Add command logging and update serialport library

Author: nylen

lib/Controller.js

@@ -191,6 +191,13 @@ Controller.prototype._sendCommand = function(command, cb) {
     var self = this;
 
     self.port.write(command + '\r\n', function(err) {
+        if (err) {
+            self.emit('log', util.format(
+                'Error sending command "%s": %s',
+                command,
+                err.message
+            ));
+        }
         if (typeof cb === 'function') {
             cb(err);
         }

package.json

@@ -5,7 +5,7 @@
         "express"     : "^4.13.4",
         "js-yaml"     : "^3.6.1",
         "moment"      : "^2.13.0",
-        "serialport"  : "^3.1.2",
+        "serialport"  : "^4.0.7",
         "split"       : "^1.0.0"
     }
 }