don't expect response to remote control commands

tello_asyncio/tello.py

@@ -530,9 +530,13 @@ async def send(self, message, timeout=DEFAULT_RESPONSE_TIMEOUT, response_parser=
         '''
         if not self._transport.is_closing():
             print(f'SEND {message}')
+
+            self._transport.sendto(message.encode())
+            if not self._expect_response(message):
+                return
+
             response = self._loop.create_future()
             self._protocol.pending.append((message, response, response_parser))
-            self._transport.sendto(message.encode())
             error = None
             try:
                 response_message, result = await asyncio.wait_for(response, timeout=timeout)
@@ -556,6 +560,10 @@ async def send(self, message, timeout=DEFAULT_RESPONSE_TIMEOUT, response_parser=
                 await self._abort()
                 raise error
 
+    def _expect_response(self, message):
+        # drone responds to everything except remote control commands
+        return not message.startswith('rc ')
+
     _aborted = False
     async def _abort(self):
         if not self._aborted:
@@ -869,7 +877,7 @@ async def send_ext_command(self, command):
         Sends a command like "EXT xxx" for the open source contoller, returning
         the response.
 
-        See the `SDK 3.0 User Guide` <https://dl.djicdn.com/downloads/RoboMaster+TT/Tello_SDK_3.0_User_Guide_en.pdf>`_ for command details.
+        See the `SDK 3.0 User Guide <https://dl.djicdn.com/downloads/RoboMaster+TT/Tello_SDK_3.0_User_Guide_en.pdf>`_ for command details.
 
         Requires SDK 3+ and the open source controller