Artnet for NodeJS

artnet.js

/*
--------------------------------------------------------------------------------
    Config
--------------------------------------------------------------------------------
*/
var dgram  = require('dgram')
  , Buffer = require('buffer').Buffer;

var HEADER   = [65, 114, 116, 45, 78, 101, 116, 0, 0, 80, 0, 14, 0, 0, 0, 0];

var HOST = '192.168.0.255';
var PORT = 6454;

/*
--------------------------------------------------------------------------------
    UDP Client
--------------------------------------------------------------------------------
*/
var udp = dgram.createSocket('udp4');

/**
 * Send UDP
 */
function _send(data, host, port)
{
    var upper  = Math.floor(data.length / 256)
      , lower  = data.length % 256
      , data   = HEADER.concat([upper, lower]).concat(data)
      , buffer = Buffer(data);

    udp.send(buffer, 0, buffer.length, port, host, function(){});
}


/*
--------------------------------------------------------------------------------
    Send Artnet
--------------------------------------------------------------------------------
*/
var CHANNEL = 150
  , LED     = []
  ;

for (var i = 0; i < CHANNEL; i++)
{
    LED[i] = 255;
}

_send(LED, HOST, PORT);

Hello, thanks for the code!

I'd like to send other OpCodes, but I don't get how you convert them. In the example above, you have an OpDMX code, but what's the conversion involved from 0x5000 to [0, 80] in JavaScript ?

I know I can do something like this in c++

#include <iostream>
using namespace std;

int main()
{
    uint16_t OpCode = 0x2400; // OpCommand
    uint8_t lo;
    uint8_t hi;
    lo = (uint8_t)OpCode;
    hi = (uint8_t)(OpCode >> 8);
    cout << unsigned(lo) << endl;
    cout << unsigned(hi) << endl;
    return 0;
}

but I'd like to see how to do it in JavaScript?

Regards,

Xavier