Merge pull request #609 from PX4/rc_status

RC status metadata cleanup and extension

src/drivers/drv_rc_input.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
@@ -62,6 +62,11 @@
  */
 #define RC_INPUT_MAX_CHANNELS	18
 
+/**
+ * Maximum RSSI value
+ */
+#define RC_INPUT_RSSI_MAX	255
+
 /**
  * Input signal type, value is a control position from zero to 100
  * percent.
@@ -83,8 +88,11 @@ enum RC_INPUT_SOURCE {
  * on the board involved.
  */
 struct rc_input_values {
-	/** decoding time */
-	uint64_t		timestamp;
+	/** publication time */
+	uint64_t		timestamp_publication;
+
+	/** last valid reception time */
+	uint64_t		timestamp_last_signal;
 
 	/** number of channels actually being seen */
 	uint32_t		channel_count;
@@ -92,6 +100,40 @@ struct rc_input_values {
 	/** receive signal strength indicator (RSSI): < 0: Undefined, 0: no signal, 255: full reception */
 	int32_t			rssi;
 
+	/**
+	 * explicit failsafe flag: true on TX failure or TX out of range , false otherwise.
+	 * Only the true state is reliable, as there are some (PPM) receivers on the market going
+	 * into failsafe without telling us explicitly.
+	 * */
+	bool			rc_failsafe;
+
+	/**
+	 * RC receiver connection status: True,if no frame has arrived in the expected time, false otherwise.
+	 * True usally means that the receiver has been disconnected, but can also indicate a radio link loss on "stupid" systems.
+	 * Will remain false, if a RX with failsafe option continues to transmit frames after a link loss.
+	 * */
+	bool			rc_lost;
+
+	/**
+	 * Number of lost RC frames.
+	 * Note: intended purpose: observe the radio link quality if RSSI is not available
+	 * This value must not be used to trigger any failsafe-alike funtionality.
+	 * */
+	uint16_t		rc_lost_frame_count;
+
+	/**
+	 * Number of total RC frames.
+	 * Note: intended purpose: observe the radio link quality if RSSI is not available
+	 * This value must not be used to trigger any failsafe-alike funtionality.
+	 * */
+	uint16_t		rc_total_frame_count;
+
+	/**
+	 * Length of a single PPM frame.
+	 * Zero for non-PPM systems
+	 */
+	uint16_t		rc_ppm_frame_length;
+
 	/** Input source */
 	enum RC_INPUT_SOURCE 	input_source;
 
@@ -107,8 +149,12 @@ ORB_DECLARE(input_rc);
 #define _RC_INPUT_BASE		0x2b00
 
 /** Fetch R/C input values into (rc_input_values *)arg */
-
 #define RC_INPUT_GET			_IOC(_RC_INPUT_BASE, 0)
 
+/** Enable RSSI input via ADC */
+#define RC_INPUT_ENABLE_RSSI_ANALOG	_IOC(_RC_INPUT_BASE, 1)
+
+/** Enable RSSI input via PWM signal */
+#define RC_INPUT_ENABLE_RSSI_PWM	_IOC(_RC_INPUT_BASE, 2)
 
 #endif /* _DRV_RC_INPUT_H */

src/drivers/drv_sbus.h

@@ -0,0 +1,58 @@
+/****************************************************************************
+ *
+ *   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 drv_sbus.h
+ *
+ * Futaba S.BUS / S.BUS 2 compatible interface.
+ */
+
+#ifndef _DRV_SBUS_H
+#define _DRV_SBUS_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+/**
+ * Path for the default S.BUS device
+ */
+#define SBUS_DEVICE_PATH	"/dev/sbus"
+
+#define _SBUS_BASE		0x2c00
+
+/** Enable S.BUS version 1 / 2 output (0 to disable) */
+#define SBUS_SET_PROTO_VERSION		_IOC(_SBUS_BASE, 0)
+
+#endif /* _DRV_SBUS_H */

src/drivers/px4fmu/fmu.cpp

@@ -626,7 +626,7 @@ PX4FMU::task_main()
 #ifdef HRT_PPM_CHANNEL
 
 		// see if we have new PPM input data
-		if (ppm_last_valid_decode != rc_in.timestamp) {
+		if (ppm_last_valid_decode != rc_in.timestamp_last_signal) {
 			// we have a new PPM frame. Publish it.
 			rc_in.channel_count = ppm_decoded_channels;
 
@@ -638,7 +638,15 @@ PX4FMU::task_main()
 				rc_in.values[i] = ppm_buffer[i];
 			}
 
-			rc_in.timestamp = ppm_last_valid_decode;
+			rc_in.timestamp_publication = ppm_last_valid_decode;
+			rc_in.timestamp_last_signal = ppm_last_valid_decode;
+
+			rc_in.rc_ppm_frame_length = ppm_frame_length;
+			rc_in.rssi = RC_INPUT_RSSI_MAX;
+			rc_in.rc_failsafe = false;
+			rc_in.rc_lost = false;
+			rc_in.rc_lost_frame_count = 0;
+			rc_in.rc_total_frame_count = 0;
 
 			/* lazily advertise on first publication */
 			if (to_input_rc == 0) {

src/drivers/px4io/px4io.cpp

@@ -61,6 +61,7 @@
 #include <drivers/device/device.h>
 #include <drivers/drv_rc_input.h>
 #include <drivers/drv_pwm_output.h>
+#include <drivers/drv_sbus.h>
 #include <drivers/drv_gpio.h>
 #include <drivers/drv_hrt.h>
 #include <drivers/drv_mixer.h>
@@ -238,6 +239,7 @@ private:
 	unsigned 		_update_interval;	///< Subscription interval limiting send rate
 	bool			_rc_handling_disabled;	///< If set, IO does not evaluate, but only forward the RC values
 	unsigned		_rc_chan_count;		///< Internal copy of the last seen number of RC channels
+	uint64_t		_rc_last_valid;		///< last valid timestamp
 
 	volatile int		_task;			///< worker task id
 	volatile bool		_task_should_exit;	///< worker terminate flag
@@ -444,7 +446,7 @@ private:
 	 * @param vservo	vservo register
 	 * @param vrssi 	vrssi register
 	 */
-	void			io_handle_vservo(uint16_t vbatt, uint16_t ibatt);
+	void			io_handle_vservo(uint16_t vservo, uint16_t vrssi);
 
 };
 
@@ -467,6 +469,7 @@ PX4IO::PX4IO(device::Device *interface) :
 	_update_interval(0),
 	_rc_handling_disabled(false),
 	_rc_chan_count(0),
+	_rc_last_valid(0),
 	_task(-1),
 	_task_should_exit(false),
 	_mavlink_fd(-1),
@@ -1357,7 +1360,10 @@ PX4IO::io_get_status()
 	uint16_t	regs[6];
 	int		ret;
 
-	/* get STATUS_FLAGS, STATUS_ALARMS, STATUS_VBATT, STATUS_IBATT in that order */
+	/* get
+	 * STATUS_FLAGS, STATUS_ALARMS, STATUS_VBATT, STATUS_IBATT,
+	 * STATUS_VSERVO, STATUS_VRSSI, STATUS_PRSSI
+	 * in that order */
 	ret = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS, &regs[0], sizeof(regs) / sizeof(regs[0]));
 
 	if (ret != OK)
@@ -1394,7 +1400,8 @@ PX4IO::io_get_raw_rc_input(rc_input_values &input_rc)
 	 *
 	 * This should be the common case (9 channel R/C control being a reasonable upper bound).
 	 */
-	input_rc.timestamp = hrt_absolute_time();
+	input_rc.timestamp_publication = hrt_absolute_time();
+
 	ret = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_COUNT, &regs[0], prolog + 9);
 
 	if (ret != OK)
@@ -1404,13 +1411,25 @@ PX4IO::io_get_raw_rc_input(rc_input_values &input_rc)
 	 * Get the channel count any any extra channels. This is no more expensive than reading the
 	 * channel count once.
 	 */
-	channel_count = regs[0];
+	channel_count = regs[PX4IO_P_RAW_RC_COUNT];
 
 	if (channel_count != _rc_chan_count)
 		perf_count(_perf_chan_count);
 
 	_rc_chan_count = channel_count;
 
+	input_rc.rc_ppm_frame_length = regs[PX4IO_P_RAW_RC_DATA];
+	input_rc.rssi = regs[PX4IO_P_RAW_RC_NRSSI];
+	input_rc.rc_failsafe = (regs[PX4IO_P_RAW_RC_FLAGS] & PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
+	input_rc.rc_lost_frame_count = regs[PX4IO_P_RAW_LOST_FRAME_COUNT];
+	input_rc.rc_total_frame_count = regs[PX4IO_P_RAW_FRAME_COUNT];
+
+	/* rc_lost has to be set before the call to this function */
+	if (!input_rc.rc_lost && !input_rc.rc_failsafe)
+		_rc_last_valid = input_rc.timestamp_publication;
+
+	input_rc.timestamp_last_signal = _rc_last_valid;
+
 	if (channel_count > 9) {
 		ret = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_BASE + 9, &regs[prolog + 9], channel_count - 9);
 
@@ -1427,13 +1446,12 @@ PX4IO::io_get_raw_rc_input(rc_input_values &input_rc)
 int
 PX4IO::io_publish_raw_rc()
 {
-	/* if no raw RC, just don't publish */
-	if (!(_status & PX4IO_P_STATUS_FLAGS_RC_OK))
-		return OK;
 
 	/* fetch values from IO */
 	rc_input_values	rc_val;
-	rc_val.timestamp = hrt_absolute_time();
+
+	/* set the RC status flag ORDER MATTERS! */
+	rc_val.rc_lost = !(_status & PX4IO_P_STATUS_FLAGS_RC_OK);
 
 	int ret = io_get_raw_rc_input(rc_val);
 
@@ -1452,13 +1470,11 @@ PX4IO::io_publish_raw_rc()
 
 	} else {
 		rc_val.input_source = RC_INPUT_SOURCE_UNKNOWN;
-	}
 
-	/* set RSSI */
-
-	if (rc_val.input_source != RC_INPUT_SOURCE_PX4IO_SBUS) {
-		// XXX the correct scaling needs to be validated here
-		rc_val.rssi = (_servorail_status.rssi_v / 3.3f) * UINT8_MAX;
+		/* we do not know the RC input, only publish if RC OK flag is set */
+		/* if no raw RC, just don't publish */
+		if (!(_status & PX4IO_P_STATUS_FLAGS_RC_OK))
+			return OK;
 	}
 
 	/* lazily advertise on first publication */
@@ -1767,15 +1783,14 @@ PX4IO::print_status()
 	printf("%u bytes free\n",
 	       io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FREEMEM));
 	uint16_t flags = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_FLAGS);
-	printf("status 0x%04x%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
+	uint16_t io_status_flags = flags;
+	printf("status 0x%04x%s%s%s%s%s%s%s%s%s%s%s%s\n",
 	       flags,
 	       ((flags & PX4IO_P_STATUS_FLAGS_OUTPUTS_ARMED) ? " OUTPUTS_ARMED" : ""),
 	       ((flags & PX4IO_P_STATUS_FLAGS_SAFETY_OFF) ? " SAFETY_OFF" : " SAFETY_SAFE"),
 	       ((flags & PX4IO_P_STATUS_FLAGS_OVERRIDE) ? " OVERRIDE" : ""),
 	       ((flags & PX4IO_P_STATUS_FLAGS_RC_OK)    ? " RC_OK" : " RC_FAIL"),
 	       ((flags & PX4IO_P_STATUS_FLAGS_RC_PPM)   ? " PPM" : ""),
-	       (((flags & PX4IO_P_STATUS_FLAGS_RC_DSM) && (!(flags & PX4IO_P_STATUS_FLAGS_RC_DSM11))) ? " DSM10" : ""),
-	       (((flags & PX4IO_P_STATUS_FLAGS_RC_DSM) && (flags & PX4IO_P_STATUS_FLAGS_RC_DSM11)) ? " DSM11" : ""),
 	       ((flags & PX4IO_P_STATUS_FLAGS_RC_SBUS)  ? " SBUS" : ""),
 	       ((flags & PX4IO_P_STATUS_FLAGS_FMU_OK)   ? " FMU_OK" : " FMU_FAIL"),
 	       ((flags & PX4IO_P_STATUS_FLAGS_RAW_PWM)  ? " RAW_PWM_PASSTHROUGH" : ""),
@@ -1834,8 +1849,17 @@ PX4IO::print_status()
 
 	printf("\n");
 
-	if ((flags & PX4IO_P_STATUS_FLAGS_RC_PPM)) {
-		int frame_len = io_reg_get(PX4IO_PAGE_STATUS, PX4IO_P_STATUS_RC_DATA);
+	flags = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_FLAGS);
+	printf("R/C flags: 0x%04x%s%s%s%s%s\n", flags,
+		(((io_status_flags & PX4IO_P_STATUS_FLAGS_RC_DSM) && (!(flags & PX4IO_P_RAW_RC_FLAGS_RC_DSM11))) ? " DSM10" : ""),
+		(((io_status_flags & PX4IO_P_STATUS_FLAGS_RC_DSM) && (flags & PX4IO_P_RAW_RC_FLAGS_RC_DSM11)) ? " DSM11" : ""),
+		((flags & PX4IO_P_RAW_RC_FLAGS_FRAME_DROP) ? " FRAME_DROP" : ""),
+		((flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE) ? " FAILSAFE" : ""),
+		((flags & PX4IO_P_RAW_RC_FLAGS_MAPPING_OK) ? " MAPPING_OK" : "")
+	       );
+
+	if ((io_status_flags & PX4IO_P_STATUS_FLAGS_RC_PPM)) {
+		int frame_len = io_reg_get(PX4IO_PAGE_RAW_RC_INPUT, PX4IO_P_RAW_RC_DATA);
 		printf("RC data (PPM frame len) %u us\n", frame_len);
 
 		if ((frame_len - raw_inputs * 2000 - 3000) < 0) {
@@ -1861,7 +1885,13 @@ PX4IO::print_status()
 	printf("\n");
 
 	/* setup and state */
-	printf("features 0x%04x\n", io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES));
+	uint16_t features = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES);
+	printf("features 0x%04x%s%s%s%s\n", features,
+		((features & PX4IO_P_SETUP_FEATURES_SBUS1_OUT) ? " S.BUS1_OUT" : ""),
+		((features & PX4IO_P_SETUP_FEATURES_SBUS2_OUT) ? " S.BUS2_OUT" : ""),
+		((features & PX4IO_P_SETUP_FEATURES_PWM_RSSI) ? " RSSI_PWM" : ""),
+		((features & PX4IO_P_SETUP_FEATURES_ADC_RSSI) ? " RSSI_ADC" : "")
+		);
 	uint16_t arming = io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_ARMING);
 	printf("arming 0x%04x%s%s%s%s%s%s\n",
 	       arming,
@@ -2283,6 +2313,38 @@ PX4IO::ioctl(file * /*filep*/, int cmd, unsigned long arg)
 
 		break;
 
+	case RC_INPUT_ENABLE_RSSI_ANALOG:
+
+		if (arg) {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_ADC_RSSI);
+		} else {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, PX4IO_P_SETUP_FEATURES_ADC_RSSI, 0);
+		}
+
+		break;
+
+	case RC_INPUT_ENABLE_RSSI_PWM:
+
+		if (arg) {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_PWM_RSSI);
+		} else {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, PX4IO_P_SETUP_FEATURES_PWM_RSSI, 0);
+		}
+
+		break;
+
+	case SBUS_SET_PROTO_VERSION:
+
+		if (arg == 1) {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_SBUS1_OUT);
+		} else if (arg == 2) {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, 0, PX4IO_P_SETUP_FEATURES_SBUS2_OUT);
+		} else {
+			ret = io_reg_modify(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_FEATURES, (PX4IO_P_SETUP_FEATURES_SBUS1_OUT | PX4IO_P_SETUP_FEATURES_SBUS2_OUT), 0);
+		}
+
+		break;
+
 	default:
 		/* not a recognized value */
 		ret = -ENOTTY;
@@ -2656,7 +2718,7 @@ monitor(void)
 	/* clear screen */
 	printf("\033[2J");
 
-	unsigned cancels = 3;
+	unsigned cancels = 2;
 
 	for (;;) {
 		pollfd fds[1];
@@ -2932,6 +2994,60 @@ px4io_main(int argc, char *argv[])
 	if (!strcmp(argv[1], "bind"))
 		bind(argc, argv);
 
+	if (!strcmp(argv[1], "sbus1_out")) {
+		/* we can cheat and call the driver directly, as it
+		 * doesn't reference filp in ioctl()
+		 */
+		int ret = g_dev->ioctl(nullptr, SBUS_SET_PROTO_VERSION, 1);
+
+		if (ret != 0) {
+			errx(ret, "S.BUS v1 failed");
+		}
+
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "sbus2_out")) {
+		/* we can cheat and call the driver directly, as it
+		 * doesn't reference filp in ioctl()
+		 */
+		int ret = g_dev->ioctl(nullptr, SBUS_SET_PROTO_VERSION, 2);
+
+		if (ret != 0) {
+			errx(ret, "S.BUS v2 failed");
+		}
+
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "rssi_analog")) {
+		/* we can cheat and call the driver directly, as it
+		 * doesn't reference filp in ioctl()
+		 */
+		int ret = g_dev->ioctl(nullptr, RC_INPUT_ENABLE_RSSI_ANALOG, 1);
+
+		if (ret != 0) {
+			errx(ret, "RSSI analog failed");
+		}
+
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "rssi_pwm")) {
+		/* we can cheat and call the driver directly, as it
+		 * doesn't reference filp in ioctl()
+		 */
+		int ret = g_dev->ioctl(nullptr, RC_INPUT_ENABLE_RSSI_PWM, 1);
+
+		if (ret != 0) {
+			errx(ret, "RSSI PWM failed");
+		}
+
+		exit(0);
+	}
+
 out:
-	errx(1, "need a command, try 'start', 'stop', 'status', 'test', 'monitor', 'debug',\n 'recovery', 'limit', 'current', 'bind', 'checkcrc', 'forceupdate' or 'update'");
+	errx(1, "need a command, try 'start', 'stop', 'status', 'test', 'monitor', 'debug <level>',\n"
+	        "'recovery', 'limit <rate>', 'current', 'bind', 'checkcrc',\n"
+	        "'forceupdate', 'update', 'sbus1_out', 'sbus2_out', 'rssi_analog' or 'rssi_pwm'");
 }

src/modules/mavlink/orb_listener.c

@@ -355,7 +355,7 @@ l_input_rc(const struct listener *l)
 		for (unsigned i = 0; (i * port_width) < rc_raw.channel_count; i++) {
 			/* Channels are sent in MAVLink main loop at a fixed interval */
 			mavlink_msg_rc_channels_raw_send(chan,
-							 rc_raw.timestamp / 1000,
+							 rc_raw.timestamp_publication / 1000,
 							 i,
 							 (rc_raw.channel_count > (i * port_width) + 0) ? rc_raw.values[(i * port_width) + 0] : UINT16_MAX,
 							 (rc_raw.channel_count > (i * port_width) + 1) ? rc_raw.values[(i * port_width) + 1] : UINT16_MAX,

src/modules/px4iofirmware/controls.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
@@ -59,6 +59,11 @@ static perf_counter_t c_gather_ppm;
 void
 controls_init(void)
 {
+	/* no channels */
+	r_raw_rc_count = 0;
+	system_state.rc_channels_timestamp_received = 0;
+	system_state.rc_channels_timestamp_valid = 0;
+
 	/* DSM input (USART1) */
 	dsm_init("/dev/ttyS0");
 
@@ -97,35 +102,62 @@ controls_tick() {
 	/* receive signal strenght indicator (RSSI). 0 = no connection, 255: perfect connection */
 	uint16_t rssi = 0;
 
+#ifdef ADC_RSSI
+	if (r_setup_features & PX4IO_P_SETUP_FEATURES_ADC_RSSI) {
+		unsigned counts = adc_measure(ADC_RSSI);
+		if (counts != 0xffff) {
+			/* use 1:1 scaling on 3.3V ADC input */
+			unsigned mV = counts * 3300 / 4096;
+
+			/* scale to 0..253 */
+			rssi = mV / 13;
+		}
+	}
+#endif
+
 	perf_begin(c_gather_dsm);
 	uint16_t temp_count = r_raw_rc_count;
 	bool dsm_updated = dsm_input(r_raw_rc_values, &temp_count);
 	if (dsm_updated) {
-		r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_DSM;
+		r_raw_rc_flags |= PX4IO_P_STATUS_FLAGS_RC_DSM;
 		r_raw_rc_count = temp_count & 0x7fff;
 		if (temp_count & 0x8000)
-			r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_DSM11;
+			r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_RC_DSM11;
 		else
-			r_status_flags &= ~PX4IO_P_STATUS_FLAGS_RC_DSM11;
+			r_raw_rc_flags &= ~PX4IO_P_RAW_RC_FLAGS_RC_DSM11;
+
+		r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FRAME_DROP);
+		r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
 
-		rssi = 255;
 	}
 	perf_end(c_gather_dsm);
 
 	perf_begin(c_gather_sbus);
-	bool sbus_updated = sbus_input(r_raw_rc_values, &r_raw_rc_count, &rssi, PX4IO_RC_INPUT_CHANNELS);
 
 	bool sbus_status = (r_status_flags & PX4IO_P_STATUS_FLAGS_RC_SBUS);
 
+	bool sbus_failsafe, sbus_frame_drop;
+	bool sbus_updated = sbus_input(r_raw_rc_values, &r_raw_rc_count, &sbus_failsafe, &sbus_frame_drop, PX4IO_RC_INPUT_CHANNELS);
+
 	if (sbus_updated) {
 		r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_SBUS;
-	}
 
-	/* switch S.Bus output pin as needed */
-	if (sbus_status != (r_status_flags & PX4IO_P_STATUS_FLAGS_RC_SBUS)) {
-		#ifdef ENABLE_SBUS_OUT
-		ENABLE_SBUS_OUT((r_status_flags & PX4IO_P_STATUS_FLAGS_RC_SBUS));
-		#endif
+		rssi = 255;
+
+		if (sbus_frame_drop) {
+			r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_FRAME_DROP;
+			rssi = 100;
+		} else {
+			r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FRAME_DROP);
+		}
+
+		if (sbus_failsafe) {
+			r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_FAILSAFE;
+			rssi = 0;
+		} else {
+			r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
+		}
+
 	}
 
 	perf_end(c_gather_sbus);
@@ -136,13 +168,12 @@ controls_tick() {
 	 * disable the PPM decoder completely if we have S.bus signal.
 	 */
 	perf_begin(c_gather_ppm);
-	bool ppm_updated = ppm_input(r_raw_rc_values, &r_raw_rc_count, &r_page_status[PX4IO_P_STATUS_RC_DATA]);
+	bool ppm_updated = ppm_input(r_raw_rc_values, &r_raw_rc_count, &r_page_raw_rc_input[PX4IO_P_RAW_RC_DATA]);
 	if (ppm_updated) {
 
-		/* XXX sample RSSI properly here */
-		rssi = 255;
-
 		r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_PPM;
+		r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FRAME_DROP);
+		r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
 	}
 	perf_end(c_gather_ppm);
 
@@ -150,6 +181,9 @@ controls_tick() {
 	if (r_raw_rc_count > PX4IO_RC_INPUT_CHANNELS)
 		r_raw_rc_count = PX4IO_RC_INPUT_CHANNELS;
 
+	/* store RSSI */
+	r_page_raw_rc_input[PX4IO_P_RAW_RC_NRSSI] = rssi;
+
 	/*
 	 * In some cases we may have received a frame, but input has still
 	 * been lost.
@@ -161,97 +195,100 @@ controls_tick() {
 	 */
 	if (dsm_updated || sbus_updated || ppm_updated) {
 
-		/* update RC-received timestamp */
-		system_state.rc_channels_timestamp = hrt_absolute_time();
-
 		/* record a bitmask of channels assigned */
 		unsigned assigned_channels = 0;
 
-		/* 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_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;
 
-				/* and update the scaled/mapped version */
-				unsigned mapped = conf[PX4IO_P_RC_CONFIG_ASSIGNMENT];
-				if (mapped < PX4IO_CONTROL_CHANNELS) {
+					/* and update the scaled/mapped version */
+					unsigned mapped = conf[PX4IO_P_RC_CONFIG_ASSIGNMENT];
+					if (mapped < PX4IO_CONTROL_CHANNELS) {
 
-					/* 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;
+						/* 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;
 
-					r_rc_values[mapped] = SIGNED_TO_REG(scaled);
-					assigned_channels |= (1 << mapped);
+						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;
+			}
 
-		/*
-		 * If we got an update with zero channels, treat it as 
-		 * a loss of input.
-		 *
-		 * This might happen if a protocol-based receiver returns an update
-		 * that contains no channels that we have mapped.
-		 */
-		if (assigned_channels == 0 || rssi == 0) {
-			rc_input_lost = true;
-		} else {
-			/* set RC OK flag */
+			/* set RC OK flag, as we got an update */
 			r_status_flags |= PX4IO_P_STATUS_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);
+			}
 		}
 
 		/*
@@ -264,7 +301,7 @@ controls_tick() {
 	 * If we haven't seen any new control data in 200ms, assume we
 	 * have lost input.
 	 */
-	if (hrt_elapsed_time(&system_state.rc_channels_timestamp) > 200000) {
+	if (hrt_elapsed_time(&system_state.rc_channels_timestamp_received) > 200000) {
 		rc_input_lost = true;
 
 		/* clear the input-kind flags here */
@@ -272,24 +309,32 @@ controls_tick() {
 			PX4IO_P_STATUS_FLAGS_RC_PPM |
 			PX4IO_P_STATUS_FLAGS_RC_DSM |
 			PX4IO_P_STATUS_FLAGS_RC_SBUS);
+
 	}
 
 	/*
 	 * Handle losing RC input
 	 */
-	if (rc_input_lost) {
 
+	/* 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)) {
 		/* Clear the RC input status flag, clear manual override flag */
 		r_status_flags &= ~(
 			PX4IO_P_STATUS_FLAGS_OVERRIDE |
 			PX4IO_P_STATUS_FLAGS_RC_OK);
 
+		/* Mark all channels as invalid, as we just lost the RX */
+		r_rc_valid = 0;
+
 		/* Set the RC_LOST alarm */
 		r_status_alarms |= PX4IO_P_STATUS_ALARMS_RC_LOST;
+	}
 
-		/* Mark the arrays as empty */
+	/* this kicks in if the receiver is completely gone */
+	if (rc_input_lost) {
+
+		/* Set channel count to zero */
 		r_raw_rc_count = 0;
-		r_rc_valid = 0;
 	}
 
 	/*

src/modules/px4iofirmware/protocol.h

@@ -111,7 +111,6 @@
 #define PX4IO_P_STATUS_FLAGS_INIT_OK		(1 << 10) /* initialisation of the IO completed without error */
 #define PX4IO_P_STATUS_FLAGS_FAILSAFE		(1 << 11) /* failsafe is active */
 #define PX4IO_P_STATUS_FLAGS_SAFETY_OFF		(1 << 12) /* safety is off */
-#define PX4IO_P_STATUS_FLAGS_RC_DSM11		(1 << 13) /* DSM input is 11 bit data */
 
 #define PX4IO_P_STATUS_ALARMS			3	 /* alarm flags - alarms latch, write 1 to a bit to clear it */
 #define PX4IO_P_STATUS_ALARMS_VBATT_LOW		(1 << 0) /* [1] VBatt is very close to regulator dropout */
@@ -128,8 +127,6 @@
 #define PX4IO_P_STATUS_VSERVO			6	/* [2] servo rail voltage in mV */
 #define PX4IO_P_STATUS_VRSSI			7	/* [2] RSSI voltage */
 #define PX4IO_P_STATUS_PRSSI			8	/* [2] RSSI PWM value */
-#define PX4IO_P_STATUS_NRSSI			9	/* [2] Normalized RSSI value, 0: no reception, 255: perfect reception */
-#define PX4IO_P_STATUS_RC_DATA			10	/* [1] + [2] Details about the RC source (PPM frame length, Spektrum protocol type) */
 
 /* array of post-mix actuator outputs, -10000..10000 */
 #define PX4IO_PAGE_ACTUATORS		2		/* 0..CONFIG_ACTUATOR_COUNT-1 */
@@ -140,7 +137,17 @@
 /* array of raw RC input values, microseconds */
 #define PX4IO_PAGE_RAW_RC_INPUT		4
 #define PX4IO_P_RAW_RC_COUNT			0	/* number of valid channels */
-#define PX4IO_P_RAW_RC_BASE			1	/* CONFIG_RC_INPUT_COUNT channels from here */
+#define PX4IO_P_RAW_RC_FLAGS			1	/* RC detail status flags */
+#define PX4IO_P_RAW_RC_FLAGS_FRAME_DROP		(1 << 0) /* single frame drop */
+#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_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) */
+#define PX4IO_P_RAW_FRAME_COUNT			4	/* Number of total received frames (wrapping counter) */
+#define PX4IO_P_RAW_LOST_FRAME_COUNT		5	/* Number of total dropped frames (wrapping counter) */
+#define PX4IO_P_RAW_RC_BASE			6	/* CONFIG_RC_INPUT_COUNT channels from here */
 
 /* array of scaled RC input values, -10000..10000 */
 #define PX4IO_PAGE_RC_INPUT		5
@@ -157,6 +164,10 @@
 /* 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_ARMING			1	 /* arming controls */
 #define PX4IO_P_SETUP_ARMING_IO_ARM_OK		(1 << 0) /* OK to arm the IO side */

src/modules/px4iofirmware/px4io.h

@@ -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
@@ -96,8 +96,9 @@ extern uint16_t			r_page_servo_disarmed[];	/* PX4IO_PAGE_DISARMED_PWM */
 
 #define r_raw_rc_count		r_page_raw_rc_input[PX4IO_P_RAW_RC_COUNT]
 #define r_raw_rc_values		(&r_page_raw_rc_input[PX4IO_P_RAW_RC_BASE])
+#define r_raw_rc_flags		r_page_raw_rc_input[PX4IO_P_RAW_RC_FLAGS]
 #define r_rc_valid		r_page_rc_input[PX4IO_P_RC_VALID]
-#define r_rc_values		(&r_page_rc_input[PX4IO_P_RAW_RC_BASE])
+#define r_rc_values		(&r_page_rc_input[PX4IO_P_RC_BASE])
 
 #define r_setup_features	r_page_setup[PX4IO_P_SETUP_FEATURES]
 #define r_setup_arming		r_page_setup[PX4IO_P_SETUP_ARMING]
@@ -115,7 +116,8 @@ extern uint16_t			r_page_servo_disarmed[];	/* PX4IO_PAGE_DISARMED_PWM */
  */
 struct sys_state_s {
 
-	volatile uint64_t	rc_channels_timestamp;
+	volatile uint64_t	rc_channels_timestamp_received;
+	volatile uint64_t	rc_channels_timestamp_valid;
 
 	/**
 	 * Last FMU receive time, in microseconds since system boot
@@ -215,7 +217,7 @@ extern int	dsm_init(const char *device);
 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, uint16_t *rssi, uint16_t max_channels);
+extern bool	sbus_input(uint16_t *values, uint16_t *num_values, bool *sbus_failsafe, bool *sbus_frame_drop, uint16_t max_channels);
 
 /** global debug level for isr_debug() */
 extern volatile uint8_t debug_level;

src/modules/px4iofirmware/registers.c

@@ -90,8 +90,6 @@ uint16_t		r_page_status[] = {
 	[PX4IO_P_STATUS_VSERVO]			= 0,
 	[PX4IO_P_STATUS_VRSSI]			= 0,
 	[PX4IO_P_STATUS_PRSSI]			= 0,
-	[PX4IO_P_STATUS_NRSSI]			= 0,
-	[PX4IO_P_STATUS_RC_DATA]		= 0
 };
 
 /**
@@ -116,6 +114,12 @@ uint16_t		r_page_servos[PX4IO_SERVO_COUNT];
 uint16_t		r_page_raw_rc_input[] =
 {
 	[PX4IO_P_RAW_RC_COUNT]			= 0,
+	[PX4IO_P_RAW_RC_FLAGS]			= 0,
+	[PX4IO_P_RAW_RC_NRSSI]			= 0,
+	[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
 };
 
@@ -144,7 +148,12 @@ uint16_t		r_page_scratch[32];
  */
 volatile uint16_t	r_page_setup[] =
 {
+#ifdef CONFIG_ARCH_BOARD_PX4IO_V2
+	/* default to RSSI ADC functionality */
+	[PX4IO_P_SETUP_FEATURES]		= PX4IO_P_SETUP_FEATURES_ADC_RSSI,
+#else
 	[PX4IO_P_SETUP_FEATURES]		= 0,
+#endif
 	[PX4IO_P_SETUP_ARMING]			= 0,
 	[PX4IO_P_SETUP_PWM_RATES]		= 0,
 	[PX4IO_P_SETUP_PWM_DEFAULTRATE]		= 50,
@@ -162,7 +171,14 @@ volatile uint16_t	r_page_setup[] =
 	[PX4IO_P_SETUP_CRC ... (PX4IO_P_SETUP_CRC+1)] = 0,
 };
 
-#define PX4IO_P_SETUP_FEATURES_VALID	(0)
+#ifdef CONFIG_ARCH_BOARD_PX4IO_V2
+#define PX4IO_P_SETUP_FEATURES_VALID	(PX4IO_P_SETUP_FEATURES_SBUS1_OUT | \
+					 PX4IO_P_SETUP_FEATURES_SBUS2_OUT | \
+					 PX4IO_P_SETUP_FEATURES_ADC_RSSI | \
+					 PX4IO_P_SETUP_FEATURES_PWM_RSSI)
+#else
+#define PX4IO_P_SETUP_FEATURES_VALID	0
+#endif
 #define PX4IO_P_SETUP_ARMING_VALID	(PX4IO_P_SETUP_ARMING_FMU_ARMED | \
 					 PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK | \
 					 PX4IO_P_SETUP_ARMING_INAIR_RESTART_OK | \
@@ -438,9 +454,35 @@ registers_set_one(uint8_t page, uint8_t offset, uint16_t value)
 		case PX4IO_P_SETUP_FEATURES:
 
 			value &= PX4IO_P_SETUP_FEATURES_VALID;
-			r_setup_features = value;
 
-			/* no implemented feature selection at this point */
+			/* some of the options conflict - give S.BUS out precedence, then ADC RSSI, then PWM RSSI */
+
+			/* switch S.Bus output pin as needed */
+			#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);
+			}
+			#endif
+
+			/* disable the conflicting options with ADC RSSI */
+			if (value & (PX4IO_P_SETUP_FEATURES_ADC_RSSI)) {
+				value &= ~(PX4IO_P_SETUP_FEATURES_PWM_RSSI |
+					PX4IO_P_SETUP_FEATURES_SBUS1_OUT |
+					PX4IO_P_SETUP_FEATURES_SBUS2_OUT);
+			}
+
+			/* disable the conflicting options with PWM RSSI (without effect here, but for completeness) */
+			if (value & (PX4IO_P_SETUP_FEATURES_PWM_RSSI)) {
+				value &= ~(PX4IO_P_SETUP_FEATURES_ADC_RSSI |
+					PX4IO_P_SETUP_FEATURES_SBUS1_OUT |
+					PX4IO_P_SETUP_FEATURES_SBUS2_OUT);
+			}
+
+			/* apply changes */
+			r_setup_features = value;
 
 			break;
 

src/modules/px4iofirmware/sbus.c

@@ -87,7 +87,7 @@ static unsigned partial_frame_count;
 
 unsigned sbus_frame_drops;
 
-static bool sbus_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values, uint16_t *rssi, uint16_t max_channels);
+static bool sbus_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values, bool *sbus_failsafe, bool *sbus_frame_drop, uint16_t max_channels);
 
 int
 sbus_init(const char *device)
@@ -118,7 +118,7 @@ sbus_init(const char *device)
 }
 
 bool
-sbus_input(uint16_t *values, uint16_t *num_values, uint16_t *rssi, uint16_t max_channels)
+sbus_input(uint16_t *values, uint16_t *num_values, bool *sbus_failsafe, bool *sbus_frame_drop, uint16_t max_channels)
 {
 	ssize_t		ret;
 	hrt_abstime	now;
@@ -175,7 +175,7 @@ sbus_input(uint16_t *values, uint16_t *num_values, uint16_t *rssi, uint16_t max_
 	 * decode it.
 	 */
 	partial_frame_count = 0;
-	return sbus_decode(now, values, num_values, rssi, max_channels);
+	return sbus_decode(now, values, num_values, sbus_failsafe, sbus_frame_drop, max_channels);
 }
 
 /*
@@ -215,7 +215,7 @@ static const struct sbus_bit_pick sbus_decoder[SBUS_INPUT_CHANNELS][3] = {
 };
 
 static bool
-sbus_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values, uint16_t *rssi, uint16_t max_values)
+sbus_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values, bool *sbus_failsafe, bool *sbus_frame_drop, uint16_t max_values)
 {
 	/* check frame boundary markers to avoid out-of-sync cases */
 	if ((frame[0] != 0x0f)) {
@@ -289,20 +289,22 @@ sbus_decode(hrt_abstime frame_time, uint16_t *values, uint16_t *num_values, uint
 	/* decode and handle failsafe and frame-lost flags */
 	if (frame[SBUS_FLAGS_BYTE] & (1 << SBUS_FAILSAFE_BIT)) { /* failsafe */
 		/* report that we failed to read anything valid off the receiver */
-		*rssi = 0;
-		return false;
+		*sbus_failsafe = true;
+		*sbus_frame_drop = true;
 	}
 	else if (frame[SBUS_FLAGS_BYTE] & (1 << SBUS_FRAMELOST_BIT)) { /* a frame was lost */
-		/* set a special warning flag or try to calculate some kind of RSSI information - to be implemented 
+		/* set a special warning flag
 		 * 
 		 * Attention! This flag indicates a skipped frame only, not a total link loss! Handling this 
 		 * condition as fail-safe greatly reduces the reliability and range of the radio link, 
 		 * e.g. by prematurely issueing return-to-launch!!! */
 
-		*rssi = 100; // XXX magic number indicating bad signal, but not a signal loss (yet)
+		*sbus_failsafe = false;
+		*sbus_frame_drop = true;
+	} else {
+		*sbus_failsafe = false;
+		*sbus_frame_drop = false;
 	}
 
-	*rssi = 255;
-
 	return true;
 }

src/modules/sensors/sensors.cpp

@@ -1276,6 +1276,9 @@ Sensors::rc_poll()
 
 		orb_copy(ORB_ID(input_rc), _rc_sub, &rc_input);
 
+		if (rc_input.rc_lost)
+			return;
+
 		struct manual_control_setpoint_s manual_control;
 		struct actuator_controls_s actuator_group_3;
 
@@ -1320,7 +1323,7 @@ Sensors::rc_poll()
 			channel_limit = _rc_max_chan_count;
 
 		/* we are accepting this message */
-		_rc_last_valid = rc_input.timestamp;
+		_rc_last_valid = rc_input.timestamp_last_signal;
 
 		/* Read out values from raw message */
 		for (unsigned int i = 0; i < channel_limit; i++) {
@@ -1369,9 +1372,9 @@ Sensors::rc_poll()
 		}
 
 		_rc.chan_count = rc_input.channel_count;
-		_rc.timestamp = rc_input.timestamp;
+		_rc.timestamp = rc_input.timestamp_last_signal;
 
-		manual_control.timestamp = rc_input.timestamp;
+		manual_control.timestamp = rc_input.timestamp_last_signal;
 
 		/* roll input - rolling right is stick-wise and rotation-wise positive */
 		manual_control.roll = limit_minus_one_to_one(_rc.chan[_rc.function[ROLL]].scaled);

src/systemcmds/tests/test_rc.c

@@ -121,7 +121,7 @@ int test_rc(int argc, char *argv[])
 						return ERROR;
 					}
 
-					if (hrt_absolute_time() - rc_input.timestamp > 100000) {
+					if (hrt_absolute_time() - rc_input.timestamp_last_signal > 100000) {
 						warnx("TIMEOUT, less than 10 Hz updates");
 						(void)close(_rc_sub);
 						return ERROR;