求助：如何用Pyodide在浏览器运行iBeacon蓝牙数据采集Python代码

1. 安装缺失的Python模块 #

报错ModuleNotFoundError: No module named 'construct'是因为Pyodide默认未预装construct包，需要通过micropip安装。修改JS代码，在加载Pyodide后先安装依赖：

async function main(){
    let pyodide = await loadPyodide();
    // 安装所需Python包
    await pyodide.runPythonAsync(`
        import micropip
        await micropip.install("construct")
    `);
    // 加载并保存beacon.py文件
    await pyodide.runPythonAsync(`
        from pyodide.http import pyfetch
        response = await pyfetch("beacon.py")
        with open("beacon.py", "wb") as f:
            f.write(await response.bytes())
    `);
    // 运行beacon.py中的main函数
    await pyodide.runPythonAsync(`
        import beacon
        await beacon.main()
    `);
}
main();

2. 修复Bleak兼容性问题 #

Bleak库无法在浏览器环境运行，它依赖桌面端系统蓝牙API（如Windows蓝牙栈、Linux BlueZ），而浏览器仅支持Web Bluetooth API，两者不兼容。需要修改beacon.py，改用Pyodide调用浏览器的Web Bluetooth能力实现iBeacon扫描：

import asyncio
from uuid import UUID
from construct import Array, Byte, Const, Int8sl, Int16ub, Struct
from construct.core import ConstError
from pyodide import to_js

ibeacon_format = Struct(
    "type_length" / Const(b"\x02\x15"),
    "uuid" / Array(16, Byte),
    "major" / Int16ub,
    "minor" / Int16ub,
    "power" / Int8sl,
)

def decode_ibeacon(manufacturer_data):
    """解析iBeacon广播数据"""
    try:
        apple_data = manufacturer_data.get(0x004C)
        if not apple_data:
            return None
        ibeacon = ibeacon_format.parse(apple_data)
        uuid = UUID(bytes=bytes(ibeacon.uuid))
        return {
            "uuid": uuid,
            "major": ibeacon.major,
            "minor": ibeacon.minor,
            "power": ibeacon.power
        }
    except (KeyError, ConstError):
        return None

async def main():
    """通过Web Bluetooth API扫描iBeacon"""
    navigator = to_js(js.navigator)
    try:
        # 请求用户授权蓝牙设备，过滤Apple厂商的广播数据
        device = await navigator.bluetooth.requestDevice(to_js({
            "acceptAllDevices": True,
            "scanFilters": [{
                "manufacturerData": [{
                    "companyIdentifier": 0x004C  # Apple公司ID
                }]
            }]
        }))
        
        print(f"已选中设备: {device.name} ({device.id})")
        # 解析iBeacon数据
        adv_data = device.advertisementData
        ibeacon_info = decode_ibeacon(adv_data.manufacturerData)
        if ibeacon_info:
            print(f"UUID: {ibeacon_info['uuid']}")
            print(f"Major: {ibeacon_info['major']}")
            print(f"Minor: {ibeacon_info['minor']}")
            print(f"TX Power: {ibeacon_info['power']} dBm")
            print(f"RSSI: {adv_data.rssi} dBm")
        
    except Exception as e:
        print(f"扫描失败: {str(e)}")

asyncio.run(main())

3. 关键注意事项 #

• Web Bluetooth权限限制：必须在HTTPS环境运行（localhost除外），且需要用户手动点击授权蓝牙访问。
• 扫描限制：Web Bluetooth无法实现无连接的全局被动扫描，必须由用户选择特定设备后才能获取其广播数据，这是浏览器的安全机制。
• 持续扫描：若需批量扫描多个iBeacon，可结合浏览器的BluetoothLEScan API（部分现代浏览器支持），通过Pyodide调用JS代码实现。

内容的提问来源于stack exchange，提问作者profundusman