Bluepy comm (#18)

* Added support for bluepy communication backend.

* Added bluepy information into the readme.

* Added tests, fixed dependency specs in setup.py.

* Fixed dep in travis.

* Removed unused import. Added ability to fail the application on dispatcher thread error.

* Fixed bluepy test to be more appropriate.

* Properly handle hub mac if set.

Author: karatheodory

.travis.yml

@@ -27,7 +27,7 @@ addons:
     - python3-dbus
     - python3-gi
 install:
-- pip install codecov nose-exclude gattlib pygatt gatt pexpect
+- pip install codecov nose-exclude gattlib pygatt gatt pexpect bluepy
 
 
 script: coverage run --source=. `which nosetests` tests --nocapture --exclude-dir=examples

README.md

@@ -257,6 +257,7 @@ You have following options to install as Bluetooth backend:
 - `pip install pygatt` - [pygatt](https://github.com/peplin/pygatt) lib, works on both Windows and Linux  
 - `pip install gatt` - [gatt](https://github.com/getsenic/gatt-python) lib, supports Linux, does not work on Windows
 - `pip install gattlib` - [gattlib](https://bitbucket.org/OscarAcena/pygattlib) - supports Linux, does not work on Windows, requires `sudo`
+- `pip install bluepy` - [bluepy](https://github.com/IanHarvey/bluepy) lib, supports Linux, including Raspbian, which allows connection to the hub from the Raspberry PI
 
 Running on Windows requires [Bluegiga BLED112 Bluetooth Smart Dongle](https://www.silabs.com/products/wireless/bluetooth/bluetooth-low-energy-modules/bled112-bluetooth-smart-dongle) hardware piece, because no other hardware currently works on Windows with Python+BLE.
 
@@ -272,6 +273,7 @@ There is optional parameter for `MoveHub` class constructor, accepting instance
 - use `GattConnection()` - if you use Gatt Backend on Linux (`gatt` library prerequisite)
 - use `GattoolConnection()` - if you use GattTool Backend on Linux (`pygatt` library prerequisite)
 - use `GattLibConnection()` - if you use GattLib Backend on Linux (`gattlib` library prerequisite)
+- use `BluepyConnection()` - if you use Bluepy backend on Linux/Raspbian (`bluepy` library prerequisite)
 - pass instance of `DebugServerConnection` if you are using [Debug Server](#debug-server) (more details below).
 
 All the functions above have optional arguments to specify adapter name and MoveHub mac address. Please look function source code for details.

pylgbst/__init__.py

@@ -29,9 +29,15 @@ def get_connection_gattlib(controller='hci0', hub_mac=None):
 
     return GattLibConnection(controller).connect(hub_mac)
 
+def get_connection_bluepy(controller='hci0', hub_mac=None):
+    from pylgbst.comms.cbluepy import BluepyConnection
+
+    return BluepyConnection(controller).connect(hub_mac)
+
 
 def get_connection_auto(controller='hci0', hub_mac=None):
     fns = [
+        get_connection_bluepy,
         get_connection_bluegiga,
         get_connection_gatt,
         get_connection_gattool,

pylgbst/comms/cbluepy.py

@@ -0,0 +1,129 @@
+import re
+import logging
+from threading import Thread, Event
+import time
+from contextlib import contextmanager
+from enum import Enum
+
+from bluepy import btle
+
+from pylgbst.comms import Connection, LEGO_MOVE_HUB
+from pylgbst.constants import MOVE_HUB_HW_UUID_CHAR
+from pylgbst.utilities import str2hex, queue
+
+log = logging.getLogger('comms-bluepy')
+
+COMPLETE_LOCAL_NAME_ADTYPE = 9
+PROPAGATE_DISPATCHER_EXCEPTION = False
+
+
+def _get_iface_number(controller):
+    """bluepy uses iface numbers instead of full names."""
+    if not controller:
+        return None
+    m = re.search(r'hci(\d+)$', controller)
+    if not m:
+        raise ValueError('Cannot find iface number in {}.'.format(controller))
+    return int(m.group(1))
+
+
+class BluepyDelegate(btle.DefaultDelegate):
+    def __init__(self, handler):
+        btle.DefaultDelegate.__init__(self)
+
+        self._handler = handler
+
+    def handleNotification(self, cHandle, data): 
+        log.debug('Incoming notification')
+        self._handler(cHandle, data)
+
+
+# We need a separate thread to wait for notifications, 
+# but calling peripheral's methods from different threads creates issues,
+# so we will wrap all the calls into a thread
+class BluepyThreadedPeripheral(object):
+    def __init__(self, addr, addrType, controller):
+        self._call_queue = queue.Queue()
+        self._addr = addr
+        self._addrType = addrType
+        self._iface_number = _get_iface_number(controller)
+
+        self._disconnect_event = Event()
+                
+        self._dispatcher_thread = Thread(target=self._dispatch_calls)
+        self._dispatcher_thread.setDaemon(True)
+        self._dispatcher_thread.setName("Bluepy call dispatcher")
+        self._dispatcher_thread.start()
+
+    def _dispatch_calls(self):
+        self._peripheral = btle.Peripheral(self._addr, self._addrType, self._iface_number)
+        try:
+            while not self._disconnect_event.is_set():
+                try:
+                    try:
+                        method = self._call_queue.get(False)
+                        method()
+                    except queue.Empty:
+                        pass
+                    self._peripheral.waitForNotifications(1.)
+                except Exception as ex:
+                    log.exception('Exception in call dispatcher thread', exc_info=ex)
+                    if PROPAGATE_DISPATCHER_EXCEPTION:
+                        log.error("Terminating dispatcher thread.")
+                        raise
+        finally:
+            self._peripheral.disconnect()
+
+
+    def write(self, handle, data):
+        self._call_queue.put(lambda: self._peripheral.writeCharacteristic(handle, data))
+
+    def set_notify_handler(self, handler):
+        delegate = BluepyDelegate(handler)
+        self._call_queue.put(lambda: self._peripheral.withDelegate(delegate))
+
+    def disconnect(self):
+        self._disconnect_event.set()
+
+
+class BluepyConnection(Connection):
+    def __init__(self, controller='hci0'):
+        Connection.__init__(self)
+        self._peripheral = None  # :type BluepyThreadedPeripheral
+        self._controller = controller
+
+    def connect(self, hub_mac=None):
+        log.debug("Trying to connect client to MoveHub with MAC: %s", hub_mac)
+        scanner = btle.Scanner()
+
+        while not self._peripheral:
+            log.info("Discovering devices...")
+            scanner.scan(1)
+            devices = scanner.getDevices()
+
+            for dev in devices:
+                address = dev.addr
+                addressType = dev.addrType
+                name = dev.getValueText(COMPLETE_LOCAL_NAME_ADTYPE)
+                log.debug("Found dev, name: {}, address: {}".format(name, address))
+
+                if (not hub_mac and name == LEGO_MOVE_HUB) or hub_mac == address:
+                    logging.info("Found %s at %s", name, address)
+                    self._peripheral = BluepyThreadedPeripheral(address, addressType, self._controller)
+                    break
+
+        return self
+
+    def disconnect(self):
+        self._peripheral.disconnect()
+
+    def write(self, handle, data):
+        log.debug("Writing to handle %s: %s", handle, str2hex(data))
+        self._peripheral.write(handle, data)
+
+    def set_notify_handler(self, handler):
+        self._peripheral.set_notify_handler(handler)
+
+    def is_alive(self):
+        return True
+

setup.py

@@ -11,5 +11,6 @@
           'gatt': ["gatt"],
           'gattlib': ["gattlib"],
           'pygatt': ["pygatt"],
+          'bluepy': ["bluepy"],
       }
       )

tests/test_cbluepy.py

@@ -0,0 +1,61 @@
+import unittest
+import time
+
+import pylgbst.comms.cbluepy as bp_backend
+
+
+class PeripheralMock(object):
+    def __init__(self, addr, addrType, ifaceNumber):
+        pass
+
+    def waitForNotifications(self, timeout):
+        pass
+
+    def writeCharacteristic(self, handle, data):
+        pass
+
+    def withDelegate(self, delegate):
+        pass
+
+    def disconnect(self):
+        pass
+
+bp_backend.PROPAGATE_DISPATCHER_EXCEPTION = True
+bp_backend.btle.Peripheral = lambda *args, **kwargs: PeripheralMock(*args, **kwargs)
+
+
+class BluepyTestCase(unittest.TestCase):
+    def test_get_iface_number(self):
+        self.assertEqual(bp_backend._get_iface_number('hci0'), 0)
+        self.assertEqual(bp_backend._get_iface_number('hci10'), 10)
+        try:
+            bp_backend._get_iface_number('ads12')
+            self.fail('Missing exception for incorrect value')
+        except ValueError:
+            pass
+
+    def test_delegate(self):
+        def _handler(handle, data):
+            _handler.called = True
+        delegate = bp_backend.BluepyDelegate(_handler)
+        delegate.handleNotification(123, 'qwe')
+        self.assertEqual(_handler.called, True)
+
+    def test_threaded_peripheral(self):
+        tp = bp_backend.BluepyThreadedPeripheral('address', 'addrType', 'hci0')
+        self.assertEqual(tp._addr, 'address')
+        self.assertEqual(tp._addrType, 'addrType')
+        self.assertEqual(tp._iface_number, 0)
+        self.assertNotEqual(tp._dispatcher_thread, None)
+
+        # Schedule some methods to async queue and give them some time to resolve
+        tp.set_notify_handler(lambda: '')
+        tp.write(123, 'qwe')
+
+        tp._dispatcher_thread.join(1)
+        self.assertEqual(tp._dispatcher_thread.is_alive(), True)
+        tp.disconnect()
+
+        tp._dispatcher_thread.join(2)
+        self.assertEqual(tp._dispatcher_thread.is_alive(), False)
+