Add activelow module for active low devices

index.js

@@ -8,5 +8,6 @@ module.exports = {
   Sensor: require('./lib/sensor'),
   Ping:   require('./lib/ping'),
   PIR:    require('./lib/pir'),
-  LCD:    require('./lib/lcd')
+  LCD:    require('./lib/lcd'),
+  Activelow:    require('./lib/activelow')
 };

lib/activelow.js

@@ -0,0 +1,63 @@
+
+/*
+ * Main ActiveLow constructor
+ * Process options
+ * Tell the board to set it up
+ */
+var Activelow = function (options) {
+  if (!options || !options.board) throw new Error('Must supply required options to ActiveLow');
+  this.board = options.board;
+  this.pin = options.pin || 13;
+  this.bright = 0;
+  this.board.pinMode(this.pin, 'out');
+  this.direction = -1;
+}
+
+/*
+ * Turn the ActiveLow device on
+ */
+Activelow.prototype.on = function () {
+  this.board.digitalWrite(this.pin, this.board.LOW);
+	this.bright = 255;
+}
+
+/* 
+ * Turn the ActiveLow device off
+ */
+Activelow.prototype.off = function () {
+  this.board.digitalWrite(this.pin, this.board.HIGH);
+	this.bright = 0;
+}
+
+Activelow.prototype.brightLevel = function(val) {
+	this.board.analogWrite(this.pin, this.bright = val);
+}
+
+Activelow.prototype.fade = function(interval) {
+	to = (interval||5000)/(255*2);
+	var self = this;
+	setInterval(function() {
+		if(!self.board.serial) return; //Interval too fast for debug messages on ^c
+		if(self.bright==0) direction = 1;
+		if(self.bright==255) direction = -1;
+		self.brightLevel(self.bright+direction);
+	},to);
+}
+
+
+/*
+ * Start a bariable blinking pattern
+ */
+Activelow.prototype.blink = function (interval) {
+  interval = interval || 1000;
+  var self = this;
+  setInterval(function(){
+    if (self.bright) {
+      self.off()
+    } else {
+      self.on();
+    }
+  }, interval);
+}
+
+module.exports = Activelow;