Merge branch 'master' into offboard2_merge

Conflicts:
	src/modules/uORB/topics/rc_channels.h

47 files changed, 689 insertions, 239 deletions

diff --git a/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_params.c b/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_params.c
index 49a892609..bc0e3b93a 100755
--- a/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_params.c
+++ b/src/modules/attitude_estimator_ekf/attitude_estimator_ekf_params.c
@@ -101,7 +101,7 @@ int parameters_update(const struct attitude_estimator_ekf_param_handles *h, stru
 	param_get(h->r3, &(p->r[3]));
 
 	param_get(h->mag_decl, &(p->mag_decl));
-	p->mag_decl *= M_PI / 180.0f;
+	p->mag_decl *= M_PI_F / 180.0f;
 
 	param_get(h->acc_comp, &(p->acc_comp));
 
diff --git a/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp b/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp
index e55b01160..e49027e47 100755
--- a/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp
+++ b/src/modules/attitude_estimator_so3/attitude_estimator_so3_main.cpp
@@ -392,8 +392,6 @@ void NonlinearSO3AHRSupdate(float gx, float gy, float gz, float ax, float ay, fl
  */
 int attitude_estimator_so3_thread_main(int argc, char *argv[])
 {
-	const unsigned int loop_interval_alarm = 6500;	// loop interval in microseconds
-
 	//! Time constant
 	float dt = 0.005f;
 	
@@ -438,11 +436,9 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 	orb_advert_t att_pub = orb_advertise(ORB_ID(vehicle_attitude), &att);
 
 	int loopcounter = 0;
-	int printcounter = 0;
 
 	thread_running = true;
 
-	float sensor_update_hz[3] = {0.0f, 0.0f, 0.0f};
 	// XXX write this out to perf regs
 
 	/* keep track of sensor updates */
@@ -513,7 +509,7 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 						gyro_offsets[0] /= offset_count;
 						gyro_offsets[1] /= offset_count;
 						gyro_offsets[2] /= offset_count;
-						warnx("gyro initialized, offsets: %.5f %.5f %.5f", gyro_offsets[0], gyro_offsets[1], gyro_offsets[2]);
+						warnx("gyro initialized, offsets: %.5f %.5f %.5f", (double)gyro_offsets[0], (double)gyro_offsets[1], (double)gyro_offsets[2]);
 					}
 
 				} else {
@@ -523,12 +519,9 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 					/* Calculate data time difference in seconds */
 					dt = (raw.timestamp - last_measurement) / 1000000.0f;
 					last_measurement = raw.timestamp;
-					uint8_t update_vect[3] = {0, 0, 0};
 
 					/* Fill in gyro measurements */
 					if (sensor_last_timestamp[0] != raw.timestamp) {
-						update_vect[0] = 1;
-						sensor_update_hz[0] = 1e6f / (raw.timestamp - sensor_last_timestamp[0]);
 						sensor_last_timestamp[0] = raw.timestamp;
 					}
 
@@ -538,8 +531,6 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 
 					/* update accelerometer measurements */
 					if (sensor_last_timestamp[1] != raw.accelerometer_timestamp) {
-						update_vect[1] = 1;
-						sensor_update_hz[1] = 1e6f / (raw.timestamp - sensor_last_timestamp[1]);
 						sensor_last_timestamp[1] = raw.accelerometer_timestamp;
 					}
 
@@ -549,8 +540,6 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 
 					/* update magnetometer measurements */
 					if (sensor_last_timestamp[2] != raw.magnetometer_timestamp) {
-						update_vect[2] = 1;
-						sensor_update_hz[2] = 1e6f / (raw.timestamp - sensor_last_timestamp[2]);
 						sensor_last_timestamp[2] = raw.magnetometer_timestamp;
 					}
 
@@ -569,8 +558,6 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 						continue;
 					}
 
-					uint64_t timing_start = hrt_absolute_time();
-
 					// NOTE : Accelerometer is reversed.
 					// Because proper mount of PX4 will give you a reversed accelerometer readings.
 					NonlinearSO3AHRSupdate(gyro[0], gyro[1], gyro[2],
@@ -609,9 +596,9 @@ int attitude_estimator_so3_thread_main(int argc, char *argv[])
 						/* due to inputs or numerical failure the output is invalid, skip it */
 						// Due to inputs or numerical failure the output is invalid
 						warnx("infinite euler angles, rotation matrix:");
-						warnx("%.3f %.3f %.3f", Rot_matrix[0], Rot_matrix[1], Rot_matrix[2]);
-						warnx("%.3f %.3f %.3f", Rot_matrix[3], Rot_matrix[4], Rot_matrix[5]);
-						warnx("%.3f %.3f %.3f", Rot_matrix[6], Rot_matrix[7], Rot_matrix[8]);
+						warnx("%.3f %.3f %.3f", (double)Rot_matrix[0], (double)Rot_matrix[1], (double)Rot_matrix[2]);
+						warnx("%.3f %.3f %.3f", (double)Rot_matrix[3], (double)Rot_matrix[4], (double)Rot_matrix[5]);
+						warnx("%.3f %.3f %.3f", (double)Rot_matrix[6], (double)Rot_matrix[7], (double)Rot_matrix[8]);
 						// Don't publish anything
 						continue;
 					}
diff --git a/src/modules/commander/accelerometer_calibration.cpp b/src/modules/commander/accelerometer_calibration.cpp
index 7180048ff..be465ab76 100644
--- a/src/modules/commander/accelerometer_calibration.cpp
+++ b/src/modules/commander/accelerometer_calibration.cpp
@@ -131,6 +131,7 @@
 #include <fcntl.h>
 #include <sys/prctl.h>
 #include <math.h>
+#include <float.h>
 #include <mathlib/mathlib.h>
 #include <string.h>
 #include <drivers/drv_hrt.h>
@@ -158,6 +159,8 @@ int calculate_calibration_values(float accel_ref[6][3], float accel_T[3][3], flo
 
 int do_accel_calibration(int mavlink_fd)
 {
+	int fd;
+
 	mavlink_log_info(mavlink_fd, CAL_STARTED_MSG, sensor_name);
 
 	struct accel_scale accel_scale = {
@@ -172,7 +175,7 @@ int do_accel_calibration(int mavlink_fd)
 	int res = OK;
 
 	/* reset all offsets to zero and all scales to one */
-	int fd = open(ACCEL_DEVICE_PATH, 0);
+	fd = open(ACCEL_DEVICE_PATH, 0);
 	res = ioctl(fd, ACCELIOCSSCALE, (long unsigned int)&accel_scale);
 	close(fd);
 
@@ -223,7 +226,7 @@ int do_accel_calibration(int mavlink_fd)
 
 	if (res == OK) {
 		/* apply new scaling and offsets */
-		int fd = open(ACCEL_DEVICE_PATH, 0);
+		fd = open(ACCEL_DEVICE_PATH, 0);
 		res = ioctl(fd, ACCELIOCSSCALE, (long unsigned int)&accel_scale);
 		close(fd);
 
@@ -524,7 +527,7 @@ int mat_invert3(float src[3][3], float dst[3][3])
 		    src[0][1] * (src[1][0] * src[2][2] - src[1][2] * src[2][0]) +
 		    src[0][2] * (src[1][0] * src[2][1] - src[1][1] * src[2][0]);
 
-	if (det == 0.0f) {
+	if (fabsf(det) < FLT_EPSILON) {
 		return ERROR;        // Singular matrix
 	}
 
diff --git a/src/modules/commander/calibration_routines.cpp b/src/modules/commander/calibration_routines.cpp
index be38ea104..43f341ae7 100644
--- a/src/modules/commander/calibration_routines.cpp
+++ b/src/modules/commander/calibration_routines.cpp
@@ -40,6 +40,7 @@
  */
 
 #include <math.h>
+#include <float.h>
 
 #include "calibration_routines.h"
 
@@ -170,7 +171,7 @@ int sphere_fit_least_squares(const float x[], const float y[], const float z[],
 	float aA, aB, aC, nA, nB, nC, dA, dB, dC;
 
 	//Iterate N times, ignore stop condition.
-	int n = 0;
+	unsigned int n = 0;
 
 	while (n < max_iterations) {
 		n++;
@@ -179,9 +180,9 @@ int sphere_fit_least_squares(const float x[], const float y[], const float z[],
 		aA = Q2 + 16.0f * (A2 - 2.0f * A * x_sum + x_sum2);
 		aB = Q2 + 16.0f * (B2 - 2.0f * B * y_sum + y_sum2);
 		aC = Q2 + 16.0f * (C2 - 2.0f * C * z_sum + z_sum2);
-		aA = (aA == 0.0f) ? 1.0f : aA;
-		aB = (aB == 0.0f) ? 1.0f : aB;
-		aC = (aC == 0.0f) ? 1.0f : aC;
+		aA = (fabsf(aA) < FLT_EPSILON) ? 1.0f : aA;
+		aB = (fabsf(aB) < FLT_EPSILON) ? 1.0f : aB;
+		aC = (fabsf(aC) < FLT_EPSILON) ? 1.0f : aC;
 
 		//Compute next iteration
 		nA = A - ((F2 + 16.0f * (B * XY + C * XZ + x_sum * (-A2 - Q0) + A * (x_sum2 + Q1 - C * z_sum - B * y_sum))) / aA);
diff --git a/src/modules/commander/commander.cpp b/src/modules/commander/commander.cpp
index ff99e7baf..38297745d 100644
--- a/src/modules/commander/commander.cpp
+++ b/src/modules/commander/commander.cpp
@@ -52,6 +52,7 @@
 #include <fcntl.h>
 #include <errno.h>
 #include <systemlib/err.h>
+#include <systemlib/circuit_breaker.h>
 #include <debug.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
@@ -76,6 +77,7 @@
 #include <uORB/topics/parameter_update.h>
 #include <uORB/topics/differential_pressure.h>
 #include <uORB/topics/safety.h>
+#include <uORB/topics/system_power.h>
 #include <uORB/topics/mission_result.h>
 #include <uORB/topics/telemetry_status.h>
 
@@ -373,16 +375,16 @@ void print_status()
 
 static orb_advert_t status_pub;
 
-transition_result_t arm_disarm(bool arm, const int mavlink_fd, const char *armedBy)
+transition_result_t arm_disarm(bool arm, const int mavlink_fd_local, const char *armedBy)
 {
 	transition_result_t arming_res = TRANSITION_NOT_CHANGED;
 
 	// Transition the armed state. By passing mavlink_fd to arming_state_transition it will
 	// output appropriate error messages if the state cannot transition.
-	arming_res = arming_state_transition(&status, &safety, arm ? ARMING_STATE_ARMED : ARMING_STATE_STANDBY, &armed, mavlink_fd);
+	arming_res = arming_state_transition(&status, &safety, arm ? ARMING_STATE_ARMED : ARMING_STATE_STANDBY, &armed, mavlink_fd_local);
 
 	if (arming_res == TRANSITION_CHANGED && mavlink_fd) {
-		mavlink_log_info(mavlink_fd, "[cmd] %s by %s", arm ? "ARMED" : "DISARMED", armedBy);
+		mavlink_log_info(mavlink_fd_local, "[cmd] %s by %s", arm ? "ARMED" : "DISARMED", armedBy);
 
 	} else if (arming_res == TRANSITION_DENIED) {
 		tune_negative(true);
@@ -513,7 +515,14 @@ bool handle_command(struct vehicle_status_s *status, const struct safety_s *safe
 				cmd_result = VEHICLE_CMD_RESULT_ACCEPTED;
 
 			} else {
-				mavlink_log_info(mavlink_fd, "Unsupported OVERRIDE_GOTO: %f %f %f %f %f %f %f %f", cmd->param1, cmd->param2, cmd->param3, cmd->param4, cmd->param5, cmd->param6, cmd->param7);
+				mavlink_log_info(mavlink_fd, "Unsupported OVERRIDE_GOTO: %f %f %f %f %f %f %f %f",
+					(double)cmd->param1,
+					(double)cmd->param2,
+					(double)cmd->param3,
+					(double)cmd->param4,
+					(double)cmd->param5,
+					(double)cmd->param6,
+					(double)cmd->param7);
 			}
 		}
 		break;
@@ -708,6 +717,12 @@ int commander_thread_main(int argc, char *argv[])
 	status.counter++;
 	status.timestamp = hrt_absolute_time();
 
+	status.condition_power_input_valid = true;
+	status.avionics_power_rail_voltage = -1.0f;
+
+	// CIRCUIT BREAKERS
+	status.circuit_breaker_engaged_power_check = false;
+
 	/* publish initial state */
 	status_pub = orb_advertise(ORB_ID(vehicle_status), &status);
 
@@ -760,7 +775,6 @@ int commander_thread_main(int argc, char *argv[])
 
 	hrt_abstime last_idle_time = 0;
 	hrt_abstime start_time = 0;
-	hrt_abstime last_auto_state_valid = 0;
 
 	bool status_changed = true;
 	bool param_init_forced = true;
@@ -853,6 +867,11 @@ int commander_thread_main(int argc, char *argv[])
 	struct position_setpoint_triplet_s pos_sp_triplet;
 	memset(&pos_sp_triplet, 0, sizeof(pos_sp_triplet));
 
+	/* Subscribe to system power */
+	int system_power_sub = orb_subscribe(ORB_ID(system_power));
+	struct system_power_s system_power;
+	memset(&system_power, 0, sizeof(system_power));
+
 	control_status_leds(&status, &armed, true);
 
 	/* now initialized */
@@ -869,6 +888,7 @@ int commander_thread_main(int argc, char *argv[])
 	bool arming_state_changed = false;
 	bool main_state_changed = false;
 	bool failsafe_old = false;
+	bool system_checked = false;
 
 	while (!thread_should_exit) {
 
@@ -910,6 +930,9 @@ int commander_thread_main(int argc, char *argv[])
 				/* check and update system / component ID */
 				param_get(_param_system_id, &(status.system_id));
 				param_get(_param_component_id, &(status.component_id));
+
+				status.circuit_breaker_engaged_power_check = circuit_breaker_enabled("CBRK_SUPPLY_CHK", CBRK_SUPPLY_CHK_KEY);
+
 				status_changed = true;
 
 				/* re-check RC calibration */
@@ -922,6 +945,15 @@ int commander_thread_main(int argc, char *argv[])
 			param_get(_param_enable_datalink_loss, &datalink_loss_enabled);
 		}
 
+		/* Perform system checks (again) once params are loaded and MAVLink is up. */
+		if (!system_checked && mavlink_fd && 
+			(telemetry.heartbeat_time > 0) &&
+			(hrt_elapsed_time(&telemetry.heartbeat_time) < 1 * 1000 * 1000)) {
+
+			(void)rc_calibration_check(mavlink_fd);
+			system_checked = true;
+		}
+
 		orb_check(sp_man_sub, &updated);
 
 		if (updated) {
@@ -965,6 +997,26 @@ int commander_thread_main(int argc, char *argv[])
 			orb_copy(ORB_ID(differential_pressure), diff_pres_sub, &diff_pres);
 		}
 
+		orb_check(system_power_sub, &updated);
+
+		if (updated) {
+			orb_copy(ORB_ID(system_power), system_power_sub, &system_power);
+
+			if (hrt_elapsed_time(&system_power.timestamp) < 200000) {
+				if (system_power.servo_valid &&
+					!system_power.brick_valid &&
+					!system_power.usb_connected) {
+					/* flying only on servo rail, this is unsafe */
+					status.condition_power_input_valid = false;
+				} else {
+					status.condition_power_input_valid = true;
+				}
+
+				/* copy avionics voltage */
+				status.avionics_power_rail_voltage = system_power.voltage5V_v;
+			}
+		}
+
 		check_valid(diff_pres.timestamp, DIFFPRESS_TIMEOUT, true, &(status.condition_airspeed_valid), &status_changed);
 
 		/* update safety topic */
@@ -1274,12 +1326,13 @@ int commander_thread_main(int argc, char *argv[])
 			if (status.arming_state == ARMING_STATE_STANDBY &&
 			    sp_man.r > STICK_ON_OFF_LIMIT && sp_man.z < 0.1f) {
 				if (stick_on_counter > STICK_ON_OFF_COUNTER_LIMIT) {
-					if (safety.safety_switch_available && !safety.safety_off && status.hil_state == HIL_STATE_OFF) {
-						print_reject_arm("#audio: NOT ARMING: Press safety switch first.");
 
-					} else if (status.main_state != MAIN_STATE_MANUAL) {
+					/* we check outside of the transition function here because the requirement
+					 * for being in manual mode only applies to manual arming actions.
+					 * the system can be armed in auto if armed via the GCS.
+					 */
+					if (status.main_state != MAIN_STATE_MANUAL) {
 						print_reject_arm("#audio: NOT ARMING: Switch to MANUAL mode first.");
-
 					} else {
 						arming_ret = arming_state_transition(&status, &safety, ARMING_STATE_ARMED, &armed, mavlink_fd);
 						if (arming_ret == TRANSITION_CHANGED) {
@@ -1309,6 +1362,7 @@ int commander_thread_main(int argc, char *argv[])
 			} else if (arming_ret == TRANSITION_DENIED) {
 				/* DENIED here indicates bug in the commander */
 				mavlink_log_critical(mavlink_fd, "ERROR: arming state transition denied");
+				tune_negative(true);
 			}
 
 			/* evaluate the main state machine according to mode switches */
diff --git a/src/modules/commander/commander_helper.cpp b/src/modules/commander/commander_helper.cpp
index 940a04aa1..80e6861f6 100644
--- a/src/modules/commander/commander_helper.cpp
+++ b/src/modules/commander/commander_helper.cpp
@@ -209,12 +209,18 @@ int led_init()
 	/* the blue LED is only available on FMUv1 & AeroCore but not FMUv2 */
 	(void)ioctl(leds, LED_ON, LED_BLUE);
 
+	/* switch blue off */
+	led_off(LED_BLUE);
+
 	/* we consider the amber led mandatory */
 	if (ioctl(leds, LED_ON, LED_AMBER)) {
 		warnx("Amber LED: ioctl fail\n");
 		return ERROR;
 	}
 
+	/* switch amber off */
+	led_off(LED_AMBER);
+
 	/* then try RGB LEDs, this can fail on FMUv1*/
 	rgbleds = open(RGBLED_DEVICE_PATH, 0);
 
diff --git a/src/modules/commander/state_machine_helper.cpp b/src/modules/commander/state_machine_helper.cpp
index 4339a7a76..210a118f6 100644
--- a/src/modules/commander/state_machine_helper.cpp
+++ b/src/modules/commander/state_machine_helper.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (C) 2013 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2013, 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
@@ -46,20 +46,32 @@
 #include <dirent.h>
 #include <fcntl.h>
 #include <string.h>
+#include <math.h>
 
 #include <uORB/uORB.h>
 #include <uORB/topics/vehicle_status.h>
 #include <uORB/topics/actuator_controls.h>
+#include <uORB/topics/differential_pressure.h>
 #include <systemlib/systemlib.h>
 #include <systemlib/param/param.h>
 #include <systemlib/err.h>
 #include <drivers/drv_hrt.h>
+#include <drivers/drv_accel.h>
+#include <drivers/drv_airspeed.h>
 #include <drivers/drv_device.h>
 #include <mavlink/mavlink_log.h>
 
 #include "state_machine_helper.h"
 #include "commander_helper.h"
 
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+static int prearm_check(const struct vehicle_status_s *status, const int mavlink_fd);
+
 // This array defines the arming state transitions. The rows are the new state, and the columns
 // are the current state. Using new state and current  state you can index into the array which
 // will be true for a valid transition or false for a invalid transition. In some cases even
@@ -98,18 +110,31 @@ arming_state_transition(struct vehicle_status_s *status,            /// current
 	ASSERT(ARMING_STATE_INIT == 0);
 	ASSERT(ARMING_STATE_IN_AIR_RESTORE == ARMING_STATE_MAX - 1);
 
-	/*
-	 * Perform an atomic state update
-	 */
-	irqstate_t flags = irqsave();
-
 	transition_result_t ret = TRANSITION_DENIED;
 
+	arming_state_t current_arming_state = status->arming_state;
+
 	/* only check transition if the new state is actually different from the current one */
-	if (new_arming_state == status->arming_state) {
+	if (new_arming_state == current_arming_state) {
 		ret = TRANSITION_NOT_CHANGED;
 
 	} else {
+
+		/*
+		 * Get sensing state if necessary
+		 */
+		int prearm_ret = OK;
+
+		/* only perform the check if we have to */
+		if (new_arming_state == ARMING_STATE_ARMED) {
+			prearm_ret = prearm_check(status, mavlink_fd);
+		}
+
+		/*
+		 * Perform an atomic state update
+		 */
+		irqstate_t flags = irqsave();
+
 		/* enforce lockdown in HIL */
 		if (status->hil_state == HIL_STATE_ON) {
 			armed->lockdown = true;
@@ -124,15 +149,44 @@ arming_state_transition(struct vehicle_status_s *status,            /// current
 		if (valid_transition) {
 			// We have a good transition. Now perform any secondary validation.
 			if (new_arming_state == ARMING_STATE_ARMED) {
-				// Fail transition if we need safety switch press
-				//      Allow if coming from in air restore
+
+				//      Do not perform pre-arm checks if coming from in air restore
 				//      Allow if HIL_STATE_ON
-				if (status->arming_state != ARMING_STATE_IN_AIR_RESTORE && status->hil_state == HIL_STATE_OFF && safety->safety_switch_available && !safety->safety_off) {
-					if (mavlink_fd) {
-						mavlink_log_critical(mavlink_fd, "#audio: NOT ARMING: Press safety switch first.");
+				if (status->arming_state != ARMING_STATE_IN_AIR_RESTORE &&
+					status->hil_state == HIL_STATE_OFF) {
+
+					// Fail transition if pre-arm check fails
+					if (prearm_ret) {
+						valid_transition = false;
+
+					// Fail transition if we need safety switch press
+					} else if (safety->safety_switch_available && !safety->safety_off) {
+
+						mavlink_log_critical(mavlink_fd, "#audio: NOT ARMING: Press safety switch!");
+
+						valid_transition = false;
+					}
+
+					// Perform power checks only if circuit breaker is not
+					// engaged for these checks
+					if (!status->circuit_breaker_engaged_power_check) {
+						// Fail transition if power is not good
+						if (!status->condition_power_input_valid) {
+
+							mavlink_log_critical(mavlink_fd, "#audio: NOT ARMING: Connect power module.");
+							valid_transition = false;
+						}
+
+						// Fail transition if power levels on the avionics rail
+						// are measured but are insufficient
+						if (status->condition_power_input_valid && (status->avionics_power_rail_voltage > 0.0f) &&
+							(status->avionics_power_rail_voltage < 4.9f)) {
+
+							mavlink_log_critical(mavlink_fd, "#audio: NOT ARMING: Avionics power low: %6.2f V.", (double)status->avionics_power_rail_voltage);
+							valid_transition = false;
+						}
 					}
 
-					valid_transition = false;
 				}
 
 			} else if (new_arming_state == ARMING_STATE_STANDBY && status->arming_state == ARMING_STATE_ARMED_ERROR) {
@@ -157,17 +211,15 @@ arming_state_transition(struct vehicle_status_s *status,            /// current
 			ret = TRANSITION_CHANGED;
 			status->arming_state = new_arming_state;
 		}
-	}
 
-	/* end of atomic state update */
-	irqrestore(flags);
+		/* end of atomic state update */
+		irqrestore(flags);
+	}
 
 	if (ret == TRANSITION_DENIED) {
-		static const char *errMsg = "Invalid arming transition from %s to %s";
+		static const char *errMsg = "INVAL: %s - %s";
 
-		if (mavlink_fd) {
-			mavlink_log_critical(mavlink_fd, errMsg, state_names[status->arming_state], state_names[new_arming_state]);
-		}
+		mavlink_log_critical(mavlink_fd, errMsg, state_names[status->arming_state], state_names[new_arming_state]);
 
 		warnx(errMsg, state_names[status->arming_state], state_names[new_arming_state]);
 	}
@@ -567,3 +619,80 @@ bool set_nav_state(struct vehicle_status_s *status, const bool data_link_loss_en
 	return status->nav_state != nav_state_old;
 }
 
+int prearm_check(const struct vehicle_status_s *status, const int mavlink_fd)
+{
+	int ret;
+
+	int fd = open(ACCEL_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0) {
+		mavlink_log_critical(mavlink_fd, "#audio: FAIL: ACCEL SENSOR MISSING");
+		ret = fd;
+		goto system_eval;
+	}
+
+	ret = ioctl(fd, ACCELIOCSELFTEST, 0);
+
+	if (ret != OK) {
+		mavlink_log_critical(mavlink_fd, "#audio: FAIL: ACCEL CALIBRATION");
+		goto system_eval;
+	}
+
+	/* check measurement result range */
+	struct accel_report acc;
+	ret = read(fd, &acc, sizeof(acc));
+
+	if (ret == sizeof(acc)) {
+		/* evaluate values */
+		float accel_scale = sqrtf(acc.x * acc.x + acc.y * acc.y + acc.z * acc.z);
+
+		if (accel_scale < 9.78f || accel_scale > 9.83f) {
+			mavlink_log_info(mavlink_fd, "#audio: Accelerometer calibration recommended.");
+		}
+
+		if (accel_scale > 30.0f /* m/s^2 */) {
+			mavlink_log_critical(mavlink_fd, "#audio: FAIL: ACCEL RANGE");
+			/* this is frickin' fatal */
+			ret = ERROR;
+			goto system_eval;
+		} else {
+			ret = OK;
+		}
+	} else {
+		mavlink_log_critical(mavlink_fd, "#audio: FAIL: ACCEL READ");
+		/* this is frickin' fatal */
+		ret = ERROR;
+		goto system_eval;
+	}
+
+	if (!status->is_rotary_wing) {
+		fd = open(AIRSPEED_DEVICE_PATH, O_RDONLY);
+
+		if (fd < 0) {
+			mavlink_log_critical(mavlink_fd, "#audio: FAIL: AIRSPEED SENSOR MISSING");
+			ret = fd;
+			goto system_eval;
+		}
+
+		struct differential_pressure_s diff_pres;
+
+		ret = read(fd, &diff_pres, sizeof(diff_pres));
+
+		if (ret == sizeof(diff_pres)) {
+			if (fabsf(diff_pres.differential_pressure_filtered_pa > 5.0f)) {
+				mavlink_log_critical(mavlink_fd, "#audio: WARNING AIRSPEED CALIBRATION MISSING");
+				// XXX do not make this fatal yet
+				ret = OK;
+			}
+		} else {
+			mavlink_log_critical(mavlink_fd, "#audio: FAIL: AIRSPEED READ");
+			/* this is frickin' fatal */
+			ret = ERROR;
+			goto system_eval;
+		}
+	}
+
+system_eval:
+	close(fd);
+	return ret;
+}
diff --git a/src/modules/dataman/dataman.c b/src/modules/dataman/dataman.c
index 1a65313e8..406293bda 100644
--- a/src/modules/dataman/dataman.c
+++ b/src/modules/dataman/dataman.c
@@ -50,6 +50,7 @@
 #include <string.h>
 
 #include "dataman.h"
+#include <systemlib/param/param.h>
 
 /**
  * data manager app start / stop handling function
@@ -187,7 +188,7 @@ create_work_item(void)
 		if (item) {
 			item->first = 1;
 			lock_queue(&g_free_q);
-			for (int i = 1; i < k_work_item_allocation_chunk_size; i++) {
+			for (size_t i = 1; i < k_work_item_allocation_chunk_size; i++) {
 				(item + i)->first = 0;
 				sq_addfirst(&(item + i)->link, &(g_free_q.q));
 			}
diff --git a/src/modules/ekf_att_pos_estimator/estimator_23states.h b/src/modules/ekf_att_pos_estimator/estimator_23states.h
index 7aad849f9..15ceb57c0 100644
--- a/src/modules/ekf_att_pos_estimator/estimator_23states.h
+++ b/src/modules/ekf_att_pos_estimator/estimator_23states.h
@@ -234,7 +234,7 @@ int RecallStates(float *statesForFusion, uint64_t msec);
 
 void ResetStoredStates();
 
-void quat2Tbn(Mat3f &Tbn, const float (&quat)[4]);
+void quat2Tbn(Mat3f &TBodyNed, const float (&quat)[4]);
 
 void calcEarthRateNED(Vector3f &omega, float latitude);
 
diff --git a/src/modules/fw_pos_control_l1/landingslope.cpp b/src/modules/fw_pos_control_l1/landingslope.cpp
index 8ce465fe8..42e00da05 100644
--- a/src/modules/fw_pos_control_l1/landingslope.cpp
+++ b/src/modules/fw_pos_control_l1/landingslope.cpp
@@ -46,16 +46,16 @@
 #include <unistd.h>
 #include <mathlib/mathlib.h>
 
-void Landingslope::update(float landing_slope_angle_rad,
-		float flare_relative_alt,
-		float motor_lim_relative_alt,
-		float H1_virt)
+void Landingslope::update(float landing_slope_angle_rad_new,
+		float flare_relative_alt_new,
+		float motor_lim_relative_alt_new,
+		float H1_virt_new)
 {
 
-	_landing_slope_angle_rad = landing_slope_angle_rad;
-	_flare_relative_alt = flare_relative_alt;
-	_motor_lim_relative_alt = motor_lim_relative_alt;
-	_H1_virt = H1_virt;
+	_landing_slope_angle_rad = landing_slope_angle_rad_new;
+	_flare_relative_alt = flare_relative_alt_new;
+	_motor_lim_relative_alt = motor_lim_relative_alt_new;
+	_H1_virt = H1_virt_new;
 
 	calculateSlopeValues();
 }
diff --git a/src/modules/fw_pos_control_l1/landingslope.h b/src/modules/fw_pos_control_l1/landingslope.h
index b54fd501c..a5975ad43 100644
--- a/src/modules/fw_pos_control_l1/landingslope.h
+++ b/src/modules/fw_pos_control_l1/landingslope.h
@@ -123,10 +123,10 @@ public:
 
 	float getFlareCurveAbsoluteAltitudeSave(float wp_distance, float bearing_lastwp_currwp, float bearing_airplane_currwp, float wp_altitude);
 
-	void update(float landing_slope_angle_rad,
-			float flare_relative_alt,
-			float motor_lim_relative_alt,
-			float H1_virt);
+	void update(float landing_slope_angle_rad_new,
+			float flare_relative_alt_new,
+			float motor_lim_relative_alt_new,
+			float H1_virt_new);
 
 
 	inline float landing_slope_angle_rad() {return _landing_slope_angle_rad;}
diff --git a/src/modules/mavlink/mavlink_main.cpp b/src/modules/mavlink/mavlink_main.cpp
index 9a5e31ef4..026a4d6c9 100644
--- a/src/modules/mavlink/mavlink_main.cpp
+++ b/src/modules/mavlink/mavlink_main.cpp
@@ -474,7 +474,7 @@ Mavlink::get_instance_id()
 	return _instance_id;
 }
 
-const mavlink_channel_t
+mavlink_channel_t
 Mavlink::get_channel()
 {
 	return _channel;
@@ -2109,7 +2109,7 @@ Mavlink::task_main(int argc, char *argv[])
                 write_ptr = (uint8_t*)&msg;
 
                 // Pull a single message from the buffer
-                int read_count = available;
+                size_t read_count = available;
                 if (read_count > sizeof(mavlink_message_t)) {
                     read_count = sizeof(mavlink_message_t);
                 }
@@ -2266,13 +2266,13 @@ Mavlink::start(int argc, char *argv[])
 }
 
 void
-Mavlink::status()
+Mavlink::display_status()
 {
 	warnx("running");
 }
 
 int
-Mavlink::stream(int argc, char *argv[])
+Mavlink::stream_command(int argc, char *argv[])
 {
 	const char *device_name = DEFAULT_DEVICE_NAME;
 	float rate = -1.0f;
@@ -2360,7 +2360,7 @@ int mavlink_main(int argc, char *argv[])
 		// 	mavlink::g_mavlink->status();
 
 	} else if (!strcmp(argv[1], "stream")) {
-		return Mavlink::stream(argc, argv);
+		return Mavlink::stream_command(argc, argv);
 
 	} else {
 		usage();
diff --git a/src/modules/mavlink/mavlink_main.h b/src/modules/mavlink/mavlink_main.h
index 6777d56c3..f94036a17 100644
--- a/src/modules/mavlink/mavlink_main.h
+++ b/src/modules/mavlink/mavlink_main.h
@@ -123,9 +123,9 @@ public:
 	/**
 	 * Display the mavlink status.
 	 */
-	void			status();
+	void			display_status();
 
-	static int		stream(int argc, char *argv[]);
+	static int		stream_command(int argc, char *argv[]);
 
 	static int		instance_count();
 
@@ -213,15 +213,15 @@ public:
 	 */
 	int			enable_flow_control(bool enabled);
 
-	const mavlink_channel_t	get_channel();
+	mavlink_channel_t	get_channel();
 
-	void configure_stream_threadsafe(const char *stream_name, const float rate);
+	void configure_stream_threadsafe(const char *stream_name, float rate);
 
 	bool			_task_should_exit;	/**< if true, mavlink task should exit */
 
 	int			get_mavlink_fd() { return _mavlink_fd; }
 
-	MavlinkStream * get_streams() { return _streams; } const
+	MavlinkStream * get_streams() const { return _streams; }
 
 
 	/* Functions for waiting to start transmission until message received. */
@@ -311,15 +311,15 @@ private:
 
 	pthread_mutex_t		_message_buffer_mutex;
 
-	perf_counter_t		_loop_perf;			/**< loop performance counter */
-	perf_counter_t		_txerr_perf;			/**< TX error counter */
-
 	bool			_param_initialized;
 	param_t			_param_system_id;
 	param_t			_param_component_id;
 	param_t			_param_system_type;
 	param_t			_param_use_hil_gps;
 
+	perf_counter_t		_loop_perf;			/**< loop performance counter */
+	perf_counter_t		_txerr_perf;			/**< TX error counter */
+
 	/**
 	 * Send one parameter.
 	 *
diff --git a/src/modules/mavlink/mavlink_messages.cpp b/src/modules/mavlink/mavlink_messages.cpp
index e1ebc16cc..667be87b7 100644
--- a/src/modules/mavlink/mavlink_messages.cpp
+++ b/src/modules/mavlink/mavlink_messages.cpp
@@ -45,7 +45,6 @@
 
 #include <uORB/uORB.h>
 #include <uORB/topics/sensor_combined.h>
-#include <uORB/topics/rc_channels.h>
 #include <uORB/topics/vehicle_attitude.h>
 #include <uORB/topics/vehicle_gps_position.h>
 #include <uORB/topics/vehicle_global_position.h>
@@ -678,7 +677,7 @@ protected:
 						     cm_uint16_from_m_float(gps.epv),
 						     gps.vel_m_s * 100.0f,
 						     _wrap_2pi(gps.cog_rad) * M_RAD_TO_DEG_F * 1e2f,
-						     gps.satellites_visible);
+						     gps.satellites_used);
 		}
 	}
 };
diff --git a/src/modules/mavlink/mavlink_orb_subscription.cpp b/src/modules/mavlink/mavlink_orb_subscription.cpp
index 901fa8f05..734f0903a 100644
--- a/src/modules/mavlink/mavlink_orb_subscription.cpp
+++ b/src/modules/mavlink/mavlink_orb_subscription.cpp
@@ -47,10 +47,10 @@
 #include "mavlink_orb_subscription.h"
 
 MavlinkOrbSubscription::MavlinkOrbSubscription(const orb_id_t topic) :
-	_fd(orb_subscribe(_topic)),
-	_published(false),
+	next(nullptr),
 	_topic(topic),
-	next(nullptr)
+	_fd(orb_subscribe(_topic)),
+	_published(false)
 {
 }
 
diff --git a/src/modules/mavlink/mavlink_receiver.cpp b/src/modules/mavlink/mavlink_receiver.cpp
index 6aba72161..3747ad3ba 100644
--- a/src/modules/mavlink/mavlink_receiver.cpp
+++ b/src/modules/mavlink/mavlink_receiver.cpp
@@ -728,9 +728,8 @@ MavlinkReceiver::handle_message_hil_gps(mavlink_message_t *msg)
 	hil_gps.vel_ned_valid = true;
 	hil_gps.cog_rad = _wrap_pi(gps.cog * M_DEG_TO_RAD_F * 1e-2f);
 
-	hil_gps.timestamp_satellites = timestamp;
 	hil_gps.fix_type = gps.fix_type;
-	hil_gps.satellites_visible = gps.satellites_visible;
+	hil_gps.satellites_used = gps.satellites_visible;  //TODO: rename mavlink_hil_gps_t sats visible to used?
 
 	if (_gps_pub < 0) {
 		_gps_pub = orb_advertise(ORB_ID(vehicle_gps_position), &hil_gps);
diff --git a/src/modules/mavlink/mavlink_stream.cpp b/src/modules/mavlink/mavlink_stream.cpp
index 5ec30bd33..7279206db 100644
--- a/src/modules/mavlink/mavlink_stream.cpp
+++ b/src/modules/mavlink/mavlink_stream.cpp
@@ -43,7 +43,11 @@
 #include "mavlink_stream.h"
 #include "mavlink_main.h"
 
-MavlinkStream::MavlinkStream() : _interval(1000000), _last_sent(0), _channel(MAVLINK_COMM_0), next(nullptr)
+MavlinkStream::MavlinkStream() :
+	next(nullptr),
+	_channel(MAVLINK_COMM_0),
+	_interval(1000000),
+	_last_sent(0)
 {
 }
 
diff --git a/src/modules/mc_att_control/mc_att_control_main.cpp b/src/modules/mc_att_control/mc_att_control_main.cpp
index 20e016da3..19c10198c 100644
--- a/src/modules/mc_att_control/mc_att_control_main.cpp
+++ b/src/modules/mc_att_control/mc_att_control_main.cpp
@@ -72,6 +72,7 @@
 #include <systemlib/err.h>
 #include <systemlib/perf_counter.h>
 #include <systemlib/systemlib.h>
+#include <systemlib/circuit_breaker.h>
 #include <lib/mathlib/mathlib.h>
 #include <lib/geo/geo.h>
 
@@ -123,6 +124,8 @@ private:
 	orb_advert_t	_v_rates_sp_pub;		/**< rate setpoint publication */
 	orb_advert_t	_actuators_0_pub;		/**< attitude actuator controls publication */
 
+	bool		_actuators_0_circuit_breaker_enabled;	/**< circuit breaker to suppress output */
+
 	struct vehicle_attitude_s			_v_att;				/**< vehicle attitude */
 	struct vehicle_attitude_setpoint_s	_v_att_sp;			/**< vehicle attitude setpoint */
 	struct vehicle_rates_setpoint_s		_v_rates_sp;		/**< vehicle rates setpoint */
@@ -267,6 +270,8 @@ MulticopterAttitudeControl::MulticopterAttitudeControl() :
 	_v_rates_sp_pub(-1),
 	_actuators_0_pub(-1),
 
+	_actuators_0_circuit_breaker_enabled(false),
+
 /* performance counters */
 	_loop_perf(perf_alloc(PC_ELAPSED, "mc_att_control"))
 
@@ -402,6 +407,8 @@ MulticopterAttitudeControl::parameters_update()
 	param_get(_params_handles.acro_yaw_max, &v);
 	_params.acro_rate_max(2) = math::radians(v);
 
+	_actuators_0_circuit_breaker_enabled = circuit_breaker_enabled("CBRK_RATE_CTRL", CBRK_RATE_CTRL_KEY);
+
 	return OK;
 }
 
@@ -840,11 +847,13 @@ MulticopterAttitudeControl::task_main()
 				_actuators.control[3] = (isfinite(_thrust_sp)) ? _thrust_sp : 0.0f;
 				_actuators.timestamp = hrt_absolute_time();
 
-				if (_actuators_0_pub > 0) {
-					orb_publish(ORB_ID(actuator_controls_0), _actuators_0_pub, &_actuators);
+				if (!_actuators_0_circuit_breaker_enabled) {
+					if (_actuators_0_pub > 0) {
+						orb_publish(ORB_ID(actuator_controls_0), _actuators_0_pub, &_actuators);
 
-				} else {
-					_actuators_0_pub = orb_advertise(ORB_ID(actuator_controls_0), &_actuators);
+					} else {
+						_actuators_0_pub = orb_advertise(ORB_ID(actuator_controls_0), &_actuators);
+					}
 				}
 			}
 		}
diff --git a/src/modules/mc_pos_control/mc_pos_control_main.cpp b/src/modules/mc_pos_control/mc_pos_control_main.cpp
index 6541788f6..4e88e260c 100644
--- a/src/modules/mc_pos_control/mc_pos_control_main.cpp
+++ b/src/modules/mc_pos_control/mc_pos_control_main.cpp
@@ -470,7 +470,7 @@ MulticopterPositionControl::update_ref()
 {
 	if (_local_pos.ref_timestamp != _ref_timestamp) {
 		double lat_sp, lon_sp;
-		float alt_sp;
+		float alt_sp = 0.0f;
 
 		if (_ref_timestamp != 0) {
 			/* calculate current position setpoint in global frame */
@@ -552,7 +552,6 @@ MulticopterPositionControl::task_main()
 	hrt_abstime t_prev = 0;
 
 	const float alt_ctl_dz = 0.2f;
-	const float pos_ctl_dz = 0.05f;
 
 	math::Vector<3> sp_move_rate;
 	sp_move_rate.zero();
@@ -950,7 +949,7 @@ MulticopterPositionControl::task_main()
 
 					if (_control_mode.flag_control_velocity_enabled) {
 						/* limit max tilt */
-						if (thr_min >= 0.0f && tilt_max < M_PI / 2 - 0.05f) {
+						if (thr_min >= 0.0f && tilt_max < M_PI_F / 2 - 0.05f) {
 							/* absolute horizontal thrust */
 							float thrust_sp_xy_len = math::Vector<2>(thrust_sp(0), thrust_sp(1)).length();
 
diff --git a/src/modules/navigator/mission_block.cpp b/src/modules/navigator/mission_block.cpp
index 9b8d3d9c7..26a573544 100644
--- a/src/modules/navigator/mission_block.cpp
+++ b/src/modules/navigator/mission_block.cpp
@@ -42,6 +42,8 @@
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <math.h>
+#include <float.h>
 
 #include <systemlib/err.h>
 #include <geo/geo.h>
@@ -222,7 +224,7 @@ MissionBlock::set_loiter_item(struct position_setpoint_triplet_s *pos_sp_triplet
 	}
 
     if (pos_sp_triplet->current.type != SETPOINT_TYPE_LOITER
-            || pos_sp_triplet->current.loiter_radius != _navigator->get_loiter_radius()
+            || (fabsf(pos_sp_triplet->current.loiter_radius - _navigator->get_loiter_radius()) > FLT_EPSILON)
             || pos_sp_triplet->current.loiter_direction != 1
             || pos_sp_triplet->previous.valid
             || !pos_sp_triplet->current.valid
diff --git a/src/modules/navigator/rtl.cpp b/src/modules/navigator/rtl.cpp
index 043f773a4..597a2c0ec 100644
--- a/src/modules/navigator/rtl.cpp
+++ b/src/modules/navigator/rtl.cpp
@@ -227,7 +227,7 @@ RTL::set_rtl_item(position_setpoint_triplet_s *pos_sp_triplet)
 		_navigator->set_can_loiter_at_sp(true);
 
 		if (autoland) {
-			mavlink_log_info(_navigator->get_mavlink_fd(), "#audio: RTL: loiter %.1fs", _mission_item.time_inside);
+			mavlink_log_info(_navigator->get_mavlink_fd(), "#audio: RTL: loiter %.1fs", (double)_mission_item.time_inside);
 
 		} else {
 			mavlink_log_info(_navigator->get_mavlink_fd(), "#audio: RTL: completed, loiter");
diff --git a/src/modules/position_estimator_inav/position_estimator_inav_main.c b/src/modules/position_estimator_inav/position_estimator_inav_main.c
index 62cee145e..05eae047c 100644
--- a/src/modules/position_estimator_inav/position_estimator_inav_main.c
+++ b/src/modules/position_estimator_inav/position_estimator_inav_main.c
@@ -49,6 +49,7 @@
 #include <sys/prctl.h>
 #include <termios.h>
 #include <math.h>
+#include <float.h>
 #include <uORB/uORB.h>
 #include <uORB/topics/parameter_update.h>
 #include <uORB/topics/actuator_controls.h>
@@ -179,15 +180,21 @@ int position_estimator_inav_main(int argc, char *argv[])
 	exit(1);
 }
 
-void write_debug_log(const char *msg, float dt, float x_est[2], float y_est[2], float z_est[2], float x_est_prev[2], float y_est_prev[2], float z_est_prev[2], float acc[3], float corr_gps[3][2], float w_xy_gps_p, float w_xy_gps_v)
+static void write_debug_log(const char *msg, float dt, float x_est[2], float y_est[2], float z_est[2], float x_est_prev[2], float y_est_prev[2], float z_est_prev[2], float acc[3], float corr_gps[3][2], float w_xy_gps_p, float w_xy_gps_v)
 {
 	FILE *f = fopen("/fs/microsd/inav.log", "a");
 
 	if (f) {
 		char *s = malloc(256);
-		unsigned n = snprintf(s, 256, "%llu %s\n\tdt=%.5f x_est=[%.5f %.5f] y_est=[%.5f %.5f] z_est=[%.5f %.5f] x_est_prev=[%.5f %.5f] y_est_prev=[%.5f %.5f] z_est_prev=[%.5f %.5f]\n", hrt_absolute_time(), msg, dt, x_est[0], x_est[1], y_est[0], y_est[1], z_est[0], z_est[1], x_est_prev[0], x_est_prev[1], y_est_prev[0], y_est_prev[1], z_est_prev[0], z_est_prev[1]);
+		unsigned n = snprintf(s, 256, "%llu %s\n\tdt=%.5f x_est=[%.5f %.5f] y_est=[%.5f %.5f] z_est=[%.5f %.5f] x_est_prev=[%.5f %.5f] y_est_prev=[%.5f %.5f] z_est_prev=[%.5f %.5f]\n",
+                              hrt_absolute_time(), msg, (double)dt,
+                              (double)x_est[0], (double)x_est[1], (double)y_est[0], (double)y_est[1], (double)z_est[0], (double)z_est[1],
+                              (double)x_est_prev[0], (double)x_est_prev[1], (double)y_est_prev[0], (double)y_est_prev[1], (double)z_est_prev[0], (double)z_est_prev[1]);
 		fwrite(s, 1, n, f);
-		n = snprintf(s, 256, "\tacc=[%.5f %.5f %.5f] gps_pos_corr=[%.5f %.5f %.5f] gps_vel_corr=[%.5f %.5f %.5f] w_xy_gps_p=%.5f w_xy_gps_v=%.5f\n", acc[0], acc[1], acc[2], corr_gps[0][0], corr_gps[1][0], corr_gps[2][0], corr_gps[0][1], corr_gps[1][1], corr_gps[2][1], w_xy_gps_p, w_xy_gps_v);
+		n = snprintf(s, 256, "\tacc=[%.5f %.5f %.5f] gps_pos_corr=[%.5f %.5f %.5f] gps_vel_corr=[%.5f %.5f %.5f] w_xy_gps_p=%.5f w_xy_gps_v=%.5f\n",
+                     (double)acc[0], (double)acc[1], (double)acc[2],
+                     (double)corr_gps[0][0], (double)corr_gps[1][0], (double)corr_gps[2][0], (double)corr_gps[0][1], (double)corr_gps[1][1], (double)corr_gps[2][1],
+                     (double)w_xy_gps_p, (double)w_xy_gps_v);
 		fwrite(s, 1, n, f);
 		free(s);
 	}
@@ -261,9 +268,6 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 
 	hrt_abstime t_prev = 0;
 
-	/* acceleration in NED frame */
-	float accel_NED[3] = { 0.0f, 0.0f, -CONSTANTS_ONE_G };
-
 	/* store error when sensor updates, but correct on each time step to avoid jumps in estimated value */
 	float acc[] = { 0.0f, 0.0f, 0.0f };	// N E D
 	float acc_bias[] = { 0.0f, 0.0f, 0.0f };	// body frame
@@ -285,7 +289,6 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 	hrt_abstime flow_prev = 0;			// time of last flow measurement
 	hrt_abstime sonar_time = 0;			// time of last sonar measurement (not filtered)
 	hrt_abstime sonar_valid_time = 0;	// time of last sonar measurement used for correction (filtered)
-	hrt_abstime xy_src_time = 0;		// time of last available position data
 
 	bool gps_valid = false;			// GPS is valid
 	bool sonar_valid = false;		// sonar is valid
@@ -370,8 +373,8 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 					} else {
 						wait_baro = false;
 						baro_offset /= (float) baro_init_cnt;
-						warnx("baro offs: %.2f", baro_offset);
-						mavlink_log_info(mavlink_fd, "[inav] baro offs: %.2f", baro_offset);
+						warnx("baro offs: %.2f", (double)baro_offset);
+						mavlink_log_info(mavlink_fd, "[inav] baro offs: %.2f", (double)baro_offset);
 						local_pos.z_valid = true;
 						local_pos.v_z_valid = true;
 					}
@@ -475,7 +478,11 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 				float flow_dt = flow_prev > 0 ? (flow.flow_timestamp - flow_prev) * 1e-6f : 0.1f;
 				flow_prev = flow.flow_timestamp;
 
-				if (flow.ground_distance_m > 0.31f && flow.ground_distance_m < 4.0f && att.R[2][2] > 0.7 && flow.ground_distance_m != sonar_prev) {
+				if ((flow.ground_distance_m > 0.31f) &&
+					(flow.ground_distance_m < 4.0f) &&
+					(att.R[2][2] > 0.7f) &&
+					(fabsf(flow.ground_distance_m - sonar_prev) > FLT_EPSILON)) {
+
 					sonar_time = t;
 					sonar_prev = flow.ground_distance_m;
 					corr_sonar = flow.ground_distance_m + surface_offset + z_est[0];
@@ -497,7 +504,7 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 							sonar_valid_time = t;
 							sonar_valid = true;
 							local_pos.surface_bottom_timestamp = t;
-							mavlink_log_info(mavlink_fd, "[inav] new surface level: %.2f", surface_offset);
+							mavlink_log_info(mavlink_fd, "[inav] new surface level: %.2f", (double)surface_offset);
 						}
 
 					} else {
@@ -510,7 +517,7 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 				float flow_q = flow.quality / 255.0f;
 				float dist_bottom = - z_est[0] - surface_offset;
 
-				if (dist_bottom > 0.3f && flow_q > params.flow_q_min && (t < sonar_valid_time + sonar_valid_timeout) && att.R[2][2] > 0.7) {
+				if (dist_bottom > 0.3f && flow_q > params.flow_q_min && (t < sonar_valid_time + sonar_valid_timeout) && att.R[2][2] > 0.7f) {
 					/* distance to surface */
 					float flow_dist = dist_bottom / att.R[2][2];
 					/* check if flow if too large for accurate measurements */
@@ -558,7 +565,7 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 					}
 
 					/* under ideal conditions, on 1m distance assume EPH = 10cm */
-					eph_flow = 0.1 / w_flow;
+					eph_flow = 0.1f / w_flow;
 
 					flow_valid = true;
 
@@ -644,25 +651,22 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 
 						} else if (t > ref_init_start + ref_init_delay) {
 							ref_inited = true;
-							/* update baro offset */
-							baro_offset -= z_est[0];
 
 							/* set position estimate to (0, 0, 0), use GPS velocity for XY */
 							x_est[0] = 0.0f;
 							x_est[1] = gps.vel_n_m_s;
 							y_est[0] = 0.0f;
 							y_est[1] = gps.vel_e_m_s;
-							z_est[0] = 0.0f;
 
 							local_pos.ref_lat = lat;
 							local_pos.ref_lon = lon;
-							local_pos.ref_alt = alt;
+							local_pos.ref_alt = alt + z_est[0];
 							local_pos.ref_timestamp = t;
 
 							/* initialize projection */
 							map_projection_init(&ref, lat, lon);
-							warnx("init ref: lat=%.7f, lon=%.7f, alt=%.2f", lat, lon, alt);
-							mavlink_log_info(mavlink_fd, "[inav] init ref: lat=%.7f, lon=%.7f, alt=%.2f", lat, lon, alt);
+							warnx("init ref: lat=%.7f, lon=%.7f, alt=%.2f", (double)lat, (double)lon, (double)alt);
+							mavlink_log_info(mavlink_fd, "[inav] init ref: %.7f, %.7f, %.2f", (double)lat, (double)lon, (double)alt);
 						}
 					}
 
@@ -746,10 +750,10 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 
 		/* increase EPH/EPV on each step */
 		if (eph < max_eph_epv) {
-			eph *= 1.0 + dt;
+			eph *= 1.0f + dt;
 		}
 		if (epv < max_eph_epv) {
-			epv += 0.005 * dt;	// add 1m to EPV each 200s (baro drift)
+			epv += 0.005f * dt;	// add 1m to EPV each 200s (baro drift)
 		}
 
 		/* use GPS if it's valid and reference position initialized */
@@ -758,11 +762,6 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 		/* use flow if it's valid and (accurate or no GPS available) */
 		bool use_flow = flow_valid && (flow_accurate || !use_gps_xy);
 
-		/* try to estimate position during some time after position sources lost */
-		if (use_gps_xy || use_flow) {
-			xy_src_time = t;
-		}
-
 		bool can_estimate_xy = (eph < max_eph_epv) || use_gps_xy || use_flow;
 
 		bool dist_bottom_valid = (t < sonar_valid_time + sonar_valid_timeout);
@@ -916,6 +915,10 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 				memcpy(x_est_prev, x_est, sizeof(x_est));
 				memcpy(y_est_prev, y_est, sizeof(y_est));
 			}
+		} else {
+			/* gradually reset xy velocity estimates */
+			inertial_filter_correct(-x_est[1], dt, x_est, 1, params.w_xy_res_v);
+			inertial_filter_correct(-y_est[1], dt, y_est, 1, params.w_xy_res_v);
 		}
 
 		/* detect land */
@@ -931,6 +934,9 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 				landed = false;
 				landed_time = 0;
 			}
+			/* reset xy velocity estimates when landed */
+			x_est[1] = 0.0f;
+			y_est[1] = 0.0f;
 
 		} else {
 			if (alt_disp2 < land_disp2 && thrust < params.land_thr) {
@@ -955,11 +961,11 @@ int position_estimator_inav_thread_main(int argc, char *argv[])
 				float updates_dt = (t - updates_counter_start) * 0.000001f;
 				warnx(
 					"updates rate: accelerometer = %.1f/s, baro = %.1f/s, gps = %.1f/s, attitude = %.1f/s, flow = %.1f/s",
-					accel_updates / updates_dt,
-					baro_updates / updates_dt,
-					gps_updates / updates_dt,
-					attitude_updates / updates_dt,
-					flow_updates / updates_dt);
+					(double)(accel_updates / updates_dt),
+					(double)(baro_updates / updates_dt),
+					(double)(gps_updates / updates_dt),
+					(double)(attitude_updates / updates_dt),
+					(double)(flow_updates / updates_dt));
 				updates_counter_start = t;
 				accel_updates = 0;
 				baro_updates = 0;
diff --git a/src/modules/position_estimator_inav/position_estimator_inav_params.c b/src/modules/position_estimator_inav/position_estimator_inav_params.c
index d88419c25..0581f8236 100644
--- a/src/modules/position_estimator_inav/position_estimator_inav_params.c
+++ b/src/modules/position_estimator_inav/position_estimator_inav_params.c
@@ -46,6 +46,7 @@ PARAM_DEFINE_FLOAT(INAV_W_Z_SONAR, 3.0f);
 PARAM_DEFINE_FLOAT(INAV_W_XY_GPS_P, 1.0f);
 PARAM_DEFINE_FLOAT(INAV_W_XY_GPS_V, 2.0f);
 PARAM_DEFINE_FLOAT(INAV_W_XY_FLOW, 5.0f);
+PARAM_DEFINE_FLOAT(INAV_W_XY_RES_V, 0.5f);
 PARAM_DEFINE_FLOAT(INAV_W_GPS_FLOW, 0.1f);
 PARAM_DEFINE_FLOAT(INAV_W_ACC_BIAS, 0.05f);
 PARAM_DEFINE_FLOAT(INAV_FLOW_K, 0.15f);
@@ -65,6 +66,7 @@ int parameters_init(struct position_estimator_inav_param_handles *h)
 	h->w_xy_gps_p = param_find("INAV_W_XY_GPS_P");
 	h->w_xy_gps_v = param_find("INAV_W_XY_GPS_V");
 	h->w_xy_flow = param_find("INAV_W_XY_FLOW");
+	h->w_xy_res_v = param_find("INAV_W_XY_RES_V");
 	h->w_gps_flow = param_find("INAV_W_GPS_FLOW");
 	h->w_acc_bias = param_find("INAV_W_ACC_BIAS");
 	h->flow_k = param_find("INAV_FLOW_K");
@@ -87,6 +89,7 @@ int parameters_update(const struct position_estimator_inav_param_handles *h, str
 	param_get(h->w_xy_gps_p, &(p->w_xy_gps_p));
 	param_get(h->w_xy_gps_v, &(p->w_xy_gps_v));
 	param_get(h->w_xy_flow, &(p->w_xy_flow));
+	param_get(h->w_xy_res_v, &(p->w_xy_res_v));
 	param_get(h->w_gps_flow, &(p->w_gps_flow));
 	param_get(h->w_acc_bias, &(p->w_acc_bias));
 	param_get(h->flow_k, &(p->flow_k));
diff --git a/src/modules/position_estimator_inav/position_estimator_inav_params.h b/src/modules/position_estimator_inav/position_estimator_inav_params.h
index df1cfaa71..423f0d879 100644
--- a/src/modules/position_estimator_inav/position_estimator_inav_params.h
+++ b/src/modules/position_estimator_inav/position_estimator_inav_params.h
@@ -47,6 +47,7 @@ struct position_estimator_inav_params {
 	float w_xy_gps_p;
 	float w_xy_gps_v;
 	float w_xy_flow;
+	float w_xy_res_v;
 	float w_gps_flow;
 	float w_acc_bias;
 	float flow_k;
@@ -66,6 +67,7 @@ struct position_estimator_inav_param_handles {
 	param_t w_xy_gps_p;
 	param_t w_xy_gps_v;
 	param_t w_xy_flow;
+	param_t w_xy_res_v;
 	param_t w_gps_flow;
 	param_t w_acc_bias;
 	param_t flow_k;
diff --git a/src/modules/px4iofirmware/i2c.c b/src/modules/px4iofirmware/i2c.c
index 79b6546b3..76762c0fc 100644
--- a/src/modules/px4iofirmware/i2c.c
+++ b/src/modules/px4iofirmware/i2c.c
@@ -331,6 +331,7 @@ i2c_tx_complete(void)
 	i2c_tx_setup();
 }
 
+#ifdef DEBUG
 static void
 i2c_dump(void)
 {
@@ -339,3 +340,4 @@ i2c_dump(void)
 	debug("CCR   0x%08x  TRISE 0x%08x", rCCR,  rTRISE);
 	debug("SR1   0x%08x  SR2   0x%08x", rSR1,  rSR2);
 }
+#endif
diff --git a/src/modules/px4iofirmware/protocol.h b/src/modules/px4iofirmware/protocol.h
index 7471faec7..d5a6b1ec4 100644
--- a/src/modules/px4iofirmware/protocol.h
+++ b/src/modules/px4iofirmware/protocol.h
@@ -312,7 +312,7 @@ struct IOPacket {
 
 #define PKT_COUNT(_p)	((_p).count_code & PKT_COUNT_MASK)
 #define PKT_CODE(_p)	((_p).count_code & PKT_CODE_MASK)
-#define PKT_SIZE(_p)	((uint8_t *)&((_p).regs[PKT_COUNT(_p)]) - ((uint8_t *)&(_p)))
+#define PKT_SIZE(_p)	((size_t)((uint8_t *)&((_p).regs[PKT_COUNT(_p)]) - ((uint8_t *)&(_p))))
 
 static const uint8_t crc8_tab[256] __attribute__((unused)) =
 {
diff --git a/src/modules/px4iofirmware/px4io.c b/src/modules/px4iofirmware/px4io.c
index d4c25911e..cd134ccb4 100644
--- a/src/modules/px4iofirmware/px4io.c
+++ b/src/modules/px4iofirmware/px4io.c
@@ -37,6 +37,7 @@
  */
 
 #include <nuttx/config.h>
+#include <nuttx/arch.h>
 
 #include <stdio.h>	// required for task_create
 #include <stdbool.h>
@@ -303,14 +304,12 @@ user_start(int argc, char *argv[])
 		 */
 		if (hrt_absolute_time() - last_debug_time > (1000 * 1000)) {
 
-			struct mallinfo minfo = mallinfo();
-
 			isr_debug(1, "d:%u s=0x%x a=0x%x f=0x%x m=%u", 
 				  (unsigned)r_page_setup[PX4IO_P_SETUP_SET_DEBUG],
 				  (unsigned)r_status_flags,
 				  (unsigned)r_setup_arming,
 				  (unsigned)r_setup_features,
-				  (unsigned)minfo.mxordblk);
+				  (unsigned)mallinfo().mxordblk);
 			last_debug_time = hrt_absolute_time();
 		}
 	}
diff --git a/src/modules/px4iofirmware/registers.c b/src/modules/px4iofirmware/registers.c
index db1836f4a..50108ea1b 100644
--- a/src/modules/px4iofirmware/registers.c
+++ b/src/modules/px4iofirmware/registers.c
@@ -119,7 +119,6 @@ uint16_t		r_page_raw_rc_input[] =
 	[PX4IO_P_RAW_RC_DATA]			= 0,
 	[PX4IO_P_RAW_FRAME_COUNT]		= 0,
 	[PX4IO_P_RAW_LOST_FRAME_COUNT]		= 0,
-	[PX4IO_P_RAW_RC_DATA]			= 0,
 	[PX4IO_P_RAW_RC_BASE ... (PX4IO_P_RAW_RC_BASE + PX4IO_RC_INPUT_CHANNELS)] = 0
 };
 
@@ -670,7 +669,7 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 
 				if (conf[PX4IO_P_RC_CONFIG_ASSIGNMENT] == UINT8_MAX) {
 					disabled = true;
-				} else if ((int)(conf[PX4IO_P_RC_CONFIG_ASSIGNMENT]) < 0 || conf[PX4IO_P_RC_CONFIG_ASSIGNMENT] >= PX4IO_RC_MAPPED_CONTROL_CHANNELS) {
+				} else if (conf[PX4IO_P_RC_CONFIG_ASSIGNMENT] >= PX4IO_RC_MAPPED_CONTROL_CHANNELS) {
 					count++;
 				}
 
diff --git a/src/modules/px4iofirmware/sbus.c b/src/modules/px4iofirmware/sbus.c
index 0e7dc621c..70ccab180 100644
--- a/src/modules/px4iofirmware/sbus.c
+++ b/src/modules/px4iofirmware/sbus.c
@@ -119,13 +119,15 @@ sbus_init(const char *device)
 bool
 sbus1_output(uint16_t *values, uint16_t num_values)
 {
-	write(sbus_fd, 'A', 1);
+	char a = 'A';
+	write(sbus_fd, &a, 1);
 }
 
 bool
 sbus2_output(uint16_t *values, uint16_t num_values)
 {
-	write(sbus_fd, 'B', 1);
+	char b = 'B';
+	write(sbus_fd, &b, 1);
 }
 
 bool
diff --git a/src/modules/sdlog2/sdlog2.c b/src/modules/sdlog2/sdlog2.c
index e483b35e8..39e5b6c41 100644
--- a/src/modules/sdlog2/sdlog2.c
+++ b/src/modules/sdlog2/sdlog2.c
@@ -74,6 +74,7 @@
 #include <uORB/topics/vehicle_global_position.h>
 #include <uORB/topics/position_setpoint_triplet.h>
 #include <uORB/topics/vehicle_gps_position.h>
+#include <uORB/topics/satellite_info.h>
 #include <uORB/topics/vehicle_vicon_position.h>
 #include <uORB/topics/vehicle_global_velocity_setpoint.h>
 #include <uORB/topics/optical_flow.h>
@@ -141,6 +142,8 @@ PARAM_DEFINE_INT32(SDLOG_EXT, -1);
 	fds[fdsc_count].events = POLLIN; \
 	fdsc_count++;
 
+#define MIN(X,Y) ((X) < (Y) ? (X) : (Y))
+
 static bool main_thread_should_exit = false;		/**< Deamon exit flag */
 static bool thread_running = false;			/**< Deamon status flag */
 static int deamon_task;						/**< Handle of deamon task / thread */
@@ -944,6 +947,7 @@ int sdlog2_thread_main(int argc, char *argv[])
 		struct tecs_status_s tecs_status;
 		struct system_power_s system_power;
 		struct servorail_status_s servorail_status;
+		struct satellite_info_s sat_info;
 		struct wind_estimate_s wind_estimate;
 	} buf;
 
@@ -1007,6 +1011,7 @@ int sdlog2_thread_main(int argc, char *argv[])
 		int global_pos_sub;
 		int triplet_sub;
 		int gps_pos_sub;
+		int sat_info_sub;
 		int vicon_pos_sub;
 		int flow_sub;
 		int rc_sub;
@@ -1026,6 +1031,7 @@ int sdlog2_thread_main(int argc, char *argv[])
 	subs.cmd_sub = orb_subscribe(ORB_ID(vehicle_command));
 	subs.status_sub = orb_subscribe(ORB_ID(vehicle_status));
 	subs.gps_pos_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
+	subs.sat_info_sub = orb_subscribe(ORB_ID(satellite_info));
 	subs.sensor_sub = orb_subscribe(ORB_ID(sensor_combined));
 	subs.att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
 	subs.att_sp_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
@@ -1066,11 +1072,14 @@ int sdlog2_thread_main(int argc, char *argv[])
 	hrt_abstime barometer_timestamp = 0;
 	hrt_abstime differential_pressure_timestamp = 0;
 
+	/* initialize calculated mean SNR */
+	float snr_mean = 0.0f;
+
 	/* enable logging on start if needed */
 	if (log_on_start) {
 		/* check GPS topic to get GPS time */
 		if (log_name_timestamp) {
-			if (copy_if_updated(ORB_ID(vehicle_gps_position), subs.gps_pos_sub, &buf_gps_pos)) {
+			if (!orb_copy(ORB_ID(vehicle_gps_position), subs.gps_pos_sub, &buf_gps_pos)) {
 				gps_time = buf_gps_pos.time_gps_usec;
 			}
 		}
@@ -1128,14 +1137,6 @@ int sdlog2_thread_main(int argc, char *argv[])
 		/* --- GPS POSITION - UNIT #1 --- */
 		if (gps_pos_updated) {
 
-			float snr_mean = 0.0f;
-
-			for (unsigned i = 0; i < buf_gps_pos.satellites_visible; i++) {
-				snr_mean += buf_gps_pos.satellite_snr[i];
-			}
-
-			snr_mean /= buf_gps_pos.satellites_visible;
-
 			log_msg.msg_type = LOG_GPS_MSG;
 			log_msg.body.log_GPS.gps_time = buf_gps_pos.time_gps_usec;
 			log_msg.body.log_GPS.fix_type = buf_gps_pos.fix_type;
@@ -1148,44 +1149,55 @@ int sdlog2_thread_main(int argc, char *argv[])
 			log_msg.body.log_GPS.vel_e = buf_gps_pos.vel_e_m_s;
 			log_msg.body.log_GPS.vel_d = buf_gps_pos.vel_d_m_s;
 			log_msg.body.log_GPS.cog = buf_gps_pos.cog_rad;
-			log_msg.body.log_GPS.sats = buf_gps_pos.satellites_visible;
+			log_msg.body.log_GPS.sats = buf_gps_pos.satellites_used;
 			log_msg.body.log_GPS.snr_mean = snr_mean;
 			log_msg.body.log_GPS.noise_per_ms = buf_gps_pos.noise_per_ms;
 			log_msg.body.log_GPS.jamming_indicator = buf_gps_pos.jamming_indicator;
 			LOGBUFFER_WRITE_AND_COUNT(GPS);
+		}
+
+		/* --- SATELLITE INFO - UNIT #1 --- */
+		if (_extended_logging) {
+
+			if (copy_if_updated(ORB_ID(satellite_info), subs.sat_info_sub, &buf.sat_info)) {
 
-			if (_extended_logging) {
 				/* log the SNR of each satellite for a detailed view of signal quality */
-				unsigned gps_msg_max_snr = sizeof(buf_gps_pos.satellite_snr) / sizeof(buf_gps_pos.satellite_snr[0]);
+				unsigned sat_info_count = MIN(buf.sat_info.count, sizeof(buf.sat_info.snr) / sizeof(buf.sat_info.snr[0]));
 				unsigned log_max_snr = sizeof(log_msg.body.log_GS0A.satellite_snr) / sizeof(log_msg.body.log_GS0A.satellite_snr[0]);
 
 				log_msg.msg_type = LOG_GS0A_MSG;
 				memset(&log_msg.body.log_GS0A, 0, sizeof(log_msg.body.log_GS0A));
-				/* fill set A */
-				for (unsigned i = 0; i < gps_msg_max_snr; i++) {
+				snr_mean = 0.0f;
 
-					int satindex = buf_gps_pos.satellite_prn[i] - 1;
+				/* fill set A and calculate mean SNR */
+				for (unsigned i = 0; i < sat_info_count; i++) {
+
+					snr_mean += buf.sat_info.snr[i];
+
+					int satindex = buf.sat_info.svid[i] - 1;
 
 					/* handles index exceeding and wraps to to arithmetic errors */
 					if ((satindex >= 0) && (satindex < (int)log_max_snr)) {
 						/* map satellites by their ID so that logs from two receivers can be compared */
-						log_msg.body.log_GS0A.satellite_snr[satindex] = buf_gps_pos.satellite_snr[i];
+						log_msg.body.log_GS0A.satellite_snr[satindex] = buf.sat_info.snr[i];
 					}
 				}
 				LOGBUFFER_WRITE_AND_COUNT(GS0A);
+				snr_mean /= sat_info_count;
 
 				log_msg.msg_type = LOG_GS0B_MSG;
 				memset(&log_msg.body.log_GS0B, 0, sizeof(log_msg.body.log_GS0B));
+
 				/* fill set B */
-				for (unsigned i = 0; i < gps_msg_max_snr; i++) {
+				for (unsigned i = 0; i < sat_info_count; i++) {
 
 					/* get second bank of satellites, thus deduct bank size from index */
-					int satindex = buf_gps_pos.satellite_prn[i] - 1 - log_max_snr;
+					int satindex = buf.sat_info.svid[i] - 1 - log_max_snr;
 
 					/* handles index exceeding and wraps to to arithmetic errors */
 					if ((satindex >= 0) && (satindex < (int)log_max_snr)) {
 						/* map satellites by their ID so that logs from two receivers can be compared */
-						log_msg.body.log_GS0B.satellite_snr[satindex] = buf_gps_pos.satellite_snr[i];
+						log_msg.body.log_GS0B.satellite_snr[satindex] = buf.sat_info.snr[i];
 					}
 				}
 				LOGBUFFER_WRITE_AND_COUNT(GS0B);
@@ -1394,8 +1406,8 @@ int sdlog2_thread_main(int argc, char *argv[])
 		if (copy_if_updated(ORB_ID(rc_channels), subs.rc_sub, &buf.rc)) {
 			log_msg.msg_type = LOG_RC_MSG;
 			/* Copy only the first 8 channels of 14 */
-			memcpy(log_msg.body.log_RC.channel, buf.rc.chan, sizeof(log_msg.body.log_RC.channel));
-			log_msg.body.log_RC.channel_count = buf.rc.chan_count;
+			memcpy(log_msg.body.log_RC.channel, buf.rc.channels, sizeof(log_msg.body.log_RC.channel));
+			log_msg.body.log_RC.channel_count = buf.rc.channel_count;
 			log_msg.body.log_RC.signal_lost = buf.rc.signal_lost;
 			LOGBUFFER_WRITE_AND_COUNT(RC);
 		}
diff --git a/src/modules/sensors/sensors.cpp b/src/modules/sensors/sensors.cpp
index cc96f8a53..6e2d906e6 100644
--- a/src/modules/sensors/sensors.cpp
+++ b/src/modules/sensors/sensors.cpp
@@ -656,7 +656,7 @@ Sensors::parameters_update()
 		if (!isfinite(tmpScaleFactor) ||
 		    (tmpRevFactor < 0.000001f) ||
 		    (tmpRevFactor > 0.2f)) {
-			warnx("RC chan %u not sane, scaling: %8.6f, rev: %d", i, tmpScaleFactor, (int)(_parameters.rev[i]));
+			warnx("RC chan %u not sane, scaling: %8.6f, rev: %d", i, (double)tmpScaleFactor, (int)(_parameters.rev[i]));
 			/* scaling factors do not make sense, lock them down */
 			_parameters.scaling_factor[i] = 0.0f;
 			rc_valid = false;
@@ -1238,9 +1238,9 @@ Sensors::parameter_update_poll(bool forced)
 		}
 
 #if 0
-		printf("CH0: RAW MAX: %d MIN %d S: %d MID: %d FUNC: %d\n", (int)_parameters.max[0], (int)_parameters.min[0], (int)(_rc.chan[0].scaling_factor * 10000), (int)(_rc.chan[0].mid), (int)_rc.function[0]);
-		printf("CH1: RAW MAX: %d MIN %d S: %d MID: %d FUNC: %d\n", (int)_parameters.max[1], (int)_parameters.min[1], (int)(_rc.chan[1].scaling_factor * 10000), (int)(_rc.chan[1].mid), (int)_rc.function[1]);
-		printf("MAN: %d %d\n", (int)(_rc.chan[0].scaled * 100), (int)(_rc.chan[1].scaled * 100));
+		printf("CH0: RAW MAX: %d MIN %d S: %d MID: %d FUNC: %d\n", (int)_parameters.max[0], (int)_parameters.min[0], (int)(_rc.channels[0].scaling_factor * 10000), (int)(_rc.channels[0].mid), (int)_rc.function[0]);
+		printf("CH1: RAW MAX: %d MIN %d S: %d MID: %d FUNC: %d\n", (int)_parameters.max[1], (int)_parameters.min[1], (int)(_rc.channels[1].scaling_factor * 10000), (int)(_rc.channels[1].mid), (int)_rc.function[1]);
+		printf("MAN: %d %d\n", (int)(_rc.channels[0] * 100), (int)(_rc.channels[1] * 100));
 		fflush(stdout);
 		usleep(5000);
 #endif
@@ -1330,7 +1330,7 @@ Sensors::adc_poll(struct sensor_combined_s &raw)
 					 * a valid voltage from a connected sensor. Also assume a non-
 					 * zero offset from the sensor if its connected.
 					 */
-					if (voltage > 0.4f && _parameters.diff_pres_analog_enabled) {
+					if (voltage > 0.4f && (_parameters.diff_pres_analog_enabled > 0)) {
 
 						float diff_pres_pa = voltage * 1000.0f - _parameters.diff_pres_offset_pa; //for MPXV7002DP sensor
 
@@ -1370,7 +1370,7 @@ float
 Sensors::get_rc_value(enum RC_CHANNELS_FUNCTION func, float min_value, float max_value)
 {
 	if (_rc.function[func] >= 0) {
-		float value = _rc.chan[_rc.function[func]].scaled;
+		float value = _rc.channels[_rc.function[func]];
 
 		if (value < min_value) {
 			return min_value;
@@ -1391,7 +1391,7 @@ switch_pos_t
 Sensors::get_rc_sw3pos_position(enum RC_CHANNELS_FUNCTION func, float on_th, bool on_inv, float mid_th, bool mid_inv)
 {
 	if (_rc.function[func] >= 0) {
-		float value = 0.5f * _rc.chan[_rc.function[func]].scaled + 0.5f;
+		float value = 0.5f * _rc.channels[_rc.function[func]] + 0.5f;
 
 		if (on_inv ? value < on_th : value > on_th) {
 			return SWITCH_POS_ON;
@@ -1412,7 +1412,7 @@ switch_pos_t
 Sensors::get_rc_sw2pos_position(enum RC_CHANNELS_FUNCTION func, float on_th, bool on_inv)
 {
 	if (_rc.function[func] >= 0) {
-		float value = 0.5f * _rc.chan[_rc.function[func]].scaled + 0.5f;
+		float value = 0.5f * _rc.channels[_rc.function[func]] + 0.5f;
 
 		if (on_inv ? value < on_th : value > on_th) {
 			return SWITCH_POS_ON;
@@ -1504,25 +1504,25 @@ Sensors::rc_poll()
 			 * DO NOT REMOVE OR ALTER STEP 1!
 			 */
 			if (rc_input.values[i] > (_parameters.trim[i] + _parameters.dz[i])) {
-				_rc.chan[i].scaled = (rc_input.values[i] - _parameters.trim[i] - _parameters.dz[i]) / (float)(_parameters.max[i] - _parameters.trim[i] - _parameters.dz[i]);
+				_rc.channels[i] = (rc_input.values[i] - _parameters.trim[i] - _parameters.dz[i]) / (float)(_parameters.max[i] - _parameters.trim[i] - _parameters.dz[i]);
 
 			} else if (rc_input.values[i] < (_parameters.trim[i] - _parameters.dz[i])) {
-				_rc.chan[i].scaled = (rc_input.values[i] - _parameters.trim[i] + _parameters.dz[i]) / (float)(_parameters.trim[i] - _parameters.min[i] - _parameters.dz[i]);
+				_rc.channels[i] = (rc_input.values[i] - _parameters.trim[i] + _parameters.dz[i]) / (float)(_parameters.trim[i] - _parameters.min[i] - _parameters.dz[i]);
 
 			} else {
 				/* in the configured dead zone, output zero */
-				_rc.chan[i].scaled = 0.0f;
+				_rc.channels[i] = 0.0f;
 			}
 
-			_rc.chan[i].scaled *= _parameters.rev[i];
+			_rc.channels[i] *= _parameters.rev[i];
 
 			/* handle any parameter-induced blowups */
-			if (!isfinite(_rc.chan[i].scaled)) {
-				_rc.chan[i].scaled = 0.0f;
+			if (!isfinite(_rc.channels[i])) {
+				_rc.channels[i] = 0.0f;
 			}
 		}
 
-		_rc.chan_count = rc_input.channel_count;
+		_rc.channel_count = rc_input.channel_count;
 		_rc.rssi = rc_input.rssi;
 		_rc.signal_lost = signal_lost;
 		_rc.timestamp = rc_input.timestamp_last_signal;
diff --git a/src/modules/systemlib/circuit_breaker.c b/src/modules/systemlib/circuit_breaker.c
new file mode 100644
index 000000000..8f697749e
--- /dev/null
+++ b/src/modules/systemlib/circuit_breaker.c
@@ -0,0 +1,93 @@
+/****************************************************************************
+ *
+ *   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 circuit_breaker.c
+ *
+ * Circuit breaker parameters.
+ * Analog to real aviation circuit breakers these parameters
+ * allow to disable subsystems. They are not supported as standard
+ * operation procedure and are only provided for development purposes.
+ * To ensure they are not activated accidentally, the associated
+ * parameter needs to set to the key (magic).
+ */
+
+#include <systemlib/param/param.h>
+#include <systemlib/circuit_breaker.h>
+
+/**
+ * Circuit breaker for power supply check
+ *
+ * Setting this parameter to 894281 will disable the power valid
+ * checks in the commander.
+ * WARNING: ENABLING THIS CIRCUIT BREAKER IS AT OWN RISK
+ *
+ * @min 0
+ * @max 894281
+ * @group Circuit Breaker
+ */
+PARAM_DEFINE_INT32(CBRK_SUPPLY_CHK, 0);
+
+/**
+ * Circuit breaker for rate controller output
+ *
+ * Setting this parameter to 140253 will disable the rate
+ * controller uORB publication.
+ * WARNING: ENABLING THIS CIRCUIT BREAKER IS AT OWN RISK
+ *
+ * @min 0
+ * @max 140253
+ * @group Circuit Breaker
+ */
+PARAM_DEFINE_INT32(CBRK_RATE_CTRL, 0);
+
+/**
+ * Circuit breaker for IO safety
+ *
+ * Setting this parameter to 894281 will disable IO safety.
+ * WARNING: ENABLING THIS CIRCUIT BREAKER IS AT OWN RISK
+ *
+ * @min 0
+ * @max 22027
+ * @group Circuit Breaker
+ */
+PARAM_DEFINE_INT32(CBRK_IO_SAFETY, 0);
+
+bool circuit_breaker_enabled(const char* breaker, int32_t magic)
+{
+	int32_t val;
+	(void)param_get(param_find(breaker), &val);
+
+	return (val == magic);
+}
+
diff --git a/src/modules/systemlib/circuit_breaker.h b/src/modules/systemlib/circuit_breaker.h
new file mode 100644
index 000000000..1175dbce8
--- /dev/null
+++ b/src/modules/systemlib/circuit_breaker.h
@@ -0,0 +1,64 @@
+/****************************************************************************
+ *
+ *   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 circuit_breaker.h
+ *
+ * Circuit breaker functionality.
+ */
+
+#ifndef CIRCUIT_BREAKER_H_
+#define CIRCUIT_BREAKER_H_
+
+/* SAFETY WARNING  --  SAFETY WARNING  --  SAFETY WARNING
+ *
+ * OBEY THE DOCUMENTATION FOR ALL CIRCUIT BREAKERS HERE,
+ * ENSURE TO READ CAREFULLY ALL SAFETY WARNINGS.
+ * http://pixhawk.org/dev/circuit_breakers
+ *
+ * CIRCUIT BREAKERS ARE NOT PART OF THE STANDARD OPERATION PROCEDURE
+ * AND MAY DISABLE CHECKS THAT ARE VITAL FOR SAFE FLIGHT.
+ */
+#define CBRK_SUPPLY_CHK_KEY	894281
+#define CBRK_RATE_CTRL_KEY	140253
+#define CBRK_IO_SAFETY_KEY	22027
+
+#include <stdbool.h>
+
+__BEGIN_DECLS
+
+__EXPORT bool circuit_breaker_enabled(const char* breaker, int32_t magic);
+
+__END_DECLS
+
+#endif /* CIRCUIT_BREAKER_H_ */
diff --git a/src/modules/systemlib/hx_stream.c b/src/modules/systemlib/hx_stream.c
index 8e9c2bfcf..52ae77de5 100644
--- a/src/modules/systemlib/hx_stream.c
+++ b/src/modules/systemlib/hx_stream.c
@@ -63,7 +63,7 @@ struct hx_stream {
 	/* TX state */
 	int			fd;
 	bool			tx_error;
-	uint8_t			*tx_buf;
+	const uint8_t		*tx_buf;
 	unsigned		tx_resid;
 	uint32_t		tx_crc;
 	enum {
diff --git a/src/modules/systemlib/mixer/mixer_multirotor.cpp b/src/modules/systemlib/mixer/mixer_multirotor.cpp
index 092c0e2b0..4b22a46d0 100644
--- a/src/modules/systemlib/mixer/mixer_multirotor.cpp
+++ b/src/modules/systemlib/mixer/mixer_multirotor.cpp
@@ -208,7 +208,6 @@ MultirotorMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handl
 	char geomname[8];
 	int s[4];
 	int used;
-	const char *end = buf + buflen;
 
 	/* enforce that the mixer ends with space or a new line */
 	for (int i = buflen - 1; i >= 0; i--) {
@@ -302,7 +301,6 @@ MultirotorMixer::mix(float *outputs, unsigned space)
 	//lowsyslog("thrust: %d, get_control3: %d\n", (int)(thrust), (int)(get_control(0, 3)));
 	float		min_out = 0.0f;
 	float		max_out = 0.0f;
-	float		scale_yaw = 1.0f;
 
 	/* perform initial mix pass yielding unbounded outputs, ignore yaw */
 	for (unsigned i = 0; i < _rotor_count; i++) {
@@ -327,7 +325,7 @@ MultirotorMixer::mix(float *outputs, unsigned space)
 	}
 
 	/* scale down roll/pitch controls if some outputs are negative, don't add yaw, keep total thrust */
-	if (min_out < 0.0) {
+	if (min_out < 0.0f) {
 		float scale_in = thrust / (thrust - min_out);
 
 		/* mix again with adjusted controls */
diff --git a/src/modules/systemlib/module.mk b/src/modules/systemlib/module.mk
index 3953b757d..147903aa0 100644
--- a/src/modules/systemlib/module.mk
+++ b/src/modules/systemlib/module.mk
@@ -1,6 +1,6 @@
 ############################################################################
 #
-#   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+#   Copyright (c) 2012-2014 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
@@ -52,5 +52,6 @@ SRCS		 = err.c \
 		   rc_check.c \
 		   otp.c \
 		   board_serial.c \
-		   pwm_limit/pwm_limit.c
+		   pwm_limit/pwm_limit.c \
+		   circuit_breaker.c
 
diff --git a/src/modules/systemlib/otp.c b/src/modules/systemlib/otp.c
index 695574fdc..0548a9f7d 100644
--- a/src/modules/systemlib/otp.c
+++ b/src/modules/systemlib/otp.c
@@ -133,7 +133,7 @@ int lock_otp(void)
 
 
 // COMPLETE, BUSY, or other flash error?
-int F_GetStatus(void)
+static int F_GetStatus(void)
 {
 	int fs = F_COMPLETE;
 
diff --git a/src/modules/systemlib/param/param.c b/src/modules/systemlib/param/param.c
index 7a499ca72..e44e6cdb0 100644
--- a/src/modules/systemlib/param/param.c
+++ b/src/modules/systemlib/param/param.c
@@ -96,8 +96,6 @@ ORB_DEFINE(parameter_update, struct parameter_update_s);
 /** parameter update topic handle */
 static orb_advert_t param_topic = -1;
 
-static sem_t param_sem = { .semcount = 1 };
-
 /** lock the parameter store */
 static void
 param_lock(void)
diff --git a/src/modules/systemlib/pwm_limit/pwm_limit.c b/src/modules/systemlib/pwm_limit/pwm_limit.c
index ea5ba9e52..c733a53d7 100644
--- a/src/modules/systemlib/pwm_limit/pwm_limit.c
+++ b/src/modules/systemlib/pwm_limit/pwm_limit.c
@@ -97,7 +97,6 @@ void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_
 	}
 
 	unsigned progress;
-	uint16_t temp_pwm;
 
 	/* then set effective_pwm based on state */
 	switch (limit->state) {
diff --git a/src/modules/systemlib/rc_check.c b/src/modules/systemlib/rc_check.c
index c0c1a5cb4..b35b333af 100644
--- a/src/modules/systemlib/rc_check.c
+++ b/src/modules/systemlib/rc_check.c
@@ -42,6 +42,7 @@
 #include <stdio.h>
 #include <fcntl.h>
 
+#include <systemlib/err.h>
 #include <systemlib/rc_check.h>
 #include <systemlib/param/param.h>
 #include <mavlink/mavlink_log.h>
@@ -98,32 +99,32 @@ int rc_calibration_check(int mavlink_fd) {
 		/* assert min..center..max ordering */
 		if (param_min < 500) {
 			count++;
-			mavlink_log_critical(mavlink_fd, "ERR: RC_%d_MIN < 500", i+1);
+			mavlink_log_critical(mavlink_fd, "#audio ERR: RC_%d_MIN < 500", i+1);
 			/* give system time to flush error message in case there are more */
 			usleep(100000);
 		}
 		if (param_max > 2500) {
 			count++;
-			mavlink_log_critical(mavlink_fd, "ERR: RC_%d_MAX > 2500", i+1);
+			mavlink_log_critical(mavlink_fd, "#audio ERR: RC_%d_MAX > 2500", i+1);
 			/* give system time to flush error message in case there are more */
 			usleep(100000);
 		}
 		if (param_trim < param_min) {
 			count++;
-			mavlink_log_critical(mavlink_fd, "ERR: RC_%d_TRIM < MIN (%d/%d)", i+1, (int)param_trim, (int)param_min);
+			mavlink_log_critical(mavlink_fd, "#audio ERR: RC_%d_TRIM < MIN (%d/%d)", i+1, (int)param_trim, (int)param_min);
 			/* give system time to flush error message in case there are more */
 			usleep(100000);
 		}
 		if (param_trim > param_max) {
 			count++;
-			mavlink_log_critical(mavlink_fd, "ERR: RC_%d_TRIM > MAX (%d/%d)", i+1, (int)param_trim, (int)param_max);
+			mavlink_log_critical(mavlink_fd, "#audio ERR: RC_%d_TRIM > MAX (%d/%d)", i+1, (int)param_trim, (int)param_max);
 			/* give system time to flush error message in case there are more */
 			usleep(100000);
 		}
 
 		/* assert deadzone is sane */
 		if (param_dz > 500) {
-			mavlink_log_critical(mavlink_fd, "ERR: RC_%d_DZ > 500", i+1);
+			mavlink_log_critical(mavlink_fd, "#audio ERR: RC_%d_DZ > 500", i+1);
 			/* give system time to flush error message in case there are more */
 			usleep(100000);
 			count++;
@@ -139,7 +140,7 @@ int rc_calibration_check(int mavlink_fd) {
 
 		/* sanity checks pass, enable channel */
 		if (count) {
-			mavlink_log_critical(mavlink_fd, "ERROR: %d config error(s) for RC channel %d.", count, (i + 1));
+			mavlink_log_critical(mavlink_fd, "#audio ERROR: %d config error(s) for RC channel %d.", count, (i + 1));
 			warnx("ERROR: %d config error(s) for RC channel %d.", count, (i + 1));
 			usleep(100000);
 		}
diff --git a/src/modules/systemlib/systemlib.c b/src/modules/systemlib/systemlib.c
index 57a751e1c..9fff3eb88 100644
--- a/src/modules/systemlib/systemlib.c
+++ b/src/modules/systemlib/systemlib.c
@@ -64,6 +64,9 @@ systemreset(bool to_bootloader)
 		*(uint32_t *)0x40002850 = 0xb007b007;
 	}
 	up_systemreset();
+
+	/* lock up here */
+	while(true);
 }
 
 static void kill_task(FAR struct tcb_s *tcb, FAR void *arg);
diff --git a/src/modules/uORB/Subscription.cpp b/src/modules/uORB/Subscription.cpp
index c1d1a938f..44b6debc7 100644
--- a/src/modules/uORB/Subscription.cpp
+++ b/src/modules/uORB/Subscription.cpp
@@ -40,6 +40,7 @@
 #include "topics/parameter_update.h"
 #include "topics/actuator_controls.h"
 #include "topics/vehicle_gps_position.h"
+#include "topics/satellite_info.h"
 #include "topics/sensor_combined.h"
 #include "topics/vehicle_attitude.h"
 #include "topics/vehicle_global_position.h"
@@ -88,6 +89,7 @@ T Subscription<T>::getData() {
 template class __EXPORT Subscription<parameter_update_s>;
 template class __EXPORT Subscription<actuator_controls_s>;
 template class __EXPORT Subscription<vehicle_gps_position_s>;
+template class __EXPORT Subscription<satellite_info_s>;
 template class __EXPORT Subscription<sensor_combined_s>;
 template class __EXPORT Subscription<vehicle_attitude_s>;
 template class __EXPORT Subscription<vehicle_global_position_s>;
diff --git a/src/modules/uORB/objects_common.cpp b/src/modules/uORB/objects_common.cpp
index 7c3bb0009..687fc1d4a 100644
--- a/src/modules/uORB/objects_common.cpp
+++ b/src/modules/uORB/objects_common.cpp
@@ -75,6 +75,9 @@ ORB_DEFINE(sensor_combined, struct sensor_combined_s);
 #include "topics/vehicle_gps_position.h"
 ORB_DEFINE(vehicle_gps_position, struct vehicle_gps_position_s);
 
+#include "topics/satellite_info.h"
+ORB_DEFINE(satellite_info, struct satellite_info_s);
+
 #include "topics/home_position.h"
 ORB_DEFINE(home_position, struct home_position_s);
 
diff --git a/src/modules/uORB/topics/rc_channels.h b/src/modules/uORB/topics/rc_channels.h
index f8048a159..829d8e57d 100644
--- a/src/modules/uORB/topics/rc_channels.h
+++ b/src/modules/uORB/topics/rc_channels.h
@@ -1,6 +1,6 @@
 /****************************************************************************
  *
- *   Copyright (c) 2012, 2013 PX4 Development Team. All rights reserved.
+ *   Copyright (c) 2012-2014 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
@@ -43,59 +43,43 @@
 #include "../uORB.h"
 
 /**
- * The number of RC channel inputs supported.
- * Current (Q4/2013) radios support up to 18 channels,
- * leaving at a sane value of 16.
- * This number can be greater then number of RC channels,
- * because single RC channel can be mapped to multiple
- * functions, e.g. for various mode switches.
- */
-#define RC_CHANNELS_MAPPED_MAX   16
-
-/**
  * This defines the mapping of the RC functions.
  * The value assigned to the specific function corresponds to the entry of
- * the channel array chan[].
+ * the channel array channels[].
  */
 enum RC_CHANNELS_FUNCTION {
 	THROTTLE = 0,
-	ROLL     = 1,
-	PITCH    = 2,
-	YAW      = 3,
-	MODE = 4,
-	RETURN = 5,
-	POSCTL = 6,
-	LOITER = 7,
-	OFFBOARD = 8,
-	ACRO    = 9,
-	FLAPS   = 10,
-	AUX_1   = 11,
-	AUX_2   = 12,
-	AUX_3   = 13,
-	AUX_4   = 14,
-	AUX_5   = 15,
-	RC_CHANNELS_FUNCTION_MAX /**< indicates the number of functions. There can be more functions than RC channels. */
+	ROLL,
+	PITCH,
+	YAW,
+	MODE,
+	RETURN,
+	POSCTL,
+	LOITER,
+	OFFBOARD_MODE,
+	ACRO,
+	FLAPS,
+	AUX_1,
+	AUX_2,
+	AUX_3,
+	AUX_4,
+	AUX_5,
+	RC_CHANNELS_FUNCTION_MAX /**< Indicates the number of functions. There can be more functions than RC channels. */
 };
 
 /**
  * @addtogroup topics
  * @{
  */
-
 struct rc_channels_s {
-
-	uint64_t timestamp;                 /**< In microseconds since boot time. */
-	uint64_t timestamp_last_valid;      /**< timestamp of last valid RC signal. */
-	struct {
-		float scaled;                     /**< Scaled to -1..1 (throttle: 0..1) */
-	} chan[RC_CHANNELS_MAPPED_MAX];
-	uint8_t chan_count;                 /**< number of valid channels */
-
-	/*String array to store the names of the functions*/
-	char function_name[RC_CHANNELS_FUNCTION_MAX][20];
-	int8_t function[RC_CHANNELS_FUNCTION_MAX];
-	uint8_t rssi;                       /**< Overall receive signal strength */
-	bool signal_lost;		/**< control signal lost, should be checked together with topic timeout */
+	uint64_t timestamp;									/**< Timestamp in microseconds since boot time */
+	uint64_t timestamp_last_valid;						/**< Timestamp of last valid RC signal */
+	float channels[RC_CHANNELS_FUNCTION_MAX];			/**< Scaled to -1..1 (throttle: 0..1) */
+	uint8_t channel_count;								/**< Number of valid channels */
+	char function_name[RC_CHANNELS_FUNCTION_MAX][20];	/**< String array to store the names of the functions */
+	int8_t function[RC_CHANNELS_FUNCTION_MAX];			/**< Functions mapping */
+	uint8_t rssi;										/**< Receive signal strength index */
+	bool signal_lost;									/**< Control signal lost, should be checked together with topic timeout */
 }; /**< radio control channels. */
 
 /**
diff --git a/src/modules/uORB/topics/satellite_info.h b/src/modules/uORB/topics/satellite_info.h
new file mode 100644
index 000000000..37c2faa96
--- /dev/null
+++ b/src/modules/uORB/topics/satellite_info.h
@@ -0,0 +1,89 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2014 PX4 Development Team. All rights reserved.
+ *   Author: @author Thomas Gubler <thomasgubler@student.ethz.ch>
+ *           @author Julian Oes <joes@student.ethz.ch>
+ *           @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 satellite_info.h
+ * Definition of the GNSS satellite info uORB topic.
+ */
+
+#ifndef TOPIC_SAT_INFO_H_
+#define TOPIC_SAT_INFO_H_
+
+#include <stdint.h>
+#include "../uORB.h"
+
+/**
+ * @addtogroup topics
+ * @{
+ */
+
+/**
+ * GNSS Satellite Info.
+ */
+
+#define SAT_INFO_MAX_SATELLITES  20
+
+struct satellite_info_s {
+	uint64_t timestamp;				/**< Timestamp of satellite info */
+	uint8_t count;					/**< Number of satellites in satellite info */
+	uint8_t svid[SAT_INFO_MAX_SATELLITES]; 		/**< Space vehicle ID [1..255], see scheme below  */
+	uint8_t used[SAT_INFO_MAX_SATELLITES];		/**< 0: Satellite not used, 1: used for navigation */
+	uint8_t elevation[SAT_INFO_MAX_SATELLITES];	/**< Elevation (0: right on top of receiver, 90: on the horizon) of satellite */
+	uint8_t azimuth[SAT_INFO_MAX_SATELLITES];	/**< Direction of satellite, 0: 0 deg, 255: 360 deg. */
+	uint8_t snr[SAT_INFO_MAX_SATELLITES];		/**< dBHz, Signal to noise ratio of satellite C/N0, range 0..99, zero when not tracking this satellite. */
+};
+
+/**
+ * NAV_SVINFO space vehicle ID (svid) scheme according to u-blox protocol specs
+ * u-bloxM8-V15_ReceiverDescriptionProtocolSpec_Public_(UBX-13003221).pdf
+ *
+ * GPS		1-32
+ * SBAS		120-158
+ * Galileo	211-246
+ * BeiDou	159-163, 33-64
+ * QZSS		193-197
+ * GLONASS	65-96, 255
+ *
+ */
+
+/**
+ * @}
+ */
+
+/* register this as object request broker structure */
+ORB_DECLARE(satellite_info);
+
+#endif
diff --git a/src/modules/uORB/topics/vehicle_gps_position.h b/src/modules/uORB/topics/vehicle_gps_position.h
index bbacb733a..dbd59f4f3 100644
--- a/src/modules/uORB/topics/vehicle_gps_position.h
+++ b/src/modules/uORB/topics/vehicle_gps_position.h
@@ -82,14 +82,7 @@ struct vehicle_gps_position_s {
 	uint64_t timestamp_time;			/**< Timestamp for time information */
 	uint64_t time_gps_usec;				/**< Timestamp (microseconds in GPS format), this is the timestamp which comes from the gps module   */
 
-	uint64_t timestamp_satellites;			/**< Timestamp for sattelite information */
-	uint8_t satellites_visible;			/**< Number of satellites visible. If unknown, set to 255 */
-	uint8_t satellite_prn[20]; 			/**< Global satellite ID */
-	uint8_t satellite_used[20];			/**< 0: Satellite not used, 1: used for localization */
-	uint8_t satellite_elevation[20]; 		/**< Elevation (0: right on top of receiver, 90: on the horizon) of satellite */
-	uint8_t satellite_azimuth[20];			/**< Direction of satellite, 0: 0 deg, 255: 360 deg. */
-	uint8_t satellite_snr[20];			/**< dBHz, Signal to noise ratio of satellite C/N0, range 0..99, zero when not tracking this satellite. */
-	bool satellite_info_available;			/**< 0 for no info, 1 for info available */
+	uint8_t satellites_used;			/**< Number of satellites used */
 };
 
 /**
diff --git a/src/modules/uORB/topics/vehicle_status.h b/src/modules/uORB/topics/vehicle_status.h
index e9e0fa841..b46c00b75 100644
--- a/src/modules/uORB/topics/vehicle_status.h
+++ b/src/modules/uORB/topics/vehicle_status.h
@@ -193,6 +193,8 @@ struct vehicle_status_s {
 	bool condition_local_altitude_valid;
 	bool condition_airspeed_valid;			/**< set to true by the commander app if there is a valid airspeed measurement available */
 	bool condition_landed;					/**< true if vehicle is landed, always true if disarmed */
+	bool condition_power_input_valid;		/**< set if input power is valid */
+	float avionics_power_rail_voltage;		/**< voltage of the avionics power rail */
 
 	bool rc_signal_found_once;
 	bool rc_signal_lost;				/**< true if RC reception lost */
@@ -222,6 +224,8 @@ struct vehicle_status_s {
 	uint16_t errors_count2;
 	uint16_t errors_count3;
 	uint16_t errors_count4;
+
+	bool circuit_breaker_engaged_power_check;
 };
 
 /**