diff --git a/scratch_link.py b/scratch_link.py
index cfe1015..5c6361a 100755
--- a/scratch_link.py
+++ b/scratch_link.py
@@ -61,12 +61,15 @@ class Session():
         Return True when the sessino should end.
         """
         logger.debug("start recv_request")
-        req = await self.websocket.recv()
+        try:
+            req = await asyncio.wait_for(self.websocket.recv(), 0.0001)
+        except asyncio.TimeoutError:
+            return False
         logger.debug(f"request: {req}")
         jsonreq = json.loads(req)
         if jsonreq['jsonrpc'] != '2.0':
-            logger.error("error: jsonrpc versino is not 2.0")
-            return
+            logger.error("error: jsonrpc version is not 2.0")
+            return True
         jsonres = self.handle_request(jsonreq['method'], jsonreq['params'])
         if 'id' in jsonreq:
             jsonres['id'] = jsonreq['id']
@@ -90,7 +93,10 @@ class Session():
         logger.debug("default end_request")
         return False
 
-    def notify(self):
+    def notify(self, key, params):
+        self.notification_queue.put((key, params))
+
+    async def _send_notifications(self):
         """
         Notify BT/BLE device events to scratch.
         """
@@ -98,17 +104,14 @@ class Session():
         # flush notification queue
         while not self.notification_queue.empty():
             method, params = self.notification_queue.get()
-            self._send_notification(method, params)
+            await self._send_notification(method, params)
 
-    def _send_notification(self, method, params):
+    async def _send_notification(self, method, params):
         jsonn = { 'jsonrpc': "2.0", 'method': method }
         jsonn['params'] = params
         notification = json.dumps(jsonn)
         logger.debug(f"notification: {notification}")
-
-        future = asyncio.run_coroutine_threadsafe(
-            self.websocket.send(notification), self.loop)
-        result = future.result()
+        await self.websocket.send(notification)
 
     async def handle(self):
         logger.debug("start session hanlder")
@@ -117,6 +120,7 @@ class Session():
         while True:
             if await self.recv_request():
                 break
+            await self._send_notifications()
             logger.debug("in handle loop")
 
 class BTSession(Session):
@@ -343,8 +347,7 @@ class BLESession(Session):
                         params = { 'rssi': d.rssi }
                         params['peripheralId'] = devices.index(d)
                         params['name'] = d.getValueText(0x9)
-                        self.session.notification_queue.put(('didDiscoverPeripheral', params))
-                        self.session.notify()
+                        self.session.notify('didDiscoverPeripheral', params)
                     time.sleep(1)
                 elif self.session.status == self.session.CONNECTED:
                     logger.debug("in connected status:")
@@ -370,7 +373,7 @@ class BLESession(Session):
                     time.sleep(0)
                 else:
                     # Nothing to do:
-                    time.sleep(1)
+                    time.sleep(0)
 
     class BLEDelegate(DefaultDelegate):
         """
@@ -394,10 +397,7 @@ class BLESession(Session):
             logger.debug(f"BLE notification: {handle} {data}")
             params = self.handles[handle].copy()
             params['message'] = base64.standard_b64encode(data).decode('ascii')
-            self.session.notification_queue.put(('characteristicDidChange', params))
-            if not self.restart_notification_event.is_set():
-                return
-            self.session.notify()
+            self.session.notify('characteristicDidChange', params)
 
     def __init__(self, websocket, loop):
         super().__init__(websocket, loop)