feat: some (bad) initial course example code

src/modules/px4_course/CMakeLists.txt

@@ -0,0 +1,8 @@
+px4_add_module (
+	MODULE modules__px4_course
+	MAIN px4_course
+	SRCS
+		px4_course.cpp
+	MODULE_CONFIG
+		module.yaml
+	)

src/modules/px4_course/Kconfig

@@ -0,0 +1,5 @@
+menuconfig MODULES_PX4_COURSE
+	bool "px4_course"
+	default n
+	---help---
+		Enable the Ascend PX4 course module

src/modules/px4_course/module.yaml

@@ -0,0 +1,14 @@
+module_name: Ascend PX4 course
+
+parameters:
+    - group: Example parameters
+      definitions:
+        PX4CS_NUM_GREET:
+            description:
+                short: How many times to greet
+                long: |
+                  When running the course module, the program will say Hello" this many times :)
+            type: int32
+            min: 1
+            max: 20
+            default: 2

src/modules/px4_course/px4_course.cpp

@@ -0,0 +1,91 @@
+#include "px4_course.h"
+
+int PX4Course::print_usage(const char *reason){
+	printf("Use the PX4 course module however you like!\n");
+	return 0;
+}
+
+int PX4Course::task_spawn(int argc, char*argv[]){
+	_task_id = px4_task_spawn_cmd("module",
+				      SCHED_DEFAULT,
+				      SCHED_PRIORITY_DEFAULT,
+				      1024,
+				      (px4_main_t)&run_trampoline,
+				      (char *const *)argv);
+
+	if (_task_id < 0) {
+		_task_id = -1;
+		return -errno;
+	}
+
+	return 0;
+}
+
+int PX4Course::custom_command(int argc, char *argv[]){
+	printf("User ran command %s with arguments \"", argv[0]);
+	for (int i = 0; i < argc; ++i){
+		printf("%s ", argv[i]);
+	}
+	printf("\"\n");
+	return 1;
+}
+
+PX4Course *PX4Course::instantiate(int argc, char *argv[])
+{
+	PX4Course *instance = new PX4Course();
+	if (instance == nullptr) {
+		PX4_ERR("alloc failed");
+	}
+
+	return instance;
+}
+
+PX4Course::PX4Course()
+	: ModuleParams(nullptr)
+{
+}
+
+void PX4Course::run()
+{
+	bool first_iteration{true};
+	while (!should_exit()) {
+
+		sleep(20);
+		PX4_INFO("PX4 course is%srunning!", first_iteration ? " " : " still ");
+
+		// Add code to beep here!
+
+		parameters_update(false);
+	}
+
+}
+
+void PX4Course::parameters_update(bool force)
+{
+	// check for parameter updates
+	if (_parameter_update_sub.updated() || force) {
+		// clear update
+		parameter_update_s update;
+		_parameter_update_sub.copy(&update);
+
+		// update parameters from storage
+		updateParams();
+	}
+}
+
+int PX4Course::print_status(){
+	auto num_hellos = _param_px4cs_num_greet.get();
+	for (int i = 0; i < num_hellos; ++i){
+		printf("Hello! ");
+	}
+	printf("\n");
+	return 0;
+}
+
+/**
+ * You don't need to change this function, it just calls main in the class.
+*/
+extern "C" __EXPORT int px4_course_main(int argc, char *argv[])
+{
+	return PX4Course::main(argc, argv);
+}

src/modules/px4_course/px4_course.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <px4_platform_common/module.h>
+#include <px4_platform_common/module_params.h>
+#include <uORB/SubscriptionInterval.hpp>
+#include <uORB/topics/parameter_update.h>
+
+using namespace time_literals;
+
+extern "C" __EXPORT int px4_course_main(int argc, char *argv[]);
+
+// Note that the PX4Course inherits from the ModuleBase, which gives us some useful features
+
+class PX4Course : public ModuleBase<PX4Course>, public ModuleParams
+{
+public:
+	PX4Course();
+
+	virtual ~PX4Course() = default;
+
+	/** @see ModuleBase */
+	static int task_spawn(int argc, char *argv[]);
+
+	/** @see ModuleBase */
+	static PX4Course *instantiate(int argc, char *argv[]);
+
+	/** @see ModuleBase */
+	static int custom_command(int argc, char *argv[]);
+
+	/** @see ModuleBase */
+	static int print_usage(const char *reason = nullptr);
+
+	/** @see ModuleBase::run() */
+	void run() override;
+
+	/** @see ModuleBase::print_status() */
+	int print_status() override;
+
+private:
+	/**
+	 * Check for parameter changes and update them if needed.
+	 * @param parameter_update_sub uorb subscription to parameter_update
+	 * @param force for a parameter update
+	 */
+	void parameters_update(bool force = false);
+
+	DEFINE_PARAMETERS(
+		(ParamInt<px4::params::PX4CS_NUM_GREET>) _param_px4cs_num_greet
+	)
+
+	// Subscriptions
+	uORB::SubscriptionInterval _parameter_update_sub{ORB_ID(parameter_update), 1_s};
+};