diff --git a/src/tutorial_pkg/src/my_first_node.cpp b/src/tutorial_pkg/src/my_first_node.cpp
index 9c60aa6..1dd6e62 100644
--- a/src/tutorial_pkg/src/my_first_node.cpp
+++ b/src/tutorial_pkg/src/my_first_node.cpp
@@ -1,5 +1,8 @@
 #include <ros/ros.h>
 #include <sensor_msgs/Image.h>
+#include <std_msgs/UInt8.h>
+
+ros::Publisher brightness_pub;
 
 void imageCallback(const sensor_msgs::ImageConstPtr &image)
 {
@@ -9,15 +12,32 @@ void imageCallback(const sensor_msgs::ImageConstPtr &image)
         sum += value;
     }
     int avg = sum / image->data.size();
-    ROS_INFO("Brightness: %d", avg);
+
+    std_msgs::UInt8 brightness_value;
+    brightness_value.data = avg;
+    brightness_pub.publish(brightness_value);
+}
+
+void timerCallback(const ros::TimerEvent&)
+{
+    ROS_INFO("Timer activate");
+
+    std_srvs::Empty srv;
+    client.call(srv);
 }
 
 int main(int argc, char **argv)
 {
-   ros::init(argc, argv, "my_first_node");
-   ros::NodeHandle n("~");
-   ros::Subscriber sub = n.subscribe("/camera/color/image_raw", 10, imageCallback);
+    ros::init(argc, argv, "my_first_node");
+    ros::NodeHandle n("~");
 
-   ROS_INFO("Node started!");
-   ros::spin();
-}
+    double timer_period_s;
+    n.param("timer_period_s", timer_period_s, 5.0);
+
+    ros::Subscriber sub = n.subscribe("/camera/color/image_raw", 10, imageCallback);
+    brightness_pub = n.advertise<std_msgs::UInt8>("brightness", 1);
+    ros::Timer timer = n.createTimer(ros::Duration(timer_period_s), timerCallback);
+
+    ROS_INFO("Node started!");
+    ros::spin();
+}
\ No newline at end of file