Merge pull request #3 from evantahler/master

enttec openDMX driver

.gitignore

@@ -10,5 +10,6 @@ lib-cov
 pids
 logs
 results
+.DS_Store
 
 node_modules

dmx.js

@@ -9,6 +9,7 @@ function DMX() {
 
 	this.registerDriver('null',                require('./drivers/null'))
 	this.registerDriver('enttec-usb-dmx-pro',  require('./drivers/enttec-usb-dmx-pro'))
+	this.registerDriver('enttec-open-usb-dmx', require('./drivers/enttec-open-usb-dmx'))
 }
 
 util.inherits(DMX, EventEmitter)

drivers/enttec-open-usb-dmx.js

@@ -0,0 +1,60 @@
+"use strict"
+
+var FTDI = require('ftdi')
+
+var	ENTTEC_PRO_DMX_STARTCODE = 0x00
+	, ENTTEC_PRO_START_OF_MSG  = 0x7e
+	, ENTTEC_PRO_END_OF_MSG    = 0xe7
+	, ENTTEC_PRO_SEND_DMX_RQ   = 0x06
+	;
+
+function EnttecOpenUsbDMX(device_id, cb) {
+	var self = this
+	cb = cb || function() {}
+	this.universe = new Buffer(512)
+	this.universe.fill(0)
+	
+	this.dev = new FTDI.FtdiDevice(device_id)
+	this.dev.open({
+		'baudrate': 115200,
+		'databits': 8,
+		'stopbits': 2,
+		'parity': 'none'
+	}, function(err) {
+		cb(err, device_id)
+		if(!err) {
+			self.send_universe()
+		}
+	})
+}
+
+EnttecOpenUsbDMX.prototype.send_universe = function() {
+	var hdr = Buffer([
+		ENTTEC_PRO_START_OF_MSG,
+		ENTTEC_PRO_SEND_DMX_RQ,
+		 // (this.universe.length + 1)       & 0xff,
+	  ((this.universe.length + 1) >> 0) & 0xff,
+		((this.universe.length + 1) >> 8) & 0xff,
+		ENTTEC_PRO_DMX_STARTCODE
+	])
+
+	var msg = Buffer.concat([
+		hdr,
+		this.universe,
+		Buffer([ENTTEC_PRO_END_OF_MSG])
+	])
+	this.dev.write(msg)
+}
+
+EnttecOpenUsbDMX.prototype.update = function(u) {
+	for(var c in u) {
+		this.universe[c] = u[c]
+	}
+	this.send_universe()
+}
+
+EnttecOpenUsbDMX.prototype.get = function(c) {
+	return this.universe[c]
+}
+
+module.exports = EnttecOpenUsbDMX