diff --git a/eq3bt/connection.py b/eq3bt/connection.py
index 052a81b..fa6dbb3 100644
--- a/eq3bt/connection.py
+++ b/eq3bt/connection.py
@@ -15,10 +15,12 @@
 class BTLEConnection(btle.DefaultDelegate):
     """Representation of a BTLE Connection."""
 
-    def __init__(self, mac):
+    def __init__(self, mac, iface=None):
         """Initialize the connection."""
         btle.DefaultDelegate.__init__(self)
 
+        self._iface = iface
+        self._keep_connected = False
         self._conn = None
         self._mac = mac
         self._callbacks = {}
@@ -29,32 +31,55 @@ def __enter__(self):
         :rtype: btle.Peripheral
         :return:
         """
-        self._conn = btle.Peripheral()
-        self._conn.withDelegate(self)
-        _LOGGER.debug("Trying to connect to %s", self._mac)
-        try:
-            self._conn.connect(self._mac)
-        except btle.BTLEException as ex:
-            _LOGGER.debug("Unable to connect to the device %s, retrying: %s", self._mac, ex)
+        conn_state = "conn"
+        if self._conn:
+            # connection active, check if still connected
             try:
-                self._conn.connect(self._mac)
-            except Exception as ex2:
-                _LOGGER.debug("Second connection try to %s failed: %s", self._mac, ex2)
-                raise
+                conn_state = self._conn.getState()
+            except (btle.BTLEInternalError, btle.BTLEDisconnectError):
+                # connection not active, set _conn object to None
+                self._conn = None
+
+        if self._conn is None or conn_state != "conn":
+            # no active connection, connect now
+            self._conn = btle.Peripheral()
+            self._conn.withDelegate(self)
+            _LOGGER.debug("Trying to connect to %s", self._mac)
+            self.connect(self._iface)
+            _LOGGER.debug("Connected to %s", self._mac)
 
-        _LOGGER.debug("Connected to %s", self._mac)
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
-        if self._conn:
+        if self._conn and self._keep_connected is False:
             self._conn.disconnect()
             self._conn = None
 
+    def connect(self, iface):
+        self._keep_connected = True
+        self._connect(iface)
+    
+    def _connect(self, iface):
+        try:
+            self._conn.connect(self._mac, iface=iface)
+        except btle.BTLEException as ex:
+            _LOGGER.debug("Unable to connect to the device %s using iface %s, retrying: %s", self._mac, iface, ex)
+            try:
+                self._conn.connect(self._mac, iface=iface)
+            except Exception as ex2:
+                _LOGGER.debug("Second connection try to %s using ifaces %s failed: %s", self._mac, iface, ex2)
+                raise
+    
+    def disconnect(self):
+        self._conn.disconnect()
+        self._conn = None
+
     def handleNotification(self, handle, data):
         """Handle Callback from a Bluetooth (GATT) request."""
         _LOGGER.debug("Got notification from %s: %s", handle, codecs.encode(data, 'hex'))
         if handle in self._callbacks:
-            self._callbacks[handle](data)
+            for callback in self._callbacks[handle]:
+                callback(data)
 
     @property
     def mac(self):
@@ -63,7 +88,9 @@ def mac(self):
 
     def set_callback(self, handle, function):
         """Set the callback for a Notification handle. It will be called with the parameter data, which is binary."""
-        self._callbacks[handle] = function
+        if handle not in self._callbacks:
+            self._callbacks[handle] = []
+        self._callbacks[handle].append(function)
 
     def make_request(self, handle, value, timeout=DEFAULT_TIMEOUT, with_response=True):
         """Write a GATT Command without callback - not utf-8."""
diff --git a/eq3bt/eq3btsmart.py b/eq3bt/eq3btsmart.py
index b510ce4..984245c 100644
--- a/eq3bt/eq3btsmart.py
+++ b/eq3bt/eq3btsmart.py
@@ -71,7 +71,7 @@ class TemperatureException(Exception):
 class Thermostat:
     """Representation of a EQ3 Bluetooth Smart thermostat."""
 
-    def __init__(self, _mac, connection_cls=BTLEConnection):
+    def __init__(self, _mac, connection_cls=BTLEConnection, iface=None):
         """Initialize the thermostat."""
 
         self._target_temperature = Mode.Unknown
@@ -94,7 +94,7 @@ def __init__(self, _mac, connection_cls=BTLEConnection):
         self._firmware_version = None
         self._device_serial = None
 
-        self._conn = connection_cls(_mac)
+        self._conn = connection_cls(_mac, iface)
         self._conn.set_callback(PROP_NTFY_HANDLE, self.handle_notification)
 
     def __str__(self):
@@ -107,6 +107,12 @@ def __str__(self):
                                                         self.mode_readable,
                                                         away_end)
 
+    def connect(self, iface):
+        self._conn.connect(iface)
+
+    def disconnect(self):
+        self._conn.disconnect()
+
     def _verify_temperature(self, temp):
         """Verifies that the temperature is valid.
             :raises TemperatureException: On invalid temperature.
diff --git a/eq3bt/eq3cli.py b/eq3bt/eq3cli.py
index 5801083..7d30ba7 100644
--- a/eq3bt/eq3cli.py
+++ b/eq3bt/eq3cli.py
@@ -21,16 +21,17 @@ def validate_mac(ctx, param, mac):
 
 @click.group(invoke_without_command=True)
 @click.option('--mac', envvar="EQ3_MAC", required=True, callback=validate_mac)
+@click.option('--interface', default=None)
 @click.option('--debug/--normal', default=False)
 @click.pass_context
-def cli(ctx, mac, debug):
+def cli(ctx, mac, interface, debug):
     """ Tool to query and modify the state of EQ3 BT smart thermostat. """
     if debug:
         logging.basicConfig(level=logging.DEBUG)
     else:
         logging.basicConfig(level=logging.INFO)
 
-    thermostat = Thermostat(mac)
+    thermostat = Thermostat(mac, iface=interface)
     thermostat.update()
     ctx.obj = thermostat