"""
A simple wrapper for bluepy's btle.Connection.
Handles Connection duties (reconnecting etc.) transparently.
"""
import logging
import codecs
from bluepy import btle
DEFAULT_TIMEOUT = 1
_LOGGER = logging.getLogger(__name__)
class BTLEConnection(btle.DefaultDelegate):
"""Representation of a BTLE Connection."""
def __init__(self, mac):
"""Initialize the connection."""
btle.DefaultDelegate.__init__(self)
self._conn = None
self._mac = mac
self._callbacks = {}
def __enter__(self):
"""
Context manager __enter__ for connecting the device
: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)
try:
self._conn.connect(self._mac)
except Exception as ex2:
_LOGGER.debug("Second connection try to %s failed: %s", self._mac, ex2)
raise
_LOGGER.debug("Connected to %s", self._mac)
return self
def __exit__(self, exc_type, exc_val, exc_tb):
if self._conn:
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)
@property
def mac(self):
"""Return the MAC address of the connected device."""
return self._mac
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
def make_request(self, handle, value, timeout=DEFAULT_TIMEOUT, with_response=True):
"""Write a GATT Command without callback - not utf-8."""
try:
with self:
_LOGGER.debug("Writing %s to %s with with_response=%s", codecs.encode(value, 'hex'), handle, with_response)
self._conn.writeCharacteristic(handle, value, withResponse=with_response)
if timeout:
_LOGGER.debug("Waiting for notifications for %s", timeout)
self._conn.waitForNotifications(timeout)
except btle.BTLEException as ex:
_LOGGER.debug("Got exception from bluepy while making a request: %s", ex)
raise
