Tag: OSC

Real time Irish train map in Max

Using node.js

Time compressed video of Irish railway data from November 30th 2012.

This map is centered on Dublin. Each train is a different color and the train number gets printed next to the current position. So for example you can see P607 coming into Dublin from the South.

It gets updates every 10 seconds or so – but sometimes the trains seem to ‘jump’ so I don’t think the actual  data itself gets updated that fast.



folder: trains


main Max patches
  • max-train3.maxpat
  • train-drawing4.maxpat
abstractions and other files
  • data_recorder_list-tz.maxpat
  • max-train1.js: (main server)
  • bigInt.js: (Osc support)
  • byteConverter.js: (Osc support)
  • libOsc.js: (Osc library)
  • max.html: (the web client file – runs in browser)

node.js installation

Install node.js on your computer (or a separate server). Instructions here: http://nodejs.org

The following node packages are required. Install using npm. For example:

npm install request

  • request
  • xml2js
  • util
  • http
  • socket.io


These instructions are a bit confusing. A simpler UI is in the works.

  • Open both Max patches: max-train3 and train-drawing4
  • To run the server, open a terminal window, go to trains folder, and type:
node ./max-train1.js
  • Back in Max, in train-drawing4, you can start and stop polling with the toggle button in the upper left corner. If you want to toggle playback from the data recorder, you’ll need to have some data recorded – or load a file (this is done from max-train3)
  •  In max-train3, select a preset in the preset object. Try the top left one, The presets go from low res to high res on Dublin (left to right).
  •  You can load train-data1.txt by clicking read message on the data recorder. Then press play, or use metro (set to low number) for high speed.
  • In train-drawing4 you’ll need to manually clear the lcd and lcdsprites in the drawing section.
  • In max-train3 you can clear the color database using labeled button (if the train names don’t print on the map)

Running the chat thing

When you connect to the node server in a web browser, for example using the following url:


You will get a message welcoming you and asking you to enter your name. After you enter your name, Max will send you a response. Then you can enter map points using the following format:

Dublin 53.15 -6.90

The map point will be drawn on the map in the Max patch.

how does it work?

Data communication is done with OSC messages. Here’s how

  • Max sends a /getTrains message to a node.js server
  • The server runs an http: request to the Irish rail API
  • The server parses the response data and sends back a bunch of /train name x y messages. to Max
  • You can also connect to the node server from web browsers in kind of a ‘chat’ thing (using Web sockets) and enter geographical place names with lat/lon – which get pinned to the map – and Max sends back personalized thank-you notes.

Here’s what the raw data looks like:

Note: if there’s no data at this link, check the time of day. Trains stop running around midnight UTC.


Essentially what this program does is collect current train position data from Ireland and display it as points on an XY grid.


  • Max/MSP
  • node.js
  • Web browser
  • Irish train API


The server is written in node.js. This was my first real project using node. So I tried to make it do a bunch of things, just to test them out.The necessary features are

  • web server to make http: requests to get the train data
  • UDP server to pass data and messages back and forth from Max to node.js using Osc
  • convert XML train data to JSON,
  • convert point data from lat/lon to XY format
Additional features of the server include:
  • chat server using socket.io which allows several web browser sessions to connect to the server, talk with each other, send point data to Max, and receive acknowledgement from Max
Localhost vs. separate server

This is probably the most confusing part about this program. You can run it on the Mac in localhost mode, or you can run the node.js program on a separate server, as long as there is a direct ip path back to the computer where Max is running.  Running a separate server makes more sense if you are using the chat or a remote web control aspect of this. I have run the node program on a Ubuntu server on my local network without making any changes other than to the IP addresses as explained next.

You need to make 2 changes to go from localhost mode, to separate server mode:

In the client program, max.html – near the top, change the ip address from localhost to the specific ip like this:

// note: if you want to run this program on something other than localhost, then put in the ip
// address of the server here, instead of local host...

//     var socket = io.connect('http://localhost:8124');
       var socket = io.connect(');


In the server program, max-train1.js – change the destination address for UDP to the address of the computer where max is running:

var dSendAddress = '';	// send response messages to max at this address
// do this if max is running somewhere other than the same computer as the node server
// var dSendAddress = '';	// send response messages to max at this address


Also in the Max patch max-train3.maxpat you will need to change the [udpsend] object to give it the host address of the node server.




Data recorder:

To be able to save and replay data I included a data recorder in the patch. Its a revision of the data recorder from CNMAT by Michael Z. This version

  • works with lists that start with a symbol (not just ones that start with numbers)
  • handles the time delta correctly on the first record
  • adds additional transport controls, for example playback using a [metro] at any speed – and ability to goto a particular position in the data file

The actual code for the patch is horrendous. Its filled with debugging objects and is a maze of patch cords lacking explanation. But it works…

what’s next

  • Make sure that the Max Patch loads a preset map setting by default
  • put a timestamp message in the node console and Max console so we know at the end of a train list what the current time is.
  • clean up  instructions 
  • make a screencast do demonstrate how to use this needlessly complicated patch.

Raspberry-Pi Osc synthesizer

A variation on the Midi synthesizer from this post: http://reactivemusic.net/?p=4960

The synthesizer was built in PureData (Pd extended) using the visual interface on a MacBook. Then the pd file was run in command line mode on the r-pi. The sound card is a Griffin i-Mic, running at 22.5 Khz sample rate. Although there’s no reason why you couldn’t use the builtin DAC on the r-pi.

The r-pi is connected via the ethernet port to a wi-fi network which receives Osc (Open Sound Control) messages from an iPod running touch-Osc. The network connection could have been made using a USB wifi adapter.

All together the cost of this arrangement (less the iPod) would be less than $50. The software is all open source.  The huge financial barriers to working with music synthesis and signal processing, that have been associated with these fields for years, simply don’t exist anymore.

Alternative ways of controlling the synth – if a wiFi router is not available, include:

  • USB keyboard (usually free)
  • USB Midi Keyboard ($25)
  • switches or dials via the GPIO pins (spare parts)
  • direct ethernet connection to another device.
Here is a screenshot of the Pd Patch.


Pd file: tkzic/rpi/pd/piSynth1_OSC.pd

recieve port is 8000 – and it uses page 1 of the simple touchOSC template

pd-extended -nogui -noadc  piSynth1_Osc.pd

Note: there is some special code to prevent seg faults when you go from page 2 to page 1 of the touchOSC template

Here’s a great tutorial on using OSC with Pure Data





Netgear Universal Wifi Adapter WNCE2001

This device works as a bridge to allow devices that have ethernet but not wifi, to become wifi devices.

To access the config page, hook up an ethernet cable, and goto: www.mywifiext.com

Here’s more documentation:


This device allows wifi access using the Arduino Ethernet Shield. This is currently the easiest solution for using touch-OSC.


MIDI wireless options

A thought exercise – to come up with various ways of making wireless Midi systems based on projects I’ve already done.

  • any combination of iOS and MacOS devices
  • use touchOSC with above setup
  • Arduino + ethernet shield to wifi router to touchOSC
  • Same as above but using wifi bridge to connect to router*
  • Arduino + wifi shield via UDP*
  • Arduino + wireless SD + xbee to same – one end connected to mac OS device
  • IR emitter/detector pair*
  • Arduino + wireless SD + WiFly rn-xv via UDP*
  • bluetooth* (here’s an app called bluemidi http://www.iosmusician.com/category/bluetooth-midi-on-ios
  • modulated laser pointer and solar panel*
  • convert to audio then use any audio transmission method and convert back to midi*
  • Use RTTY with ham radio*
  • cell phone*

* indicates method not tried yet.



Arduino with touchOSC and Max

Bi-directional communication from touchOSC to Arduino using an ethernet shield.

In this version, the Macbook is directly connected to the Arduino to provide a serial monitor for status updates. 

How it works: press a toggle, or move a fader, in touchOSC – it sends a message to the Arduino which lights up, or fades, an LED – then sends back an OSC message to touchOSC to light up the toggle button. (note: local feedback should be off for the toggle button in touchOSC. This is the default)

Arduino circuit
  • Use an ethernet shield. 
  • Connect ethernet cable. (I am using a Netgear WNCE2001 ethernet to wiFi adapter)
  • LED is connected to pin 5 and ground. The shorter lead connects to ground.



folder: arduino-osc

  • Arduino sketch: OSC_ethernet_test1/
  • touchOSC screen: simple (default) uses /1/fader1 and /1/toggle1
  • Max patch: arduino-osc-ethernet1.maxpat
Arduino files and libraries

***update 1/20/2016 there is a new sketch that uses the OSCuino library from CNMAT instead of ardosc. The sketches should be interchangeable. https://github.com/CNMAT/OSC . The sketch is in a folder called: OSCuino_tz and is based on work by Trippylightning at: http://trippylighting.com/teensy-arduino-ect/touchosc-and-arduino-oscuino/

Copy the OSC_ethernet_test1/ folder to Documents/Arduino. This puts it in the Arduino sketchbook.

The sketch uses: #include <ArdOSC.h>

Download ArdOSC from: https://github.com/recotana/ArdOSC

  1. After downloading, copy the ArdOSC-master folder to /Documents/Arduino/Libraries
  2. Rename the folder to ArdOSC

This post was the key to figuring out how to make this work: http://arduino.cc/forum/index.php?topic=137549.0

  1. Connect Arduino to Macbook via USB.
  2. Open the Arduino serial monitor to initialize the ethernet connection and display the IP address.
  1. In touchOSC or Max, set the target IP to the one just displayed in the Arduino serial monitor
  2. From touchOSC (or Max) send on port 8000, receive on port 9000.
  3. Use the default touchOSC layout (simple)
  4. Use /fader1 and /toggle1 to control the LED
  1. Open arduino-osc-ethernet1.maxpat
  2. Set ip address in [udpsend] to the one just displayed in the Arduino serial monitor
  3. Have some fun
Fixed IP address

update 1/2016: A version of the Arduino sketch that uses a fixed IP instead of DHCP is located in the folder: OSC_ethernet_fixedIP/

The IP is set to but you can change it to any valid address on your network.

Arduino sketch
// generic Arduino OSC program 
// works from Max or touchOSC
// plug LED into pin 5 (and gnd)
// requires ethernet shield
// use serial monitor to get the ip address
// use these OSC commands (will work from first page of touchOSC simple layout
// /1/fader1
// /1/toggle1
#include <SPI.h>
#include <Ethernet.h>
#include <ArdOSC.h>

byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0x0B, 0xCE }; //physical mac address
OSCServer server;
OSCClient client;
int serverPort = 8000; //Touch OSC Port (outgoing)
int destPort = 9000; //Touch OSC Port (incoming)
int ledPin = 5; 
int flag=0;
void setup(){
pinMode(2, OUTPUT);
 Serial.println("DNS and DHCP-based OSC server");
 // start the Ethernet connection:
 if (Ethernet.begin(mac) == 0) {
 Serial.println("Failed to configure Ethernet using DHCP");
 // no point in carrying on, so do nothing forevermore:
 // print your local IP address:
 Serial.print("Arduino IP address: ");
 for (byte thisByte = 0; thisByte < 4; thisByte++) {
 // print the value of each byte of the IP address:
 Serial.print(Ethernet.localIP()[thisByte], DEC);
//start the OSCserver
//add OSC callback function. One function is needed for every TouchOSC interface element that is to send/receive OSC commands.
 server.addCallback("/1/toggle1", &funcOnOff);
 server.addCallback("/1/fader1", &funcFader);
void loop(){
 // Serial.println("alive! ");
//When the button on the TouchOSC inteface is pressed, a message is sent from the iDevice
//to the Arduino to switch (togle) the LED on the Arduino on/off
//then a messeage is sent bak from the Arduino to the iDevice to toggle the buttom on/off
void funcOnOff(OSCMessage *_mes){
 float value = _mes->getArgFloat(0); //TouchOSC expects float values
//create new osc message
 OSCMessage newMes;
//set destination ip address & port no
 if(value < 1.0) {
 digitalWrite(ledPin, LOW);
 digitalWrite(ledPin, HIGH);
//send osc message
 // turn local feedback off on touch-osc control to test this
// new callback for fader - using same comments
//When the button on the TouchOSC inteface is pressed, a message is sent from the iDevice
//to the Arduino to switch (togle) the LED on the Arduino on/off
//then a messeage is sent bak from the Arduino to the iDevice to toggle the buttom on/off
void funcFader(OSCMessage *_mes){
 float value = _mes->getArgFloat(0); //TouchOSC expects float values
//create new osc message
 OSCMessage newMes;
//set destination ip address & port no
 int ledValue = value * 255.0;
 analogWrite(ledPin, ledValue);
//send osc message
 // turn local feedback off on touch-osc control to test this




touchOsc plus Arduino



Processing + Arduino + touchOSC

uses the p5 library in processing



This post was the key to making Arduino+EthernetShield work with touchOSC. Without using Processing as an intermediary.  Got it working  tonight and will update this post with details.