diff --git a/backend/lib/Dispatcher.php b/backend/lib/Dispatcher.php
index e556b52..df9f8b3 100644
--- a/backend/lib/Dispatcher.php
+++ b/backend/lib/Dispatcher.php
@@ -34,6 +34,8 @@ final class Dispatcher {
 	protected $view;		// View
 	protected $controller;	// Controller
 	
+	protected $debug = NULL;	// optional debugging instance
+	
 	/*
 	 * constructor
 	 */
@@ -48,6 +50,12 @@ final class Dispatcher {
 		// initialize entity manager
 		$this->em = Dispatcher::createEntityManager();
 		
+		// staring debugging
+		if (($request->getParameter('debug') && $request->getParameter('debug') > 0) || Util\Configuration::read('debug')) {
+			$this->debug = new Util\Debug($request->getParameter('debug'));
+			$this->em->getConnection()->getConfiguration()->setSQLLogger($this->debug);
+		}
+		
 		// initialize view
 		if (in_array($format, array('png', 'jpeg', 'gif'))) {
 			$this->view = new View\JpGraph($request, $response, $format);
@@ -80,6 +88,11 @@ final class Dispatcher {
 		$action = ($this->view->request->getParameter('action')) ? 'get' : $this->view->request->getParameter('action');	// default action
 		
 		$this->controller->run($action);	// run controllers actions (usually CRUD: http://de.wikipedia.org/wiki/CRUD)
+		
+		if (Util\Debug::isActivated()) {
+			$this->view->addDebug($this->debug);
+		}
+		
 		$this->view->render();				// render view & send http response
 	}
 	
@@ -104,11 +117,7 @@ final class Dispatcher {
 		$config->setProxyNamespace('Volkszaehler\Model\Proxies');
 		$config->setAutoGenerateProxyClasses(DEV_ENV == true);
 		
-		$config->setSQLLogger(Util\Debug::getSQLLogger());
-		
-		$em = \Doctrine\ORM\EntityManager::create(Util\Configuration::read('db'), $config);
-		
-		return $em;
+		return \Doctrine\ORM\EntityManager::create(Util\Configuration::read('db'), $config);
 	}
 }
 
diff --git a/backend/lib/Util/Configuration.php b/backend/lib/Util/Configuration.php
index 94fb492..f0d663d 100644
--- a/backend/lib/Util/Configuration.php
+++ b/backend/lib/Util/Configuration.php
@@ -22,7 +22,7 @@
 namespace Volkszaehler\Util;
 
 class Configuration {
-	static public $values = array();	// TODO protected
+	static protected $values = array();
 
 	static public function write($var, $value) {
 		if (!is_scalar($value) && !is_array($value)) {
@@ -32,7 +32,7 @@ class Configuration {
 		$values =& self::$values;
 		$tree = explode('.', $var);
 		foreach ($tree as $part) {
-			$values =& $values[$part];
+			$values =& $values[$part];	// TODO array_merge_recursive()
 		}
 		
 		$values = $value;
diff --git a/backend/lib/Util/Debug.php b/backend/lib/Util/Debug.php
index f3095d8..b86f8ce 100644
--- a/backend/lib/Util/Debug.php
+++ b/backend/lib/Util/Debug.php
@@ -21,15 +21,89 @@
 
 namespace Volkszaehler\Util;
 
-class Debug {
-	private static $logger = NULL;
+use Doctrine\DBAL\Logging;
+
+class Debug implements Logging\SQLLogger {
+	protected static $instance = NULL;
 	
-	static public function getSQLLogger() {
-		if (is_null(self::$logger)) {
-			self::$logger = new \Doctrine\DBAL\Logging\DebugStack();
+	protected $queries = array();
+	protected $messages = array();
+	
+	protected $started;	// holds timestamp of initialization, used later to return time of execution
+	protected $level;
+	
+	/*
+	 * constructor
+	 */
+	public function __construct($level) {
+		// taking timestamp to stop execution time
+		$this->created = microtime(true);
+		
+		$this->level = $level;
+		
+		if (!is_null(self::$instance)) {
+			throw new \Exception('debugging has already been started. please use the static functions!');
 		}
-		return self::$logger;
+		self::$instance = $this;
+		
+		// assert options
+		assert_options(ASSERT_ACTIVE, true);
+		assert_options(ASSERT_BAIL, false);
+		assert_options(ASSERT_WARNING, false);
+		assert_options(ASSERT_CALLBACK, array($this, 'assertHandler'));
+		
+		
 	}
+	
+	/*
+	 * interface for doctrine's dbal sql logger
+	 */ 
+	function logSQL($sql, array $params = null) {
+		$this->queries[] = array('sql' => $sql, 'parameter' => $params);
+	}
+	
+	static public function log($message) {
+		if (!is_null(self::$instance)) {
+			$trace = debug_backtrace();
+			
+			self::$instance->messages[] = array(
+				'message' => $message,
+				'file' => $trace[0]['file'],
+				'line' => $trace[0]['line'],
+				'time' => date('r'),
+				'args' => array_slice($trace[0]['args'], 1),
+				'trace' => $trace
+			);
+		}
+	}
+	
+	/*
+	 * simple assertion passthrough for future improvements
+	 * 
+	 * @todo check how should be en/disabled (options etc..)
+	 */
+	public static function assert($code) {
+		assert($code);
+	}
+	
+	public function assertHandler($file, $line, $code) {
+		$trace = debug_backtrace();
+		$info = $trace[2];
+		
+		$this->messages[] = array(
+			'message' => 'assertion failed: ' . $code,
+			'file' => $info['file'],
+			'line' => $info['line'],
+			'time' => date('r'),
+			'trace' => array_slice($trace, 2)
+		);
+	}
+	
+	public static function isActivated() { return !is_null(self::$instance); }
+	
+	public function getExecutionTime() { return round((microtime(true) - $this->created), 5); }
+	public function getQueries() { return $this->queries; }
+	public function getMessages() { return $this->messages; }
 }
 
 ?>
\ No newline at end of file
diff --git a/backend/lib/View/Csv/Csv.php b/backend/lib/View/Csv/Csv.php
index c713469..3b35873 100644
--- a/backend/lib/View/Csv/Csv.php
+++ b/backend/lib/View/Csv/Csv.php
@@ -62,7 +62,6 @@ abstract class Csv extends \Volkszaehler\View\View {
 	}
 	
 	public function addDebug() {
-
 		$this->footer[] = 'time: ' . $this->getTime();
 		$this->footer[] = 'database: ' . Util\Configuration::read('db.driver');
 		
diff --git a/backend/lib/View/Json/Json.php b/backend/lib/View/Json/Json.php
index 43a1254..9731ae6 100644
--- a/backend/lib/View/Json/Json.php
+++ b/backend/lib/View/Json/Json.php
@@ -39,19 +39,15 @@ abstract class Json extends \Volkszaehler\View\View {
 	}
 
 	public function render() {
-		parent::render();
-		// TODO solve rendering order problem
-		
 		$json = json_encode($this->json);
 		
-		if ($this->request->getParameter('debug')) {
-			echo self::format($json);
-		}
-		else {
-			echo $json;
+		if (Util\Debug::isActivated()) {
+			$json = self::format($json);
 		}
+
+		echo $json;
 		
-		
+		parent::render();
 	}
 
 	protected static function format($json) {
@@ -104,21 +100,25 @@ abstract class Json extends \Volkszaehler\View\View {
 		return $formatted;
 	}
 
-	public function addDebug() {
-		$this->json['debug'] = array('time' => $this->getTime(),
-										'database' => array('driver' => Util\Configuration::read('db.driver'),
-																'queries' => Util\Debug::getSQLLogger()->queries)
+	public function addDebug(Util\Debug $debug) {
+		$this->json['debug'] = array(
+			'time' => $debug->getExecutionTime(),
+			'messages' => $debug->getMessages(),							
+			'database' => array(
+				'driver' => Util\Configuration::read('db.driver'),
+				'queries' => $debug->getQueries()
+			)
 		);
-
 	}
 
 	public function addException(\Exception $exception) {
-		$this->json['exception'] = array('type' => get_class($exception),
-										'message' => $exception->getMessage(),
-										'code' => $exception->getCode(),
-										'file' => $exception->getFile(),
-										'line' => $exception->getLine(),
-										'trace' => $exception->getTrace()
+		$this->json['exception'] = array(
+			'type' => get_class($exception),
+			'message' => $exception->getMessage(),
+			'code' => $exception->getCode(),
+			'file' => $exception->getFile(),
+			'line' => $exception->getLine(),
+			'trace' => $exception->getTrace()
 		);
 	}
 }
diff --git a/backend/lib/View/View.php b/backend/lib/View/View.php
index 6177766..b92ccdc 100644
--- a/backend/lib/View/View.php
+++ b/backend/lib/View/View.php
@@ -21,19 +21,16 @@
 
 namespace Volkszaehler\View;
 
+use Volkszaehler\Util;
+
 abstract class View {
 	public $request;
 	protected $response;
 	
-	private $created;	// holds timestamp of creation, used later to return time of execution
-	
 	public function __construct(Http\Request $request, Http\Response $response) {
 		$this->request = $request;
 		$this->response = $response;
 		
-		// TODO move to Debug or State class
-		$this->created = microtime(true);
-		
 		// error & exception handling by view
 		set_exception_handler(array($this, 'exceptionHandler'));
 		set_error_handler(array($this, 'errorHandler'));
@@ -58,16 +55,7 @@ abstract class View {
 		die();
 	}
 	
-	// TODO move this into Debug or State Class
-	protected function getTime() {
-		return round(microtime(true) - $this->created, 4);
-	}
-	
 	public function render() {
-		if (!is_null($this->request->getParameter('debug')) && $this->request->getParameter('debug') > 0) {
-			$this->addDebug();
-		}
-		
 		$this->response->send();
 	}
 	
@@ -75,7 +63,7 @@ abstract class View {
 		echo $e;
 	}
 	
-	public function addDebug() {
+	public function addDebug(Util\Debug $debug) {
 		
 	}
 }
\ No newline at end of file