocoupler     6N 137          reichelt
1       ic              SN 75176BP      reichelt
1       box             BOPLA KS 420    reichelt
1       resistor        10K
1       resistor        470
3       resistor        10
1       resistor        120
2       cap             10uF
1       cap             100uF
1       regulator       LF 33 CV
1       micro           ESP8266-01
1       socket          4x2
1       usb cable

f0dmx kicad schematics

example of how to send osc from supercollider to the f0dmx box. make sure you send integers and not floats.

//make sure you are connected to the f0dmx wifi network
n= NetAddr("", 19999);  //the ip and port of the f0dmx box
n.sendMsg(\dmx, 9, 255)  //dmx channel 9, value 255
n.sendMsg(\dmx, 9, 0)
n.sendMsg(\dmx, 7, 100)  //dmx channel 7, value 100
n.sendMsg(\dmx, 7, 0)

n.sendMsg(\stop)  //usually not needed

Package icon kicad schematics27.48 KB


here's some python code for reading serial input from optoforce's 3d sensor and sending it over osc to maxmsp or supercollider.

the slightly odd baudrate of 1000000 isn't supported in sc nor max under osx, so i had to use python for this.

#for the 3d sensor OMD-30-SE-100N
#f.olofsson 2017

#first argument is serial port, second ip and third port.  e.g.
#python optoforceOsc.py '/dev/tty.usbmodem1451' '' 9999

import sys
from struct import *
from threading import Thread
import serial
from OSC import OSCServer, OSCClient, OSCMessage, OSCClientError

osc= OSCClient()
if len(sys.argv)>3:
  osc.connect((sys.argv[2], int(sys.argv[3])))  #send to address and port
        osc.connect(('', 57120))  #default send to sc on same computer

serport= '/dev/cu.usbmodem1411'
if len(sys.argv)>1:
  serport= sys.argv[1]

ser= serial.Serial(
  port= serport,
  baudrate= 1000000,
  parity= serial.PARITY_NONE,
  stopbits= serial.STOPBITS_ONE,
  bytesize= serial.EIGHTBITS,
  timeout= 1
print('connected to serial port: '+ser.portstr)

def oscInput(addr, tags, stuff, source):
  print stuff  #for now do nothing

server= OSCServer(('', 9998))  #receive from everywhere
server.addMsgHandler('/optoforceConfig', oscInput)
server_thread= Thread(target= server.serve_forever)

print('sending osc to: '+str(osc.address()))
print('listening for osc on port: '+str(server.address()[1]))

###configure sensor (optional)
conf= bytearray(9)
speed= 10  #0, 1, 3, 10, 33, 100 (default 10)
filter= 3   #0 - 6 (default 4)
zero= 255   #0, 255
checksum= 170+0+50+3+speed+filter+zero
conf[0]= 170
conf[1]= 0
conf[2]= 50
conf[3]= 3
conf[4]= speed
conf[5]= filter
conf[6]= zero
conf[7]= checksum>>8
conf[8]= checksum&255

def main():
  while True:
    b= ser.read(4)
    header= unpack('BBBB', b)
    if header==(170, 7, 8, 10): #data
      b= ser.read(12)
      counter= unpack('>H', b[0:2])[0]
      status= unpack('>H', b[2:4])[0]
      xyz= unpack('>hhh', b[4:10])
      checksum= unpack('>H', b[10:12])[0]
      sum= (170+7+8+10)
      for i in range(10):
        sum= sum+ord(b[i])
      if checksum==sum:
        #print(counter, status, xyz)
        msg= OSCMessage()
        except OSCClientError:
          print 'osc: could not send to address'
        print 'data: checksum error'
        print checksum
      if header==(170, 0, 80, 1): #status
        b= ser.read(3)
        status= unpack('B', b[0])[0]
        checksum= unpack('>H', b[1:3])[0]
        if checksum!=(170+0+80+1+status):
          print 'status: checksum error'
          print checksum
        print 'header: serial read error'
        print header

if __name__ == '__main__':
  except KeyboardInterrupt:

optoforce 3d sensor with maxmsp from redFrik on Vimeo.

optoforce 3d sensor with supercollider from redFrik on Vimeo.

supercollider firmata 3

reading digital inputs from an arduino with the SCFirmata is a little bit more complicated than needed.

here an example that reads 6 analog and 6 digital at the same time.

NOTE: use resistors (10K) to pull up or pull down the digital inputs. (i couldn't figure out how to activate the built in pullups.)

d= SerialPort.devices[0]; // or d= "/dev/tty.usbserial-A1001NeZ" - edit number (or string) to match your arduino
f= FirmataDevice(d);//if it works it should post 'Protocol version: 2.5' after a few seconds

~analog= [0, 1, 2, 3, 4, 5];  //A0-A5
~digital= [2, 3, 4, 5, 6, 12];  //some digital input pins
s.latency= 0.05;
        var freqsArr= 0!~analog.size;
        var ampsArr= 0!~digital.size;
        Ndef(\snd3, {Splay.ar(SinOsc.ar(\freqs.kr(freqsArr, 0.05), 0, \amps.kr(ampsArr.lag(0.01))).tanh)}).play;
                f.reportAnalogPin(x, true);      //start reading analog pins
        f.analogPinAction= {|num, val|
                //[num, val].postln;
                freqsArr.put(~analog.indexOf(num), val);
                Ndef(\snd3).setn(\freqs, freqsArr);
                f.setPinMode(x, \INPUT);
        f.reportDigitalPort(0, true);
        f.reportDigitalPort(1, true);
        f.digitalPortAction= {|port, mask|
                var dig;
                //[port, mask, mask.asBinaryString].postln;
                dig= ~digital.collect{|x| ((mask<<(port*8))&(1<<x)==(1<<x)).binaryValue};
                Ndef(\snd3).set(\amps, dig.postln);

        f.reportAnalogPin(i, false);     //stop reading A0-Anum
f.reportDigitalPort(0, false);
f.reportDigitalPort(1, false);

previous articles...



supercollider firmata 2

+2 years ago i put up a simple example of how to use firmata with arduino and supercollider here. that code still work but it only show how to read a single analog input on the arduino.

here is how one can read both A0 and A1 and map those to synth parameters in supercollider...

//how to read pins A0 and A1 with SCFirmata...
//tested with Arduino1.8.0 and SC3.8.0
//first in Arduino IDE:
//  * select File / Examples / Firmata / StandardFirmata
//  * upload this example to an arduino
//then in SC install the SCFirmata classes
//  * download zip file https://github.com/blacksound/SCFirmata
//  * extract files and put them in your sc application support directory
//  * recompile sc

d= SerialPort.devices[0]; // or d= "/dev/tty.usbserial-A1001NeZ" - edit number (or string) to match your arduino
f= FirmataDevice(d);//if it works it should post 'Protocol version: 2.5' after a few seconds


Ndef(\snd, {|freq1= 400, freq2= 500, amp= 0.5| SinOsc.ar([freq1, freq2].lag(0.08), 0, amp.lag(0.08)).tanh}).play;
f.reportAnalogPin(0, true);      //start reading A0
f.reportAnalogPin(1, true);      //start reading A1
f.analogPinAction= {|num, val|
        [num, val].postln;
                0, {
                        Ndef(\snd).set(\freq1, val.linexp(0, 1023, 400, 800)); //A0 mapped to freq1
                1, {
                        Ndef(\snd).set(\freq2, val.linexp(0, 1023, 400, 800)); //A1 mapped to freq2

f.reportAnalogPin(0, false);     //stop reading A0
f.reportAnalogPin(1, false);     //stop reading A1

and to read all six analog inputs (A0-A5) one can do...

d= SerialPort.devices[0]; // or d= "/dev/tty.usbserial-A1001NeZ" - edit number (or string) to match your arduino
f= FirmataDevice(d);//if it works it should post 'Protocol version: 2.5' after a few seconds

~numberOfAna= 6;  //number of analog inputs (here A0-A5)

var freqsArr= 0!~numberOfAna;
Ndef(\snd2, {|amp= 0.5| Splay.ar(SinOsc.ar(\freqs.kr(freqsArr, 0.05), 0, amp.lag(0.08)).tanh)}).play;
        f.reportAnalogPin(i, true);      //start reading A0-Anum
f.analogPinAction= {|num, val|
        [num, val].postln;
        freqsArr.put(num, val);
        Ndef(\snd2).setn(\freqs, freqsArr);

        f.reportAnalogPin(i, false);     //stop reading A0-Anum

wireless mqtt circuits

i've stared using mqtt for talking to microcontrollers over wifi and here's some code and instructions on how to set up such a system.

there are two programs that have to run in the background. they handle all the communication between the wireless hardware and the client software (maxmsp, supercollider etc). one is mosquitto. mosquitto is a mqtt broker and the central pub/sub hub of the system. the second program is a python mqtt-osc bridge script using the paho client. this python script lets programs like maxmsp or supercollider talk to mosquitto via osc. see the readme.txt included below on how to install and configure these programs.

on the hardware side i build send/receive circuit nodes consisting of a esp8266 module and an arduino pro-mini. these circuits run on 3v, are small and configurable and the parts cost almost nothing. the esp8266 module provides wifi communication and runs a mqtt client (i'm using the adafruit mqtt library), while the pro-mini does the physical inputs and outputs (sensors, leds etc). the two modules talk to each other via serial.
some circuits i've build do 12 digital + 8 analog inputs, while others have 12 leds in combination with 8 analog inputs. but any combination is possible and the number of ins/outs depends on how the pro-mini is programmed. (see portable_promini_ana and portable_promini_led in the zip archive below.)



so far i'm really pleased with this new technique. it seems to scale well and work more reliable than what i used before (sending raw osc via cc3000 or esp8266).

Package icon portable.zip16.11 KB


i got to design and build version 2 of syntjuntan's sewable synthesizer circuit. for this version they wanted to add an on-board amplifier that could drive a passive speaker element.

the circuit now has three schmitt triggers and can run on 3-12V. the amplifier is the classic lm386 and the connector pads around the board are made to fit needle and conductive thread as well as being crocodile friendly.

there are some options as standard through-hole soldering pads (a fourth schmitt trigger and x10 extra gain). the circuit can also be used as a standalone audio amplifier - just ignore the schmitt triggers and connect your own signal to the in pad.

anyway, lots of fun mass producing this and in the process i learned how to do hot-air smd soldering with stencil and solder paste plus got to know kicad a bit better.

i also built a test rig with an arduino and some pogo pins. it both scans for short-cuts and tests the sound.

syntjuntakrets 2 2

syntjuntakrets 2 4

syntjuntakrets 2 5


this board is using an old raspberry pi 1 to control the speed of computer fans. the electronics are pretty simple (see attached schematics below): it takes 7-36V input power, has twelve mosfets for pwm control and finally a dc/dc converter to power the rpi.
it was built for controlling pc cooling fans but can also drive other types of dc motors, lightbulbs or solenoids.
the off button is there to safely power down the raspberry pi.

the trick with this though is that the system can be livecoded over wifi using supercollider, maxmsp or any other osc capable program. so when you start the board the rpi sets up a wireless access point and starts a python script that accepts incoming opensoundcontrol messages. at startup the rpi1 will also start supercollider and load a file (dragspelFans.scd) that is meant to contain whatever code you'd like to run as default. this file you later overwrite with your own sc code that you've developed/livecoded using your laptop.


below are step-by-step instructions on how i set this up plus the relevant python and supercollider code. it should work on all rpi models but here the rpi1 or rpi0 is assumed.

* download and install raspbian-stretch-lite onto a 2gb sd card
* to enable ssh create an empty file on the sd card. call it ssh. (this terminal command touch /Volumes/boot/ssh will do it on osx or just create an empty textfile and save it without any file extension)
* connect your rpi to your home router via ethernet and type the following in terminal on your laptop:
* ssh-keygen -R raspberrypi.local
* ssh pi@raspberrypi.local #default password is raspberry
* sudo raspi-config #change password to _____, set memory split to 16 under advanced, change hostname to fans under network, update, finish and reboot (sudo reboot)
* ssh pi@fans.local #log in again from your laptop
* sudo apt-get update
* sudo apt-get upgrade
* sudo apt-get dist-upgrade

this section will install osc and gpio libraries for python and also set up the python script to automatically start at system boot.
* sudo apt-get install python-liblo pigpio python-pigpio
* sudo crontab -e #and add the following line at the end (use ctrl+o and ctrl+x to save and exit):

@reboot /usr/bin/pigpiod -s 5 && /usr/bin/python /home/pi/dragspelFans.py

* nano ~/dragspelFans.py #and copy&paste in the following:

#pwm control for 12 fans/motors/leds

#NOTE: make sure to run this in terminal first...
# sudo pigpiod -s 5

import sys
from os import system
from time import sleep
import pigpio
from liblo import *

inport= 9999  #for osc commands to this python script
pinoff= 2  #bcm numbering
pins= [3, 4, 14, 15, 17, 18, 27, 22, 23, 24, 10, 9]  #bcm numbering - more can be added here
target= ('', 57120)  #for osc to sclang
hz= 800  #pwm frequency in hz - note may need to adapt -s option in sudo pigpio -s 5 above
range= 100  #duty cycle range 0 to 100

pi= pigpio.pi()
pi.set_mode(pinoff, pigpio.INPUT)  #no internal pullup needed
for pin in pins:
  pi.set_mode(pin, pigpio.OUTPUT)
  pi.set_PWM_frequency(pin, hz)
  pi.set_PWM_range(pin, range)
  pi.set_PWM_dutycycle(pin, 0)

class MyServer(ServerThread):
        def __init__(self):
                ServerThread.__init__(self, inport)
        @make_method('/pwms', 'i'*len(pins))
        def pwms_callback(self, path, args):
                #print args  #debug
                i= 0
                for pin in pins:
                        pi.set_PWM_dutycycle(pin, min(max(0, args[i]), range))
                        i= i+1
        @make_method('/shutdown', '')
        def shutdown_callback(self, path, args):
                stop('sudo halt -p')  #turn off rpi
        @make_method('/reboot', '')
        def reboot_callback(self, path, args):
                stop('sudo reboot')  #reboot rpi
        @make_method('/start', '')
        def start_callback(self, path, args):
                send(target, '/start', 1)  #start default program in supercollider
        @make_method('/stop', '')
        def stop_callback(self, path, args):
                send(target, '/stop', 0)  #stop default program in supercollider
                for pin in pins:  #and also set all pwm to 0
                        pi.set_PWM_dutycycle(pin, 0)
        @make_method(None, None)
        def fallback(self, path, args):
                print 'received unknown message "%s"' % path

def stop(cmd):
        system('killall pigpiod sclang')

        server= MyServer()
except ServerError, err:
        print str(err)

def main():
        while True:
                if pi.read(pinoff)==0:
                        print 'shutting down...'
                        stop('sudo halt -p')

if __name__ == '__main__':
        except KeyboardInterrupt:

again use ctrl+o and ctrl+x to save and exit. now sudo reboot and then try to send osc commands to the rpi. here's how to send some test osc messages from your laptop to the rpi using supercollider...

n= NetAddr("fans.local", 9999);
n.sendMsg(\pwms, *[50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])  //the number of integers should match the number of pins and range in your python code (here 12 pins, 0-100)
n.sendMsg(\pwms, *[25, 50, 75, 0, 0, 0, 0, 0, 0, 0, 0, 0])  //first pin 25%, second %50 third 75%, rest 0
n.sendMsg(\pwms, *[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])  //all off

you can also try to connect pin bcm2 to ground. that should now act like an off button and turn off the rpi in a safe way.

this section is optional. only install supercollider if you want to run your rpi as a standalone installation or something similar. so if you plan to always remote control the system you can skip over this step.
note: this is for rpi0&rpi1, for rpi2&rpi3 change all references to supercolliderStandaloneRPI1 below to supercolliderStandaloneRPI2
see https://github.com/redFrik/supercolliderStandaloneRPI1#stretch-lite for more details (this page also show how to install jackd if you need audio from your rpi).
* sudo apt-get install libqt5webkit5 libqt5sensors5 libqt5positioning5 libfftw3-bin libcwiid1 git libasound2-dev libsamplerate0-dev libsndfile1-dev libreadline-dev xvfb libjack-jackd2-0
* cd ~
* git clone https://github.com/redFrik/supercolliderStandaloneRPI1 --depth 1
* mkdir -p ~/.config/SuperCollider
* cp supercolliderStandaloneRPI1/sc_ide_conf_temp.yaml ~/.config/SuperCollider/sc_ide_conf.yaml
* cd supercolliderStandaloneRPI1
* nano autostart.sh #and change the script to look like this:

./sclang -a -l sclang.yaml ../dragspelFans.scd

* nano share/user/startup.scd #and add the following two lines:

OSCFunc({"/home/pi/dragspelFans.scd".load}, \start).permanent= true;
OSCFunc({CmdPeriod.run}, \stop).permanent= true;

* mkdir share/user/Extensions
* nano share/user/Extensions/DragspelFans.sc #and copy&paste in the following:

//f.olofsson2016-2018 - for controlling 12ch computer fan switch board
DragspelFans {
        var <rpi, num, vals, lastv, <>debug;
        *new {|debug= false, rpi, num= 12|
                ^super.new.initDragspelFans(debug, rpi, num);
        initDragspelFans {|d, r, n|
                num= n;
                if(r.notNil, {
                        rpi= r;
                }, {
                                rpi= NetAddr("fans.local", 9999);
                        } {|err|
                                "could not connect to rpi.\n make sure you are connected to the wifi network 'dragspel'.".warn;
                                rpi= NetAddr("", 9999);  //temp just for testing
                debug= d;
                vals= 0!num;

        setAll {|val= 100|  //val should be 0 to 100
                vals= val!num;
        clearAll {
                vals= 0!num;
        val {|index, val|  //index should be 0-11, val 0-100
                vals= vals.put(index, val);
        arr {|arr|  //arr should be 12 numbers in an array
                vals= arr;

        shutdown {
        reboot {
        start {
        stop {

        prSend {|v|
                if(debug, {
                v= vals.clip(0, 100).round.asInteger;
                if(v!=lastv, {  //filter out repeats
                        lastv= v;
                        rpi.sendMsg(\pwms, *v);  //send to dragspelFans.py

* nano ~/dragspelFans.scd #and copy&paste in the following:

//demo autostart script - put your own standalone code in here
d= DragspelFans.new;
Event.addEventType(\fans, {d.val(~index, ~val)});
Pbind(\type, \fans, \dur, 0.5, \index, Pseq([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11], inf), \val, Pwhite(0, 100, inf)).play;

* crontab -e #and add the following to the end (note no sudo here this time)

@reboot cd /home/pi/supercolliderStandaloneRPI1 && xvfb-run ./autostart.sh

now sudo reboot and supercollider should automatically start the code in dragspelFans.scd. it'll take a while so give it a minute or two.

to test it more run the following supercollider code on your laptop...

n= NetAddr("fans.local", 9999);
n.sendMsg(\stop);  //first stop the dragspelFans.scd script
n.sendMsg(\pwms, *[25, 50, 75, 0, 0, 0, 0, 0, 0, 0, 0, 0]);  //set pwm manually

//install the DragspelFans.sc class on your laptop sc and also try the following example code

a= DragspelFans(true);  //might take a moment or two
CmdPeriod.doOnce({a.clearAll});  //optional

//version0 - all on or off
a.setAll(50)  //set all to some value 0-100

//version1 - using an array
a.arr([0, 0, 100, 0, 0, 100, 0, 0, 100, 0, 0, 100])  //turn on some
a.arr([0, 100, 0, 0, 100, 0, 0, 100, 0, 0, 100, 0])  //turn some other fans
a.arr([30, 0, 0, 40, 100, 0, 40, 0, 0, 80, 0, 0])  //a few slower

//version2 - set index to value
a.val(9, 100);
a.val(9, 0);
a.val(11, 100);
a.val(11, 0);
a.val(11, 60);
a.val(11, 0);

//fade in each fan in order
r= Routine.run({
                        a.val(j, i);
                        a.val(j, 99-i);

//using patterns
a= DragspelFans.new;
Event.addEventType(\fans, {a.val(~index, ~val)});
Pdef(\test, Pbind(\type, \fans, \dur, 0.125, \index, Pseq([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11].scramble, inf), \val, Pwhite(0, 100, inf))).play;

a.start;  //start the dragspelFans.scd script on the rpi again

or test it using the attached maxmsp patch.


//--wifi softap
this section is optional. it will set up a wifi access point served from the rpi. basically taken from https://www.raspberrypi.org/documentation/configuration/wireless/access-point.md
* sudo apt-get install dnsmasq hostapd
* sudo systemctl stop dnsmasq
* sudo systemctl stop hostapd
* sudo nano /etc/dhcpcd.conf #and add the following to the end:

interface wlan0
    static ip_address=

* sudo service dhcpcd restart
* sudo nano /etc/dnsmasq.conf #and add the following two lines to the bottom:


* sudo nano /etc/hostapd/hostapd.conf #and add the following (remember to set passphrase 8-64 characters):


* sudo nano /etc/default/hostapd #and change one line to the following:


* sudo systemctl start hostapd
* sudo systemctl start dnsmasq

now sudo reboot on the rpi, log on to dragspel wifi network from your laptop and try to send some osc commands.

update 180225: major rewrite to use pigpio instead of RPi.GPIO and also raspbian stretch instead of jessie. pwm works much better.


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