fix

raspberry/roberto/__init__.py

@@ -55,7 +55,7 @@ def initialize_extensions(app):
     from roberto.model import db
     db.init_app(app)
     #login.init_app(app)
-    socketio.init_app(app, cors_allowed_origins="*")
+    socketio.init_app(app, cors_allowed_origins="*", engineio_logger=True)
     pass
 
 def register_blueprints(app):

raspberry/roberto/views/websocket/routes.py

@@ -89,7 +89,10 @@ def disconnect():
     leave_room(ROOM)
     webrtccamera.disconnect_client(sid, ROOM)
     from roberto import serial
-    serial.del_callback('B', display_battery, sid)
+    try:
+        serial.del_callback('B', display_battery, sid)
+    except:
+        pass
 
 @socketio.on('connect')
 def connect():
@@ -108,5 +111,6 @@ def default_error_handler(e):
         print('%s: %s' % (key, repr(request[key])))
 
 def display_battery(val, sid=ROOM):
+    print("sending battery value %s to client %s" % (val, sid))
     socketio.emit('battery', data=val, room=sid)
     #socketio.emit('battery', data=val)