add timeout exception to _discover_device

api/ble.py

@@ -65,13 +65,26 @@ class SensorReading:
 # --------------------------------------------------------------------------- #
 async def _discover_device(mac: str) -> Optional[str]:
     """Scan once for the given MAC and return its address if found."""
-    devices = await BleakScanner.discover(timeout=SCAN_TIMEOUT)
-    for d in devices:
-        if d.address.lower() == mac.lower():
-            log.info("Found device %s (%s)", d.name or d.address, d.address)
-            return d.address
-    log.warning("Device %s not found in scan", mac)
+    try:
+        devices = await asyncio.wait_for(
+            BleakScanner.discover(timeout=SCAN_TIMEOUT),
+            timeout=SCAN_TIMEOUT + 2.0,  # give a small buffer over scan timeout
+        )
+        for d in devices:
+            if d.address.lower() == mac.lower():
+                log.info("Found device %s (%s)", d.name or d.address, d.address)
+                return d.address
+        log.warning("Device %s not found in scan", mac)
+    except asyncio.TimeoutError:
+        log.warning("Discover call timed out after %.1fs for %s", SCAN_TIMEOUT + 2.0, mac)
     return None
+    
+    #for d in devices:
+    #    if d.address.lower() == mac.lower():
+    #        log.info("Found device %s (%s)", d.name or d.address, d.address)
+    #        return d.address
+    #log.warning("Device %s not found in scan", mac)
+    #return None
 
 
 def _parse_sensor_data(raw: bytes) -> (float, int):