Merged master into safelinksafelink

9 files changed, 232 insertions, 153 deletions

diff --git a/src/modules/px4iofirmware/controls.c b/src/modules/px4iofirmware/controls.c
index 12258d9f0..4f5a86fcb 100644
--- a/src/modules/px4iofirmware/controls.c
+++ b/src/modules/px4iofirmware/controls.c
@@ -47,8 +47,8 @@
 #include "px4io.h"
 
 #define RC_FAILSAFE_TIMEOUT		2000000		/**< two seconds failsafe timeout */
-#define RC_CHANNEL_HIGH_THRESH		5000
-#define RC_CHANNEL_LOW_THRESH		-5000
+#define RC_CHANNEL_HIGH_THRESH		5000	/* 75% threshold */
+#define RC_CHANNEL_LOW_THRESH		-8000	/* 10% threshold */
 
 static bool	ppm_input(uint16_t *values, uint16_t *num_values, uint16_t *frame_len);
 
@@ -144,10 +144,7 @@ controls_tick() {
 
 		perf_begin(c_gather_sbus);
 
-		bool sbus_status = (r_status_flags & PX4IO_P_STATUS_FLAGS_RC_SBUS);
-
 		bool sbus_failsafe, sbus_frame_drop;
-
 		sbus_updated = sbus_input(r_raw_rc_values, &r_raw_rc_count, &sbus_failsafe, &sbus_frame_drop, PX4IO_RC_INPUT_CHANNELS);
 
 		if (sbus_updated) {
@@ -213,94 +210,105 @@ controls_tick() {
 		/* update RC-received timestamp */
 		system_state.rc_channels_timestamp_received = hrt_absolute_time();
 
-		/* do not command anything in failsafe, kick in the RC loss counter */
-		if (!(r_raw_rc_flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE)) {
-
-			/* update RC-received timestamp */
-			system_state.rc_channels_timestamp_valid = system_state.rc_channels_timestamp_received;
-
-			/* map raw inputs to mapped inputs */
-			/* XXX mapping should be atomic relative to protocol */
-			for (unsigned i = 0; i < r_raw_rc_count; i++) {
-
-				/* map the input channel */
-				uint16_t *conf = &r_page_rc_input_config[i * PX4IO_P_RC_CONFIG_STRIDE];
-
-				if (conf[PX4IO_P_RC_CONFIG_OPTIONS] & PX4IO_P_RC_CONFIG_OPTIONS_ENABLED) {
-
-					uint16_t raw = r_raw_rc_values[i];
-
-					int16_t scaled;
-
-					/*
-					 * 1) Constrain to min/max values, as later processing depends on bounds.
-					 */
-					if (raw < conf[PX4IO_P_RC_CONFIG_MIN])
-						raw = conf[PX4IO_P_RC_CONFIG_MIN];
-					if (raw > conf[PX4IO_P_RC_CONFIG_MAX])
-						raw = conf[PX4IO_P_RC_CONFIG_MAX];
-
-					/*
-					 * 2) Scale around the mid point differently for lower and upper range.
-					 *
-					 * This is necessary as they don't share the same endpoints and slope.
-					 *
-					 * First normalize to 0..1 range with correct sign (below or above center),
-					 * then scale to 20000 range (if center is an actual center, -10000..10000,
-					 * if parameters only support half range, scale to 10000 range, e.g. if
-					 * center == min 0..10000, if center == max -10000..0).
-					 *
-					 * As the min and max bounds were enforced in step 1), division by zero
-					 * cannot occur, as for the case of center == min or center == max the if
-					 * statement is mutually exclusive with the arithmetic NaN case.
-					 *
-					 * DO NOT REMOVE OR ALTER STEP 1!
-					 */
-					if (raw > (conf[PX4IO_P_RC_CONFIG_CENTER] + conf[PX4IO_P_RC_CONFIG_DEADZONE])) {
-						scaled = 10000.0f * ((raw - conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE]) / (float)(conf[PX4IO_P_RC_CONFIG_MAX] - conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE]));
-
-					} else if (raw < (conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE])) {
-						scaled = 10000.0f * ((raw - conf[PX4IO_P_RC_CONFIG_CENTER] + conf[PX4IO_P_RC_CONFIG_DEADZONE]) / (float)(conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE] - conf[PX4IO_P_RC_CONFIG_MIN]));
-
-					} else {
-						/* in the configured dead zone, output zero */
-						scaled = 0;
-					}
-
-					/* invert channel if requested */
-					if (conf[PX4IO_P_RC_CONFIG_OPTIONS] & PX4IO_P_RC_CONFIG_OPTIONS_REVERSE)
-						scaled = -scaled;
+		/* update RC-received timestamp */
+		system_state.rc_channels_timestamp_valid = system_state.rc_channels_timestamp_received;
+
+		/* map raw inputs to mapped inputs */
+		/* XXX mapping should be atomic relative to protocol */
+		for (unsigned i = 0; i < r_raw_rc_count; i++) {
+
+			/* map the input channel */
+			uint16_t *conf = &r_page_rc_input_config[i * PX4IO_P_RC_CONFIG_STRIDE];
+
+			if (conf[PX4IO_P_RC_CONFIG_OPTIONS] & PX4IO_P_RC_CONFIG_OPTIONS_ENABLED) {
+
+				uint16_t raw = r_raw_rc_values[i];
+
+				int16_t scaled;
+
+				/*
+				 * 1) Constrain to min/max values, as later processing depends on bounds.
+				 */
+				if (raw < conf[PX4IO_P_RC_CONFIG_MIN])
+					raw = conf[PX4IO_P_RC_CONFIG_MIN];
+				if (raw > conf[PX4IO_P_RC_CONFIG_MAX])
+					raw = conf[PX4IO_P_RC_CONFIG_MAX];
+
+				/*
+				 * 2) Scale around the mid point differently for lower and upper range.
+				 *
+				 * This is necessary as they don't share the same endpoints and slope.
+				 *
+				 * First normalize to 0..1 range with correct sign (below or above center),
+				 * then scale to 20000 range (if center is an actual center, -10000..10000,
+				 * if parameters only support half range, scale to 10000 range, e.g. if
+				 * center == min 0..10000, if center == max -10000..0).
+				 *
+				 * As the min and max bounds were enforced in step 1), division by zero
+				 * cannot occur, as for the case of center == min or center == max the if
+				 * statement is mutually exclusive with the arithmetic NaN case.
+				 *
+				 * DO NOT REMOVE OR ALTER STEP 1!
+				 */
+				if (raw > (conf[PX4IO_P_RC_CONFIG_CENTER] + conf[PX4IO_P_RC_CONFIG_DEADZONE])) {
+					scaled = 10000.0f * ((raw - conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE]) / (float)(conf[PX4IO_P_RC_CONFIG_MAX] - conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE]));
+
+				} else if (raw < (conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE])) {
+					scaled = 10000.0f * ((raw - conf[PX4IO_P_RC_CONFIG_CENTER] + conf[PX4IO_P_RC_CONFIG_DEADZONE]) / (float)(conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE] - conf[PX4IO_P_RC_CONFIG_MIN]));
+
+				} else {
+					/* in the configured dead zone, output zero */
+					scaled = 0;
+				}
 
-					/* and update the scaled/mapped version */
-					unsigned mapped = conf[PX4IO_P_RC_CONFIG_ASSIGNMENT];
-					if (mapped < PX4IO_CONTROL_CHANNELS) {
+				/* invert channel if requested */
+				if (conf[PX4IO_P_RC_CONFIG_OPTIONS] & PX4IO_P_RC_CONFIG_OPTIONS_REVERSE) {
+					scaled = -scaled;
+				}
 
-						/* invert channel if pitch - pulling the lever down means pitching up by convention */
-						if (mapped == 1) /* roll, pitch, yaw, throttle, override is the standard order */
-							scaled = -scaled;
+				/* and update the scaled/mapped version */
+				unsigned mapped = conf[PX4IO_P_RC_CONFIG_ASSIGNMENT];
+				if (mapped < PX4IO_CONTROL_CHANNELS) {
 
-						r_rc_values[mapped] = SIGNED_TO_REG(scaled);
-						assigned_channels |= (1 << mapped);
+					/* invert channel if pitch - pulling the lever down means pitching up by convention */
+					if (mapped == 1) {
+						/* roll, pitch, yaw, throttle, override is the standard order */
+						scaled = -scaled;
+					}
 
+					if (mapped == 3 && r_setup_rc_thr_failsafe) {
+						/* throttle failsafe detection */
+						if (((raw < conf[PX4IO_P_RC_CONFIG_MIN]) && (raw < r_setup_rc_thr_failsafe)) ||
+						    ((raw > conf[PX4IO_P_RC_CONFIG_MAX]) && (raw > r_setup_rc_thr_failsafe))) {
+							r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_FAILSAFE;
+						} else {
+							r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
+						}
 					}
+
+					r_rc_values[mapped] = SIGNED_TO_REG(scaled);
+					assigned_channels |= (1 << mapped);
+
 				}
 			}
+		}
 
-			/* set un-assigned controls to zero */
-			for (unsigned i = 0; i < PX4IO_CONTROL_CHANNELS; i++) {
-				if (!(assigned_channels & (1 << i)))
-					r_rc_values[i] = 0;
+		/* set un-assigned controls to zero */
+		for (unsigned i = 0; i < PX4IO_CONTROL_CHANNELS; i++) {
+			if (!(assigned_channels & (1 << i))) {
+				r_rc_values[i] = 0;
 			}
+		}
 
-			/* set RC OK flag, as we got an update */
-			r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_OK;
+		/* set RC OK flag, as we got an update */
+		r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_OK;
+		r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_RC_OK;
 
-			/* if we have enough channels (5) to control the vehicle, the mapping is ok */
-			if (assigned_channels > 4) {
-				r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_MAPPING_OK;
-			} else {
-				r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_MAPPING_OK);
-			}
+		/* if we have enough channels (5) to control the vehicle, the mapping is ok */
+		if (assigned_channels > 4) {
+			r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_MAPPING_OK;
+		} else {
+			r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_MAPPING_OK);
 		}
 
 		/*
@@ -328,37 +336,42 @@ controls_tick() {
 	 * Handle losing RC input
 	 */
 
-	/* this kicks in if the receiver is gone or the system went to failsafe */
-	if (rc_input_lost || (r_raw_rc_flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE)) {
+	/* if we are in failsafe, clear the override flag */
+	if (r_raw_rc_flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE) {
+		r_status_flags &= ~(PX4IO_P_STATUS_FLAGS_OVERRIDE);
+	}
+
+	/* this kicks in if the receiver is gone, but there is not on failsafe (indicated by separate flag) */
+	if (rc_input_lost) {
 		/* Clear the RC input status flag, clear manual override flag */
 		r_status_flags &= ~(
 			PX4IO_P_STATUS_FLAGS_OVERRIDE |
 			PX4IO_P_STATUS_FLAGS_RC_OK);
 
+		/* flag raw RC as lost */
+		r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_RC_OK);
+
 		/* Mark all channels as invalid, as we just lost the RX */
 		r_rc_valid = 0;
 
+		/* Set raw channel count to zero */
+		r_raw_rc_count = 0;
+
 		/* Set the RC_LOST alarm */
 		r_status_alarms |= PX4IO_P_STATUS_ALARMS_RC_LOST;
 	}
 
-	/* this kicks in if the receiver is completely gone */
-	if (rc_input_lost) {
-
-		/* Set channel count to zero */
-		r_raw_rc_count = 0;
-	}
-
 	/*
 	 * Check for manual override.
 	 *
 	 * The PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK flag must be set, and we
-	 * must have R/C input.
+	 * must have R/C input (NO FAILSAFE!).
 	 * Override is enabled if either the hardcoded channel / value combination
 	 * is selected, or the AP has requested it.
 	 */
 	if ((r_setup_arming & PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK) && 
-		(r_status_flags & PX4IO_P_STATUS_FLAGS_RC_OK)) {
+		(r_status_flags & PX4IO_P_STATUS_FLAGS_RC_OK) &&
+		!(r_raw_rc_flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE)) {
 
 		bool override = false;
 
@@ -381,10 +394,10 @@ controls_tick() {
 				mixer_tick();
 
 		} else {
-			r_status_flags &= ~PX4IO_P_STATUS_FLAGS_OVERRIDE;
+			r_status_flags &= ~(PX4IO_P_STATUS_FLAGS_OVERRIDE);
 		}
 	} else {
-		r_status_flags &= ~PX4IO_P_STATUS_FLAGS_OVERRIDE;
+		r_status_flags &= ~(PX4IO_P_STATUS_FLAGS_OVERRIDE);
 	}
 }
 
@@ -407,8 +420,9 @@ ppm_input(uint16_t *values, uint16_t *num_values, uint16_t *frame_len)
 		if (*num_values > PX4IO_RC_INPUT_CHANNELS)
 			*num_values = PX4IO_RC_INPUT_CHANNELS;
 
-		for (unsigned i = 0; i < *num_values; i++)
+		for (unsigned i = 0; i < *num_values; i++) {
 			values[i] = ppm_buffer[i];
+		}
 
 		/* clear validity */
 		ppm_last_valid_decode = 0;
diff --git a/src/modules/px4iofirmware/dsm.c b/src/modules/px4iofirmware/dsm.c
index 60eda2319..d3f365822 100644
--- a/src/modules/px4iofirmware/dsm.c
+++ b/src/modules/px4iofirmware/dsm.c
@@ -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
@@ -162,6 +162,7 @@ dsm_guess_format(bool reset)
 		0xff,	/* 8 channels (DX8) */
 		0x1ff,	/* 9 channels (DX9, etc.) */
 		0x3ff,	/* 10 channels (DX10) */
+		0x1fff,	/* 13 channels (DX10t) */
 		0x3fff	/* 18 channels (DX10) */
 	};
 	unsigned votes10 = 0;
@@ -368,11 +369,25 @@ dsm_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values)
 		if (channel >= *num_values)
 			*num_values = channel + 1;
 
-		/* convert 0-1024 / 0-2048 values to 1000-2000 ppm encoding in a very sloppy fashion */
-		if (dsm_channel_shift == 11)
-			value /= 2;
+		/* convert 0-1024 / 0-2048 values to 1000-2000 ppm encoding. */
+		if (dsm_channel_shift == 10)
+			value *= 2;
 
-		value += 998;
+		/*
+		 * Spektrum scaling is special. There are these basic considerations
+		 *
+		 *   * Midpoint is 1520 us
+		 *   * 100% travel channels are +- 400 us
+		 *
+		 * We obey the original Spektrum scaling (so a default setup will scale from
+		 * 1100 - 1900 us), but we do not obey the weird 1520 us center point
+		 * and instead (correctly) center the center around 1500 us. This is in order
+		 * to get something useful without requiring the user to calibrate on a digital
+		 * link for no reason.
+		 */
+
+		/* scaled integer for decent accuracy while staying efficient */
+		value = ((((int)value - 1024) * 1000) / 1700) + 1500;
 
 		/*
 		 * Store the decoded channel into the R/C input buffer, taking into
@@ -400,6 +415,15 @@ dsm_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values)
 		values[channel] = value;
 	}
 
+	/*
+	 * Spektrum likes to send junk in higher channel numbers to fill
+	 * their packets. We don't know about a 13 channel model in their TX
+	 * lines, so if we get a channel count of 13, we'll return 12 (the last
+	 * data index that is stable).
+	 */
+	if (*num_values == 13)
+		*num_values = 12;
+
 	if (dsm_channel_shift == 11) {
 		/* Set the 11-bit data indicator */
 		*num_values |= 0x8000;
diff --git a/src/modules/px4iofirmware/i2c.c b/src/modules/px4iofirmware/i2c.c
index 79b6546b3..6d1d1fc2d 100644
--- a/src/modules/px4iofirmware/i2c.c
+++ b/src/modules/px4iofirmware/i2c.c
@@ -64,12 +64,15 @@
 #define rCCR		REG(STM32_I2C_CCR_OFFSET)
 #define rTRISE		REG(STM32_I2C_TRISE_OFFSET)
 
+void			i2c_reset(void);
 static int		i2c_interrupt(int irq, void *context);
 static void		i2c_rx_setup(void);
 static void		i2c_tx_setup(void);
 static void		i2c_rx_complete(void);
 static void		i2c_tx_complete(void);
+#ifdef DEBUG
 static void		i2c_dump(void);
+#endif
 
 static DMA_HANDLE	rx_dma;
 static DMA_HANDLE	tx_dma;
@@ -331,6 +334,7 @@ i2c_tx_complete(void)
 	i2c_tx_setup();
 }
 
+#ifdef DEBUG
 static void
 i2c_dump(void)
 {
@@ -339,3 +343,4 @@ 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/mixer.cpp b/src/modules/px4iofirmware/mixer.cpp
index 5a834e07f..3a82a5821 100644
--- a/src/modules/px4iofirmware/mixer.cpp
+++ b/src/modules/px4iofirmware/mixer.cpp
@@ -192,7 +192,7 @@ mixer_tick(void)
 							    ((r_setup_arming & PX4IO_P_SETUP_ARMING_FMU_ARMED)
 		/* and there is valid input via or mixer */         &&   (r_status_flags & PX4IO_P_STATUS_FLAGS_MIXER_OK) )
 		/* or direct PWM is set */               || (r_status_flags & PX4IO_P_STATUS_FLAGS_RAW_PWM)
-		/* or failsafe was set manually */	 || (r_setup_arming & PX4IO_P_SETUP_ARMING_FAILSAFE_CUSTOM)
+		/* or failsafe was set manually */	 || ((r_setup_arming & PX4IO_P_SETUP_ARMING_FAILSAFE_CUSTOM) && !(r_status_flags & PX4IO_P_STATUS_FLAGS_FMU_OK))
 						     )
 	);
 
@@ -247,6 +247,7 @@ mixer_tick(void)
 		actuator_count = mixed;
 		in_mixer = false;
 
+		/* the pwm limit call takes care of out of band errors */
 		pwm_limit_calc(should_arm, mixed, r_page_servo_disarmed, r_page_servo_control_min, r_page_servo_control_max, outputs, r_page_servos, &pwm_limit);
 
 		for (unsigned i = mixed; i < PX4IO_SERVO_COUNT; i++)
@@ -289,17 +290,17 @@ mixer_tick(void)
 			up_pwm_servo_set(i, r_page_servos[i]);
 
 		/* update S.BUS1 outputs */
-		if (r_page_setup[PX4IO_P_SETUP_FEATURES] & PX4IO_P_SETUP_FEATURES_SBUS1_OUT) {
+		if (r_setup_features & PX4IO_P_SETUP_FEATURES_SBUS1_OUT) {
 			sbus1_output(r_page_servos, actuator_count);
 		}
 
 		/* update S.BUS2 outputs */
-		if (r_page_setup[PX4IO_P_SETUP_FEATURES] & PX4IO_P_SETUP_FEATURES_SBUS2_OUT) {
+		if (r_setup_features & PX4IO_P_SETUP_FEATURES_SBUS2_OUT) {
 			sbus2_output(r_page_servos, actuator_count);
 		}
 
 		/* update safelink outputs */
-		if (source != MIX_FAILSAFE && r_page_setup[PX4IO_P_SETUP_FEATURES] & PX4IO_P_SETUP_FEATURES_SAFELINK_OUT) {
+		if (source != MIX_FAILSAFE && r_setup_features & PX4IO_P_SETUP_FEATURES_SAFELINK_OUT) {
 			safelink_output(r_page_servos, actuator_count);
 		}
 
@@ -309,17 +310,17 @@ mixer_tick(void)
 			up_pwm_servo_set(i, r_page_servo_disarmed[i]);
 
 		/* update S.BUS1 outputs */
-		if (r_page_setup[PX4IO_P_SETUP_FEATURES] & PX4IO_P_SETUP_FEATURES_SBUS1_OUT) {
+		if (r_setup_features & PX4IO_P_SETUP_FEATURES_SBUS1_OUT) {
 			sbus1_output(r_page_servos, actuator_count);
 		}
 
 		/* update S.BUS2 outputs */
-		if (r_page_setup[PX4IO_P_SETUP_FEATURES] & PX4IO_P_SETUP_FEATURES_SBUS2_OUT) {
+		if (r_setup_features & PX4IO_P_SETUP_FEATURES_SBUS2_OUT) {
 			sbus2_output(r_page_servos, actuator_count);
 		}
 
 		/* update safelink outputs */
-		if (source != MIX_FAILSAFE && r_page_setup[PX4IO_P_SETUP_FEATURES] & PX4IO_P_SETUP_FEATURES_SAFELINK_OUT) {
+		if (source != MIX_FAILSAFE && r_setup_features & PX4IO_P_SETUP_FEATURES_SAFELINK_OUT) {
 			safelink_output(r_page_servos, actuator_count);
 		}
 	}
@@ -331,7 +332,7 @@ mixer_callback(uintptr_t handle,
 	       uint8_t control_index,
 	       float &control)
 {
-	if (control_group > 3)
+	if (control_group >= PX4IO_CONTROL_GROUPS)
 		return -1;
 
 	switch (source) {
diff --git a/src/modules/px4iofirmware/protocol.h b/src/modules/px4iofirmware/protocol.h
index 0006b137c..b55ac698b 100644
--- a/src/modules/px4iofirmware/protocol.h
+++ b/src/modules/px4iofirmware/protocol.h
@@ -143,6 +143,7 @@
 #define PX4IO_P_RAW_RC_FLAGS_FAILSAFE		(1 << 1) /* receiver is in failsafe mode */
 #define PX4IO_P_RAW_RC_FLAGS_RC_DSM11		(1 << 2) /* DSM decoding is 11 bit mode */
 #define PX4IO_P_RAW_RC_FLAGS_MAPPING_OK		(1 << 3) /* Channel mapping is ok */
+#define PX4IO_P_RAW_RC_FLAGS_RC_OK		(1 << 4) /* RC reception ok */
 
 #define PX4IO_P_RAW_RC_NRSSI			2	/* [2] Normalized RSSI value, 0: no reception, 255: perfect reception */
 #define PX4IO_P_RAW_RC_DATA			3	/* [1] + [2] Details about the RC source (PPM frame length, Spektrum protocol type) */
@@ -169,12 +170,12 @@
 /* setup page */
 #define PX4IO_PAGE_SETUP		50
 #define PX4IO_P_SETUP_FEATURES			0
-#define PX4IO_P_SETUP_FEATURES_SBUS1_OUT	(1 << 0) /* enable S.Bus v1 output */
-#define PX4IO_P_SETUP_FEATURES_SBUS2_OUT	(1 << 1) /* enable S.Bus v2 output */
-#define PX4IO_P_SETUP_FEATURES_PWM_RSSI		(1 << 2) /* enable PWM RSSI parsing */
-#define PX4IO_P_SETUP_FEATURES_ADC_RSSI		(1 << 3) /* enable ADC RSSI parsing */
-#define PX4IO_P_SETUP_FEATURES_SAFELINK_IN	(1 << 4) /* enable SAFELINK input parsing on S.BUS port */
-#define PX4IO_P_SETUP_FEATURES_SAFELINK_OUT	(1 << 5) /* enable SAFELINK output on S.BUS port */
+#define PX4IO_P_SETUP_FEATURES_SBUS1_OUT	(1 << 0) /**< enable S.Bus v1 output */
+#define PX4IO_P_SETUP_FEATURES_SBUS2_OUT	(1 << 1) /**< enable S.Bus v2 output */
+#define PX4IO_P_SETUP_FEATURES_PWM_RSSI		(1 << 2) /**< enable PWM RSSI parsing */
+#define PX4IO_P_SETUP_FEATURES_ADC_RSSI		(1 << 3) /**< enable ADC RSSI parsing */
+#define PX4IO_P_SETUP_FEATURES_SAFELINK_IN	(1 << 4) /**< enable SAFELINK input parsing on S.BUS port */
+#define PX4IO_P_SETUP_FEATURES_SAFELINK_OUT	(1 << 5) /**< enable SAFELINK output on S.BUS port */
 
 #define PX4IO_P_SETUP_ARMING			1	 /* arming controls */
 #define PX4IO_P_SETUP_ARMING_IO_ARM_OK		(1 << 0) /* OK to arm the IO side */
@@ -196,6 +197,8 @@
 #define PX4IO_P_SETUP_RELAYS_POWER2		(1<<1)	/* hardware rev [1] power relay 2 */
 #define PX4IO_P_SETUP_RELAYS_ACC1		(1<<2)	/* hardware rev [1] accessory power 1 */
 #define PX4IO_P_SETUP_RELAYS_ACC2		(1<<3)	/* hardware rev [1] accessory power 2 */
+#else
+#define PX4IO_P_SETUP_RELAYS_PAD		5
 #endif
 
 #define PX4IO_P_SETUP_VBATT_SCALE		6	/* hardware rev [1] battery voltage correction factor (float) */
@@ -208,26 +211,33 @@ enum {							/* DSM bind states */
 	dsm_bind_send_pulses,
 	dsm_bind_reinit_uart
 };
- 					     /*	8 */
-#define PX4IO_P_SETUP_SET_DEBUG			9		/* debug level for IO board */
+						/* 8 */
+#define PX4IO_P_SETUP_SET_DEBUG			9	/* debug level for IO board */
 
-#define PX4IO_P_SETUP_REBOOT_BL		       10	/* reboot IO into bootloader */
-#define PX4IO_REBOOT_BL_MAGIC               14662       /* required argument for reboot (random) */
+#define PX4IO_P_SETUP_REBOOT_BL			10	/* reboot IO into bootloader */
+#define PX4IO_REBOOT_BL_MAGIC			14662	/* required argument for reboot (random) */
 
-#define PX4IO_P_SETUP_CRC		       11	/* get CRC of IO firmware */
+#define PX4IO_P_SETUP_CRC			11	/* get CRC of IO firmware */
+						/* storage space of 12 occupied by CRC */
+#define PX4IO_P_SETUP_FORCE_SAFETY_OFF		12	/* force safety switch into
+                                                           'armed' (PWM enabled) state - this is a non-data write and
+                                                           hence index 12 can safely be used. */
+#define PX4IO_P_SETUP_RC_THR_FAILSAFE_US	13	/**< the throttle failsafe pulse length in microseconds */
+
+#define PX4IO_FORCE_SAFETY_MAGIC		22027	/* required argument for force safety (random) */
 
 /* autopilot control values, -10000..10000 */
-#define PX4IO_PAGE_CONTROLS			51		/**< actuator control groups, one after the other, 8 wide */
+#define PX4IO_PAGE_CONTROLS			51	/**< actuator control groups, one after the other, 8 wide */
 #define PX4IO_P_CONTROLS_GROUP_0		(PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 0)	/**< 0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1 */
 #define PX4IO_P_CONTROLS_GROUP_1		(PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 1)	/**< 0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1 */
 #define PX4IO_P_CONTROLS_GROUP_2		(PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 2)	/**< 0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1 */
 #define PX4IO_P_CONTROLS_GROUP_3		(PX4IO_PROTOCOL_MAX_CONTROL_COUNT * 3)	/**< 0..PX4IO_PROTOCOL_MAX_CONTROL_COUNT - 1 */
 
 #define PX4IO_P_CONTROLS_GROUP_VALID		64
-#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP0	(1 << 0) /* group 0 is valid / received */
-#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP1	(1 << 1) /* group 1 is valid / received */
-#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP2	(1 << 2) /* group 2 is valid / received */
-#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP3	(1 << 3) /* group 3 is valid / received */
+#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP0	(1 << 0) /**< group 0 is valid / received */
+#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP1	(1 << 1) /**< group 1 is valid / received */
+#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP2	(1 << 2) /**< group 2 is valid / received */
+#define PX4IO_P_CONTROLS_GROUP_VALID_GROUP3	(1 << 3) /**< group 3 is valid / received */
 
 /* raw text load to the mixer parser - ignores offset */
 #define PX4IO_PAGE_MIXERLOAD			52
@@ -309,7 +319,7 @@ 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/px4io.h b/src/modules/px4iofirmware/px4io.h
index 0a159f7f5..b809ccf7e 100644
--- a/src/modules/px4iofirmware/px4io.h
+++ b/src/modules/px4iofirmware/px4io.h
@@ -53,7 +53,7 @@
  */
 #define PX4IO_SERVO_COUNT		8
 #define PX4IO_CONTROL_CHANNELS		8
-#define PX4IO_CONTROL_GROUPS		2
+#define PX4IO_CONTROL_GROUPS		4
 #define PX4IO_RC_INPUT_CHANNELS		18
 #define PX4IO_RC_MAPPED_CONTROL_CHANNELS		8 /**< This is the maximum number of channels mapped/used */
 
@@ -109,6 +109,7 @@ extern uint16_t			r_page_servo_disarmed[];	/* PX4IO_PAGE_DISARMED_PWM */
 #ifdef CONFIG_ARCH_BOARD_PX4IO_V1
 #define r_setup_relays		r_page_setup[PX4IO_P_SETUP_RELAYS]
 #endif
+#define r_setup_rc_thr_failsafe	r_page_setup[PX4IO_P_SETUP_RC_THR_FAILSAFE_US]
 
 #define r_control_values	(&r_page_controls[0])
 #define r_safelink_values	(&r_page_safelink[PX4IO_P_SAFELINK_BASE])
@@ -221,6 +222,8 @@ extern bool	dsm_input(uint16_t *values, uint16_t *num_values);
 extern void	dsm_bind(uint16_t cmd, int pulses);
 extern int	sbus_init(const char *device);
 extern bool	sbus_input(uint16_t *values, uint16_t *num_values, bool *sbus_failsafe, bool *sbus_frame_drop, uint16_t max_channels);
+extern void	sbus1_output(uint16_t *values, uint16_t num_values);
+extern void	sbus2_output(uint16_t *values, uint16_t num_values);
 
 extern void	sbus1_output(uint16_t *values, uint16_t num_values);
 extern void	sbus2_output(uint16_t *values, uint16_t num_values);
diff --git a/src/modules/px4iofirmware/registers.c b/src/modules/px4iofirmware/registers.c
index 19fae3dc2..03849cf65 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
 };
 
@@ -170,6 +169,9 @@ volatile uint16_t	r_page_setup[] =
 	[PX4IO_P_SETUP_PWM_ALTRATE]		= 200,
 #ifdef CONFIG_ARCH_BOARD_PX4IO_V1
 	[PX4IO_P_SETUP_RELAYS]			= 0,
+#else
+	/* this is unused, but we will pad it for readability (the compiler pads it automatically) */
+	[PX4IO_P_SETUP_RELAYS_PAD]		= 0,
 #endif
 #ifdef ADC_VSERVO
 	[PX4IO_P_SETUP_VSERVO_SCALE]		= 10000,
@@ -179,6 +181,7 @@ volatile uint16_t	r_page_setup[] =
 	[PX4IO_P_SETUP_SET_DEBUG]		= 0,
 	[PX4IO_P_SETUP_REBOOT_BL]		= 0,
 	[PX4IO_P_SETUP_CRC ... (PX4IO_P_SETUP_CRC+1)] = 0,
+	[PX4IO_P_SETUP_RC_THR_FAILSAFE_US] = 0,
 };
 
 #ifdef CONFIG_ARCH_BOARD_PX4IO_V2
@@ -474,9 +477,18 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 			#ifdef ENABLE_SBUS_OUT
 			ENABLE_SBUS_OUT(value & (PX4IO_P_SETUP_FEATURES_SBUS1_OUT | PX4IO_P_SETUP_FEATURES_SBUS2_OUT));
 
-			/* disable the conflicting options */
-			if (value & (PX4IO_P_SETUP_FEATURES_SBUS1_OUT | PX4IO_P_SETUP_FEATURES_SBUS2_OUT)) {
-				value &= ~(PX4IO_P_SETUP_FEATURES_PWM_RSSI | PX4IO_P_SETUP_FEATURES_ADC_RSSI);
+			/* disable the conflicting options with SBUS 1 */
+			if (value & (PX4IO_P_SETUP_FEATURES_SBUS1_OUT)) {
+				value &= ~(PX4IO_P_SETUP_FEATURES_PWM_RSSI |
+					PX4IO_P_SETUP_FEATURES_ADC_RSSI |
+					PX4IO_P_SETUP_FEATURES_SBUS2_OUT);
+			}
+
+			/* disable the conflicting options with SBUS 2 */
+			if (value & (PX4IO_P_SETUP_FEATURES_SBUS2_OUT)) {
+				value &= ~(PX4IO_P_SETUP_FEATURES_PWM_RSSI |
+					PX4IO_P_SETUP_FEATURES_ADC_RSSI |
+					PX4IO_P_SETUP_FEATURES_SBUS1_OUT);
 			}
 			#endif
 
@@ -527,18 +539,22 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 			break;
 
 		case PX4IO_P_SETUP_PWM_DEFAULTRATE:
-			if (value < 50)
+			if (value < 50) {
 				value = 50;
-			if (value > 400)
+			}
+			if (value > 400) {
 				value = 400;
+			}
 			pwm_configure_rates(r_setup_pwm_rates, value, r_setup_pwm_altrate);
 			break;
 
 		case PX4IO_P_SETUP_PWM_ALTRATE:
-			if (value < 50)
+			if (value < 50) {
 				value = 50;
-			if (value > 400)
+			}
+			if (value > 400) {
 				value = 400;
+			}
 			pwm_configure_rates(r_setup_pwm_rates, r_setup_pwm_defaultrate, value);
 			break;
 
@@ -570,8 +586,9 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 			}
 
 			// check the magic value
-			if (value != PX4IO_REBOOT_BL_MAGIC)
+			if (value != PX4IO_REBOOT_BL_MAGIC) {
 				break;
+			}
 
                         // we schedule a reboot rather than rebooting
                         // immediately to allow the IO board to ACK
@@ -580,7 +597,19 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 			break;
 
 		case PX4IO_P_SETUP_DSM:
-			dsm_bind(value & 0x0f, (value >> 4) & 7);
+			dsm_bind(value & 0x0f, (value >> 4) & 0xF);
+			break;
+
+		case PX4IO_P_SETUP_FORCE_SAFETY_OFF:
+			if (value == PX4IO_FORCE_SAFETY_MAGIC) {
+				r_status_flags |= PX4IO_P_STATUS_FLAGS_SAFETY_OFF;
+			}
+			break;
+
+		case PX4IO_P_SETUP_RC_THR_FAILSAFE_US:
+			if (value > 650 && value < 2350) {
+				r_page_setup[PX4IO_P_SETUP_RC_THR_FAILSAFE_US] = value;
+			}
 			break;
 
 		default:
@@ -654,7 +683,7 @@ 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++;
 				}
 
@@ -696,7 +725,7 @@ registers_get(uint8_t page, uint8_t offset, uint16_t **values, unsigned *num_val
 {
 #define SELECT_PAGE(_page_name)							\
 	do {									\
-		*values = &_page_name[0];					\
+		*values = (uint16_t *)&_page_name[0];				\
 		*num_values = sizeof(_page_name) / sizeof(_page_name[0]);	\
 	} while(0)
 
diff --git a/src/modules/px4iofirmware/sbus.c b/src/modules/px4iofirmware/sbus.c
index d89021d24..1db22b7fc 100644
--- a/src/modules/px4iofirmware/sbus.c
+++ b/src/modules/px4iofirmware/sbus.c
@@ -104,7 +104,7 @@ int
 sbus_init(const char *device)
 {
 	if (sbus_fd < 0)
-		sbus_fd = open(device, O_RDONLY | O_NONBLOCK);
+		sbus_fd = open(device, O_RDWR | O_NONBLOCK);
 
 	if (sbus_fd >= 0) {
 		struct termios t;
@@ -133,21 +133,15 @@ sbus_init(const char *device)
 void
 sbus1_output(uint16_t *values, uint16_t num_values)
 {
-	/*
-	 * S.BUS2 outputs are defined as:
-	 *
-	 */
-	 #warning SBUS1 output is not yet implemented
+	char a = 'A';
+	write(sbus_fd, &a, 1);
 }
 
 void
 sbus2_output(uint16_t *values, uint16_t num_values)
 {
-	/*
-	 * S.BUS2 outputs are defined as:
-	 *
-	 */
-	#warning SBUS2 output is not yet implemented
+	char b = 'B';
+	write(sbus_fd, &b, 1);
 }
 
 bool