Don't gitignore utils folder

.gitignore

@@ -1,5 +1,4 @@
 .idea
 build
 install
-utils
 log

utils/CMakeLists.txt

@@ -0,0 +1,35 @@
+cmake_minimum_required(VERSION 3.8)
+project(utils)
+
+if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+  add_compile_options(-Wall -Wextra -Wpedantic)
+endif()
+
+# find dependencies
+find_package(ament_cmake REQUIRED)
+find_package(ament_cmake_python REQUIRED)
+find_package(rclpy REQUIRED)
+
+ament_python_install_package(${PROJECT_NAME})
+
+install(PROGRAMS
+  utils/heartbeat_helper.py
+  DESTINATION lib/${PROJECT_NAME}
+)
+# uncomment the following section in order to fill in
+# further dependencies manually.
+# find_package(<dependency> REQUIRED)
+
+if(BUILD_TESTING)
+  find_package(ament_lint_auto REQUIRED)
+  # the following line skips the linter which checks for copyrights
+  # comment the line when a copyright and license is added to all source files
+  set(ament_cmake_copyright_FOUND TRUE)
+  # the following line skips cpplint (only works in a git repo)
+  # comment the line when this package is in a git repo and when
+  # a copyright and license is added to all source files
+  set(ament_cmake_cpplint_FOUND TRUE)
+  ament_lint_auto_find_test_dependencies()
+endif()
+
+ament_package()

utils/package.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0"?>
+<?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
+<package format="3">
+  <name>utils</name>
+  <version>0.0.0</version>
+  <description>TODO: Package description</description>
+  <maintainer email="akahl@purdue.edu">adam</maintainer>
+  <license>TODO: License declaration</license>
+
+  <buildtool_depend>ament_cmake</buildtool_depend>
+  <buildtool_depend>ament_cmake_python</buildtool_depend>
+  <buildtool_depend>rosidl_default_generators</buildtool_depend>
+
+  <depend>rclpy</depend>
+
+  <test_depend>ament_lint_auto</test_depend>
+  <test_depend>ament_lint_common</test_depend>
+
+  <exec_depend>builtin_interfaces</exec_depend>
+  <exec_depend>rosidl_default_generators</exec_depend>
+
+  <member_of_group>rosidl_interface_packages</member_of_group>
+
+  <export>
+    <build_type>ament_cmake</build_type>
+  </export>
+</package>

utils/utils/heartbeat_helper.py

@@ -0,0 +1,31 @@
+#! /usr/bin/python3
+
+from rclpy.node import Node
+from std_msgs.msg import Header
+
+class HeartbeatHelper:
+    def __init__(self, node: Node, topic_name="heartbeat", timer_period=5.0):
+        """This class is used to publish a heartbeat message on a given topic at a given interval"""
+        self.timer_period = timer_period
+        self.node = node
+        self.publisher = self.node.create_publisher(Header, topic_name, 10)
+        self.timer = self.node.create_timer(timer_period, self.publish_heartbeat)
+
+    def publish_heartbeat(self):
+        """Publish a heartbeat message on the topic"""
+        self.node.get_logger().info("Publishing heartbeat from {}".format(self.node.get_name()))
+        msg = Header()
+        msg.stamp = self.node.get_clock().now().to_msg()
+        msg.frame_id = self.node.get_name()
+        self.publisher.publish(msg)
+
+    def stop_heartbeat(self):
+        """Stop the heartbeat timer"""
+        self.timer.cancel()
+        self.node.destroy_publisher(self.publisher)
+        self.node.get_logger().info(f'Heartbeat stopped for {self.node.get_name()}')
+
+    def start_heartbeat(self):
+        """Start the heartbeat timer"""
+        self.timer = self.node.create_timer(self.timer_period, self.publish_heartbeat)
+        self.node.get_logger().info(f'Heartbeat started for {self.node.get_name()}')