diff --git a/scripts/libraries/ble_advertising.py b/scripts/libraries/ble_advertising.py new file mode 100644 index 000000000..e520af57c --- /dev/null +++ b/scripts/libraries/ble_advertising.py @@ -0,0 +1,116 @@ +# The MIT License (MIT) +# +# Copyright (c) 2013-2021 Damien P. George +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# +# Helpers for generating BLE advertising payloads. + +from micropython import const +import struct +import bluetooth + +# Advertising payloads are repeated packets of the following form: +# 1 byte data length (N + 1) +# 1 byte type (see constants below) +# N bytes type-specific data + +_ADV_TYPE_FLAGS = const(0x01) +_ADV_TYPE_NAME = const(0x09) +_ADV_TYPE_UUID16_COMPLETE = const(0x3) +_ADV_TYPE_UUID32_COMPLETE = const(0x5) +_ADV_TYPE_UUID128_COMPLETE = const(0x7) +_ADV_TYPE_UUID16_MORE = const(0x2) +_ADV_TYPE_UUID32_MORE = const(0x4) +_ADV_TYPE_UUID128_MORE = const(0x6) +_ADV_TYPE_APPEARANCE = const(0x19) + + +# Generate a payload to be passed to gap_advertise(adv_data=...). +def advertising_payload(limited_disc=False, br_edr=False, name=None, services=None, appearance=0): + payload = bytearray() + + def _append(adv_type, value): + nonlocal payload + payload += struct.pack("BB", len(value) + 1, adv_type) + value + + _append( + _ADV_TYPE_FLAGS, + struct.pack("B", (0x01 if limited_disc else 0x02) + (0x18 if br_edr else 0x04)), + ) + + if name: + _append(_ADV_TYPE_NAME, name) + + if services: + for uuid in services: + b = bytes(uuid) + if len(b) == 2: + _append(_ADV_TYPE_UUID16_COMPLETE, b) + elif len(b) == 4: + _append(_ADV_TYPE_UUID32_COMPLETE, b) + elif len(b) == 16: + _append(_ADV_TYPE_UUID128_COMPLETE, b) + + # See org.bluetooth.characteristic.gap.appearance.xml + if appearance: + _append(_ADV_TYPE_APPEARANCE, struct.pack("