diff --git a/protocol.py b/protocol.py
index 8979ae1..14e2e6c 100644
--- a/protocol.py
+++ b/protocol.py
@@ -49,20 +49,23 @@ class ControllerProtocol(BaseProtocol):
         # classify sub command
         sub_command = report.get_sub_command()
         logging.info(f'received output report - {sub_command}')
-        if sub_command is None:
-            logger.error(f'No sub command found')
-        elif sub_command == SubCommand.REQUEST_DEVICE_INFO:
+        if sub_command == SubCommand.REQUEST_DEVICE_INFO:
             await self._command_request_device_info(report)
+
         elif sub_command == SubCommand.SET_SHIPMENT_STATE:
             await self._command_set_shipment_state(report)
+
         elif sub_command == SubCommand.SPI_FLASH_READ:
             await self._command_spi_flash_read(report)
+
         elif sub_command == SubCommand.SET_INPUT_REPORT_MODE:
             await self._command_set_input_report_mode(report)
+
         elif sub_command == SubCommand.TRIGGER_BUTTONS_ELAPSED_TIME:
             await self._command_trigger_buttons_elapsed_time(report)
+
         elif sub_command == SubCommand.NOT_IMPLEMENTED:
-            logger.error(f'Sub command not implemented')
+            logger.error(f'Sub command not implemented - ignoring')
 
     async def _command_request_device_info(self, output_report):
         address = self.transport.get_extra_info('sockname')
diff --git a/report.py b/report.py
index 5ad36bd..0e37e4d 100644
--- a/report.py
+++ b/report.py
@@ -1,11 +1,5 @@
-from enum import Enum, auto
+from enum import Enum
 
-#[0xA1 0, 0x21 1, 0x05 2, 0x8E 3,
-# 0x84, 0x00, 0x12, button
-# 0x01, 0x18, 0x80, left analog
-# 0x01, 0x18, 0x80, right analog
-# 0x80, vibrator?
-# 0x82, 0x02, 0x03, 0x48, 0x01, 0x02, 0xDC, 0xA6, 0x32, 0x71, 0x58, 0xBB, 0x01, 0x01]
 from controller import Controller
 
 
@@ -113,12 +107,12 @@ class InputReport:
 
 
 class SubCommand(Enum):
-    REQUEST_DEVICE_INFO = auto()
-    SET_SHIPMENT_STATE = auto()
-    SPI_FLASH_READ = auto()
-    SET_INPUT_REPORT_MODE = auto()
-    NOT_IMPLEMENTED = auto()
-    TRIGGER_BUTTONS_ELAPSED_TIME = auto()
+    REQUEST_DEVICE_INFO = 0x02
+    SET_INPUT_REPORT_MODE = 0x03
+    TRIGGER_BUTTONS_ELAPSED_TIME = 0x04
+    SET_SHIPMENT_STATE = 0x08
+    SPI_FLASH_READ = 0x10
+    NOT_IMPLEMENTED = 0xFF
 
 
 class OutputReport:
@@ -128,20 +122,10 @@ class OutputReport:
         self.data = data
 
     def get_sub_command(self):
-        print('subcommand:', self.data[11])
-        sub_command_byte = self.data[11]
-        if sub_command_byte == 0x02:
-            return SubCommand.REQUEST_DEVICE_INFO
-        elif sub_command_byte == 0x08:
-            return SubCommand.SET_SHIPMENT_STATE
-        elif sub_command_byte == 0x10:
-            return SubCommand.SPI_FLASH_READ
-        elif sub_command_byte == 0x03:
-            return SubCommand.SET_INPUT_REPORT_MODE
-        elif sub_command_byte == 0x04:
-            return SubCommand.TRIGGER_BUTTONS_ELAPSED_TIME
-        else:
-            return None
+        try:
+            return SubCommand(self.data[11])
+        except ValueError:
+            return SubCommand.NOT_IMPLEMENTED
 
     def __bytes__(self):
         return bytes(self.data)
diff --git a/transport.py b/transport.py
index 2793905..02cdf94 100644
--- a/transport.py
+++ b/transport.py
@@ -60,10 +60,10 @@ class L2CAP_Transport(asyncio.Transport):
         return super().get_write_buffer_size()
 
     async def write(self, data: Any) -> None:
-
         if isinstance(data, bytes):
             _bytes = data
         elif isinstance(data, InputReport):
+            # set timer byte of input report
             data.set_timer(self._input_report_timer)
             self._input_report_timer = (self._input_report_timer + 1) % 256
             _bytes = bytes(data)
@@ -99,4 +99,4 @@ class L2CAP_Transport(asyncio.Transport):
         self._protocol = protocol
 
     def get_protocol(self) -> asyncio.BaseProtocol:
-        return self._protocol
\ No newline at end of file
+        return self._protocol