light_ble_decorator.py

from gpiozero import LED
from bubblepy import peripheral, gatt

@gatt.service(0x1234)
class Light:

    def __init__(self):
        self.led = LED(17)

    @gatt.characteristic(0xABCD, ['write'], "Set Light State")
    def light_state(self):
        return [self.led.is_lit]

    @light_state.setter
    def light_state(self, bytes):
        if len(bytes)>0 and bytes[0]>0:
            self.led.on()
        else:
            self.led.off()

peripheral.add_service(Light())
peripheral.start()