since only uses of forEachWithCB are getStates and setStates, use that as a mutex point to avoid race between two setStates calls. fixes #2

Author: natevw

index.js

@@ -1,16 +1,18 @@
 var q = require('queue-async'),
+    fifo = require('fifolock'),
     stream = require('stream'),
     util = require('util'),
     events = require('events'),
     SPI = require('pi-spi'),
     GPIO = require('pi-pins'),
     _m = require("./magicnums");
 
-function forEachWithCB(fn, cb) {
+var mutex = fifo();   // HACK: avoid https://github.com/natevw/node-nrf/commit/8d80dabde1026e949f4eb4ea6d25624cbf3c70ec
+function forEachWithCB(fn, cb) { cb = mutex.TRANSACTION_WRAPPER(cb, function () {
     var process = q(1);
     this.forEach(function (d) { process.defer(fn, d); });
     process.awaitAll(cb);
-};
+}.bind(this)); }
 
 function _extend(obj) {
     for (var i = 1, len = arguments.length; i < len; i++) {

package.json

@@ -24,8 +24,9 @@
     "url": "https://github.com/natevw/node-nrf/issues"
   },
   "dependencies": {
+    "fifolock": "^1.0.0",
+    "pi-pins": "^1.0.0",
     "pi-spi": "~0.8.1",
-    "queue-async": "~1.0.4",
-    "pi-pins": "^1.0.0"
+    "queue-async": "~1.0.4"
   }
 }