python中将蓝牙广播中读取的心率每隔一秒多行写到txt文件，使用bleak库来连接蓝牙设备并接收心率

在Python中，你可以使用`bleak`库来连接蓝牙低功耗（BLE）设备，并通过`uuid}`来查找特定的服务和特性获取心率数据。以下是一个简单的示例，展示如何每秒将接收到的心率数据写入文本文件：

import bleak
from bleak.backends.device import BLEDevice
import time

# 替换为你要连接的蓝牙设备的MAC地址或名称
target_device = "XX:XX:XX:XX:XX:XX"  # 或者 "your_device_name"

def on_data_received(sender, data):
    heart_rate = int.from_bytes(data, byteorder='little')  # 假设心率数据是一个字节流，需要解析
    with open('heart_rate_log.txt', 'a') as f:
        f.write(f"{time.strftime('%Y-%m-%d %H:%M:%S', time.localtime())}, {heart_rate}\n")
    print(f"Heart rate at {time.strftime('%Y-%m-%d %H:%M:%S', time.localtime())}: {heart_rate}")

# 连接到蓝牙设备并订阅心率服务
async def connect_and_monitor(device: BLEDevice):
    async with bleak BleakClient(device) as client:
        service_uuid = "0x180D"  # 心率服务的UUID
        characteristics = await client.get_services(service_uuid)
        for characteristic in characteristics:
            if characteristic.properties.read:
                client.add_reader(characteristic.uuid, on_data_received)

        while True:
            try:
                await client.is_connected()
                print("Connected to device.")
                await client.start_notify(service_uuid, on_data_received)
                while True:
                    await asyncio.sleep(1)
            except bleak.exc.BleakError as e:
                print(f"Connection lost: {e}")
                await client.disconnect()
                await asyncio.sleep(5)  # 等待5秒再尝试连接

# 主程序入口
if __name__ == "__main__":
    devices = bleak.discover()
    target_device = next((device for device in devices if target_device in str(device.address)), None)
    if target_device:
        asyncio.run(connect_and_monitor(target_device))
    else:
        print("Device not found.")

注意：这个示例假设心率服务的UUID是0x180D，这是苹果HealthKit的心率数据标准。实际应用中，你需要根据你的蓝牙设备提供的心率服务查找相应的UUID。