+ LED blue on exit

controller/main.py

@@ -230,7 +230,9 @@ def main():
         root.mainloop()
     except Exception as e:
         print(f"Error connecting to Robomaster: {e}")
-        print("Make sure the Robomaster is powered on and connected.")
+    finally:
+        if cmd:
+            cmd.led_control(comp="all", effect="solid", r=0, g=0, b=255)
 
 if __name__ == "__main__":
     main()