Add IC engine control module (#24055)

Internal combustion engine control module.
New actuator functions and RPM based start/restart logic.
Not enabled by default. 

---------

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>
Co-authored-by: Pernilla <pernilla@auterion.com>

src/lib/mixer_module/CMakeLists.txt

@@ -48,6 +48,7 @@ px4_add_library(mixer_module
 	functions/FunctionConstantMax.hpp
 	functions/FunctionConstantMin.hpp
 	functions/FunctionGimbal.hpp
+	functions/FunctionICEngineControl.hpp
 	functions/FunctionLandingGear.hpp
 	functions/FunctionManualRC.hpp
 	functions/FunctionMotors.hpp

src/lib/mixer_module/functions/FunctionICEngineControl.hpp

@@ -0,0 +1,83 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2025 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include "FunctionProviderBase.hpp"
+
+#include <uORB/topics/internal_combustion_engine_control.h>
+
+/**
+ * Functions: ICE...
+ */
+class FunctionICEControl : public FunctionProviderBase
+{
+public:
+	FunctionICEControl()
+	{
+		resetAllToDisarmedValue();
+	}
+
+	static FunctionProviderBase *allocate(const Context &context) { return new FunctionICEControl(); }
+
+	void update() override
+	{
+		internal_combustion_engine_control_s internal_combustion_engine_control;
+
+		// map [0, 1] to [-1, 1] which is the interface for non-motor PWM channels
+		if (_internal_combustion_engine_control_sub.update(&internal_combustion_engine_control)) {
+			_data[0] = internal_combustion_engine_control.ignition_on * 2.f - 1.f;
+			_data[1] = internal_combustion_engine_control.throttle_control * 2.f - 1.f;
+			_data[2] = internal_combustion_engine_control.choke_control * 2.f - 1.f;
+			_data[3] = internal_combustion_engine_control.starter_engine_control * 2.f - 1.f;
+		}
+	}
+
+	float value(OutputFunction func) override { return _data[(int)func - (int)OutputFunction::IC_Engine_Ignition]; }
+
+private:
+	static constexpr int num_data_points = 4;
+
+	void resetAllToDisarmedValue()
+	{
+		for (int i = 0; i < num_data_points; ++i) {
+			_data[i] = NAN;
+		}
+	}
+
+	static_assert(num_data_points == (int)OutputFunction::IC_Engine_Starter - (int)OutputFunction::IC_Engine_Ignition + 1,
+		      "number of functions mismatch");
+
+	uORB::Subscription _internal_combustion_engine_control_sub{ORB_ID(internal_combustion_engine_control)};
+	float _data[num_data_points] {};
+};

src/lib/mixer_module/mixer_module.cpp

@@ -64,6 +64,7 @@ static const FunctionProvider all_function_providers[] = {
 	{OutputFunction::Gripper, &FunctionGripper::allocate},
 	{OutputFunction::RC_Roll, OutputFunction::RC_AUXMax, &FunctionManualRC::allocate},
 	{OutputFunction::Gimbal_Roll, OutputFunction::Gimbal_Yaw, &FunctionGimbal::allocate},
+	{OutputFunction::IC_Engine_Ignition, OutputFunction::IC_Engine_Starter, &FunctionICEControl::allocate},
 };
 
 MixingOutput::MixingOutput(const char *param_prefix, uint8_t max_num_outputs, OutputModuleInterface &interface,

src/lib/mixer_module/mixer_module.hpp

@@ -40,6 +40,7 @@
 #include "functions/FunctionConstantMin.hpp"
 #include "functions/FunctionGimbal.hpp"
 #include "functions/FunctionGripper.hpp"
+#include "functions/FunctionICEngineControl.hpp"
 #include "functions/FunctionLandingGear.hpp"
 #include "functions/FunctionLandingGearWheel.hpp"
 #include "functions/FunctionManualRC.hpp"

src/lib/mixer_module/output_functions.yaml

@@ -38,6 +38,11 @@ functions:
 
     Landing_Gear_Wheel: 440
 
+    IC_Engine_Ignition: 450
+    IC_Engine_Throttle: 451
+    IC_Engine_Choke: 452
+    IC_Engine_Starter: 453
+
     # Add your own here:
     #MyCustomFunction: 10000