feat(hw1): First iteration of custom interface, rename clock

- Rename `hw1-clock` -> `hw1_clock`

src/hw1_clock/CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.8)
-project(hw_1_clock)
+project(hw1-clock)
 
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   add_compile_options(-Wall -Wextra -Wpedantic)

src/hw1_clock/package.xml

@@ -1,7 +1,7 @@
 <?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>hw_1_clock</name>
+  <name>hw1-clock</name>
   <version>0.0.0</version>
   <description>TODO: Package description</description>
   <maintainer email="wessel@todo.todo">wessel</maintainer>

src/hw1_interface/CMakeLists.txt

@@ -0,0 +1,18 @@
+cmake_minimum_required(VERSION 3.8)
+project(hw1_interface)
+
+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(rosidl_default_generators REQUIRED)
+
+rosidl_generate_interfaces(${PROJECT_NAME}
+  "msg/StudentResult.msg"
+)
+
+ament_export_dependencies(rosidl_default_runtime)
+
+ament_package()

src/hw1_interface/msg/StudentResult.msg

@@ -0,0 +1,2 @@
+string student
+float64 result

src/hw1_interface/package.xml

@@ -0,0 +1,22 @@
+<?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>hw1_interface</name>
+  <version>0.0.0</version>
+  <description>TODO: Package description</description>
+  <maintainer email="wessel@todo.todo">wessel</maintainer>
+  <license>TODO: License declaration</license>
+
+  <buildtool_depend>ament_cmake</buildtool_depend>
+  
+  <build_depend>rosidl_default_generators</build_depend>
+  <exec_depend>rosidl_default_runtime</exec_depend>
+  <member_of_group>rosidl_interface_packages</member_of_group>
+
+  <test_depend>ament_lint_auto</test_depend>
+  <test_depend>ament_lint_common</test_depend>
+
+  <export>
+    <build_type>ament_cmake</build_type>
+  </export>
+</package>

src/hw1_interface_usage/CMakeLists.txt

@@ -0,0 +1,41 @@
+cmake_minimum_required(VERSION 3.8)
+project(hw1_interface_usage)
+
+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(rclcpp REQUIRED)
+find_package(hw1_interface REQUIRED)
+# uncomment the following section in order to fill in
+# further dependencies manually.
+# find_package(<dependency> REQUIRED)
+
+add_executable(1_pub src/1-publisher.cpp)
+add_executable(2_sub src/2-subscriber.cpp)
+
+ament_target_dependencies(1_pub rclcpp hw1_interface)
+ament_target_dependencies(2_sub rclcpp hw1_interface)
+
+install (
+  TARGETS
+    1_pub
+    2_sub
+  DESTINATION lib/${PROJECT_NAME}
+)
+
+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()

src/hw1_interface_usage/package.xml

@@ -0,0 +1,20 @@
+<?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>hw1_interface_usage</name>
+  <version>0.0.0</version>
+  <description>TODO: Package description</description>
+  <maintainer email="wessel@todo.todo">wessel</maintainer>
+  <license>TODO: License declaration</license>
+
+  <buildtool_depend>ament_cmake</buildtool_depend>
+
+  <depend>hw1_interface</depend>
+
+  <test_depend>ament_lint_auto</test_depend>
+  <test_depend>ament_lint_common</test_depend>
+
+  <export>
+    <build_type>ament_cmake</build_type>
+  </export>
+</package>

src/hw1_interface_usage/src/1-publisher.cpp

@@ -0,0 +1,54 @@
+/* hw1_interface_usage/1-publisher.cpp.cpp
+ * A node that will publish a custom static message
+ * every 3 seconds.
+ *
+ * Reviewed by: <x>
+ * Changelog:
+ * [04-09-2025] Wessel T: Implement template
+ * [09-09-2025] Wessel T: (BASE) Work out assignment
+ */
+
+#include <cstdlib>
+
+#include "rclcpp/rclcpp.hpp"
+#include "hw1_interface/msg/student_result.hpp"
+
+class NodeHw1StudentPublisher : public rclcpp::Node {
+public:
+	NodeHw1StudentPublisher()
+		: Node("node_hw1_student_publisher")
+	{
+		publisher_student_result_ =
+			this->create_publisher<hw1_interface::msg::StudentResult>("student_result", 10);
+
+		timer_student_result_ = this->create_wall_timer(
+			std::chrono::seconds(3),
+			std::bind(&NodeHw1StudentPublisher::timer_student_result_function, this)
+		);
+	}
+
+	void timer_student_result_function() {
+		hw1_interface::msg::StudentResult msg;
+		msg.student = "Wessel T";
+		msg.result = 7.0;
+
+		publisher_student_result_->publish(msg);
+		RCLCPP_INFO(this->get_logger(), 
+      "Published: student=%s, result=%f", msg.student.c_str(), msg.result
+    );
+	}
+
+private:
+	rclcpp::Publisher<hw1_interface::msg::StudentResult>::SharedPtr publisher_student_result_;
+	rclcpp::TimerBase::SharedPtr timer_student_result_;
+};
+
+int main(int argc, char *argv[]) {
+	rclcpp::init(argc, argv);
+	
+  auto node = std::make_shared<NodeHw1StudentPublisher>();
+	rclcpp::spin(node);
+	rclcpp::shutdown();
+	
+  return 0;
+}

src/hw1_interface_usage/src/2-subscriber.cpp

@@ -0,0 +1,48 @@
+/* hw1_interface_usage/2-subscriber.cpp
+ * A node that will subscribe to a custom static message
+ *
+ * Reviewed by: <x>
+ * Changelog:
+ * [04-09-2025] Wessel T: Implement template
+ * [09-09-2025] Wessel T: (BASE) Work out assignment
+ */
+
+#include <cstdlib>
+
+#include "rclcpp/rclcpp.hpp"
+#include "hw1_interface/msg/student_result.hpp"
+
+using namespace std::placeholders;
+
+class NodeHw1StudentSubscriber : public rclcpp::Node {
+public:
+  NodeHw1StudentSubscriber()
+    : Node("node_hw1_student_subscriber")
+  {
+    subscriber_student_result_ =
+      this->create_subscription<hw1_interface::msg::StudentResult>(
+        "student_result", 10,
+        std::bind(&NodeHw1StudentSubscriber::callback_student_result, this, _1)
+      );
+  }
+
+  void callback_student_result(const hw1_interface::msg::StudentResult::SharedPtr msg) {
+    RCLCPP_INFO(this->get_logger(), 
+      "Received: student=%s, result=%f", msg->student.c_str(), msg->result
+    );
+  }
+
+private:
+  rclcpp::Subscription<hw1_interface::msg::StudentResult>::SharedPtr subscriber_student_result_;
+};
+
+int main(int argc,char *argv[]) {
+  rclcpp::init(argc,argv);
+
+  auto node = std::make_shared<NodeHw1StudentSubscriber>();
+
+  rclcpp::spin(node);
+  rclcpp::shutdown();
+
+  return 0;
+}