96 lines
3.1 KiB
Python
96 lines
3.1 KiB
Python
"""
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A simple wrapper for bluepy's btle.Connection.
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Handles Connection duties (reconnecting etc.) transparently.
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"""
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import codecs
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import logging
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from bluepy import btle
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from . import BackendException
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DEFAULT_TIMEOUT = 1
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_LOGGER = logging.getLogger(__name__)
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class BTLEConnection(btle.DefaultDelegate):
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"""Representation of a BTLE Connection."""
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def __init__(self, mac, iface):
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"""Initialize the connection."""
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btle.DefaultDelegate.__init__(self)
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self._conn = None
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self._mac = mac
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self._iface = iface
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self._callbacks = {}
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def __enter__(self):
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"""
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Context manager __enter__ for connecting the device
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:rtype: btle.Peripheral
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:return:
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"""
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self._conn = btle.Peripheral()
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self._conn.withDelegate(self)
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_LOGGER.debug("Trying to connect to %s", self._mac)
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try:
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self._conn.connect(self._mac, iface=self._iface)
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except btle.BTLEException as ex:
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_LOGGER.debug(
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"Unable to connect to the device %s, retrying: %s", self._mac, ex
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)
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try:
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self._conn.connect(self._mac, iface=self._iface)
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except Exception as ex2:
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_LOGGER.debug("Second connection try to %s failed: %s", self._mac, ex2)
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raise BackendException(
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"Unable to connect to device using bluepy"
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) from ex2
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_LOGGER.debug("Connected to %s", self._mac)
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return self
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def __exit__(self, exc_type, exc_val, exc_tb):
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if self._conn:
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self._conn.disconnect()
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self._conn = None
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def handleNotification(self, handle, data):
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"""Handle Callback from a Bluetooth (GATT) request."""
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_LOGGER.debug(
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"Got notification from %s: %s", handle, codecs.encode(data, "hex")
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)
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if handle in self._callbacks:
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self._callbacks[handle](data)
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@property
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def mac(self):
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"""Return the MAC address of the connected device."""
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return self._mac
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def set_callback(self, handle, function):
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"""Set the callback for a Notification handle. It will be called with the parameter data, which is binary."""
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self._callbacks[handle] = function
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def make_request(self, handle, value, timeout=DEFAULT_TIMEOUT, with_response=True):
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"""Write a GATT Command without callback - not utf-8."""
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try:
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with self:
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_LOGGER.debug(
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"Writing %s to %s with with_response=%s",
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codecs.encode(value, "hex"),
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handle,
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with_response,
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)
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self._conn.writeCharacteristic(
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handle, value, withResponse=with_response
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)
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if timeout:
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_LOGGER.debug("Waiting for notifications for %s", timeout)
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self._conn.waitForNotifications(timeout)
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except btle.BTLEException as ex:
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_LOGGER.debug("Got exception from bluepy while making a request: %s", ex)
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raise BackendException("Exception on write using bluepy") from ex
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