diff --git a/serial_to_mqtt_bridge/serial_to_mqtt.py b/serial_to_mqtt_bridge/serial_to_mqtt.py
index 4a0825f7b22d23047f637ce07df1f62f954edf5b..456d548daca19418b959926958b552def92bb2bc 100755
--- a/serial_to_mqtt_bridge/serial_to_mqtt.py
+++ b/serial_to_mqtt_bridge/serial_to_mqtt.py
@@ -24,10 +24,10 @@ def cyclic_file_reader(file_path):
                 yield line.strip()  # Yield each line, stripped of whitespace
 
 # Main function to handle serial data or send lines from file if no port is provided
-def main(serial_port=None, baud_rate=115200, file_path="sim_data.txt", mqtt_broker="localhost", mqtt_port=1883, mqtt_topic="serial2MQTT", sim_interval=1):
+def main(serial_port=None, baud_rate=115200, file_path="sim_data.txt", mqtt_broker="192.168.52.5", mqtt_port=1883, mqtt_topic="serial2MQTT", sim_interval=1):
     connect_mqtt(mqtt_broker, mqtt_port)
     
-    if serial_port:
+    if serial_port.lower() != "sim":
         # If serial port is provided, read from it
         ser = serial.Serial(serial_port, baud_rate, timeout=1)
         try:
@@ -51,7 +51,7 @@ def main(serial_port=None, baud_rate=115200, file_path="sim_data.txt", mqtt_brok
             client.loop_stop()
             client.disconnect()
     else:
-        # If no serial port is provided, send lines from the file cyclically
+                        # If simulation mode is selected, send lines from the file cyclically
         file_reader = cyclic_file_reader(file_path)
         cnt=0
         try:
@@ -70,13 +70,15 @@ def main(serial_port=None, baud_rate=115200, file_path="sim_data.txt", mqtt_brok
             client.loop_stop()
             client.disconnect()
 
+
+
 if __name__ == "__main__":
     # Load configuration from YAML
     config = load_config()
     
     # Argument parser for serial port, baud rate, and file path
-    parser = argparse.ArgumentParser(description="Read from serial port and publish to MQTT.")
-    parser.add_argument("--serial_port", type=str, default=config['serial'].get('port'), help="Serial port to connect to (e.g., /dev/ttyUSB0)")
+    parser = argparse.ArgumentParser(description="Read data from serial port and publish to MQTT.")
+    parser.add_argument("serial_port", type=str, help="Serial port to connect to (e.g., /dev/ttyUSB0) or 'sim' for simulation mode")
     parser.add_argument("--baud_rate", type=int, default=config['serial'].get('baud_rate', 115200), help="Baud rate for serial communication")
     parser.add_argument("--file_path", type=str, default=config['sim'].get('file_path'), help="Path to the file with data for MQTT")
     parser.add_argument("--mqtt_broker", type=str, default=config['mqtt'].get('broker', "localhost"), help="MQTT broker address")