call the ready callback only after the initial gpio value was read

Author: sa-linetco

lib/gpio.js

@@ -77,7 +77,7 @@ var _testwrite = function (file, fn) {
 // fs.watch doesn't get fired because the file never
 // gets 'accessed' when setting header via hardware
 // manually watching value changes
-var FileWatcher = function (path, interval, fn) {
+var FileWatcher = function (path, interval, fn, readyCallback) {
     if (typeof fn === 'undefined') {
         fn = interval;
         interval = 100;
@@ -86,14 +86,20 @@ var FileWatcher = function (path, interval, fn) {
     if (typeof fn !== 'function') return false;
 
     var value;
-    var readTimer = setInterval(function () {
+    function watchForChange() {
         _read(path, function (val) {
             if (value !== val) {
-                if (typeof value !== 'undefined') fn(val);
+                if (typeof value === 'undefined') {
+                    readyCallback();
+                } else {
+                    fn(val);
+                }
                 value = val;
             }
         });
-    }, interval);
+    }
+    watchForChange();
+    var readTimer = setInterval(watchForChange, interval);
 
     this.stop = function () {
         clearInterval(readTimer);
@@ -171,7 +177,7 @@ GPIO.prototype.setDirection = function (dir, fn) {
 
     logMessage('Setting direction "' + dir + '" on gpio' + this.headerNum);
 
-    function watch() {
+    function watch(watchFinished) {
         if (dir === 'in') {
             if (!self.valueWatcher) {
                 // watch for value changes only for direction "in"
@@ -181,14 +187,17 @@ GPIO.prototype.setDirection = function (dir, fn) {
                     self.value = val;
                     self.emit("valueChange", val);
                     self.emit("change", val);
-                });
+                }, watchFinished);
+            } else {
+                watchFinished();
             }
         } else {
             // if direction is "out", try to clear the valueWatcher
             if (self.valueWatcher) {
                 self.valueWatcher.stop();
                 self.valueWatcher = null;
             }
+            watchFinished();
         }
     }
 
@@ -201,12 +210,12 @@ GPIO.prototype.setDirection = function (dir, fn) {
             changedDirection = true;
         }
         _write(dir, path, function () {
-            watch();
-            
-            if (typeof fn === 'function') fn();
-            if (changedDirection) {
-                self.emit('directionChange', dir);
-            }
+            watch(function() {
+                if (typeof fn === 'function') fn();
+                if (changedDirection) {
+                    self.emit('directionChange', dir);
+                }
+            });
         }, 1);
 
     });

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gpio",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "author": {
     "name": "Sebastian Alkemade",
     "email": "[email protected]"