Files
python/meshtastic/ble_interface.py
2024-03-19 13:18:15 -07:00

237 lines
8.0 KiB
Python

"""Bluetooth interface
"""
import logging
import time
import struct
import asyncio
from threading import Thread, Event
from bleak import BleakScanner, BleakClient
from meshtastic.mesh_interface import MeshInterface
from meshtastic.util import our_exit
SERVICE_UUID = "6ba1b218-15a8-461f-9fa8-5dcae273eafd"
TORADIO_UUID = "f75c76d2-129e-4dad-a1dd-7866124401e7"
FROMRADIO_UUID = "2c55e69e-4993-11ed-b878-0242ac120002"
FROMNUM_UUID = "ed9da18c-a800-4f66-a670-aa7547e34453"
class BLEInterface(MeshInterface):
"""MeshInterface using BLE to connect to devices"""
class BLEError(Exception):
"""An exception class for BLE errors"""
def __init__(self, message):
self.message = message
super().__init__(self.message)
class BLEState(): # pylint: disable=C0115
THREADS = False
BLE = False
MESH = False
def __init__(self, address, noProto = False, debugOut = None):
self.state = BLEInterface.BLEState()
if not address:
return
self.should_read = False
logging.debug("Threads starting")
self._receiveThread = Thread(target = self._receiveFromRadioImpl)
self._receiveThread_started = Event()
self._receiveThread_stopped = Event()
self._receiveThread.start()
self._receiveThread_started.wait(1)
self.state.THREADS = True
logging.debug("Threads running")
try:
logging.debug(f"BLE connecting to: {address}")
self.client = self.connect(address)
self.state.BLE = True
logging.debug("BLE connected")
except BLEInterface.BLEError as e:
self.close()
our_exit(e.message, 1)
return
logging.debug("Mesh init starting")
MeshInterface.__init__(self, debugOut = debugOut, noProto = noProto)
self._startConfig()
if not self.noProto:
self._waitConnected(timeout = 60.0)
self.waitForConfig()
self.state.MESH = True
logging.debug("Mesh init finished")
logging.debug("Register FROMNUM notify callback")
self.client.start_notify(FROMNUM_UUID, self.from_num_handler)
async def from_num_handler(self, _, b): # pylint: disable=C0116
from_num = struct.unpack('<I', bytes(b))[0]
logging.debug(f"FROMNUM notify: {from_num}")
self.should_read = True
def scan(self):
"Scan for available BLE devices"
with BLEClient() as client:
return [
(x[0], x[1]) for x in (client.discover(
return_adv = True,
service_uuids = [ SERVICE_UUID ]
)).values()
]
def find_device(self, address):
"Find a device by address"
meshtastic_devices = self.scan()
addressed_devices = list(filter(lambda x: address in (x[1].local_name, x[0].name), meshtastic_devices))
# If nothing is found try on the address
if len(addressed_devices) == 0:
addressed_devices = list(filter(
lambda x: BLEInterface._sanitize_address(address) == BLEInterface._sanitize_address(x[0].address),
meshtastic_devices))
if len(addressed_devices) == 0:
raise BLEInterface.BLEError(f"No Meshtastic BLE peripheral with identifier or address '{address}' found. Try --ble-scan to find it.")
if len(addressed_devices) > 1:
raise BLEInterface.BLEError(f"More than one Meshtastic BLE peripheral with identifier or address '{address}' found.")
return addressed_devices[0][0]
def _sanitize_address(address): # pylint: disable=E0213
"Standardize BLE address by removing extraneous characters and lowercasing"
return address \
.replace("-", "") \
.replace("_", "") \
.replace(":", "") \
.lower()
def connect(self, address):
"Connect to a device by address"
device = self.find_device(address)
client = BLEClient(device.address)
client.connect()
try:
client.pair()
except NotImplementedError:
# Some bluetooth backends do not require explicit pairing.
# See Bleak docs for details on this.
pass
return client
def _receiveFromRadioImpl(self):
self._receiveThread_started.set()
while self._receiveThread_started.is_set():
if self.should_read:
self.should_read = False
retries = 0
while True:
b = bytes(self.client.read_gatt_char(FROMRADIO_UUID))
if not b:
if retries < 5:
time.sleep(0.1)
retries += 1
continue
break
logging.debug(f"FROMRADIO read: {b.hex()}")
self._handleFromRadio(b)
else:
time.sleep(0.1)
self._receiveThread_stopped.set()
def _sendToRadioImpl(self, toRadio):
b = toRadio.SerializeToString()
if b:
logging.debug(f"TORADIO write: {b.hex()}")
self.client.write_gatt_char(TORADIO_UUID, b, response = True)
# Allow to propagate and then make sure we read
time.sleep(0.1)
self.should_read = True
def close(self):
if self.state.MESH:
MeshInterface.close(self)
if self.state.THREADS:
self._receiveThread_started.clear()
self._receiveThread_stopped.wait(5)
if self.state.BLE:
self.client.disconnect()
self.client.close()
class BLEClient():
"""Client for managing connection to a BLE device"""
def __init__(self, address = None, **kwargs):
self._eventThread = Thread(target = self._run_event_loop)
self._eventThread_started = Event()
self._eventThread_stopped = Event()
self._eventThread.start()
self._eventThread_started.wait(1)
if not address:
logging.debug("No address provided - only discover method will work.")
return
self.bleak_client = BleakClient(address, **kwargs)
def discover(self, **kwargs): # pylint: disable=C0116
return self.async_await(BleakScanner.discover(**kwargs))
def pair(self, **kwargs): # pylint: disable=C0116
return self.async_await(self.bleak_client.pair(**kwargs))
def connect(self, **kwargs): # pylint: disable=C0116
return self.async_await(self.bleak_client.connect(**kwargs))
def disconnect(self, **kwargs): # pylint: disable=C0116
self.async_await(self.bleak_client.disconnect(**kwargs))
def read_gatt_char(self, *args, **kwargs): # pylint: disable=C0116
return self.async_await(self.bleak_client.read_gatt_char(*args, **kwargs))
def write_gatt_char(self, *args, **kwargs): # pylint: disable=C0116
self.async_await(self.bleak_client.write_gatt_char(*args, **kwargs))
def start_notify(self, *args, **kwargs): # pylint: disable=C0116
self.async_await(self.bleak_client.start_notify(*args, **kwargs))
def close(self): # pylint: disable=C0116
self.async_run(self._stop_event_loop())
self._eventThread_stopped.wait(5)
def __enter__(self):
return self
def __exit__(self, _type, _value, _traceback):
self.close()
def async_await(self, coro, timeout = None): # pylint: disable=C0116
return self.async_run(coro).result(timeout)
def async_run(self, coro): # pylint: disable=C0116
return asyncio.run_coroutine_threadsafe(coro, self._eventLoop)
def _run_event_loop(self):
# I don't know if the event loop can be initialized in __init__ so silencing pylint
self._eventLoop = asyncio.new_event_loop() # pylint: disable=W0201
self._eventThread_started.set()
try:
self._eventLoop.run_forever()
finally:
self._eventLoop.close()
self._eventThread_stopped.set()
async def _stop_event_loop(self):
self._eventLoop.stop()