Some minor fixes

README.md

@@ -12,6 +12,7 @@ Best way to start is to look at [demo.py](demo.py) file, and run it.
 - angled and timed movement for motors
 - LED color change
 - sensor data subscribe/unsubscribe
+- battery voltage available
 
 ## Usage
 

demo.py

@@ -172,9 +172,9 @@ if __name__ == '__main__':
 
     hub = MoveHub(connection)
 
-    hub.devices[PORT_BATTERY].subscribe(cb_log, 0x00, granularity=2)
+    #hub.devices[PORT_SOMETHING1].subscribe(cb_log, 0x00, granularity=1)
     sleep(10)
     demo_port_cd_motor(hub)
-    sleep(60)
-    hub.devices[PORT_BATTERY].unsubscribe(cb_log)
+    sleep(10)
+    #hub.devices[PORT_SOMETHING1].unsubscribe(cb_log)
     # demo_all(hub)

pylgbst/comms.py

@@ -16,7 +16,7 @@ from threading import Thread
 
 from pylgbst.constants import LEGO_MOVE_HUB, MSG_DEVICE_SHUTDOWN
 
-log = logging.getLogger('transport')
+log = logging.getLogger('comms')
 
 
 def str2hex(data):  # TODO: eliminate it
@@ -171,7 +171,7 @@ class DebugServer(object):
         self.sock.close()
 
     def _notify_dummy(self, handle, data):
-        log.debug("Notification from handle %s: %s", handle, binascii.hexlify(data.strip()))
+        log.debug("Dropped notification from handle %s: %s", handle, binascii.hexlify(data.strip()))
         self._check_shutdown(data)
 
     def _notify(self, conn, handle, data):
@@ -291,7 +291,10 @@ class DebugServerConnection(Connection):
                 if line:
                     item = json.loads(line)
                     if item['type'] == 'notification' and self.notify_handler:
-                        self.notify_handler(item['handle'], unhexlify(item['data']))
+                        try:
+                            self.notify_handler(item['handle'], unhexlify(item['data']))
+                        except BaseException:
+                            log.error("Failed to notify handler: %s", traceback.format_exc())
                     elif item['type'] == 'response':
                         self.incoming.append(item)
                     else:

pylgbst/peripherals.py

@@ -61,7 +61,9 @@ class Peripheral(object):
         if callback in self._subscribers:
             self._subscribers.remove(callback)
 
-        if not self._subscribers:
+        if not self._port_subscription_mode:
+            log.warning("Attempt to unsubscribe while never subscribed: %s", self)
+        elif not self._subscribers:
             self._port_subscribe(self._port_subscription_mode, 0, False)
             self._port_subscription_mode = None
 
@@ -273,8 +275,9 @@ class ColorDistanceSensor(Peripheral):
 
 
 class Battery(Peripheral):
+    # we know only voltage subscription from it. is it really battery or just onboard voltage?
     def handle_port_data(self, data):
-        self._notify_subscribers(unpack("<H", data))
+        self._notify_subscribers(unpack("<H", data[4:6]))
 
 
 class Button(Peripheral):