diff --git a/README.md b/README.md
index fa4f46b..6913946 100644
--- a/README.md
+++ b/README.md
@@ -26,3 +26,9 @@ source mqttmock/bin/activate
 pip install -r requirements.txt
 ```
 
+
+```
+apt install mosquitto-clients
+
+mosquitto_pub -h localhost -p 1883 -t "device" -m '{"msg": "test""}'
+```
diff --git a/client/mqtt_client.py b/client/mqtt_client.py
index 2fd94b8..1f1626e 100644
--- a/client/mqtt_client.py
+++ b/client/mqtt_client.py
@@ -9,11 +9,11 @@ load_dotenv(dotenv_path=".env.test")
 
 MQTT_HOST = os.getenv("MQTT_HOST")
 MQTT_PORT = int(os.getenv("MQTT_PORT"))
-MQTT_DEVICE_CODE = int(os.getenv("MQTT_DEVICE_CODE"))
+MQTT_DEVICE_CODE = os.getenv("MQTT_DEVICE_CODE")
 
 
-def on_connect_mock(client, userdata, flags, rc, properties):
-    print(f"Connected with result code {rc}")
+def on_connect_mock(client, userdata, flags, rc):
+    print(f"Connected with result code rc={rc}")
 
 
 def test_mqtt_mock():
@@ -22,7 +22,26 @@ def test_mqtt_mock():
     client = mqtt.Client()
     client.on_connect = on_connect_mock
     client.connect(MQTT_HOST, MQTT_PORT, 60)
-    time.sleep(5)
+    topic = f"device/{MQTT_DEVICE_CODE}/command"
+    client.subscribe(topic, qos=1)
+    client.loop_start()
+    while True:
+        try:
+            print("publish start.")
+            topic = f"device/{MQTT_DEVICE_CODE}/send"
+            data = {"message": "test"}
+            message = json.dumps(data).encode('utf-8')
+            client.publish(topic, message, qos=1)
+            time.sleep(30)
+        except KeyboardInterrupt as e:
+            time.sleep(30)
+            break
+        except Exception as e:
+            print(f"error:{e}")
+            time.sleep(30)
+
+    print(f"end")
+    client.loop_stop()
 
 
 def main():