List of changes: * Retrieve UUID property from Bluez device object before connecting to retrieve UUID contained in advertisement * Read Characteristic User Descriptions attribute of each UUID for mapping endpoint names * To support older implementations with hardcoded Name-UUID map, revert to fallback mode in order if advertisement data has no UUID field
67 lines
2.7 KiB
Python
67 lines
2.7 KiB
Python
# Copyright 2018 Espressif Systems (Shanghai) PTE LTD
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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#
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from __future__ import print_function
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from .transport import Transport
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from . import ble_cli
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class Transport_BLE(Transport):
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def __init__(self, devname, service_uuid, nu_lookup):
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# Expect service UUID like '0000ffff-0000-1000-8000-00805f9b34fb'
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for name in nu_lookup.keys():
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# Calculate characteristic UUID for each endpoint
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nu_lookup[name] = service_uuid[:4] + '{:02x}'.format(
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int(nu_lookup[name], 16) & int(service_uuid[4:8], 16)) + service_uuid[8:]
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# Get BLE client module
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self.cli = ble_cli.get_client()
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# Use client to connect to BLE device and bind to service
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if not self.cli.connect(devname=devname, iface='hci0',
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chrc_names=nu_lookup.keys(),
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fallback_srv_uuid=service_uuid):
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raise RuntimeError("Failed to initialize transport")
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# Irrespective of provided parameters, let the client
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# generate a lookup table by reading advertisement data
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# and characteristic user descriptors
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self.name_uuid_lookup = self.cli.get_nu_lookup()
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# If that doesn't work, use the lookup table provided as parameter
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if self.name_uuid_lookup is None:
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self.name_uuid_lookup = nu_lookup
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# Check if expected characteristics are provided by the service
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for name in self.name_uuid_lookup.keys():
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if not self.cli.has_characteristic(self.name_uuid_lookup[name]):
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raise RuntimeError("'" + name + "' endpoint not found")
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def __del__(self):
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# Make sure device is disconnected before application gets closed
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try:
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self.disconnect()
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except Exception:
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pass
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def disconnect(self):
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self.cli.disconnect()
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def send_data(self, ep_name, data):
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# Write (and read) data to characteristic corresponding to the endpoint
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if ep_name not in self.name_uuid_lookup.keys():
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raise RuntimeError("Invalid endpoint : " + ep_name)
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return self.cli.send_data(self.name_uuid_lookup[ep_name], data)
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