Merge pull request #1128 from PX4/uavcan

Basic UAVCAN support

src/modules/uavcan/.gitignore

@@ -0,0 +1 @@
+./dsdlc_generated/

src/modules/uavcan/esc_controller.cpp

@@ -0,0 +1,138 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2014 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 esc_controller.cpp
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+#include "esc_controller.hpp"
+#include <systemlib/err.h>
+
+UavcanEscController::UavcanEscController(uavcan::INode &node) :
+	_node(node),
+	_uavcan_pub_raw_cmd(node),
+	_uavcan_sub_status(node),
+	_orb_timer(node)
+{
+}
+
+UavcanEscController::~UavcanEscController()
+{
+	perf_free(_perfcnt_invalid_input);
+	perf_free(_perfcnt_scaling_error);
+}
+
+int UavcanEscController::init()
+{
+	// ESC status subscription
+	int res = _uavcan_sub_status.start(StatusCbBinder(this, &UavcanEscController::esc_status_sub_cb));
+	if (res < 0)
+	{
+		warnx("ESC status sub failed %i", res);
+		return res;
+	}
+
+	// ESC status will be relayed from UAVCAN bus into ORB at this rate
+	_orb_timer.setCallback(TimerCbBinder(this, &UavcanEscController::orb_pub_timer_cb));
+	_orb_timer.startPeriodic(uavcan::MonotonicDuration::fromMSec(1000 / ESC_STATUS_UPDATE_RATE_HZ));
+
+	return res;
+}
+
+void UavcanEscController::update_outputs(float *outputs, unsigned num_outputs)
+{
+	if ((outputs == nullptr) || (num_outputs > MAX_ESCS)) {
+		perf_count(_perfcnt_invalid_input);
+		return;
+	}
+
+	/*
+	 * Rate limiting - we don't want to congest the bus
+	 */
+	const auto timestamp = _node.getMonotonicTime();
+	if ((timestamp - _prev_cmd_pub).toUSec() < (1000000 / MAX_RATE_HZ)) {
+		return;
+	}
+	_prev_cmd_pub = timestamp;
+
+	/*
+	 * Fill the command message
+	 * If unarmed, we publish an empty message anyway
+	 */
+	uavcan::equipment::esc::RawCommand msg;
+
+	if (_armed) {
+		for (unsigned i = 0; i < num_outputs; i++) {
+
+			float scaled = (outputs[i] + 1.0F) * 0.5F * uavcan::equipment::esc::RawCommand::CMD_MAX;
+			if (scaled < 1.0F) {
+				scaled = 1.0F;  // Since we're armed, we don't want to stop it completely
+			}
+
+			if (scaled < uavcan::equipment::esc::RawCommand::CMD_MIN) {
+				scaled = uavcan::equipment::esc::RawCommand::CMD_MIN;
+				perf_count(_perfcnt_scaling_error);
+			} else if (scaled > uavcan::equipment::esc::RawCommand::CMD_MAX) {
+				scaled = uavcan::equipment::esc::RawCommand::CMD_MAX;
+				perf_count(_perfcnt_scaling_error);
+			} else {
+				; // Correct value
+			}
+
+			msg.cmd.push_back(static_cast<unsigned>(scaled));
+		}
+	}
+
+	/*
+	 * Publish the command message to the bus
+	 * Note that for a quadrotor it takes one CAN frame
+	 */
+	(void)_uavcan_pub_raw_cmd.broadcast(msg);
+}
+
+void UavcanEscController::arm_esc(bool arm)
+{
+	_armed = arm;
+}
+
+void UavcanEscController::esc_status_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::esc::Status> &msg)
+{
+	// TODO save status into a local storage; publish to ORB later from orb_pub_timer_cb()
+}
+
+void UavcanEscController::orb_pub_timer_cb(const uavcan::TimerEvent&)
+{
+	// TODO publish to ORB
+}

src/modules/uavcan/esc_controller.hpp

@@ -0,0 +1,107 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2014 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 esc_controller.hpp
+ *
+ * UAVCAN <--> ORB bridge for ESC messages:
+ *     uavcan.equipment.esc.RawCommand
+ *     uavcan.equipment.esc.RPMCommand
+ *     uavcan.equipment.esc.Status
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+#pragma once
+
+#include <uavcan/uavcan.hpp>
+#include <uavcan/equipment/esc/RawCommand.hpp>
+#include <uavcan/equipment/esc/Status.hpp>
+#include <systemlib/perf_counter.h>
+
+class UavcanEscController
+{
+public:
+	UavcanEscController(uavcan::INode& node);
+	~UavcanEscController();
+
+	int init();
+
+	void update_outputs(float *outputs, unsigned num_outputs);
+
+	void arm_esc(bool arm);
+
+private:
+	/**
+	 * ESC status message reception will be reported via this callback.
+	 */
+	void esc_status_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::esc::Status> &msg);
+
+	/**
+	 * ESC status will be published to ORB from this callback (fixed rate).
+	 */
+	void orb_pub_timer_cb(const uavcan::TimerEvent &event);
+
+
+	static constexpr unsigned MAX_RATE_HZ = 100;			///< XXX make this configurable
+	static constexpr unsigned ESC_STATUS_UPDATE_RATE_HZ = 5;
+	static constexpr unsigned MAX_ESCS = uavcan::equipment::esc::RawCommand::FieldTypes::cmd::MaxSize;
+
+	typedef uavcan::MethodBinder<UavcanEscController*,
+		void (UavcanEscController::*)(const uavcan::ReceivedDataStructure<uavcan::equipment::esc::Status>&)>
+		StatusCbBinder;
+
+	typedef uavcan::MethodBinder<UavcanEscController*, void (UavcanEscController::*)(const uavcan::TimerEvent&)>
+		TimerCbBinder;
+
+	/*
+	 * libuavcan related things
+	 */
+	uavcan::MonotonicTime							_prev_cmd_pub;   ///< rate limiting
+	uavcan::INode								&_node;
+	uavcan::Publisher<uavcan::equipment::esc::RawCommand>			_uavcan_pub_raw_cmd;
+	uavcan::Subscriber<uavcan::equipment::esc::Status, StatusCbBinder>	_uavcan_sub_status;
+	uavcan::TimerEventForwarder<TimerCbBinder>				_orb_timer;
+
+	/*
+	 * ESC states
+	 */
+	bool 				_armed = false;
+	uavcan::equipment::esc::Status	_states[MAX_ESCS];
+
+	/*
+	 * Perf counters
+	 */
+	perf_counter_t _perfcnt_invalid_input = perf_alloc(PC_COUNT, "uavcan_esc_invalid_input");
+	perf_counter_t _perfcnt_scaling_error = perf_alloc(PC_COUNT, "uavcan_esc_scaling_error");
+};

src/modules/uavcan/gnss_receiver.cpp

@@ -0,0 +1,153 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2014 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 gnss_receiver.cpp
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ * @author Andrew Chambers <achamber@gmail.com>
+ *
+ */
+
+#include "gnss_receiver.hpp"
+#include <systemlib/err.h>
+#include <mathlib/mathlib.h>
+
+#define MM_PER_CM 			10	// Millimeters per centimeter
+
+UavcanGnssReceiver::UavcanGnssReceiver(uavcan::INode &node) :
+_node(node),
+_uavcan_sub_status(node),
+_report_pub(-1)
+{
+}
+
+int UavcanGnssReceiver::init()
+{
+	int res = -1;
+
+	// GNSS fix subscription
+	res = _uavcan_sub_status.start(FixCbBinder(this, &UavcanGnssReceiver::gnss_fix_sub_cb));
+	if (res < 0)
+	{
+		warnx("GNSS fix sub failed %i", res);
+		return res;
+	}
+
+	// Clear the uORB GPS report
+	memset(&_report, 0, sizeof(_report));
+
+	return res;
+}
+
+void UavcanGnssReceiver::gnss_fix_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::gnss::Fix> &msg)
+{
+	_report.timestamp_position = hrt_absolute_time();
+	_report.lat = msg.lat_1e7;
+	_report.lon = msg.lon_1e7;
+	_report.alt = msg.alt_1e2 * MM_PER_CM;	// Convert from centimeter (1e2) to millimeters (1e3)
+
+	_report.timestamp_variance = _report.timestamp_position;
+
+
+	// Check if the msg contains valid covariance information
+	const bool valid_position_covariance = !msg.position_covariance.empty();
+	const bool valid_velocity_covariance = !msg.velocity_covariance.empty();
+
+	if (valid_position_covariance) {
+		float pos_cov[9];
+		msg.position_covariance.unpackSquareMatrix(pos_cov);
+
+		// Horizontal position uncertainty
+		const float horizontal_pos_variance = math::max(pos_cov[0], pos_cov[4]);
+		_report.eph = (horizontal_pos_variance > 0) ? sqrtf(horizontal_pos_variance) : -1.0F;
+
+		// Vertical position uncertainty
+		_report.epv = (pos_cov[8] > 0) ? sqrtf(pos_cov[8]) : -1.0F;
+	} else {
+		_report.eph = -1.0F;
+		_report.epv = -1.0F;
+	}
+
+	if (valid_velocity_covariance) {
+	    float vel_cov[9];
+	    msg.velocity_covariance.unpackSquareMatrix(vel_cov);
+		_report.s_variance_m_s = math::max(math::max(vel_cov[0], vel_cov[4]), vel_cov[8]);
+
+		/* There is a nonlinear relationship between the velocity vector and the heading.
+		 * Use Jacobian to transform velocity covariance to heading covariance
+		 *
+		 * Nonlinear equation:
+		 * heading = atan2(vel_e_m_s, vel_n_m_s)
+		 * For math, see http://en.wikipedia.org/wiki/Atan2#Derivative
+		 *
+		 * To calculate the variance of heading from the variance of velocity,
+		 * cov(heading) = J(velocity)*cov(velocity)*J(velocity)^T
+		 */
+		float vel_n = msg.ned_velocity[0];
+		float vel_e = msg.ned_velocity[1];
+		float vel_n_sq = vel_n * vel_n;
+		float vel_e_sq = vel_e * vel_e;
+		_report.c_variance_rad =
+				(vel_e_sq * vel_cov[0] +
+						-2 * vel_n * vel_e * vel_cov[1] +	// Covariance matrix is symmetric
+						vel_n_sq* vel_cov[4]) / ((vel_n_sq + vel_e_sq) * (vel_n_sq + vel_e_sq));
+
+	} else {
+		_report.s_variance_m_s = -1.0F;
+		_report.c_variance_rad = -1.0F;
+	}
+
+	_report.fix_type = msg.status;
+
+	_report.timestamp_velocity = _report.timestamp_position;
+	_report.vel_n_m_s = msg.ned_velocity[0];
+	_report.vel_e_m_s = msg.ned_velocity[1];
+	_report.vel_d_m_s = msg.ned_velocity[2];
+	_report.vel_m_s = sqrtf(_report.vel_n_m_s * _report.vel_n_m_s + _report.vel_e_m_s * _report.vel_e_m_s + _report.vel_d_m_s * _report.vel_d_m_s);
+	_report.cog_rad = atan2f(_report.vel_e_m_s, _report.vel_n_m_s);
+	_report.vel_ned_valid = true;
+
+	_report.timestamp_time = _report.timestamp_position;
+	_report.time_gps_usec = uavcan::UtcTime(msg.gnss_timestamp).toUSec();	// Convert to microseconds
+
+	_report.satellites_used = msg.sats_used;
+
+	if (_report_pub > 0) {
+		orb_publish(ORB_ID(vehicle_gps_position), _report_pub, &_report);
+
+	} else {
+		_report_pub = orb_advertise(ORB_ID(vehicle_gps_position), &_report);
+	}
+
+}

src/modules/uavcan/gnss_receiver.hpp

@@ -0,0 +1,84 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2014 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 gnss_receiver.hpp
+ *
+ * UAVCAN --> ORB bridge for GNSS messages:
+ *     uavcan.equipment.gnss.Fix
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ * @author Andrew Chambers <achamber@gmail.com>
+ */
+
+#pragma once
+
+#include <drivers/drv_hrt.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_gps_position.h>
+
+#include <uavcan/uavcan.hpp>
+#include <uavcan/equipment/gnss/Fix.hpp>
+
+class UavcanGnssReceiver
+{
+public:
+	UavcanGnssReceiver(uavcan::INode& node);
+
+	int init();
+
+private:
+	/**
+	 * GNSS fix message will be reported via this callback.
+	 */
+	void gnss_fix_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::gnss::Fix> &msg);
+
+
+	typedef uavcan::MethodBinder<UavcanGnssReceiver*,
+		void (UavcanGnssReceiver::*)(const uavcan::ReceivedDataStructure<uavcan::equipment::gnss::Fix>&)>
+		FixCbBinder;
+
+	/*
+	 * libuavcan related things
+	 */
+	uavcan::INode													&_node;
+	uavcan::Subscriber<uavcan::equipment::gnss::Fix, FixCbBinder>	_uavcan_sub_status;
+
+	/*
+	 * uORB
+	 */
+	struct vehicle_gps_position_s 	_report;					///< uORB topic for gnss position
+	orb_advert_t			_report_pub;					///< uORB pub for gnss position
+
+};

src/modules/uavcan/module.mk

@@ -0,0 +1,74 @@
+############################################################################
+#
+#   Copyright (C) 2013 PX4 Development Team. All rights reserved.
+#   Author: Pavel Kirienko <pavel.kirienko@gmail.com>
+#
+# 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.
+#
+############################################################################
+
+#
+# UAVCAN <--> uORB bridge
+#
+
+MODULE_COMMAND = uavcan
+
+MAXOPTIMIZATION = -Os
+
+SRCS += uavcan_main.cpp         \
+        uavcan_clock.cpp        \
+        esc_controller.cpp      \
+        gnss_receiver.cpp
+
+#
+# libuavcan
+#
+include $(UAVCAN_DIR)/libuavcan/include.mk
+SRCS += $(LIBUAVCAN_SRC)
+INCLUDE_DIRS += $(LIBUAVCAN_INC)
+# Since actual compiler mode is C++11, the library will default to UAVCAN_CPP11, but it will fail to compile
+# because this platform lacks most of the standard library and STL. Hence we need to force C++03 mode.
+override EXTRADEFINES := $(EXTRADEFINES) -DUAVCAN_CPP_VERSION=UAVCAN_CPP03 -DUAVCAN_NO_ASSERTIONS
+
+#
+# libuavcan drivers for STM32
+#
+include $(UAVCAN_DIR)/libuavcan_drivers/stm32/driver/include.mk
+SRCS += $(LIBUAVCAN_STM32_SRC)
+INCLUDE_DIRS += $(LIBUAVCAN_STM32_INC)
+override EXTRADEFINES := $(EXTRADEFINES) -DUAVCAN_STM32_NUTTX -DUAVCAN_STM32_NUM_IFACES=2
+
+#
+# Invoke DSDL compiler
+# TODO: Add make target for this, or invoke dsdlc manually.
+#       The second option assumes that the generated headers shall be saved
+#       under the version control, which may be undesirable.
+#       The first option requires any Python and the Python Mako library for the sources to be built.
+#
+$(info $(shell $(LIBUAVCAN_DSDLC) $(UAVCAN_DSDL_DIR)))
+INCLUDE_DIRS += dsdlc_generated

src/modules/uavcan/uavcan_clock.cpp

@@ -0,0 +1,79 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2014 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.
+ *
+ ****************************************************************************/
+
+#include <uavcan_stm32/uavcan_stm32.hpp>
+#include <drivers/drv_hrt.h>
+
+/**
+ * @file uavcan_clock.cpp
+ *
+ * Implements a clock for the CAN node.
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+namespace uavcan_stm32
+{
+namespace clock
+{
+
+uavcan::MonotonicTime getMonotonic()
+{
+	return uavcan::MonotonicTime::fromUSec(hrt_absolute_time());
+}
+
+uavcan::UtcTime getUtc()
+{
+	return uavcan::UtcTime();
+}
+
+void adjustUtc(uavcan::UtcDuration adjustment)
+{
+	(void)adjustment;
+}
+
+uavcan::uint64_t getUtcUSecFromCanInterrupt()
+{
+	return 0;
+}
+
+} // namespace clock
+
+SystemClock &SystemClock::instance()
+{
+	static SystemClock inst;
+	return inst;
+}
+
+}
+

src/modules/uavcan/uavcan_main.cpp

@@ -0,0 +1,582 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2014 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.
+ *
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <cstdlib>
+#include <cstring>
+#include <fcntl.h>
+#include <systemlib/err.h>
+#include <systemlib/systemlib.h>
+#include <systemlib/mixer/mixer.h>
+#include <arch/board/board.h>
+#include <arch/chip/chip.h>
+
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_pwm_output.h>
+
+#include "uavcan_main.hpp"
+
+/**
+ * @file uavcan_main.cpp
+ *
+ * Implements basic functinality of UAVCAN node.
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+/*
+ * UavcanNode
+ */
+UavcanNode *UavcanNode::_instance;
+
+UavcanNode::UavcanNode(uavcan::ICanDriver &can_driver, uavcan::ISystemClock &system_clock) :
+	CDev("uavcan", UAVCAN_DEVICE_PATH),
+	_node(can_driver, system_clock),
+	_esc_controller(_node),
+	_gnss_receiver(_node)
+{
+	_control_topics[0] = ORB_ID(actuator_controls_0);
+	_control_topics[1] = ORB_ID(actuator_controls_1);
+	_control_topics[2] = ORB_ID(actuator_controls_2);
+	_control_topics[3] = ORB_ID(actuator_controls_3);
+
+	// memset(_controls, 0, sizeof(_controls));
+	// memset(_poll_fds, 0, sizeof(_poll_fds));
+}
+
+UavcanNode::~UavcanNode()
+{
+	if (_task != -1) {
+		/* tell the task we want it to go away */
+		_task_should_exit = true;
+
+		unsigned i = 10;
+
+		do {
+			/* wait 5ms - it should wake every 10ms or so worst-case */
+			usleep(5000);
+
+			/* if we have given up, kill it */
+			if (--i == 0) {
+				task_delete(_task);
+				break;
+			}
+
+		} while (_task != -1);
+	}
+
+	/* clean up the alternate device node */
+		// unregister_driver(PWM_OUTPUT_DEVICE_PATH);
+
+	::close(_armed_sub);
+
+	_instance = nullptr;
+}
+
+int UavcanNode::start(uavcan::NodeID node_id, uint32_t bitrate)
+{
+	if (_instance != nullptr) {
+		warnx("Already started");
+		return -1;
+	}
+
+	/*
+	 * GPIO config.
+	 * Forced pull up on CAN2 is required for Pixhawk v1 where the second interface lacks a transceiver.
+	 * If no transceiver is connected, the RX pin will float, occasionally causing CAN controller to
+	 * fail during initialization.
+	 */
+	stm32_configgpio(GPIO_CAN1_RX);
+	stm32_configgpio(GPIO_CAN1_TX);
+	stm32_configgpio(GPIO_CAN2_RX | GPIO_PULLUP);
+	stm32_configgpio(GPIO_CAN2_TX);
+
+	/*
+	 * CAN driver init
+	 */
+	static CanInitHelper can;
+	static bool can_initialized = false;
+
+	if (!can_initialized) {
+		const int can_init_res = can.init(bitrate);
+
+		if (can_init_res < 0) {
+			warnx("CAN driver init failed %i", can_init_res);
+			return can_init_res;
+		}
+
+		can_initialized = true;
+	}
+
+	/*
+	 * Node init
+	 */
+	_instance = new UavcanNode(can.driver, uavcan_stm32::SystemClock::instance());
+
+	if (_instance == nullptr) {
+		warnx("Out of memory");
+		return -1;
+	}
+
+	const int node_init_res = _instance->init(node_id);
+
+	if (node_init_res < 0) {
+		delete _instance;
+		_instance = nullptr;
+		warnx("Node init failed %i", node_init_res);
+		return node_init_res;
+	}
+
+	/*
+	 * Start the task. Normally it should never exit.
+	 */
+	static auto run_trampoline = [](int, char *[]) {return UavcanNode::_instance->run();};
+	_instance->_task = task_spawn_cmd("uavcan", SCHED_DEFAULT, SCHED_PRIORITY_DEFAULT, StackSize,
+			      static_cast<main_t>(run_trampoline), nullptr);
+
+	if (_instance->_task < 0) {
+		warnx("start failed: %d", errno);
+		return -errno;
+	}
+
+	return OK;
+}
+
+int UavcanNode::init(uavcan::NodeID node_id)
+{
+	int ret = -1;
+
+	/* do regular cdev init */
+	ret = CDev::init();
+
+	if (ret != OK)
+		return ret;
+
+	ret = _esc_controller.init();
+	if (ret < 0)
+		return ret;
+
+	ret = _gnss_receiver.init();
+	if (ret < 0)
+		return ret;
+
+	uavcan::protocol::SoftwareVersion swver;
+	swver.major = 12;                        // TODO fill version info
+	swver.minor = 34;
+	_node.setSoftwareVersion(swver);
+
+	uavcan::protocol::HardwareVersion hwver;
+	hwver.major = 42;                        // TODO fill version info
+	hwver.minor = 42;
+	_node.setHardwareVersion(hwver);
+
+	_node.setName("org.pixhawk"); // Huh?
+
+	_node.setNodeID(node_id);
+
+	return _node.start();
+}
+
+void UavcanNode::node_spin_once()
+{
+	const int spin_res = _node.spin(uavcan::MonotonicTime());
+	if (spin_res < 0) {
+		warnx("node spin error %i", spin_res);
+	}
+}
+
+int UavcanNode::run()
+{
+	const unsigned PollTimeoutMs = 50;
+
+	// XXX figure out the output count
+	_output_count = 2;
+
+
+	_armed_sub = orb_subscribe(ORB_ID(actuator_armed));
+
+	actuator_outputs_s outputs;
+	memset(&outputs, 0, sizeof(outputs));
+
+	const int busevent_fd = ::open(uavcan_stm32::BusEvent::DevName, 0);
+	if (busevent_fd < 0)
+	{
+		warnx("Failed to open %s", uavcan_stm32::BusEvent::DevName);
+		_task_should_exit = true;
+	}
+
+	/*
+	 * XXX Mixing logic/subscriptions shall be moved into UavcanEscController::update();
+	 *     IO multiplexing shall be done here.
+	 */
+
+	_node.setStatusOk();
+
+	while (!_task_should_exit) {
+
+		if (_groups_subscribed != _groups_required) {
+			subscribe();
+			_groups_subscribed = _groups_required;
+			/*
+			 * This event is needed to wake up the thread on CAN bus activity (RX/TX/Error).
+			 * Please note that with such multiplexing it is no longer possible to rely only on
+			 * the value returned from poll() to detect whether actuator control has timed out or not.
+			 * Instead, all ORB events need to be checked individually (see below).
+			 */
+			_poll_fds[_poll_fds_num] = ::pollfd();
+			_poll_fds[_poll_fds_num].fd = busevent_fd;
+			_poll_fds[_poll_fds_num].events = POLLIN;
+			_poll_fds_num += 1;
+		}
+
+		const int poll_ret = ::poll(_poll_fds, _poll_fds_num, PollTimeoutMs);
+
+		node_spin_once();  // Non-blocking
+
+		// this would be bad...
+		if (poll_ret < 0) {
+			log("poll error %d", errno);
+			continue;
+		} else {
+			// get controls for required topics
+			bool controls_updated = false;
+			unsigned poll_id = 0;
+			for (unsigned i = 0; i < NUM_ACTUATOR_CONTROL_GROUPS; i++) {
+				if (_control_subs[i] > 0) {
+					if (_poll_fds[poll_id].revents & POLLIN) {
+						controls_updated = true;
+						orb_copy(_control_topics[i], _control_subs[i], &_controls[i]);
+					}
+					poll_id++;
+				}
+			}
+
+			if (!controls_updated) {
+				// timeout: no control data, switch to failsafe values
+				// XXX trigger failsafe
+			}
+
+			//can we mix?
+			if (controls_updated && (_mixers != nullptr)) {
+
+				// XXX one output group has 8 outputs max,
+				// but this driver could well serve multiple groups.
+				unsigned num_outputs_max = 8;
+
+				// Do mixing
+				outputs.noutputs = _mixers->mix(&outputs.output[0], num_outputs_max);
+				outputs.timestamp = hrt_absolute_time();
+
+				// iterate actuators
+				for (unsigned i = 0; i < outputs.noutputs; i++) {
+					// last resort: catch NaN, INF and out-of-band errors
+					if (!isfinite(outputs.output[i])) {
+						/*
+						 * Value is NaN, INF or out of band - set to the minimum value.
+						 * This will be clearly visible on the servo status and will limit the risk of accidentally
+						 * spinning motors. It would be deadly in flight.
+						 */
+						outputs.output[i] = -1.0f;
+					}
+
+					// limit outputs to valid range
+
+					// never go below min
+					if (outputs.output[i] < -1.0f) {
+						outputs.output[i] = -1.0f;
+					}
+
+					// never go below max
+					if (outputs.output[i] > 1.0f) {
+						outputs.output[i] = 1.0f;
+					}
+				}
+
+				// Output to the bus
+				_esc_controller.update_outputs(outputs.output, outputs.noutputs);
+			}
+
+		}
+
+		// Check arming state
+		bool updated = false;
+		orb_check(_armed_sub, &updated);
+
+		if (updated) {
+			orb_copy(ORB_ID(actuator_armed), _armed_sub, &_armed);
+
+			// Update the armed status and check that we're not locked down
+			bool set_armed = _armed.armed && !_armed.lockdown;
+
+			arm_actuators(set_armed);
+		}
+	}
+
+	teardown();
+	warnx("exiting.");
+
+	exit(0);
+}
+
+int
+UavcanNode::control_callback(uintptr_t handle,
+			 uint8_t control_group,
+			 uint8_t control_index,
+			 float &input)
+{
+	const actuator_controls_s *controls = (actuator_controls_s *)handle;
+
+	input = controls[control_group].control[control_index];
+	return 0;
+}
+
+int
+UavcanNode::teardown()
+{
+	for (unsigned i = 0; i < NUM_ACTUATOR_CONTROL_GROUPS; i++) {
+		if (_control_subs[i] > 0) {
+			::close(_control_subs[i]);
+			_control_subs[i] = -1;
+		}
+	}
+	return ::close(_armed_sub);
+}
+
+int
+UavcanNode::arm_actuators(bool arm)
+{
+	_is_armed = arm;
+	_esc_controller.arm_esc(arm);
+	return OK;
+}
+
+void
+UavcanNode::subscribe()
+{
+	// Subscribe/unsubscribe to required actuator control groups
+	uint32_t sub_groups = _groups_required & ~_groups_subscribed;
+	uint32_t unsub_groups = _groups_subscribed & ~_groups_required;
+	_poll_fds_num = 0;
+	for (unsigned i = 0; i < NUM_ACTUATOR_CONTROL_GROUPS; i++) {
+		if (sub_groups & (1 << i)) {
+			warnx("subscribe to actuator_controls_%d", i);
+			_control_subs[i] = orb_subscribe(_control_topics[i]);
+		}
+		if (unsub_groups & (1 << i)) {
+			warnx("unsubscribe from actuator_controls_%d", i);
+			::close(_control_subs[i]);
+			_control_subs[i] = -1;
+		}
+
+		if (_control_subs[i] > 0) {
+			_poll_fds[_poll_fds_num].fd = _control_subs[i];
+			_poll_fds[_poll_fds_num].events = POLLIN;
+			_poll_fds_num++;
+		}
+	}
+}
+
+int
+UavcanNode::ioctl(file *filp, int cmd, unsigned long arg)
+{
+	int ret = OK;
+
+	lock();
+
+	switch (cmd) {
+	case PWM_SERVO_ARM:
+		arm_actuators(true);
+		break;
+
+	case PWM_SERVO_SET_ARM_OK:
+	case PWM_SERVO_CLEAR_ARM_OK:
+	case PWM_SERVO_SET_FORCE_SAFETY_OFF:
+		// these are no-ops, as no safety switch
+		break;
+
+	case PWM_SERVO_DISARM:
+		arm_actuators(false);
+		break;
+
+	case MIXERIOCGETOUTPUTCOUNT:
+		*(unsigned *)arg = _output_count;
+		break;
+
+	case MIXERIOCRESET:
+		if (_mixers != nullptr) {
+			delete _mixers;
+			_mixers = nullptr;
+			_groups_required = 0;
+		}
+
+		break;
+
+	case MIXERIOCLOADBUF: {
+			const char *buf = (const char *)arg;
+			unsigned buflen = strnlen(buf, 1024);
+
+			if (_mixers == nullptr)
+				_mixers = new MixerGroup(control_callback, (uintptr_t)_controls);
+
+			if (_mixers == nullptr) {
+				_groups_required = 0;
+				ret = -ENOMEM;
+
+			} else {
+
+				ret = _mixers->load_from_buf(buf, buflen);
+
+				if (ret != 0) {
+					warnx("mixer load failed with %d", ret);
+					delete _mixers;
+					_mixers = nullptr;
+					_groups_required = 0;
+					ret = -EINVAL;
+				} else {
+
+					_mixers->groups_required(_groups_required);
+				}
+			}
+
+			break;
+		}
+
+	default:
+		ret = -ENOTTY;
+		break;
+	}
+
+	unlock();
+
+	if (ret == -ENOTTY) {
+		ret = CDev::ioctl(filp, cmd, arg);
+	}
+
+	return ret;
+}
+
+void
+UavcanNode::print_info()
+{
+	if (!_instance) {
+		warnx("not running, start first");
+	}
+
+	warnx("groups: sub: %u / req: %u / fds: %u", (unsigned)_groups_subscribed, (unsigned)_groups_required, _poll_fds_num);
+	warnx("mixer: %s", (_mixers == nullptr) ? "FAIL" : "OK");
+}
+
+/*
+ * App entry point
+ */
+static void print_usage()
+{
+	warnx("usage: uavcan start <node_id> [can_bitrate]");
+}
+
+extern "C" __EXPORT int uavcan_main(int argc, char *argv[]);
+
+int uavcan_main(int argc, char *argv[])
+{
+	constexpr unsigned DEFAULT_CAN_BITRATE = 1000000;
+
+	if (argc < 2) {
+		print_usage();
+		::exit(1);
+	}
+
+	if (!std::strcmp(argv[1], "start")) {
+		if (argc < 3) {
+			print_usage();
+			::exit(1);
+		}
+
+		/*
+		 * Node ID
+		 */
+		const int node_id = atoi(argv[2]);
+
+		if (node_id < 0 || node_id > uavcan::NodeID::Max || !uavcan::NodeID(node_id).isUnicast()) {
+			warnx("Invalid Node ID %i", node_id);
+			::exit(1);
+		}
+
+		/*
+		 * CAN bitrate
+		 */
+		unsigned bitrate = 0;
+
+		if (argc > 3) {
+			bitrate = atol(argv[3]);
+		}
+
+		if (bitrate <= 0) {
+			bitrate = DEFAULT_CAN_BITRATE;
+		}
+
+		if (UavcanNode::instance()) {
+			errx(1, "already started");
+		}
+
+		/*
+		 * Start
+		 */
+		warnx("Node ID %u, bitrate %u", node_id, bitrate);
+		return UavcanNode::start(node_id, bitrate);
+
+	}
+
+	/* commands below require the app to be started */
+	UavcanNode *inst = UavcanNode::instance();
+
+	if (!inst) {
+		errx(1, "application not running");
+	}
+
+	if (!std::strcmp(argv[1], "status") || !std::strcmp(argv[1], "info")) {
+		
+			inst->print_info();
+			return OK;
+	}
+
+	if (!std::strcmp(argv[1], "stop")) {
+		
+			delete inst;
+			inst = nullptr;
+			return OK;
+	}
+
+	print_usage();
+	::exit(1);
+}

src/modules/uavcan/uavcan_main.hpp

@@ -0,0 +1,123 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2014 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 <nuttx/config.h>
+
+#include <uavcan_stm32/uavcan_stm32.hpp>
+#include <drivers/device/device.h>
+
+#include <uORB/topics/actuator_controls.h>
+#include <uORB/topics/actuator_outputs.h>
+#include <uORB/topics/actuator_armed.h>
+
+#include "esc_controller.hpp"
+#include "gnss_receiver.hpp"
+
+/**
+ * @file uavcan_main.hpp
+ *
+ * Defines basic functinality of UAVCAN node.
+ *
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+#define NUM_ACTUATOR_CONTROL_GROUPS_UAVCAN	4
+#define UAVCAN_DEVICE_PATH	"/dev/uavcan/esc"
+
+/**
+ * A UAVCAN node.
+ */
+class UavcanNode : public device::CDev
+{
+	static constexpr unsigned MemPoolSize        = 10752;
+	static constexpr unsigned RxQueueLenPerIface = 64;
+	static constexpr unsigned StackSize          = 3000;
+
+public:
+	typedef uavcan::Node<MemPoolSize> Node;
+	typedef uavcan_stm32::CanInitHelper<RxQueueLenPerIface> CanInitHelper;
+
+	UavcanNode(uavcan::ICanDriver &can_driver, uavcan::ISystemClock &system_clock);
+
+	virtual		~UavcanNode();
+
+	virtual int	ioctl(file *filp, int cmd, unsigned long arg);
+
+	static int	start(uavcan::NodeID node_id, uint32_t bitrate);
+
+	Node&		getNode() { return _node; }
+
+	static int	control_callback(uintptr_t handle,
+					 uint8_t control_group,
+					 uint8_t control_index,
+					 float &input);
+
+	void		subscribe();
+
+	int		teardown();
+	int		arm_actuators(bool arm);
+
+	void		print_info();
+
+	static UavcanNode* instance() { return _instance; }
+
+private:
+	int		init(uavcan::NodeID node_id);
+	void		node_spin_once();
+	int		run();
+
+	int			_task = -1;			///< handle to the OS task
+	bool			_task_should_exit = false;	///< flag to indicate to tear down the CAN driver
+	int			_armed_sub = -1;		///< uORB subscription of the arming status
+	actuator_armed_s	_armed;				///< the arming request of the system
+	bool			_is_armed = false;		///< the arming status of the actuators on the bus
+
+	unsigned		_output_count = 0;		///< number of actuators currently available
+
+	static UavcanNode	*_instance;			///< singleton pointer
+	Node			_node;				///< library instance
+	UavcanEscController	_esc_controller;
+	UavcanGnssReceiver 	_gnss_receiver;
+
+	MixerGroup		*_mixers = nullptr;
+
+	uint32_t		_groups_required = 0;
+	uint32_t		_groups_subscribed = 0;
+	int			_control_subs[NUM_ACTUATOR_CONTROL_GROUPS_UAVCAN] = {};
+	actuator_controls_s 	_controls[NUM_ACTUATOR_CONTROL_GROUPS_UAVCAN] = {};
+	orb_id_t		_control_topics[NUM_ACTUATOR_CONTROL_GROUPS_UAVCAN] = {};
+	pollfd			_poll_fds[NUM_ACTUATOR_CONTROL_GROUPS_UAVCAN + 1] = {};	///< +1 for /dev/uavcan/busevent
+	unsigned		_poll_fds_num = 0;
+};