蓝牙双重discover

@@ -127,6 +127,7 @@ class BLEClient:
         self.notification_records = defaultdict(lambda: (None, 0.0))  # 特征ID: (最后消息, 时间戳)
         self._notification_callbacks = {}  # 存储通知回调，用于清理
         self._shutdown = False  # 添加关闭标志
+        self._scanner = None  # 当前扫描器实例
 
     def on_disconnect(self, client):
         print("BLE连接断开，关闭WebSocket")
@@ -159,8 +160,22 @@ class BLEClient:
                 print(f"制造商数据: {adv_data.manufacturer_data}")
                 print(f"服务数据: {adv_data.service_data}")
                 print(f"本地名称: {adv_data.local_name}")
+                # 发现设备后，尝试立即停止扫描
+                try:
+                    if self._scanner is not None:
+                        # 在事件循环中停止扫描，避免阻塞回调
+                        asyncio.create_task(self._stop_scan_early())
+                except Exception:
+                    pass
             return self.target_device
 
+    async def _stop_scan_early(self):
+        try:
+            if self._scanner is not None:
+                await self._scanner.stop()
+        except Exception:
+            pass
+
     async def handle_client(self, websocket, path):
         self.websocket = websocket
         if path != "/scratch/ble":
@@ -186,24 +201,32 @@ class BLEClient:
                             self.services.extend(filt.get("services", []))
                         self.optional_services = params.get("optionalServices", [])
 
-                        scanner = BleakScanner(scanning_mode="active")
-                        scanner.register_detection_callback(self.detection_callback)
-                        
-                        max_retries = 3
+                        # 双重扫描：快速扫描后若未发现，再进行扩展扫描；发现即停
+                        phases = [("active", 3.0), ("passive", 6.0)]
                         found = False
-                        for attempt in range(max_retries):
+                        for phase_index, (scan_mode, duration) in enumerate(phases, start=1):
                             self.target_device = None
-                            await scanner.start()
-                            await asyncio.sleep(5)
-                            await scanner.stop()
+                            self._scanner = BleakScanner(scanning_mode=scan_mode)
+                            self._scanner.register_detection_callback(self.detection_callback)
+                            print(f"开始第{phase_index}阶段扫描（模式: {scan_mode}, 时长: {duration}s）...")
+                            try:
+                                await self._scanner.start()
+                                # 轮询检查是否已找到，找到则提前停止
+                                start_ts = time.time()
+                                while time.time() - start_ts < duration and not self.target_device:
+                                    await asyncio.sleep(0.1)
+                            finally:
+                                try:
+                                    await self._scanner.stop()
+                                except Exception:
+                                    pass
+                                self._scanner = None
                             
                             if self.target_device:
                                 found = True
                                 break
-                            
-                            if attempt < max_retries - 1:
-                                print(f"未找到设备，第{attempt+1}次重试...")
-                                await asyncio.sleep(3)
+                            else:
+                                print(f"第{phase_index}阶段未找到设备")
 
                         if found:
                             device, adv_data = self.target_device