diff --git a/software/logger.js b/software/logger.js
index 4297ff5..7bc8a12 100644
--- a/software/logger.js
+++ b/software/logger.js
@@ -14,12 +14,15 @@
 
 var toWriteBeforeOpen = [];
 
-var writeLog = module.exports = function(jsonObj){
+var writeLog = module.exports = function(jsonObj, callback){
 	if(logFileReady){
-		logStream.write(JSON.stringify(jsonObj));
+		logStream.write(JSON.stringify({time: Date.now(), msg: jsonObj}));
 		logStream.write(", \n");
 	}else{
 		toWriteBeforeOpen.push(jsonObj);
 	}
+	if(callback !== undefined){
+		logStream.once('drain', callback)
+	}
 };