vmount: refactor architecture & use C++

This splits vmount into inputs and outputs modules with a small API in
between. It allows for greater flexibility, as any input method can be
combined with any output method. At the same time it is easy to add a new
input or output module.

src/drivers/vmount/input_rc.cpp

@@ -0,0 +1,146 @@
+/****************************************************************************
+*
+*   Copyright (c) 2016 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.
+*
+****************************************************************************/
+
+/**
+ * @file input_rc.cpp
+ * @author Beat Küng <beat-kueng@gmx.net>
+ *
+ */
+
+#include "input_rc.h"
+
+#include <errno.h>
+#include <px4_posix.h>
+#include <px4_defines.h>
+
+
+namespace vmount
+{
+
+
+InputRC::InputRC(int aux_channel_roll, int aux_channel_pitch, int aux_channel_yaw)
+{
+	_aux_channels[0] = aux_channel_roll;
+	_aux_channels[1] = aux_channel_pitch;
+	_aux_channels[2] = aux_channel_yaw;
+}
+
+InputRC::~InputRC()
+{
+	if (_manual_control_setpoint_sub >= 0) {
+		orb_unsubscribe(_manual_control_setpoint_sub);
+	}
+}
+
+int InputRC::initialize()
+{
+	_manual_control_setpoint_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
+
+	if (_manual_control_setpoint_sub < 0) {
+		return -errno;
+	}
+
+	return 0;
+}
+
+int InputRC::update_impl(unsigned int timeout_ms, ControlData **control_data)
+{
+	px4_pollfd_struct_t polls[1];
+	polls[0].fd = 		_manual_control_setpoint_sub;
+	polls[0].events = 	POLLIN;
+
+	int ret = px4_poll(polls, 1, timeout_ms);
+
+	if (ret < 0) {
+		return -errno;
+	}
+
+	if (ret == 0) {
+		*control_data = nullptr;
+
+	} else {
+		if (polls[0].revents & POLLIN) {
+			_read_control_data_from_subscription(_control_data);
+			*control_data = &_control_data;
+		}
+	}
+
+	return 0;
+}
+
+void InputRC::_read_control_data_from_subscription(ControlData &control_data)
+{
+	manual_control_setpoint_s manual_control_setpoint;
+	orb_copy(ORB_ID(manual_control_setpoint), _manual_control_setpoint_sub, &manual_control_setpoint);
+	control_data.type = ControlData::Type::Angle;
+
+	for (int i = 0; i < 3; ++i) {
+		control_data.type_data.angle.is_speed[i] = false;
+		control_data.type_data.angle.angles[i] = _get_aux_value(manual_control_setpoint, i) * M_PI_F;
+
+		control_data.stabilize_axis[i] = false;
+	}
+
+	control_data.gimbal_shutter_retract = false;
+}
+
+float InputRC::_get_aux_value(const manual_control_setpoint_s &manual_control_setpoint, int channel_idx)
+{
+	switch (_aux_channels[channel_idx]) {
+
+	case 1:
+		return manual_control_setpoint.aux1;
+
+	case 2:
+		return manual_control_setpoint.aux2;
+
+	case 3:
+		return manual_control_setpoint.aux3;
+
+	case 4:
+		return manual_control_setpoint.aux4;
+
+	case 5:
+		return manual_control_setpoint.aux5;
+
+	default:
+		return 0.0f;
+	}
+}
+
+void InputRC::print_status()
+{
+	PX4_INFO("Input: RC (channels: roll=%i, pitch=%i, yaw=%i)", _aux_channels[0], _aux_channels[1], _aux_channels[2]);
+}
+
+} /* namespace vmount */