CP BLE Central for Countdown Clock

ble.py

import _bleio
import adafruit_ble
from adafruit_ble.advertising.standard import Advertisement
from adafruit_ble.services.standard.device_info import DeviceInfoService

from adafruit_ble import Service
from adafruit_ble.characteristics import Characteristic
from adafruit_ble.characteristics.int import Uint16Characteristic
from adafruit_ble.uuid import VendorUUID




class CountdownClockService(Service):
	"""Countdown Clock Service"""
	
	uuid					=	VendorUUID("F1B8ED4E-648B-4689-8A0C-4930BC3A2325")
	countdownStart			=	Uint16Characteristic(max_value = 9 * 60 + 59,
													 uuid = VendorUUID("955CB941-F229-4AAB-81FB-44349AFB6CA7"),
													 properties = Characteristic.WRITE | Characteristic.READ)
	
	def __init__(
		self,
		countdownStart = 10
	) -> None:
		super().__init__(
			manufacturer = "Latency: Zero, LLC",
			software_revision = "1.0",
			model_number = "CC",
			serial_number = "12345",
			firmware_revision = "1.0",
			hardware_revision = "1.0",
		)




gBLE = adafruit_ble.BLERadio()

gConnection = None

while True:
	print("Scanning...")
	for adv in gBLE.start_scan(Advertisement, timeout=5):
		name = adv.complete_name
		if name == "Countdown Clock BLE":
			print(f"Found device: { name }")
			gConnection = gBLE.connect(adv)
			break
	gBLE.stop_scan()
	
	try:
		if gConnection and gConnection.connected:
			print("Connected")
			if DeviceInfoService in gConnection:
				dis = gConnection[DeviceInfoService]
				print(f"Man: { dis.manufacturer }")
			else:
				print("No device info")
			
			service = gConnection[CountdownClockService]
			service.countdownStart = 25
			print("Wrote countdown start, exting")
			break
							
	except ConnectionError:
		try:
			gConnection.disconnect()
		except ConnectionError:
			pass
		gConnection = None