Advertising Services¶

In BLE advertising is required for other devices to discover services that surrounding peripherals offer. To allow multiple adverts to operate simultaneously advertising is time-division multiplexed.

Hint

The “message bus” referred to here is a dbus_fast.aio.MessageBus.

A minimal advert requires:

A name for the device transmitting the advert (the localName).
A collection of service UUIDs.
An appearance describing how the device should appear to a user (see Bluetooth SIG Assigned Numbers).
A timeout specifying roughly how long the advert should be broadcast for (roughly since this is complicated by advert multiplexing).
A reference to a specific bluetooth adapter (since unlike with services, adverts are per-adapter).

from bluez_peripheral import get_message_bus, Advertisement
from bluez_peripheral.adapter import Adapter

async def main():
    adapter = await Adapter.get_first(bus)

    # "Heart Monitor" is the name the user will be shown for this device.
    # "180D"          is the uuid16 for a heart rate service.
    # 0x0340          is the appearance code for a generic heart rate sensor.
    # 60              is the time (in seconds) until the advert stops.
    advert = Advertisement("Heart Monitor", ["180D"], appearance=0x0340, timeout=60)
    await advert.register(bus, adapter)

if __name__ == "__main__":
    asyncio.run(main())