#!/usr/bin/env python # # Copyright 2019 Espressif Systems (Shanghai) PTE LTD # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # DBus-Bluez BLE library from __future__ import print_function import sys import time import traceback try: from future.moves.itertools import zip_longest import dbus import dbus.mainloop.glib from gi.repository import GLib except ImportError as e: if 'linux' not in sys.platform: raise e print(e) print("Install packages `libgirepository1.0-dev gir1.2-gtk-3.0 libcairo2-dev libdbus-1-dev libdbus-glib-1-dev` for resolving the issue") print("Run `pip install -r $IDF_PATH/tools/ble/requirements.txt` for resolving the issue") raise import lib_gatt import lib_gap srv_added_old_cnt = 0 srv_added_new_cnt = 0 verify_signal_check = 0 blecent_retry_check_cnt = 0 verify_service_cnt = 0 verify_readchars_cnt = 0 blecent_adv_uuid = '1811' gatt_app_obj_check = False gatt_app_reg_check = False adv_data_check = False adv_reg_check = False read_req_check = False write_req_check = False subscribe_req_check = False ble_hr_chrc = False DISCOVERY_START = False SIGNAL_CAUGHT = False TEST_CHECKS_PASS = False ADV_STOP = False SERVICES_RESOLVED = False SERVICE_UUID_FOUND = False BLUEZ_SERVICE_NAME = 'org.bluez' DBUS_OM_IFACE = 'org.freedesktop.DBus.ObjectManager' DBUS_PROP_IFACE = 'org.freedesktop.DBus.Properties' ADAPTER_IFACE = 'org.bluez.Adapter1' DEVICE_IFACE = 'org.bluez.Device1' GATT_MANAGER_IFACE = 'org.bluez.GattManager1' LE_ADVERTISING_MANAGER_IFACE = 'org.bluez.LEAdvertisingManager1' GATT_SERVICE_IFACE = 'org.bluez.GattService1' GATT_CHRC_IFACE = 'org.bluez.GattCharacteristic1' ADAPTER_ON = False DEVICE_CONNECTED = False GATT_APP_REGISTERED = False ADV_REGISTERED = False ADV_ACTIVE_INSTANCE = False CHRC_VALUE_CNT = False # Set up the main loop. dbus.mainloop.glib.DBusGMainLoop(set_as_default=True) dbus.mainloop.glib.threads_init() # Set up the event main loop. event_loop = GLib.MainLoop() def verify_signal_is_caught(): global verify_signal_check verify_signal_check += 1 if (not SIGNAL_CAUGHT and verify_signal_check == 15) or (SIGNAL_CAUGHT): if event_loop.is_running(): event_loop.quit() return False # polling for checks will stop return True # polling will continue def set_props_status(props): """ Set Adapter status if it is powered on or off """ global ADAPTER_ON, SERVICES_RESOLVED, GATT_OBJ_REMOVED, GATT_APP_REGISTERED, \ ADV_REGISTERED, ADV_ACTIVE_INSTANCE, DEVICE_CONNECTED, CHRC_VALUE, CHRC_VALUE_CNT, \ SIGNAL_CAUGHT is_service_uuid = False # Signal caught for change in Adapter Powered property if 'Powered' in props: if props['Powered'] == 1: SIGNAL_CAUGHT = True ADAPTER_ON = True else: SIGNAL_CAUGHT = True ADAPTER_ON = False if 'ServicesResolved' in props: if props['ServicesResolved'] == 1: SIGNAL_CAUGHT = True SERVICES_RESOLVED = True else: SIGNAL_CAUGHT = True SERVICES_RESOLVED = False if 'UUIDs' in props: # Signal caught for add/remove GATT data having service uuid for uuid in props['UUIDs']: if blecent_adv_uuid in uuid: is_service_uuid = True if not is_service_uuid: # Signal caught for removing GATT data having service uuid # and for unregistering GATT application GATT_APP_REGISTERED = False lib_gatt.GATT_APP_OBJ = False if 'ActiveInstances' in props: # Signal caught for Advertising - add/remove Instances property if props['ActiveInstances'] == 1: ADV_ACTIVE_INSTANCE = True elif props['ActiveInstances'] == 0: ADV_ACTIVE_INSTANCE = False ADV_REGISTERED = False lib_gap.ADV_OBJ = False if 'Connected' in props: # Signal caught for device connect/disconnect if props['Connected'] == 1: SIGNAL_CAUGHT = True DEVICE_CONNECTED = True else: SIGNAL_CAUGHT = True DEVICE_CONNECTED = False if 'Value' in props: # Signal caught for change in chars value if ble_hr_chrc: CHRC_VALUE_CNT += 1 print(props['Value']) if CHRC_VALUE_CNT == 10: SIGNAL_CAUGHT = True return False return False def props_change_handler(iface, changed_props, invalidated): """ PropertiesChanged Signal handler. Catch and print information about PropertiesChanged signal. """ if iface == ADAPTER_IFACE: set_props_status(changed_props) if iface == LE_ADVERTISING_MANAGER_IFACE: set_props_status(changed_props) if iface == DEVICE_IFACE: set_props_status(changed_props) if iface == GATT_CHRC_IFACE: set_props_status(changed_props) class BLE_Bluez_Client: def __init__(self, iface, devname=None, devaddr=None): self.bus = None self.device = None self.devname = devname self.devaddr = devaddr self.iface = iface self.ble_objs = None self.props_iface_obj = None self.adapter_path = [] self.adapter = None self.services = [] self.srv_uuid = [] self.chars = {} self.char_uuid = [] try: self.bus = dbus.SystemBus() om_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, "/"), DBUS_OM_IFACE) self.ble_objs = om_iface_obj.GetManagedObjects() except Exception as e: print(e) def __del__(self): try: print("Test Exit") except Exception as e: print(e) sys.exit(1) def set_adapter(self): ''' Discover Bluetooth Adapter Power On Bluetooth Adapter ''' global verify_signal_check, SIGNAL_CAUGHT, ADAPTER_ON verify_signal_check = 0 ADAPTER_ON = False try: print("discovering adapter...") for path, interfaces in self.ble_objs.items(): adapter = interfaces.get(ADAPTER_IFACE) if adapter is not None: if path.endswith(self.iface): self.adapter = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, path), ADAPTER_IFACE) # Create Properties Interface object only after adapter is found self.props_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, path), DBUS_PROP_IFACE) self.adapter_path = [path, interfaces] # Check adapter status - power on/off set_props_status(interfaces[ADAPTER_IFACE]) break if self.adapter is None: raise Exception("Bluetooth adapter not found") if self.props_iface_obj is None: raise Exception("Properties interface not found") print("bluetooth adapter discovered") # Check if adapter is already powered on if ADAPTER_ON: print("Adapter already powered on") return True # Power On Adapter print("powering on adapter...") self.props_iface_obj.connect_to_signal('PropertiesChanged', props_change_handler) self.props_iface_obj.Set(ADAPTER_IFACE, "Powered", dbus.Boolean(1)) SIGNAL_CAUGHT = False GLib.timeout_add_seconds(5, verify_signal_is_caught) event_loop.run() if ADAPTER_ON: print("bluetooth adapter powered on") return True else: raise Exception("Failure: bluetooth adapter not powered on") except Exception: print(traceback.format_exc()) return False def connect(self): ''' Connect to the device discovered Retry 10 times to discover and connect to device ''' global DISCOVERY_START, SIGNAL_CAUGHT, DEVICE_CONNECTED, verify_signal_check device_found = False DEVICE_CONNECTED = False try: self.adapter.StartDiscovery() print("\nStarted Discovery") DISCOVERY_START = True for retry_cnt in range(10,0,-1): verify_signal_check = 0 try: if self.device is None: print("\nConnecting to device...") # Wait for device to be discovered time.sleep(5) device_found = self.get_device() if device_found: self.device.Connect(dbus_interface=DEVICE_IFACE) time.sleep(15) SIGNAL_CAUGHT = False GLib.timeout_add_seconds(5, verify_signal_is_caught) event_loop.run() if DEVICE_CONNECTED: print("\nConnected to device") return True else: raise Exception except Exception as e: print(e) print("\nRetries left", retry_cnt - 1) continue # Device not found return False except Exception: print(traceback.format_exc()) self.device = None return False def get_device(self): ''' Discover device based on device name and device address and connect ''' dev_path = None om_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, "/"), DBUS_OM_IFACE) self.ble_objs = om_iface_obj.GetManagedObjects() for path, interfaces in self.ble_objs.items(): if DEVICE_IFACE not in interfaces.keys(): continue device_addr_iface = (path.replace('_', ':')).lower() dev_addr = self.devaddr.lower() if dev_addr in device_addr_iface and \ interfaces[DEVICE_IFACE].get("Name") == self.devname: dev_path = path break if dev_path is None: raise Exception("\nBLE device not found") device_props_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, dev_path), DBUS_PROP_IFACE) device_props_iface_obj.connect_to_signal('PropertiesChanged', props_change_handler) self.device = self.bus.get_object(BLUEZ_SERVICE_NAME, dev_path) return True def srvc_iface_added_handler(self, path, interfaces): ''' Add services found as lib_ble_client obj ''' if self.device and path.startswith(self.device.object_path): if GATT_SERVICE_IFACE in interfaces.keys(): service = self.bus.get_object(BLUEZ_SERVICE_NAME, path) uuid = service.Get(GATT_SERVICE_IFACE, 'UUID', dbus_interface=DBUS_PROP_IFACE) if uuid not in self.srv_uuid: self.srv_uuid.append(uuid) if path not in self.services: self.services.append(path) def verify_service_uuid_found(self, service_uuid): ''' Verify service uuid found ''' global SERVICE_UUID_FOUND srv_uuid_found = [uuid for uuid in self.srv_uuid if service_uuid in uuid] if srv_uuid_found: SERVICE_UUID_FOUND = True def get_services(self, service_uuid=None): ''' Retrieve Services found in the device connected ''' global SIGNAL_CAUGHT, SERVICE_UUID_FOUND, SERVICES_RESOLVED, verify_signal_check verify_signal_check = 0 SERVICE_UUID_FOUND = False SERVICES_RESOLVED = False SIGNAL_CAUGHT = False try: om_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, "/"), DBUS_OM_IFACE) self.ble_objs = om_iface_obj.GetManagedObjects() for path, interfaces in self.ble_objs.items(): self.srvc_iface_added_handler(path, interfaces) # If services not found, then they may not have been added yet on dbus if not self.services: GLib.timeout_add_seconds(5, verify_signal_is_caught) om_iface_obj.connect_to_signal('InterfacesAdded', self.srvc_iface_added_handler) event_loop.run() if not SERVICES_RESOLVED: raise Exception("Services not found...") if service_uuid: self.verify_service_uuid_found(service_uuid) if not SERVICE_UUID_FOUND: raise Exception("Service with uuid: %s not found..." % service_uuid) # Services found return self.srv_uuid except Exception: print(traceback.format_exc()) return False def chrc_iface_added_handler(self, path, interfaces): ''' Add services found as lib_ble_client obj ''' global chrc, chrc_discovered, SIGNAL_CAUGHT chrc_val = None if self.device and path.startswith(self.device.object_path): if GATT_CHRC_IFACE in interfaces.keys(): chrc = self.bus.get_object(BLUEZ_SERVICE_NAME, path) chrc_props = chrc.GetAll(GATT_CHRC_IFACE, dbus_interface=DBUS_PROP_IFACE) chrc_flags = chrc_props['Flags'] if 'read' in chrc_flags: chrc_val = chrc.ReadValue({}, dbus_interface=GATT_CHRC_IFACE) uuid = chrc_props['UUID'] self.chars[path] = chrc_val, chrc_flags, uuid SIGNAL_CAUGHT = True def read_chars(self): ''' Read characteristics found in the device connected ''' global iface_added, chrc_discovered, SIGNAL_CAUGHT, verify_signal_check verify_signal_check = 0 chrc_discovered = False iface_added = False SIGNAL_CAUGHT = False try: om_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, "/"), DBUS_OM_IFACE) self.ble_objs = om_iface_obj.GetManagedObjects() for path, interfaces in self.ble_objs.items(): self.chrc_iface_added_handler(path, interfaces) # If chars not found, then they have not been added yet to interface time.sleep(15) if not self.chars: iface_added = True GLib.timeout_add_seconds(5, verify_signal_is_caught) om_iface_obj.connect_to_signal('InterfacesAdded', self.chars_iface_added_handler) event_loop.run() return self.chars except Exception: print(traceback.format_exc()) return False def write_chars(self, write_val): ''' Write characteristics to the device connected ''' chrc = None chrc_val = None char_write_props = False try: for path, props in self.chars.items(): if 'write' in props[1]: # check permission char_write_props = True chrc = self.bus.get_object(BLUEZ_SERVICE_NAME, path) chrc.WriteValue(write_val,{},dbus_interface=GATT_CHRC_IFACE) if 'read' in props[1]: chrc_val = chrc.ReadValue({}, dbus_interface=GATT_CHRC_IFACE) else: print("Warning: Cannot read value. Characteristic does not have read permission.") if not (ord(write_val) == int(chrc_val[0])): print("\nWrite Failed") return False self.chars[path] = chrc_val, props[1], props[2] # update value if not char_write_props: raise Exception("Failure: Cannot perform write operation. Characteristic does not have write permission.") return self.chars except Exception: print(traceback.format_exc()) return False def hr_update_simulation(self, hr_srv_uuid, hr_char_uuid): ''' Start Notifications Retrieve updated value Stop Notifications ''' global ble_hr_chrc, verify_signal_check, SIGNAL_CAUGHT, CHRC_VALUE_CNT srv_path = None chrc = None uuid = None chrc_path = None chars_ret = None ble_hr_chrc = True CHRC_VALUE_CNT = 0 try: # Get HR Measurement characteristic services = list(zip_longest(self.srv_uuid, self.services)) for uuid, path in services: if hr_srv_uuid in uuid: srv_path = path break if srv_path is None: raise Exception("Failure: HR UUID:", hr_srv_uuid, "not found") chars_ret = self.read_chars() for path, props in chars_ret.items(): if path.startswith(srv_path): chrc = self.bus.get_object(BLUEZ_SERVICE_NAME, path) chrc_path = path if hr_char_uuid in props[2]: # uuid break if chrc is None: raise Exception("Failure: Characteristics for service: ", srv_path, "not found") # Subscribe to notifications print("\nSubscribe to notifications: On") chrc.StartNotify(dbus_interface=GATT_CHRC_IFACE) chrc_props_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, chrc_path), DBUS_PROP_IFACE) chrc_props_iface_obj.connect_to_signal('PropertiesChanged', props_change_handler) SIGNAL_CAUGHT = False verify_signal_check = 0 GLib.timeout_add_seconds(5, verify_signal_is_caught) event_loop.run() chrc.StopNotify(dbus_interface=GATT_CHRC_IFACE) time.sleep(2) print("\nSubscribe to notifications: Off") ble_hr_chrc = False return True except Exception: print(traceback.format_exc()) return False def create_gatt_app(self): ''' Create GATT data Register GATT Application ''' global gatt_app_obj, gatt_manager_iface_obj, GATT_APP_REGISTERED gatt_app_obj = None gatt_manager_iface_obj = None GATT_APP_REGISTERED = False lib_gatt.GATT_APP_OBJ = False try: gatt_app_obj = lib_gatt.Application(self.bus, self.adapter_path[0]) gatt_manager_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME,self.adapter_path[0]), GATT_MANAGER_IFACE) gatt_manager_iface_obj.RegisterApplication(gatt_app_obj, {}, reply_handler=self.gatt_app_handler, error_handler=self.gatt_app_error_handler) return True except Exception: print(traceback.format_exc()) return False def gatt_app_handler(self): ''' GATT Application Register success handler ''' global GATT_APP_REGISTERED GATT_APP_REGISTERED = True def gatt_app_error_handler(self, error): ''' GATT Application Register error handler ''' global GATT_APP_REGISTERED GATT_APP_REGISTERED = False def start_advertising(self, adv_host_name, adv_iface_index, adv_type, adv_uuid): ''' Create Advertising data Register Advertisement Start Advertising ''' global le_adv_obj, le_adv_manager_iface_obj, ADV_ACTIVE_INSTANCE, ADV_REGISTERED le_adv_obj = None le_adv_manager_iface_obj = None le_adv_iface_path = None ADV_ACTIVE_INSTANCE = False ADV_REGISTERED = False lib_gap.ADV_OBJ = False try: print("Advertising started") gatt_app_ret = self.create_gatt_app() if not gatt_app_ret: raise Exception for path,interface in self.ble_objs.items(): if LE_ADVERTISING_MANAGER_IFACE in interface: le_adv_iface_path = path if le_adv_iface_path is None: raise Exception('\n Cannot start advertising. LEAdvertisingManager1 Interface not found') le_adv_obj = lib_gap.Advertisement(self.bus, adv_iface_index, adv_type, adv_uuid, adv_host_name) le_adv_manager_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, le_adv_iface_path), LE_ADVERTISING_MANAGER_IFACE) le_adv_manager_iface_obj.RegisterAdvertisement(le_adv_obj.get_path(), {}, reply_handler=self.adv_handler, error_handler=self.adv_error_handler) GLib.timeout_add_seconds(2, self.verify_blecent) event_loop.run() if TEST_CHECKS_PASS: return True else: raise Exception except Exception: print(traceback.format_exc()) return False def adv_handler(self): ''' Advertisement Register success handler ''' global ADV_REGISTERED ADV_REGISTERED = True def adv_error_handler(self, error): ''' Advertisement Register error handler ''' global ADV_REGISTERED ADV_REGISTERED = False def verify_blecent(self): """ Verify blecent test commands are successful """ global blecent_retry_check_cnt, gatt_app_obj_check, gatt_app_reg_check,\ adv_data_check, adv_reg_check, read_req_check, write_req_check,\ subscribe_req_check, TEST_CHECKS_PASS # Get device when connected if not self.device: om_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, "/"), DBUS_OM_IFACE) self.ble_objs = om_iface_obj.GetManagedObjects() for path, interfaces in self.ble_objs.items(): if DEVICE_IFACE not in interfaces.keys(): continue device_props_iface_obj = dbus.Interface(self.bus.get_object(BLUEZ_SERVICE_NAME, path), DBUS_PROP_IFACE) device_props_iface_obj.connect_to_signal('PropertiesChanged', props_change_handler) self.device = self.bus.get_object(BLUEZ_SERVICE_NAME, path) # Check for failures after 10 retries if blecent_retry_check_cnt == 10: # check for failures if not gatt_app_obj_check: print("Failure: GATT Data could not be created") if not gatt_app_reg_check: print("Failure: GATT Application could not be registered") if not adv_data_check: print("Failure: Advertising data could not be created") if not adv_reg_check: print("Failure: Advertisement could not be registered") if not read_req_check: print("Failure: Read Request not received") if not write_req_check: print("Failure: Write Request not received") if not subscribe_req_check: print("Failure: Subscribe Request not received") # Blecent Test failed TEST_CHECKS_PASS = False if subscribe_req_check: lib_gatt.alert_status_char_obj.StopNotify() else: # Check for success if not gatt_app_obj_check and lib_gatt.GATT_APP_OBJ: print("GATT Data created") gatt_app_obj_check = True if not gatt_app_reg_check and GATT_APP_REGISTERED: print("GATT Application registered") gatt_app_reg_check = True if not adv_data_check and lib_gap.ADV_OBJ: print("Advertising data created") adv_data_check = True if not adv_reg_check and ADV_REGISTERED and ADV_ACTIVE_INSTANCE: print("Advertisement registered") adv_reg_check = True if not read_req_check and lib_gatt.CHAR_READ: read_req_check = True if not write_req_check and lib_gatt.CHAR_WRITE: write_req_check = True if not subscribe_req_check and lib_gatt.CHAR_SUBSCRIBE: subscribe_req_check = True if read_req_check and write_req_check and subscribe_req_check: # all checks passed # Blecent Test passed TEST_CHECKS_PASS = True lib_gatt.alert_status_char_obj.StopNotify() if (blecent_retry_check_cnt == 10 or TEST_CHECKS_PASS): if event_loop.is_running(): event_loop.quit() return False # polling for checks will stop # Increment retry count blecent_retry_check_cnt += 1 # Default return True - polling for checks will continue return True def verify_blecent_disconnect(self): """ Verify cleanup is successful """ global blecent_retry_check_cnt, gatt_app_obj_check, gatt_app_reg_check,\ adv_data_check, adv_reg_check, ADV_STOP if blecent_retry_check_cnt == 0: gatt_app_obj_check = False gatt_app_reg_check = False adv_data_check = False adv_reg_check = False # Check for failures after 10 retries if blecent_retry_check_cnt == 10: # check for failures if not gatt_app_obj_check: print("Warning: GATT Data could not be removed") if not gatt_app_reg_check: print("Warning: GATT Application could not be unregistered") if not adv_data_check: print("Warning: Advertising data could not be removed") if not adv_reg_check: print("Warning: Advertisement could not be unregistered") # Blecent Test failed ADV_STOP = False else: # Check for success if not gatt_app_obj_check and not lib_gatt.GATT_APP_OBJ: print("GATT Data removed") gatt_app_obj_check = True if not gatt_app_reg_check and not GATT_APP_REGISTERED: print("GATT Application unregistered") gatt_app_reg_check = True if not adv_data_check and not adv_reg_check and not (ADV_REGISTERED or ADV_ACTIVE_INSTANCE or lib_gap.ADV_OBJ): print("Advertising data removed") print("Advertisement unregistered") adv_data_check = True adv_reg_check = True # all checks passed ADV_STOP = True if (blecent_retry_check_cnt == 10 or ADV_STOP): if event_loop.is_running(): event_loop.quit() return False # polling for checks will stop # Increment retry count blecent_retry_check_cnt += 1 # Default return True - polling for checks will continue return True def disconnect(self): ''' Before application exits: Advertisement is unregistered Advertisement object created is removed from dbus GATT Application is unregistered GATT Application object created is removed from dbus Disconnect device if connected Adapter is powered off ''' try: global blecent_retry_check_cnt, DISCOVERY_START, verify_signal_check, SIGNAL_CAUGHT blecent_retry_check_cnt = 0 verify_signal_check = 0 print("\nexiting from test...") self.props_iface_obj.connect_to_signal('PropertiesChanged', props_change_handler) if ADV_REGISTERED: # Unregister Advertisement le_adv_manager_iface_obj.UnregisterAdvertisement(le_adv_obj.get_path()) # Remove Advertising data dbus.service.Object.remove_from_connection(le_adv_obj) if GATT_APP_REGISTERED: # Unregister GATT Application gatt_manager_iface_obj.UnregisterApplication(gatt_app_obj.get_path()) # Remove GATT data dbus.service.Object.remove_from_connection(gatt_app_obj) GLib.timeout_add_seconds(5, self.verify_blecent_disconnect) event_loop.run() if ADV_STOP: print("Stop Advertising status: ", ADV_STOP) else: print("Warning: Stop Advertising status: ", ADV_STOP) # Disconnect device if self.device: print("disconnecting device...") self.device.Disconnect(dbus_interface=DEVICE_IFACE) if self.adapter: self.adapter.RemoveDevice(self.device) self.device = None if DISCOVERY_START: self.adapter.StopDiscovery() DISCOVERY_START = False time.sleep(15) SIGNAL_CAUGHT = False GLib.timeout_add_seconds(5, verify_signal_is_caught) event_loop.run() if not DEVICE_CONNECTED: print("device disconnected") else: print("Warning: device could not be disconnected") except Exception: print(traceback.format_exc()) return False