circuitpython/examples/bluetooth/ble_advertising.py
Jim Mussared 25a228af7e examples/bluetooth: Add basic BLE peripheral examples.
Consisting of:
- ble_advertising.py -- helper to generate advertising payload.
- ble_temperature.py -- simple temperature device.
- ble_uart_periperhal.py -- BLE UART wrapper.
- ble_uart_repl.py -- dupterm-compatible uart.
2019-10-18 13:36:51 +11:00

38 lines
1.2 KiB
Python

# Helpers for generating BLE advertising payloads.
from micropython import const
import struct
# 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_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) + (0x00 if br_edr else 0x04)))
if name:
_append(_ADV_TYPE_NAME, name)
if services:
for uuid in services:
# TODO: Support bluetooth.UUID class.
_append(_ADV_TYPE_UUID16_COMPLETE, struct.pack('<h', uuid))
# See org.bluetooth.characteristic.gap.appearance.xml
_append(_ADV_TYPE_APPEARANCE, struct.pack('<h', appearance))
return payload