DMX Input / Output

I've been working on creating a module for DMX... Not done this before, how does this stack up?

var exports = {};

function DMX( serial, interrupt ) {
  this.data = new Uint8Array( 512 );
  this.id = 0;
  this.serial = serial;
  this.interrupt = interrupt;
  
  // Setup serial port
  this.serial.setup( 250000 );
  this.serial.on( 'data', this.newData );
  
  // Listeners
  this.dataListeners = [];
  this.channelListeners = {};
  
  // Listen for the interrupt pin to drop
  setWatch( this.newFrame, this.interrupt, { repeat: true, edge: 'falling' } );
}

// Handle new bytes of data as they come in
DMX.prototype.newData = function( d ) {
  // Store the bytes received at the buffer index
  DMX.data.set( d, DMX.id );
  
  // Move the buffer index along.
  DMX.id += d.length;
};

// Send out notifications to all event listeners when frame is complete.
DMX.prototype.newFrame = function() {
  // Reset the byte buffer index to 0 for the next frame of data.
  DMX.id = 0;
  
  // Itterate through all the registered data listeners and send them the data
  for ( var i in DMX.dataListeners )
    DMX.dataListeners[i]( DMX.data );

  // Itterate through all the registered channel listeners and send them their channel values
  for ( var ch in DMX.channelListeners )
    for ( var j in DMX.channelListeners[ch] )
      DMX.channelListeners[ch][j]( DMX.data[ ch ] );
};

// Handle registration to event notifications
DMX.prototype.on = function( type, handler ) {
  // If data listener: push function onto array
  if ( type == 'data' ) DMX.dataListeners.push( handler ); 
  
  // If channel listener
  if ( type >= 1 && type <= 512 ) {
    
    // Check channel for existing listeners
    if ( DMX.channelListeners[type] !== undefined ) {
      // Push additional listener onto array
      DMX.channelListeners[type].push( handler );
    } else {
      // Otherwise: create new array with listener in it
      DMX.channelListeners[type] = [ handler ];
    }
  }
};

// Export the module
exports.connect = function( serial, interrupt ) {
  return new DMX( serial, interrupt );
};

///////////////

var DMX = exports.connect( Serial2, B9 );

// Listen for changes on channel 1
DMX.on( 1, function( val ) {
  analogWrite( LED1, val / 255, { forceSoft: true } );
} );

// Listen for changes on channel 2
DMX.on( 2, function( val ) {
  analogWrite( LED2, val / 255, { forceSoft: true } );
} );

// Listen for changes on channel 3
DMX.on( 3, function( val ) {
  analogWrite( LED3, val / 255, { forceSoft: true } );
} );

// Listen for full frames of data
DMX.on( 'data', function( data ) {
//  console.log( data );
} );