fix: BLE interface refactoring with race condition fixes and improved shutdown

examples/reconnect_example.py

@@ -0,0 +1,91 @@
+"""
+Example demonstrating a robust client-side reconnection loop for a
+long-running application that uses the BLE interface.
+
+The key is to instantiate the BLEInterface with `auto_reconnect=True` (the default).
+This prevents the library from calling `close()` on the entire interface when a
+disconnect occurs. Instead, it cleans up the underlying BLE client and notifies
+listeners via the `onConnection` event with a `connected=False` payload.
+
+The application can then listen for this event and attempt to create a new
+BLEInterface instance to re-establish the connection, as shown in this example.
+"""
+import argparse
+import logging
+import threading
+import time
+
+from pubsub import pub
+
+import meshtastic
+import meshtastic.ble_interface
+
+# Retry delay in seconds when connection fails
+RETRY_DELAY_SECONDS = 5
+
+logger = logging.getLogger(__name__)
+
+# A thread-safe flag to signal disconnection
+disconnected_event = threading.Event()
+
+
+def on_connection_change(interface, connected):
+    """Callback for connection changes."""
+    iface_label = getattr(interface, "address", repr(interface))
+    logger.info(
+        "Connection changed for %s: %s", iface_label, "Connected" if connected else "Disconnected"
+    )
+    if not connected:
+        # Signal the main loop that we've been disconnected
+        disconnected_event.set()
+
+
+def main():
+    """Main function."""
+    logging.basicConfig(level=logging.INFO)
+    parser = argparse.ArgumentParser(
+        description="Meshtastic BLE interface automatic reconnection example."
+    )
+    parser.add_argument("address", help="The BLE address of your Meshtastic device.")
+    args = parser.parse_args()
+    address = args.address
+
+    # Subscribe to the connection change event
+    pub.subscribe(on_connection_change, "meshtastic.connection.status")
+
+    while True:
+        iface = None
+        try:
+            disconnected_event.clear()
+            logger.info("Attempting to connect to %s...", address)
+            # Set auto_reconnect=True to prevent the interface from closing on disconnect.
+            # This allows us to handle the reconnection here.
+            iface = meshtastic.ble_interface.BLEInterface(
+                address,
+                noProto=True,  # Set to False in a real application
+                auto_reconnect=True,
+            )
+
+            logger.info("Connection successful. Waiting for disconnection event...")
+            # Wait until the on_connection_change callback signals a disconnect
+            disconnected_event.wait()
+            logger.info("Disconnected normally.")
+
+        except KeyboardInterrupt:
+            logger.info("Exiting...")
+            break
+        except meshtastic.ble_interface.BLEInterface.BLEError:
+            logger.exception("Connection failed")
+        except Exception:
+            logger.exception("An unexpected error occurred")
+        finally:
+            if iface:
+                iface.close()
+                logger.info("Interface closed.")
+
+        logger.info("Retrying in %d seconds...", RETRY_DELAY_SECONDS)
+        time.sleep(RETRY_DELAY_SECONDS)
+
+
+if __name__ == "__main__":
+    main()