Cut over MAVLink to new build system

1 files changed, 825 insertions, 0 deletions

diff --git a/src/modules/mavlink/mavlink.c b/src/modules/mavlink/mavlink.c
new file mode 100644
index 000000000..de78cd139
--- /dev/null
+++ b/src/modules/mavlink/mavlink.c
@@ -0,0 +1,825 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *   Author: Lorenz Meier <lm@inf.ethz.ch>
+ *
+ * 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 mavlink.c
+ * MAVLink 1.0 protocol implementation.
+ *
+ * @author Lorenz Meier <lm@inf.ethz.ch>
+ */
+
+#include <nuttx/config.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <math.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <mqueue.h>
+#include <string.h>
+#include "mavlink_bridge_header.h"
+#include <v1.0/common/mavlink.h>
+#include <drivers/drv_hrt.h>
+#include <time.h>
+#include <float.h>
+#include <unistd.h>
+#include <nuttx/sched.h>
+#include <sys/prctl.h>
+#include <termios.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <poll.h>
+
+#include <systemlib/param/param.h>
+#include <systemlib/systemlib.h>
+#include <systemlib/err.h>
+#include <mavlink/mavlink_log.h>
+
+#include "waypoints.h"
+#include "orb_topics.h"
+#include "missionlib.h"
+#include "mavlink_hil.h"
+#include "util.h"
+#include "waypoints.h"
+#include "mavlink_parameters.h"
+
+/* define MAVLink specific parameters */
+PARAM_DEFINE_INT32(MAV_SYS_ID, 1);
+PARAM_DEFINE_INT32(MAV_COMP_ID, 50);
+PARAM_DEFINE_INT32(MAV_TYPE, MAV_TYPE_FIXED_WING);
+
+__EXPORT int mavlink_main(int argc, char *argv[]);
+
+static int mavlink_thread_main(int argc, char *argv[]);
+
+/* thread state */
+volatile bool thread_should_exit = false;
+static volatile bool thread_running = false;
+static int mavlink_task;
+
+/* pthreads */
+static pthread_t receive_thread;
+static pthread_t uorb_receive_thread;
+
+/* terminate MAVLink on user request - disabled by default */
+static bool mavlink_link_termination_allowed = false;
+
+mavlink_system_t mavlink_system = {
+	100,
+	50,
+	MAV_TYPE_FIXED_WING,
+	0,
+	0,
+	0
+}; // System ID, 1-255, Component/Subsystem ID, 1-255
+
+/* XXX not widely used */
+uint8_t chan = MAVLINK_COMM_0;
+
+/* XXX probably should be in a header... */
+extern pthread_t receive_start(int uart);
+
+/* Allocate storage space for waypoints */
+static mavlink_wpm_storage wpm_s;
+mavlink_wpm_storage *wpm = &wpm_s;
+
+bool mavlink_hil_enabled = false;
+
+/* protocol interface */
+static int uart;
+static int baudrate;
+bool gcs_link = true;
+
+/* interface mode */
+static enum {
+	MAVLINK_INTERFACE_MODE_OFFBOARD,
+	MAVLINK_INTERFACE_MODE_ONBOARD
+} mavlink_link_mode = MAVLINK_INTERFACE_MODE_OFFBOARD;
+
+static struct mavlink_logbuffer lb;
+
+static void mavlink_update_system(void);
+static int mavlink_open_uart(int baudrate, const char *uart_name, struct termios *uart_config_original, bool *is_usb);
+static void usage(void);
+int set_mavlink_interval_limit(struct mavlink_subscriptions *subs, int mavlink_msg_id, int min_interval);
+
+
+
+int
+set_hil_on_off(bool hil_enabled)
+{
+	int ret = OK;
+
+	/* Enable HIL */
+	if (hil_enabled && !mavlink_hil_enabled) {
+
+		/* Advertise topics */
+		pub_hil_attitude = orb_advertise(ORB_ID(vehicle_attitude), &hil_attitude);
+		pub_hil_global_pos = orb_advertise(ORB_ID(vehicle_global_position), &hil_global_pos);
+
+		/* sensore level hil */
+		pub_hil_sensors = orb_advertise(ORB_ID(sensor_combined), &hil_sensors);
+		pub_hil_gps = orb_advertise(ORB_ID(vehicle_gps_position), &hil_gps);
+
+		mavlink_hil_enabled = true;
+
+		/* ramp up some HIL-related subscriptions */
+		unsigned hil_rate_interval;
+
+		if (baudrate < 19200) {
+			/* 10 Hz */
+			hil_rate_interval = 100;
+
+		} else if (baudrate < 38400) {
+			/* 10 Hz */
+			hil_rate_interval = 100;
+
+		} else if (baudrate < 115200) {
+			/* 20 Hz */
+			hil_rate_interval = 50;
+
+		} else {
+			/* 200 Hz */
+			hil_rate_interval = 5;
+		}
+
+		orb_set_interval(mavlink_subs.spa_sub, hil_rate_interval);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, hil_rate_interval);
+	}
+
+	if (!hil_enabled && mavlink_hil_enabled) {
+		mavlink_hil_enabled = false;
+		orb_set_interval(mavlink_subs.spa_sub, 200);
+
+	} else {
+		ret = ERROR;
+	}
+
+	return ret;
+}
+
+void
+get_mavlink_mode_and_state(uint8_t *mavlink_state, uint8_t *mavlink_mode)
+{
+	/* reset MAVLink mode bitfield */
+	*mavlink_mode = 0;
+
+	/* set mode flags independent of system state */
+
+	/* HIL */
+	if (v_status.flag_hil_enabled) {
+		*mavlink_mode |= MAV_MODE_FLAG_HIL_ENABLED;
+	}
+
+	/* manual input */
+	if (v_status.flag_control_manual_enabled) {
+		*mavlink_mode |= MAV_MODE_FLAG_MANUAL_INPUT_ENABLED;
+	}
+
+	/* attitude or rate control */
+	if (v_status.flag_control_attitude_enabled ||
+	    v_status.flag_control_rates_enabled) {
+		*mavlink_mode |= MAV_MODE_FLAG_STABILIZE_ENABLED;
+	}
+
+	/* vector control */
+	if (v_status.flag_control_velocity_enabled ||
+	    v_status.flag_control_position_enabled) {
+		*mavlink_mode |= MAV_MODE_FLAG_GUIDED_ENABLED;
+	}
+
+	/* autonomous mode */
+	if (v_status.state_machine == SYSTEM_STATE_AUTO) {
+		*mavlink_mode |= MAV_MODE_FLAG_AUTO_ENABLED;
+	}
+
+	/* set arming state */
+	if (armed.armed) {
+		*mavlink_mode |= MAV_MODE_FLAG_SAFETY_ARMED;
+
+	} else {
+		*mavlink_mode &= ~MAV_MODE_FLAG_SAFETY_ARMED;
+	}
+
+	switch (v_status.state_machine) {
+	case SYSTEM_STATE_PREFLIGHT:
+		if (v_status.flag_preflight_gyro_calibration ||
+		    v_status.flag_preflight_mag_calibration ||
+		    v_status.flag_preflight_accel_calibration) {
+			*mavlink_state = MAV_STATE_CALIBRATING;
+
+		} else {
+			*mavlink_state = MAV_STATE_UNINIT;
+		}
+
+		break;
+
+	case SYSTEM_STATE_STANDBY:
+		*mavlink_state = MAV_STATE_STANDBY;
+		break;
+
+	case SYSTEM_STATE_GROUND_READY:
+		*mavlink_state = MAV_STATE_ACTIVE;
+		break;
+
+	case SYSTEM_STATE_MANUAL:
+		*mavlink_state = MAV_STATE_ACTIVE;
+		break;
+
+	case SYSTEM_STATE_STABILIZED:
+		*mavlink_state = MAV_STATE_ACTIVE;
+		break;
+
+	case SYSTEM_STATE_AUTO:
+		*mavlink_state = MAV_STATE_ACTIVE;
+		break;
+
+	case SYSTEM_STATE_MISSION_ABORT:
+		*mavlink_state = MAV_STATE_EMERGENCY;
+		break;
+
+	case SYSTEM_STATE_EMCY_LANDING:
+		*mavlink_state = MAV_STATE_EMERGENCY;
+		break;
+
+	case SYSTEM_STATE_EMCY_CUTOFF:
+		*mavlink_state = MAV_STATE_EMERGENCY;
+		break;
+
+	case SYSTEM_STATE_GROUND_ERROR:
+		*mavlink_state = MAV_STATE_EMERGENCY;
+		break;
+
+	case SYSTEM_STATE_REBOOT:
+		*mavlink_state = MAV_STATE_POWEROFF;
+		break;
+	}
+
+}
+
+
+int set_mavlink_interval_limit(struct mavlink_subscriptions *subs, int mavlink_msg_id, int min_interval)
+{
+	int ret = OK;
+
+	switch (mavlink_msg_id) {
+	case MAVLINK_MSG_ID_SCALED_IMU:
+		/* sensor sub triggers scaled IMU */
+		orb_set_interval(subs->sensor_sub, min_interval);
+		break;
+
+	case MAVLINK_MSG_ID_HIGHRES_IMU:
+		/* sensor sub triggers highres IMU */
+		orb_set_interval(subs->sensor_sub, min_interval);
+		break;
+
+	case MAVLINK_MSG_ID_RAW_IMU:
+		/* sensor sub triggers RAW IMU */
+		orb_set_interval(subs->sensor_sub, min_interval);
+		break;
+
+	case MAVLINK_MSG_ID_ATTITUDE:
+		/* attitude sub triggers attitude */
+		orb_set_interval(subs->att_sub, min_interval);
+		break;
+
+	case MAVLINK_MSG_ID_SERVO_OUTPUT_RAW:
+		/* actuator_outputs triggers this message */
+		orb_set_interval(subs->act_0_sub, min_interval);
+		orb_set_interval(subs->act_1_sub, min_interval);
+		orb_set_interval(subs->act_2_sub, min_interval);
+		orb_set_interval(subs->act_3_sub, min_interval);
+		orb_set_interval(subs->actuators_sub, min_interval);
+		break;
+
+	case MAVLINK_MSG_ID_MANUAL_CONTROL:
+		/* manual_control_setpoint triggers this message */
+		orb_set_interval(subs->man_control_sp_sub, min_interval);
+		break;
+
+	case MAVLINK_MSG_ID_NAMED_VALUE_FLOAT:
+		orb_set_interval(subs->debug_key_value, min_interval);
+		break;
+
+	default:
+		/* not found */
+		ret = ERROR;
+		break;
+	}
+
+	return ret;
+}
+
+
+/****************************************************************************
+ * MAVLink text message logger
+ ****************************************************************************/
+
+static int	mavlink_dev_ioctl(struct file *filep, int cmd, unsigned long arg);
+
+static const struct file_operations mavlink_fops = {
+	.ioctl = mavlink_dev_ioctl
+};
+
+static int
+mavlink_dev_ioctl(struct file *filep, int cmd, unsigned long arg)
+{
+	static unsigned int total_counter = 0;
+
+	switch (cmd) {
+	case (int)MAVLINK_IOC_SEND_TEXT_INFO:
+	case (int)MAVLINK_IOC_SEND_TEXT_CRITICAL:
+	case (int)MAVLINK_IOC_SEND_TEXT_EMERGENCY: {
+			const char *txt = (const char *)arg;
+			struct mavlink_logmessage msg;
+			strncpy(msg.text, txt, sizeof(msg.text));
+			mavlink_logbuffer_write(&lb, &msg);
+			total_counter++;
+			return OK;
+		}
+
+	default:
+		return ENOTTY;
+	}
+}
+
+#define MAVLINK_OFFBOARD_CONTROL_FLAG_ARMED 0x10
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+int mavlink_open_uart(int baud, const char *uart_name, struct termios *uart_config_original, bool *is_usb)
+{
+	/* process baud rate */
+	int speed;
+
+	switch (baud) {
+	case 0:      speed = B0;      break;
+
+	case 50:     speed = B50;     break;
+
+	case 75:     speed = B75;     break;
+
+	case 110:    speed = B110;    break;
+
+	case 134:    speed = B134;    break;
+
+	case 150:    speed = B150;    break;
+
+	case 200:    speed = B200;    break;
+
+	case 300:    speed = B300;    break;
+
+	case 600:    speed = B600;    break;
+
+	case 1200:   speed = B1200;   break;
+
+	case 1800:   speed = B1800;   break;
+
+	case 2400:   speed = B2400;   break;
+
+	case 4800:   speed = B4800;   break;
+
+	case 9600:   speed = B9600;   break;
+
+	case 19200:  speed = B19200;  break;
+
+	case 38400:  speed = B38400;  break;
+
+	case 57600:  speed = B57600;  break;
+
+	case 115200: speed = B115200; break;
+
+	case 230400: speed = B230400; break;
+
+	case 460800: speed = B460800; break;
+
+	case 921600: speed = B921600; break;
+
+	default:
+		fprintf(stderr, "[mavlink] ERROR: Unsupported baudrate: %d\n\tsupported examples:\n\n\t9600\n19200\n38400\n57600\n115200\n230400\n460800\n921600\n\n", baud);
+		return -EINVAL;
+	}
+
+	/* open uart */
+	printf("[mavlink] UART is %s, baudrate is %d\n", uart_name, baud);
+	uart = open(uart_name, O_RDWR | O_NOCTTY);
+
+	/* Try to set baud rate */
+	struct termios uart_config;
+	int termios_state;
+	*is_usb = false;
+
+	/* make some wild guesses including that USB serial is indicated by either /dev/ttyACM0 or /dev/console */
+	if (strcmp(uart_name, "/dev/ttyACM0") != OK && strcmp(uart_name, "/dev/console") != OK) {
+		/* Back up the original uart configuration to restore it after exit */
+		if ((termios_state = tcgetattr(uart, uart_config_original)) < 0) {
+			fprintf(stderr, "[mavlink] ERROR getting baudrate / termios config for %s: %d\n", uart_name, termios_state);
+			close(uart);
+			return -1;
+		}
+
+		/* Fill the struct for the new configuration */
+		tcgetattr(uart, &uart_config);
+
+		/* Clear ONLCR flag (which appends a CR for every LF) */
+		uart_config.c_oflag &= ~ONLCR;
+
+		/* Set baud rate */
+		if (cfsetispeed(&uart_config, speed) < 0 || cfsetospeed(&uart_config, speed) < 0) {
+			fprintf(stderr, "[mavlink] ERROR setting baudrate / termios config for %s: %d (cfsetispeed, cfsetospeed)\n", uart_name, termios_state);
+			close(uart);
+			return -1;
+		}
+
+
+		if ((termios_state = tcsetattr(uart, TCSANOW, &uart_config)) < 0) {
+			fprintf(stderr, "[mavlink] ERROR setting baudrate / termios config for %s (tcsetattr)\n", uart_name);
+			close(uart);
+			return -1;
+		}
+
+	} else {
+		*is_usb = true;
+	}
+
+	return uart;
+}
+
+void
+mavlink_send_uart_bytes(mavlink_channel_t channel, uint8_t *ch, int length)
+{
+	write(uart, ch, (size_t)(sizeof(uint8_t) * length));
+}
+
+/*
+ * Internal function to give access to the channel status for each channel
+ */
+mavlink_status_t *mavlink_get_channel_status(uint8_t channel)
+{
+	static mavlink_status_t m_mavlink_status[MAVLINK_COMM_NUM_BUFFERS];
+	return &m_mavlink_status[channel];
+}
+
+/*
+ * Internal function to give access to the channel buffer for each channel
+ */
+mavlink_message_t *mavlink_get_channel_buffer(uint8_t channel)
+{
+	static mavlink_message_t m_mavlink_buffer[MAVLINK_COMM_NUM_BUFFERS];
+	return &m_mavlink_buffer[channel];
+}
+
+void mavlink_update_system(void)
+{
+	static bool initialized = false;
+	static param_t param_system_id;
+	static param_t param_component_id;
+	static param_t param_system_type;
+
+	if (!initialized) {
+		param_system_id = param_find("MAV_SYS_ID");
+		param_component_id = param_find("MAV_COMP_ID");
+		param_system_type = param_find("MAV_TYPE");
+		initialized = true;
+	}
+
+	/* update system and component id */
+	int32_t system_id;
+	param_get(param_system_id, &system_id);
+
+	if (system_id > 0 && system_id < 255) {
+		mavlink_system.sysid = system_id;
+	}
+
+	int32_t component_id;
+	param_get(param_component_id, &component_id);
+
+	if (component_id > 0 && component_id < 255) {
+		mavlink_system.compid = component_id;
+	}
+
+	int32_t system_type;
+	param_get(param_system_type, &system_type);
+
+	if (system_type >= 0 && system_type < MAV_TYPE_ENUM_END) {
+		mavlink_system.type = system_type;
+	}
+}
+
+/**
+ * MAVLink Protocol main function.
+ */
+int mavlink_thread_main(int argc, char *argv[])
+{
+	/* initialize mavlink text message buffering */
+	mavlink_logbuffer_init(&lb, 5);
+
+	int ch;
+	char *device_name = "/dev/ttyS1";
+	baudrate = 57600;
+
+	/* work around some stupidity in task_create's argv handling */
+	argc -= 2;
+	argv += 2;
+
+	while ((ch = getopt(argc, argv, "b:d:eo")) != EOF) {
+		switch (ch) {
+		case 'b':
+			baudrate = strtoul(optarg, NULL, 10);
+
+			if (baudrate == 0)
+				errx(1, "invalid baud rate '%s'", optarg);
+
+			break;
+
+		case 'd':
+			device_name = optarg;
+			break;
+
+		case 'e':
+			mavlink_link_termination_allowed = true;
+			break;
+
+		case 'o':
+			mavlink_link_mode = MAVLINK_INTERFACE_MODE_ONBOARD;
+			break;
+
+		default:
+			usage();
+		}
+	}
+
+	struct termios uart_config_original;
+
+	bool usb_uart;
+
+	/* print welcome text */
+	warnx("MAVLink v1.0 serial interface starting...");
+
+	/* inform about mode */
+	warnx((mavlink_link_mode == MAVLINK_INTERFACE_MODE_ONBOARD) ? "ONBOARD MODE" : "DOWNLINK MODE");
+
+	/* Flush stdout in case MAVLink is about to take it over */
+	fflush(stdout);
+
+	/* default values for arguments */
+	uart = mavlink_open_uart(baudrate, device_name, &uart_config_original, &usb_uart);
+
+	if (uart < 0)
+		err(1, "could not open %s", device_name);
+
+	/* create the device node that's used for sending text log messages, etc. */
+	register_driver(MAVLINK_LOG_DEVICE, &mavlink_fops, 0666, NULL);
+
+	/* Initialize system properties */
+	mavlink_update_system();
+
+	/* start the MAVLink receiver */
+	receive_thread = receive_start(uart);
+
+	/* start the ORB receiver */
+	uorb_receive_thread = uorb_receive_start();
+
+	/* initialize waypoint manager */
+	mavlink_wpm_init(wpm);
+
+	/* all subscriptions are now active, set up initial guess about rate limits */
+	if (baudrate >= 230400) {
+		/* 200 Hz / 5 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_HIGHRES_IMU, 20);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_RAW_IMU, 20);
+		/* 50 Hz / 20 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_ATTITUDE, 30);
+		/* 20 Hz / 50 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_NAMED_VALUE_FLOAT, 10);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, 50);
+		/* 10 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_GPS_RAW_INT, 100);
+		/* 10 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_MANUAL_CONTROL, 100);
+
+	} else if (baudrate >= 115200) {
+		/* 20 Hz / 50 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_HIGHRES_IMU, 50);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_RAW_IMU, 50);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_ATTITUDE, 50);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_NAMED_VALUE_FLOAT, 50);
+		/* 5 Hz / 200 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, 200);
+		/* 5 Hz / 200 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_GPS_RAW_INT, 200);
+		/* 2 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_MANUAL_CONTROL, 500);
+
+	} else if (baudrate >= 57600) {
+		/* 10 Hz / 100 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_RAW_IMU, 300);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_HIGHRES_IMU, 300);
+		/* 10 Hz / 100 ms ATTITUDE */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_ATTITUDE, 200);
+		/* 5 Hz / 200 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_NAMED_VALUE_FLOAT, 200);
+		/* 5 Hz / 200 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, 500);
+		/* 2 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_MANUAL_CONTROL, 500);
+		/* 2 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_GPS_RAW_INT, 500);
+
+	} else {
+		/* very low baud rate, limit to 1 Hz / 1000 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_RAW_IMU, 1000);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_ATTITUDE, 1000);
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_HIGHRES_IMU, 1000);
+		/* 1 Hz / 1000 ms */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_NAMED_VALUE_FLOAT, 1000);
+		/* 0.5 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_SERVO_OUTPUT_RAW, 2000);
+		/* 0.1 Hz */
+		set_mavlink_interval_limit(&mavlink_subs, MAVLINK_MSG_ID_MANUAL_CONTROL, 10000);
+	}
+
+	thread_running = true;
+
+	/* arm counter to go off immediately */
+	unsigned lowspeed_counter = 10;
+
+	while (!thread_should_exit) {
+
+		/* 1 Hz */
+		if (lowspeed_counter == 10) {
+			mavlink_update_system();
+
+			/* translate the current system state to mavlink state and mode */
+			uint8_t mavlink_state = 0;
+			uint8_t mavlink_mode = 0;
+			get_mavlink_mode_and_state(&mavlink_state, &mavlink_mode);
+
+			/* send heartbeat */
+			mavlink_msg_heartbeat_send(chan, mavlink_system.type, MAV_AUTOPILOT_PX4, mavlink_mode, v_status.state_machine, mavlink_state);
+
+			/* switch HIL mode if required */
+			set_hil_on_off(v_status.flag_hil_enabled);
+
+			/* send status (values already copied in the section above) */
+			mavlink_msg_sys_status_send(chan,
+						    v_status.onboard_control_sensors_present,
+						    v_status.onboard_control_sensors_enabled,
+						    v_status.onboard_control_sensors_health,
+						    v_status.load,
+						    v_status.voltage_battery * 1000.0f,
+						    v_status.current_battery * 1000.0f,
+						    v_status.battery_remaining,
+						    v_status.drop_rate_comm,
+						    v_status.errors_comm,
+						    v_status.errors_count1,
+						    v_status.errors_count2,
+						    v_status.errors_count3,
+						    v_status.errors_count4);
+			lowspeed_counter = 0;
+		}
+
+		lowspeed_counter++;
+
+		/* sleep quarter the time */
+		usleep(25000);
+
+		/* check if waypoint has been reached against the last positions */
+		mavlink_waypoint_eventloop(mavlink_missionlib_get_system_timestamp(), &global_pos, &local_pos);
+
+		/* sleep quarter the time */
+		usleep(25000);
+
+		/* send parameters at 20 Hz (if queued for sending) */
+		mavlink_pm_queued_send();
+
+		/* sleep quarter the time */
+		usleep(25000);
+
+		if (baudrate > 57600) {
+			mavlink_pm_queued_send();
+		}
+
+		/* sleep 10 ms */
+		usleep(10000);
+
+		/* send one string at 10 Hz */
+		if (!mavlink_logbuffer_is_empty(&lb)) {
+			struct mavlink_logmessage msg;
+			int lb_ret = mavlink_logbuffer_read(&lb, &msg);
+
+			if (lb_ret == OK) {
+				mavlink_missionlib_send_gcs_string(msg.text);
+			}
+		}
+
+		/* sleep 15 ms */
+		usleep(15000);
+	}
+
+	/* wait for threads to complete */
+	pthread_join(receive_thread, NULL);
+	pthread_join(uorb_receive_thread, NULL);
+
+	/* Reset the UART flags to original state */
+	if (!usb_uart)
+		tcsetattr(uart, TCSANOW, &uart_config_original);
+
+	thread_running = false;
+
+	exit(0);
+}
+
+static void
+usage()
+{
+	fprintf(stderr, "usage: mavlink start [-d <devicename>] [-b <baud rate>]\n"
+		"       mavlink stop\n"
+		"       mavlink status\n");
+	exit(1);
+}
+
+int mavlink_main(int argc, char *argv[])
+{
+
+	if (argc < 2) {
+		warnx("missing command");
+		usage();
+	}
+
+	if (!strcmp(argv[1], "start")) {
+
+		/* this is not an error */
+		if (thread_running)
+			errx(0, "mavlink already running\n");
+
+		thread_should_exit = false;
+		mavlink_task = task_spawn("mavlink",
+					  SCHED_DEFAULT,
+					  SCHED_PRIORITY_DEFAULT,
+					  2048,
+					  mavlink_thread_main,
+					  (const char **)argv);
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+		thread_should_exit = true;
+
+		while (thread_running) {
+			usleep(200000);
+			printf(".");
+		}
+
+		warnx("terminated.");
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (thread_running) {
+			errx(0, "running");
+
+		} else {
+			errx(1, "not running");
+		}
+	}
+
+	warnx("unrecognized command");
+	usage();
+	/* not getting here */
+	return 0;
+}
+