Designing UI for effects project
If OSC is Open Sound Control, there is a library for it at https://github.com/CNMAT/OSC       

Physically, you could hook a potentiometer or two to analog inputs and drive it like the sample in http://cnmat.berkeley.edu/oscuino  

The code below is copied from that site, with a couple untested changes to not use the USB serial, and appears to use an analogread to sens some sort of message to the OSC system.

#include &lt;OSCMessage.h&gt;

//Teensy and Leonardo variants have special USB serial
//#if defined(CORE_TEENSY)|| defined(__AVR_ATmega32U4__)
//#include &lt;SLIPEncodedUSBSerial.h&gt;
//SLIPEncodedUSBSerial SLIPSerial(Serial);
//#else
// any hardware serial port
#include &lt;SLIPEncodedSerial.h&gt;
SLIPEncodedSerial SLIPSerial(Serial1);
#endif


void setup() {
  //begin SLIPSerial just like Serial
  Serial.begin(38400);
  //while(!Serial)
  //  ; //Leonardo "feature"
}


void loop(){
  //the message wants an OSC address as first argument
  OSCMessage msg("/analog/0");
  msg.add(analogRead(0));
  msg.send(SLIPSerial); // send the bytes to the SLIP stream
  SLIPSerial.endPacket(); // mark the end of the OSC Packet
  msg.empty(); // free space occupied by message

  delay(20);
}


If DMX is https://en.wikipedia.org/wiki/DMX512 then...there is another library at http://www.mathertel.de/Arduino/DMXSerial.aspx