upload NK server code

SERVER_CODE/donwlink_message.py

@@ -0,0 +1,26 @@
+from azure.iot.hub import IoTHubRegistryManager
+from azure.iot.hub.models import CloudToDeviceMethod, CloudToDeviceMethodResult
+
+CONNECTION_STRING = "HostName=AgriHub.azure-devices.net;SharedAccessKeyName=iothubowner;SharedAccessKey=v0auIwbmqfBDz3BY8aZtbnOzg8+6119LWylk1Jq1G0A="
+DEVICE_ID = "Guard_Node_00001"
+METHOD_PAYLOAD = "server_to_device_message"
+
+def send_to_device(request_name):
+    try:
+        # Create IoTHubRegistryManager
+        registry_manager = IoTHubRegistryManager(CONNECTION_STRING)
+
+        # Call the direct method.
+        deviceMethod = CloudToDeviceMethod(method_name=request_name, payload=METHOD_PAYLOAD)
+        print ( "Device Method called" )
+        print ( "Device Method name       : {0}".format(request_name) )
+        print ( "Device Method payload    : {0}".format(METHOD_PAYLOAD) )
+        response = registry_manager.invoke_device_method(DEVICE_ID, deviceMethod)
+        print ( "Response status          : {0}".format(response.status) )
+        print ( "Response payload         : {0}".format(response.payload) )
+
+    except Exception as ex:
+        print ( "Unexpected error {0}".format(ex) )
+        return
+    except KeyboardInterrupt:
+        print ( "IoTHubDeviceMethod sample stopped" )