my bad

rpi/main.py

@@ -5,6 +5,7 @@ from hardware.rfid.reader import RfidReader
 from services.mqtt_service import MQTTService
 
 screen = Screen()
+service = MQTTService("127.0.0.1", 1883)
 
 def publish(uid : int) :
     screen.displayMessage(str(uid))
@@ -13,7 +14,6 @@ def publish(uid : int) :
 if __name__ == "__main__":
     screen.enableBackground()
     screen.displayMessage("Waiting for scan...")
-    service = MQTTService("127.0.0.1", 1883)
     reader = RfidReader("/dev/serial0", 9600)
     reader.subscribe(publish)
     reader.start()