Merge remote-tracking branch 'upstream/master' into diff_press_filter

Conflicts:
	src/modules/sdlog2/sdlog2.c

7 files changed, 2093 insertions, 108 deletions

diff --git a/src/drivers/drv_px4flow.h b/src/drivers/drv_px4flow.h
new file mode 100644
index 000000000..bef02d54e
--- /dev/null
+++ b/src/drivers/drv_px4flow.h
@@ -0,0 +1,84 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2013 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 Rangefinder driver interface.
+ */
+
+#ifndef _DRV_PX4FLOW_H
+#define _DRV_PX4FLOW_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_sensor.h"
+#include "drv_orb_dev.h"
+
+#define PX4FLOW_DEVICE_PATH	"/dev/px4flow"
+
+/**
+ * Optical flow in NED body frame in SI units.
+ *
+ * @see http://en.wikipedia.org/wiki/International_System_of_Units
+ */
+struct px4flow_report {
+
+	uint64_t timestamp;		/**< in microseconds since system start          */
+
+	int16_t flow_raw_x;		/**< flow in pixels in X direction, not rotation-compensated */
+	int16_t flow_raw_y;		/**< flow in pixels in Y direction, not rotation-compensated */
+	float flow_comp_x_m;		/**< speed over ground in meters, rotation-compensated */
+	float flow_comp_y_m;		/**< speed over ground in meters, rotation-compensated */
+	float ground_distance_m;	/**< Altitude / distance to ground in meters */
+	uint8_t	quality;		/**< Quality of the measurement, 0: bad quality, 255: maximum quality */
+	uint8_t sensor_id;		/**< id of the sensor emitting the flow value */
+
+};
+
+/*
+ * ObjDev tag for px4flow data.
+ */
+ORB_DECLARE(optical_flow);
+
+/*
+ * ioctl() definitions
+ *
+ * px4flow drivers also implement the generic sensor driver
+ * interfaces from drv_sensor.h
+ */
+
+#define _PX4FLOWIOCBASE			(0x7700)
+#define __PX4FLOWIOC(_n)		(_IOC(_PX4FLOWIOCBASE, _n))
+
+
+#endif /* _DRV_PX4FLOW_H */
diff --git a/src/drivers/mb12xx/mb12xx.cpp b/src/drivers/mb12xx/mb12xx.cpp
index c910e2890..5adb8cf69 100644
--- a/src/drivers/mb12xx/mb12xx.cpp
+++ b/src/drivers/mb12xx/mb12xx.cpp
@@ -37,7 +37,7 @@
  *
  * Driver for the Maxbotix sonar range finders connected via I2C.
  */
-	 
+
 #include <nuttx/config.h>
 
 #include <drivers/device/i2c.h>
@@ -84,7 +84,7 @@
 /* Device limits */
 #define MB12XX_MIN_DISTANCE (0.20f)
 #define MB12XX_MAX_DISTANCE (7.65f)
-	 
+
 #define MB12XX_CONVERSION_INTERVAL 60000 /* 60ms */
 
 /* oddly, ERROR is not defined for c++ */
@@ -102,17 +102,17 @@ class MB12XX : public device::I2C
 public:
 	MB12XX(int bus = MB12XX_BUS, int address = MB12XX_BASEADDR);
 	virtual ~MB12XX();
-	
+
 	virtual int 		init();
-	
+
 	virtual ssize_t		read(struct file *filp, char *buffer, size_t buflen);
 	virtual int			ioctl(struct file *filp, int cmd, unsigned long arg);
-	
+
 	/**
 	* Diagnostics - print some basic information about the driver.
 	*/
 	void				print_info();
-	
+
 protected:
 	virtual int			probe();
 
@@ -124,13 +124,13 @@ private:
 	bool				_sensor_ok;
 	int					_measure_ticks;
 	bool				_collect_phase;
-	
+
 	orb_advert_t		_range_finder_topic;
 
 	perf_counter_t		_sample_perf;
 	perf_counter_t		_comms_errors;
 	perf_counter_t		_buffer_overflows;
-	
+
 	/**
 	* Test whether the device supported by the driver is present at a
 	* specific address.
@@ -139,7 +139,7 @@ private:
 	* @return		True if the device is present.
 	*/
 	int					probe_address(uint8_t address);
-	
+
 	/**
 	* Initialise the automatic measurement state machine and start it.
 	*
@@ -147,12 +147,12 @@ private:
 	*       to make it more aggressive about resetting the bus in case of errors.
 	*/
 	void				start();
-	
+
 	/**
 	* Stop the automatic measurement state machine.
 	*/
 	void				stop();
-	
+
 	/**
 	* Set the min and max distance thresholds if you want the end points of the sensors
 	* range to be brought in at all, otherwise it will use the defaults MB12XX_MIN_DISTANCE
@@ -162,7 +162,7 @@ private:
 	void				set_maximum_distance(float max);
 	float				get_minimum_distance();
 	float				get_maximum_distance();
-	
+
 	/**
 	* Perform a poll cycle; collect from the previous measurement
 	* and start a new one.
@@ -177,8 +177,8 @@ private:
 	* @param arg		Instance pointer for the driver that is polling.
 	*/
 	static void		cycle_trampoline(void *arg);
-	
-	
+
+
 };
 
 /*
@@ -200,8 +200,8 @@ MB12XX::MB12XX(int bus, int address) :
 	_buffer_overflows(perf_alloc(PC_COUNT, "mb12xx_buffer_overflows"))
 {
 	// enable debug() calls
-	_debug_enabled = true;
-	
+	_debug_enabled = false;
+
 	// work_cancel in the dtor will explode if we don't do this...
 	memset(&_work, 0, sizeof(_work));
 }
@@ -212,8 +212,9 @@ MB12XX::~MB12XX()
 	stop();
 
 	/* free any existing reports */
-	if (_reports != nullptr)
+	if (_reports != nullptr) {
 		delete _reports;
+	}
 }
 
 int
@@ -222,22 +223,25 @@ MB12XX::init()
 	int ret = ERROR;
 
 	/* do I2C init (and probe) first */
-	if (I2C::init() != OK)
+	if (I2C::init() != OK) {
 		goto out;
+	}
 
 	/* allocate basic report buffers */
 	_reports = new RingBuffer(2, sizeof(range_finder_report));
 
-	if (_reports == nullptr)
+	if (_reports == nullptr) {
 		goto out;
+	}
 
 	/* get a publish handle on the range finder topic */
 	struct range_finder_report zero_report;
 	memset(&zero_report, 0, sizeof(zero_report));
 	_range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &zero_report);
 
-	if (_range_finder_topic < 0)
+	if (_range_finder_topic < 0) {
 		debug("failed to create sensor_range_finder object. Did you start uOrb?");
+	}
 
 	ret = OK;
 	/* sensor is ok, but we don't really know if it is within range */
@@ -256,13 +260,13 @@ void
 MB12XX::set_minimum_distance(float min)
 {
 	_min_distance = min;
-}	
+}
 
 void
 MB12XX::set_maximum_distance(float max)
 {
 	_max_distance = max;
-}	
+}
 
 float
 MB12XX::get_minimum_distance()
@@ -284,20 +288,20 @@ MB12XX::ioctl(struct file *filp, int cmd, unsigned long arg)
 	case SENSORIOCSPOLLRATE: {
 			switch (arg) {
 
-				/* switching to manual polling */
+			/* switching to manual polling */
 			case SENSOR_POLLRATE_MANUAL:
 				stop();
 				_measure_ticks = 0;
 				return OK;
 
-				/* external signalling (DRDY) not supported */
+			/* external signalling (DRDY) not supported */
 			case SENSOR_POLLRATE_EXTERNAL:
 
-				/* zero would be bad */
+			/* zero would be bad */
 			case 0:
 				return -EINVAL;
 
-				/* set default/max polling rate */
+			/* set default/max polling rate */
 			case SENSOR_POLLRATE_MAX:
 			case SENSOR_POLLRATE_DEFAULT: {
 					/* do we need to start internal polling? */
@@ -307,13 +311,14 @@ MB12XX::ioctl(struct file *filp, int cmd, unsigned long arg)
 					_measure_ticks = USEC2TICK(MB12XX_CONVERSION_INTERVAL);
 
 					/* if we need to start the poll state machine, do it */
-					if (want_start)
+					if (want_start) {
 						start();
+					}
 
 					return OK;
 				}
 
-				/* adjust to a legal polling interval in Hz */
+			/* adjust to a legal polling interval in Hz */
 			default: {
 					/* do we need to start internal polling? */
 					bool want_start = (_measure_ticks == 0);
@@ -322,15 +327,17 @@ MB12XX::ioctl(struct file *filp, int cmd, unsigned long arg)
 					unsigned ticks = USEC2TICK(1000000 / arg);
 
 					/* check against maximum rate */
-					if (ticks < USEC2TICK(MB12XX_CONVERSION_INTERVAL))
+					if (ticks < USEC2TICK(MB12XX_CONVERSION_INTERVAL)) {
 						return -EINVAL;
+					}
 
 					/* update interval for next measurement */
 					_measure_ticks = ticks;
 
 					/* if we need to start the poll state machine, do it */
-					if (want_start)
+					if (want_start) {
 						start();
+					}
 
 					return OK;
 				}
@@ -338,45 +345,49 @@ MB12XX::ioctl(struct file *filp, int cmd, unsigned long arg)
 		}
 
 	case SENSORIOCGPOLLRATE:
-		if (_measure_ticks == 0)
+		if (_measure_ticks == 0) {
 			return SENSOR_POLLRATE_MANUAL;
+		}
 
 		return (1000 / _measure_ticks);
 
 	case SENSORIOCSQUEUEDEPTH: {
-		/* lower bound is mandatory, upper bound is a sanity check */
-		if ((arg < 1) || (arg > 100))
-			return -EINVAL;
-		
-		irqstate_t flags = irqsave();
-		if (!_reports->resize(arg)) {
+			/* lower bound is mandatory, upper bound is a sanity check */
+			if ((arg < 1) || (arg > 100)) {
+				return -EINVAL;
+			}
+
+			irqstate_t flags = irqsave();
+
+			if (!_reports->resize(arg)) {
+				irqrestore(flags);
+				return -ENOMEM;
+			}
+
 			irqrestore(flags);
-			return -ENOMEM;
+
+			return OK;
 		}
-		irqrestore(flags);
-		
-		return OK;
-	}
 
 	case SENSORIOCGQUEUEDEPTH:
 		return _reports->size();
-		
+
 	case SENSORIOCRESET:
 		/* XXX implement this */
 		return -EINVAL;
-	
-	case RANGEFINDERIOCSETMINIUMDISTANCE:
-	{
-		set_minimum_distance(*(float *)arg);
-		return 0;
-	}
-	break;
-	case RANGEFINDERIOCSETMAXIUMDISTANCE:
-	{
-		set_maximum_distance(*(float *)arg);
-		return 0;
-	}
-	break;
+
+	case RANGEFINDERIOCSETMINIUMDISTANCE: {
+			set_minimum_distance(*(float *)arg);
+			return 0;
+		}
+		break;
+
+	case RANGEFINDERIOCSETMAXIUMDISTANCE: {
+			set_maximum_distance(*(float *)arg);
+			return 0;
+		}
+		break;
+
 	default:
 		/* give it to the superclass */
 		return I2C::ioctl(filp, cmd, arg);
@@ -391,8 +402,9 @@ MB12XX::read(struct file *filp, char *buffer, size_t buflen)
 	int ret = 0;
 
 	/* buffer must be large enough */
-	if (count < 1)
+	if (count < 1) {
 		return -ENOSPC;
+	}
 
 	/* if automatic measurement is enabled */
 	if (_measure_ticks > 0) {
@@ -453,14 +465,14 @@ MB12XX::measure()
 	uint8_t cmd = MB12XX_TAKE_RANGE_REG;
 	ret = transfer(&cmd, 1, nullptr, 0);
 
-	if (OK != ret)
-	{
+	if (OK != ret) {
 		perf_count(_comms_errors);
 		log("i2c::transfer returned %d", ret);
 		return ret;
 	}
+
 	ret = OK;
-	
+
 	return ret;
 }
 
@@ -468,32 +480,31 @@ int
 MB12XX::collect()
 {
 	int	ret = -EIO;
-	
+
 	/* read from the sensor */
 	uint8_t val[2] = {0, 0};
-	
+
 	perf_begin(_sample_perf);
-	
+
 	ret = transfer(nullptr, 0, &val[0], 2);
-	
-	if (ret < 0)
-	{
+
+	if (ret < 0) {
 		log("error reading from sensor: %d", ret);
 		perf_count(_comms_errors);
 		perf_end(_sample_perf);
 		return ret;
 	}
-	
+
 	uint16_t distance = val[0] << 8 | val[1];
-	float si_units = (distance * 1.0f)/ 100.0f; /* cm to m */
+	float si_units = (distance * 1.0f) / 100.0f; /* cm to m */
 	struct range_finder_report report;
 
 	/* this should be fairly close to the end of the measurement, so the best approximation of the time */
 	report.timestamp = hrt_absolute_time();
-        report.error_count = perf_event_count(_comms_errors);
+	report.error_count = perf_event_count(_comms_errors);
 	report.distance = si_units;
 	report.valid = si_units > get_minimum_distance() && si_units < get_maximum_distance() ? 1 : 0;
-	
+
 	/* publish it */
 	orb_publish(ORB_ID(sensor_range_finder), _range_finder_topic, &report);
 
@@ -519,17 +530,19 @@ MB12XX::start()
 
 	/* schedule a cycle to start things */
 	work_queue(HPWORK, &_work, (worker_t)&MB12XX::cycle_trampoline, this, 1);
-	
+
 	/* notify about state change */
 	struct subsystem_info_s info = {
 		true,
 		true,
 		true,
-		SUBSYSTEM_TYPE_RANGEFINDER};
+		SUBSYSTEM_TYPE_RANGEFINDER
+	};
 	static orb_advert_t pub = -1;
 
 	if (pub > 0) {
 		orb_publish(ORB_ID(subsystem_info), pub, &info);
+
 	} else {
 		pub = orb_advertise(ORB_ID(subsystem_info), &info);
 	}
@@ -583,8 +596,9 @@ MB12XX::cycle()
 	}
 
 	/* measurement phase */
-	if (OK != measure())
+	if (OK != measure()) {
 		log("measure error");
+	}
 
 	/* next phase is collection */
 	_collect_phase = true;
@@ -635,33 +649,37 @@ start()
 {
 	int fd;
 
-	if (g_dev != nullptr)
+	if (g_dev != nullptr) {
 		errx(1, "already started");
+	}
 
 	/* create the driver */
 	g_dev = new MB12XX(MB12XX_BUS);
 
-	if (g_dev == nullptr)
+	if (g_dev == nullptr) {
 		goto fail;
+	}
 
-	if (OK != g_dev->init())
+	if (OK != g_dev->init()) {
 		goto fail;
+	}
 
 	/* set the poll rate to default, starts automatic data collection */
 	fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
 
-	if (fd < 0)
+	if (fd < 0) {
 		goto fail;
+	}
 
-	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0)
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
 		goto fail;
+	}
 
 	exit(0);
 
 fail:
 
-	if (g_dev != nullptr) 
-	{
+	if (g_dev != nullptr) {
 		delete g_dev;
 		g_dev = nullptr;
 	}
@@ -674,15 +692,14 @@ fail:
  */
 void stop()
 {
-	if (g_dev != nullptr)
-	{
+	if (g_dev != nullptr) {
 		delete g_dev;
 		g_dev = nullptr;
-	}
-	else
-	{
+
+	} else {
 		errx(1, "driver not running");
 	}
+
 	exit(0);
 }
 
@@ -700,22 +717,25 @@ test()
 
 	int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
 
-	if (fd < 0)
+	if (fd < 0) {
 		err(1, "%s open failed (try 'mb12xx start' if the driver is not running", RANGE_FINDER_DEVICE_PATH);
+	}
 
 	/* do a simple demand read */
 	sz = read(fd, &report, sizeof(report));
 
-	if (sz != sizeof(report))
+	if (sz != sizeof(report)) {
 		err(1, "immediate read failed");
+	}
 
 	warnx("single read");
 	warnx("measurement: %0.2f m", (double)report.distance);
 	warnx("time:        %lld", report.timestamp);
 
 	/* start the sensor polling at 2Hz */
-	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2))
+	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) {
 		errx(1, "failed to set 2Hz poll rate");
+	}
 
 	/* read the sensor 5x and report each value */
 	for (unsigned i = 0; i < 5; i++) {
@@ -726,20 +746,27 @@ test()
 		fds.events = POLLIN;
 		ret = poll(&fds, 1, 2000);
 
-		if (ret != 1)
+		if (ret != 1) {
 			errx(1, "timed out waiting for sensor data");
+		}
 
 		/* now go get it */
 		sz = read(fd, &report, sizeof(report));
 
-		if (sz != sizeof(report))
+		if (sz != sizeof(report)) {
 			err(1, "periodic read failed");
+		}
 
 		warnx("periodic read %u", i);
 		warnx("measurement: %0.3f", (double)report.distance);
 		warnx("time:        %lld", report.timestamp);
 	}
 
+	/* reset the sensor polling to default rate */
+	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT)) {
+		errx(1, "failed to set default poll rate");
+	}
+
 	errx(0, "PASS");
 }
 
@@ -751,14 +778,17 @@ reset()
 {
 	int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
 
-	if (fd < 0)
+	if (fd < 0) {
 		err(1, "failed ");
+	}
 
-	if (ioctl(fd, SENSORIOCRESET, 0) < 0)
+	if (ioctl(fd, SENSORIOCRESET, 0) < 0) {
 		err(1, "driver reset failed");
+	}
 
-	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0)
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
 		err(1, "driver poll restart failed");
+	}
 
 	exit(0);
 }
@@ -769,8 +799,9 @@ reset()
 void
 info()
 {
-	if (g_dev == nullptr)
+	if (g_dev == nullptr) {
 		errx(1, "driver not running");
+	}
 
 	printf("state @ %p\n", g_dev);
 	g_dev->print_info();
@@ -786,32 +817,37 @@ mb12xx_main(int argc, char *argv[])
 	/*
 	 * Start/load the driver.
 	 */
-	if (!strcmp(argv[1], "start"))
+	if (!strcmp(argv[1], "start")) {
 		mb12xx::start();
-	
-	 /*
-	  * Stop the driver
-	  */
-	 if (!strcmp(argv[1], "stop"))
-		 mb12xx::stop();
+	}
+
+	/*
+	 * Stop the driver
+	 */
+	if (!strcmp(argv[1], "stop")) {
+		mb12xx::stop();
+	}
 
 	/*
 	 * Test the driver/device.
 	 */
-	if (!strcmp(argv[1], "test"))
+	if (!strcmp(argv[1], "test")) {
 		mb12xx::test();
+	}
 
 	/*
 	 * Reset the driver.
 	 */
-	if (!strcmp(argv[1], "reset"))
+	if (!strcmp(argv[1], "reset")) {
 		mb12xx::reset();
+	}
 
 	/*
 	 * Print driver information.
 	 */
-	if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status"))
+	if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status")) {
 		mb12xx::info();
+	}
 
 	errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'");
 }
diff --git a/src/drivers/px4flow/module.mk b/src/drivers/px4flow/module.mk
new file mode 100644
index 000000000..d3062e457
--- /dev/null
+++ b/src/drivers/px4flow/module.mk
@@ -0,0 +1,40 @@
+############################################################################
+#
+#   Copyright (c) 2013 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.
+#
+############################################################################
+
+#
+# Makefile to build the PX4FLOW driver.
+#
+
+MODULE_COMMAND	= px4flow
+
+SRCS		= px4flow.cpp
diff --git a/src/drivers/px4flow/px4flow.cpp b/src/drivers/px4flow/px4flow.cpp
new file mode 100644
index 000000000..50089282a
--- /dev/null
+++ b/src/drivers/px4flow/px4flow.cpp
@@ -0,0 +1,806 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 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 px4flow.cpp
+ * @author Dominik Honegger
+ *
+ * Driver for the PX4FLOW module connected via I2C.
+ */
+	 
+#include <nuttx/config.h>
+
+#include <drivers/device/i2c.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <semaphore.h>
+#include <string.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <math.h>
+#include <unistd.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/wqueue.h>
+#include <nuttx/clock.h>
+
+#include <systemlib/perf_counter.h>
+#include <systemlib/err.h>
+
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_px4flow.h>
+#include <drivers/device/ringbuffer.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/subsystem_info.h>
+//#include <uORB/topics/optical_flow.h>
+
+#include <board_config.h>
+
+/* Configuration Constants */
+#define PX4FLOW_BUS 			PX4_I2C_BUS_EXPANSION
+#define I2C_FLOW_ADDRESS 		0x45 //* 7-bit address. 8-bit address is 0x8A
+//range 0x42 - 0x49
+
+/* PX4FLOW Registers addresses */
+#define PX4FLOW_REG	0x00		/* Measure Register */
+
+#define PX4FLOW_CONVERSION_INTERVAL 8000 /* 8ms 125Hz
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+#ifndef CONFIG_SCHED_WORKQUEUE
+# error This requires CONFIG_SCHED_WORKQUEUE.
+#endif
+
+//struct i2c_frame
+//{
+//    uint16_t frame_count;
+//    int16_t pixel_flow_x_sum;
+//    int16_t pixel_flow_y_sum;
+//    int16_t flow_comp_m_x;
+//    int16_t flow_comp_m_y;
+//    int16_t qual;
+//    int16_t gyro_x_rate;
+//    int16_t gyro_y_rate;
+//    int16_t gyro_z_rate;
+//    uint8_t gyro_range;
+//    uint8_t sonar_timestamp;
+//    int16_t ground_distance;
+//};
+//
+//struct i2c_frame f;
+
+class PX4FLOW : public device::I2C
+{
+public:
+	PX4FLOW(int bus = PX4FLOW_BUS, int address = I2C_FLOW_ADDRESS);
+	virtual ~PX4FLOW();
+	
+	virtual int 		init();
+	
+	virtual ssize_t		read(struct file *filp, char *buffer, size_t buflen);
+	virtual int			ioctl(struct file *filp, int cmd, unsigned long arg);
+	
+	/**
+	* Diagnostics - print some basic information about the driver.
+	*/
+	void				print_info();
+	
+protected:
+	virtual int			probe();
+
+private:
+
+	work_s				_work;
+	RingBuffer			*_reports;
+	bool				_sensor_ok;
+	int					_measure_ticks;
+	bool				_collect_phase;
+	
+	orb_advert_t		_px4flow_topic;
+
+	perf_counter_t		_sample_perf;
+	perf_counter_t		_comms_errors;
+	perf_counter_t		_buffer_overflows;
+	
+	/**
+	* Test whether the device supported by the driver is present at a
+	* specific address.
+	*
+	* @param address	The I2C bus address to probe.
+	* @return		True if the device is present.
+	*/
+	int					probe_address(uint8_t address);
+	
+	/**
+	* Initialise the automatic measurement state machine and start it.
+	*
+	* @note This function is called at open and error time.  It might make sense
+	*       to make it more aggressive about resetting the bus in case of errors.
+	*/
+	void				start();
+	
+	/**
+	* Stop the automatic measurement state machine.
+	*/
+	void				stop();
+	
+	/**
+	* Perform a poll cycle; collect from the previous measurement
+	* and start a new one.
+	*/
+	void				cycle();
+	int					measure();
+	int					collect();
+	/**
+	* Static trampoline from the workq context; because we don't have a
+	* generic workq wrapper yet.
+	*
+	* @param arg		Instance pointer for the driver that is polling.
+	*/
+	static void		cycle_trampoline(void *arg);
+	
+	
+};
+
+/*
+ * Driver 'main' command.
+ */
+extern "C" __EXPORT int px4flow_main(int argc, char *argv[]);
+
+PX4FLOW::PX4FLOW(int bus, int address) :
+	I2C("PX4FLOW", PX4FLOW_DEVICE_PATH, bus, address, 400000),//400khz
+	_reports(nullptr),
+	_sensor_ok(false),
+	_measure_ticks(0),
+	_collect_phase(false),
+	_px4flow_topic(-1),
+	_sample_perf(perf_alloc(PC_ELAPSED, "px4flow_read")),
+	_comms_errors(perf_alloc(PC_COUNT, "px4flow_comms_errors")),
+	_buffer_overflows(perf_alloc(PC_COUNT, "px4flow_buffer_overflows"))
+{
+	// enable debug() calls
+	_debug_enabled = true;
+	
+	// work_cancel in the dtor will explode if we don't do this...
+	memset(&_work, 0, sizeof(_work));
+}
+
+PX4FLOW::~PX4FLOW()
+{
+	/* make sure we are truly inactive */
+	stop();
+
+	/* free any existing reports */
+	if (_reports != nullptr)
+		delete _reports;
+}
+
+int
+PX4FLOW::init()
+{
+	int ret = ERROR;
+
+	/* do I2C init (and probe) first */
+	if (I2C::init() != OK)
+		goto out;
+
+	/* allocate basic report buffers */
+	_reports = new RingBuffer(2, sizeof(px4flow_report));
+
+	if (_reports == nullptr)
+		goto out;
+
+	/* get a publish handle on the px4flow topic */
+	struct px4flow_report zero_report;
+	memset(&zero_report, 0, sizeof(zero_report));
+	_px4flow_topic = orb_advertise(ORB_ID(optical_flow), &zero_report);
+
+	if (_px4flow_topic < 0)
+		debug("failed to create px4flow object. Did you start uOrb?");
+
+	ret = OK;
+	/* sensor is ok, but we don't really know if it is within range */
+	_sensor_ok = true;
+out:
+	return ret;
+}
+
+int
+PX4FLOW::probe()
+{
+	return measure();
+}
+
+int
+PX4FLOW::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+
+	case SENSORIOCSPOLLRATE: {
+			switch (arg) {
+
+				/* switching to manual polling */
+			case SENSOR_POLLRATE_MANUAL:
+				stop();
+				_measure_ticks = 0;
+				return OK;
+
+				/* external signalling (DRDY) not supported */
+			case SENSOR_POLLRATE_EXTERNAL:
+
+				/* zero would be bad */
+			case 0:
+				return -EINVAL;
+
+				/* set default/max polling rate */
+			case SENSOR_POLLRATE_MAX:
+			case SENSOR_POLLRATE_DEFAULT: {
+					/* do we need to start internal polling? */
+					bool want_start = (_measure_ticks == 0);
+
+					/* set interval for next measurement to minimum legal value */
+					_measure_ticks = USEC2TICK(PX4FLOW_CONVERSION_INTERVAL);
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start)
+						start();
+
+					return OK;
+				}
+
+				/* adjust to a legal polling interval in Hz */
+			default: {
+					/* do we need to start internal polling? */
+					bool want_start = (_measure_ticks == 0);
+
+					/* convert hz to tick interval via microseconds */
+					unsigned ticks = USEC2TICK(1000000 / arg);
+
+					/* check against maximum rate */
+					if (ticks < USEC2TICK(PX4FLOW_CONVERSION_INTERVAL))
+						return -EINVAL;
+
+					/* update interval for next measurement */
+					_measure_ticks = ticks;
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start)
+						start();
+
+					return OK;
+				}
+			}
+		}
+
+	case SENSORIOCGPOLLRATE:
+		if (_measure_ticks == 0)
+			return SENSOR_POLLRATE_MANUAL;
+
+		return (1000 / _measure_ticks);
+
+	case SENSORIOCSQUEUEDEPTH: {
+		/* lower bound is mandatory, upper bound is a sanity check */
+		if ((arg < 1) || (arg > 100))
+			return -EINVAL;
+		
+		irqstate_t flags = irqsave();
+		if (!_reports->resize(arg)) {
+			irqrestore(flags);
+			return -ENOMEM;
+		}
+		irqrestore(flags);
+		
+		return OK;
+	}
+
+	case SENSORIOCGQUEUEDEPTH:
+		return _reports->size();
+		
+	case SENSORIOCRESET:
+		/* XXX implement this */
+		return -EINVAL;
+	
+	default:
+		/* give it to the superclass */
+		return I2C::ioctl(filp, cmd, arg);
+	}
+}
+
+ssize_t
+PX4FLOW::read(struct file *filp, char *buffer, size_t buflen)
+{
+	unsigned count = buflen / sizeof(struct px4flow_report);
+	struct px4flow_report *rbuf = reinterpret_cast<struct px4flow_report *>(buffer);
+	int ret = 0;
+
+	/* buffer must be large enough */
+	if (count < 1)
+		return -ENOSPC;
+
+	/* if automatic measurement is enabled */
+	if (_measure_ticks > 0) {
+
+		/*
+		 * While there is space in the caller's buffer, and reports, copy them.
+		 * Note that we may be pre-empted by the workq thread while we are doing this;
+		 * we are careful to avoid racing with them.
+		 */
+		while (count--) {
+			if (_reports->get(rbuf)) {
+				ret += sizeof(*rbuf);
+				rbuf++;
+			}
+		}
+
+		/* if there was no data, warn the caller */
+		return ret ? ret : -EAGAIN;
+	}
+
+	/* manual measurement - run one conversion */
+	do {
+		_reports->flush();
+
+		/* trigger a measurement */
+		if (OK != measure()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* wait for it to complete */
+		usleep(PX4FLOW_CONVERSION_INTERVAL);
+
+		/* run the collection phase */
+		if (OK != collect()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* state machine will have generated a report, copy it out */
+		if (_reports->get(rbuf)) {
+			ret = sizeof(*rbuf);
+		}
+
+	} while (0);
+
+	return ret;
+}
+
+int
+PX4FLOW::measure()
+{
+	int ret;
+
+	/*
+	 * Send the command to begin a measurement.
+	 */
+	uint8_t cmd = PX4FLOW_REG;
+	ret = transfer(&cmd, 1, nullptr, 0);
+
+	if (OK != ret)
+	{
+		perf_count(_comms_errors);
+		log("i2c::transfer returned %d", ret);
+		 printf("i2c::transfer flow returned %d");
+		return ret;
+	}
+	ret = OK;
+	
+	return ret;
+}
+
+int
+PX4FLOW::collect()
+{
+	int	ret = -EIO;
+	
+	/* read from the sensor */
+	uint8_t val[22] = {0, 0,0, 0,0, 0,0, 0,0, 0,0, 0,0, 0,0, 0,0, 0,0, 0,0, 0};
+	
+	perf_begin(_sample_perf);
+	
+	ret = transfer(nullptr, 0, &val[0], 22);
+	
+	if (ret < 0)
+	{
+		log("error reading from sensor: %d", ret);
+		perf_count(_comms_errors);
+		perf_end(_sample_perf);
+		return ret;
+	}
+	
+//	f.frame_count = val[1] << 8 | val[0];
+//	f.pixel_flow_x_sum= val[3] << 8 | val[2];
+//	f.pixel_flow_y_sum= val[5] << 8 | val[4];
+//	f.flow_comp_m_x= val[7] << 8 | val[6];
+//	f.flow_comp_m_y= val[9] << 8 | val[8];
+//	f.qual= val[11] << 8 | val[10];
+//	f.gyro_x_rate= val[13] << 8 | val[12];
+//	f.gyro_y_rate= val[15] << 8 | val[14];
+//	f.gyro_z_rate= val[17] << 8 | val[16];
+//	f.gyro_range= val[18];
+//	f.sonar_timestamp= val[19];
+//	f.ground_distance= val[21] << 8 | val[20];
+
+	int16_t flowcx = val[7] << 8 | val[6];
+	int16_t flowcy = val[9] << 8 | val[8];
+	int16_t gdist = val[21] << 8 | val[20];
+
+	struct px4flow_report report;
+	report.flow_comp_x_m = float(flowcx)/1000.0f;
+	report.flow_comp_y_m = float(flowcy)/1000.0f;
+	report.flow_raw_x= val[3] << 8 | val[2];
+	report.flow_raw_y= val[5] << 8 | val[4];
+	report.ground_distance_m =float(gdist)/1000.0f;
+	report.quality=  val[10];
+	report.sensor_id = 0;
+	report.timestamp = hrt_absolute_time();
+
+
+	/* publish it */
+	orb_publish(ORB_ID(optical_flow), _px4flow_topic, &report);
+
+	/* post a report to the ring */
+	if (_reports->force(&report)) {
+		perf_count(_buffer_overflows);
+	}
+
+	/* notify anyone waiting for data */
+	poll_notify(POLLIN);
+
+	ret = OK;
+
+	perf_end(_sample_perf);
+	return ret;
+}
+
+void
+PX4FLOW::start()
+{
+	/* reset the report ring and state machine */
+	_collect_phase = false;
+	_reports->flush();
+
+	/* schedule a cycle to start things */
+	work_queue(HPWORK, &_work, (worker_t)&PX4FLOW::cycle_trampoline, this, 1);
+	
+	/* notify about state change */
+	struct subsystem_info_s info = {
+		true,
+		true,
+		true,
+		SUBSYSTEM_TYPE_OPTICALFLOW};
+	static orb_advert_t pub = -1;
+
+	if (pub > 0) {
+		orb_publish(ORB_ID(subsystem_info), pub, &info);
+	} else {
+		pub = orb_advertise(ORB_ID(subsystem_info), &info);
+	}
+}
+
+void
+PX4FLOW::stop()
+{
+	work_cancel(HPWORK, &_work);
+}
+
+void
+PX4FLOW::cycle_trampoline(void *arg)
+{
+	PX4FLOW *dev = (PX4FLOW *)arg;
+
+	dev->cycle();
+}
+
+void
+PX4FLOW::cycle()
+{
+	/* collection phase? */
+	if (_collect_phase) {
+
+		/* perform collection */
+		if (OK != collect()) {
+			log("collection error");
+			/* restart the measurement state machine */
+			start();
+			return;
+		}
+
+		/* next phase is measurement */
+		_collect_phase = false;
+
+		/*
+		 * Is there a collect->measure gap?
+		 */
+		if (_measure_ticks > USEC2TICK(PX4FLOW_CONVERSION_INTERVAL)) {
+
+			/* schedule a fresh cycle call when we are ready to measure again */
+			work_queue(HPWORK,
+				   &_work,
+				   (worker_t)&PX4FLOW::cycle_trampoline,
+				   this,
+				   _measure_ticks - USEC2TICK(PX4FLOW_CONVERSION_INTERVAL));
+
+			return;
+		}
+	}
+
+	/* measurement phase */
+	if (OK != measure())
+		log("measure error");
+
+	/* next phase is collection */
+	_collect_phase = true;
+
+	/* schedule a fresh cycle call when the measurement is done */
+	work_queue(HPWORK,
+		   &_work,
+		   (worker_t)&PX4FLOW::cycle_trampoline,
+		   this,
+		   USEC2TICK(PX4FLOW_CONVERSION_INTERVAL));
+}
+
+void
+PX4FLOW::print_info()
+{
+	perf_print_counter(_sample_perf);
+	perf_print_counter(_comms_errors);
+	perf_print_counter(_buffer_overflows);
+	printf("poll interval:  %u ticks\n", _measure_ticks);
+	_reports->print_info("report queue");
+}
+
+/**
+ * Local functions in support of the shell command.
+ */
+namespace px4flow
+{
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+const int ERROR = -1;
+
+PX4FLOW	*g_dev;
+
+void	start();
+void	stop();
+void	test();
+void	reset();
+void	info();
+
+/**
+ * Start the driver.
+ */
+void
+start()
+{
+	int fd;
+
+	if (g_dev != nullptr)
+		errx(1, "already started");
+
+	/* create the driver */
+	g_dev = new PX4FLOW(PX4FLOW_BUS);
+
+	if (g_dev == nullptr)
+		goto fail;
+
+	if (OK != g_dev->init())
+		goto fail;
+
+	/* set the poll rate to default, starts automatic data collection */
+	fd = open(PX4FLOW_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0)
+		goto fail;
+
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_MAX) < 0)
+		goto fail;
+
+	exit(0);
+
+fail:
+
+	if (g_dev != nullptr) 
+	{
+		delete g_dev;
+		g_dev = nullptr;
+	}
+
+	errx(1, "driver start failed");
+}
+
+/**
+ * Stop the driver
+ */
+void stop()
+{
+	if (g_dev != nullptr)
+	{
+		delete g_dev;
+		g_dev = nullptr;
+	}
+	else
+	{
+		errx(1, "driver not running");
+	}
+	exit(0);
+}
+
+/**
+ * Perform some basic functional tests on the driver;
+ * make sure we can collect data from the sensor in polled
+ * and automatic modes.
+ */
+void
+test()
+{
+	struct px4flow_report report;
+	ssize_t sz;
+	int ret;
+
+	int fd = open(PX4FLOW_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0)
+		err(1, "%s open failed (try 'px4flow start' if the driver is not running", PX4FLOW_DEVICE_PATH);
+
+	/* do a simple demand read */
+	sz = read(fd, &report, sizeof(report));
+
+	if (sz != sizeof(report))
+	//	err(1, "immediate read failed");
+
+	warnx("single read");
+	warnx("flowx: %0.2f m/s", (double)report.flow_comp_x_m);
+	warnx("flowy: %0.2f m/s", (double)report.flow_comp_y_m);
+	warnx("time:        %lld", report.timestamp);
+
+
+	/* start the sensor polling at 2Hz */
+	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2))
+		errx(1, "failed to set 2Hz poll rate");
+
+	/* read the sensor 5x and report each value */
+	for (unsigned i = 0; i < 5; i++) {
+		struct pollfd fds;
+
+		/* wait for data to be ready */
+		fds.fd = fd;
+		fds.events = POLLIN;
+		ret = poll(&fds, 1, 2000);
+
+		if (ret != 1)
+			errx(1, "timed out waiting for sensor data");
+
+		/* now go get it */
+		sz = read(fd, &report, sizeof(report));
+
+		if (sz != sizeof(report))
+			err(1, "periodic read failed");
+
+		warnx("periodic read %u", i);
+		warnx("flowx: %0.2f m/s", (double)report.flow_comp_x_m);
+		warnx("flowy: %0.2f m/s", (double)report.flow_comp_y_m);
+		warnx("time:        %lld", report.timestamp);
+
+
+	}
+
+	errx(0, "PASS");
+}
+
+/**
+ * Reset the driver.
+ */
+void
+reset()
+{
+	int fd = open(PX4FLOW_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0)
+		err(1, "failed ");
+
+	if (ioctl(fd, SENSORIOCRESET, 0) < 0)
+		err(1, "driver reset failed");
+
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0)
+		err(1, "driver poll restart failed");
+
+	exit(0);
+}
+
+/**
+ * Print a little info about the driver.
+ */
+void
+info()
+{
+	if (g_dev == nullptr)
+		errx(1, "driver not running");
+
+	printf("state @ %p\n", g_dev);
+	g_dev->print_info();
+
+	exit(0);
+}
+
+} // namespace
+
+int
+px4flow_main(int argc, char *argv[])
+{
+	/*
+	 * Start/load the driver.
+	 */
+	if (!strcmp(argv[1], "start"))
+		px4flow::start();
+	
+	 /*
+	  * Stop the driver
+	  */
+	 if (!strcmp(argv[1], "stop"))
+		 px4flow::stop();
+
+	/*
+	 * Test the driver/device.
+	 */
+	if (!strcmp(argv[1], "test"))
+		px4flow::test();
+
+	/*
+	 * Reset the driver.
+	 */
+	if (!strcmp(argv[1], "reset"))
+		px4flow::reset();
+
+	/*
+	 * Print driver information.
+	 */
+	if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status"))
+		px4flow::info();
+
+	errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'");
+}
diff --git a/src/drivers/px4io/px4io.cpp b/src/drivers/px4io/px4io.cpp
index 7c7b3dcb7..8e990aa6f 100644
--- a/src/drivers/px4io/px4io.cpp
+++ b/src/drivers/px4io/px4io.cpp
@@ -1921,12 +1921,14 @@ PX4IO::print_status()
 	       io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_PWM_ALTRATE));
 #endif
 	printf("debuglevel %u\n", io_reg_get(PX4IO_PAGE_SETUP, PX4IO_P_SETUP_SET_DEBUG));
-	printf("controls");
+	for (unsigned group = 0; group < 4; group++) {
+		printf("controls %u:", group);
 
-	for (unsigned i = 0; i < _max_controls; i++)
-		printf(" %u", io_reg_get(PX4IO_PAGE_CONTROLS, i));
+		for (unsigned i = 0; i < _max_controls; i++)
+			printf(" %d", (int16_t) io_reg_get(PX4IO_PAGE_CONTROLS, group * PX4IO_PROTOCOL_MAX_CONTROL_COUNT + i));
 
-	printf("\n");
+		printf("\n");
+	}
 
 	for (unsigned i = 0; i < _max_rc_input; i++) {
 		unsigned base = PX4IO_P_RC_CONFIG_STRIDE * i;
diff --git a/src/drivers/sf0x/module.mk b/src/drivers/sf0x/module.mk
new file mode 100644
index 000000000..dc93a90e7
--- /dev/null
+++ b/src/drivers/sf0x/module.mk
@@ -0,0 +1,40 @@
+############################################################################
+#
+#   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.
+#
+############################################################################
+
+#
+# Makefile to build the Lightware laser range finder driver.
+#
+
+MODULE_COMMAND	= sf0x
+
+SRCS		= sf0x.cpp
diff --git a/src/drivers/sf0x/sf0x.cpp b/src/drivers/sf0x/sf0x.cpp
new file mode 100644
index 000000000..70cd1ab1e
--- /dev/null
+++ b/src/drivers/sf0x/sf0x.cpp
@@ -0,0 +1,977 @@
+/****************************************************************************
+ *
+ *   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 sf0x.cpp
+ * @author Lorenz Meier <lm@inf.ethz.ch>
+ * @author Greg Hulands
+ *
+ * Driver for the Lightware SF0x laser rangefinder series
+ */
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <semaphore.h>
+#include <string.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <errno.h>
+#include <stdio.h>
+#include <math.h>
+#include <unistd.h>
+#include <termios.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/wqueue.h>
+#include <nuttx/clock.h>
+
+#include <systemlib/perf_counter.h>
+#include <systemlib/err.h>
+
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_range_finder.h>
+#include <drivers/device/device.h>
+#include <drivers/device/ringbuffer.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/subsystem_info.h>
+
+#include <board_config.h>
+
+/* Configuration Constants */
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+#ifndef CONFIG_SCHED_WORKQUEUE
+# error This requires CONFIG_SCHED_WORKQUEUE.
+#endif
+
+#define SF0X_CONVERSION_INTERVAL	83334
+#define SF0X_TAKE_RANGE_REG		'd'
+#define SF02F_MIN_DISTANCE		0.0f
+#define SF02F_MAX_DISTANCE		40.0f
+#define SF0X_DEFAULT_PORT		"/dev/ttyS2"
+
+class SF0X : public device::CDev
+{
+public:
+	SF0X(const char *port = SF0X_DEFAULT_PORT);
+	virtual ~SF0X();
+
+	virtual int 			init();
+
+	virtual ssize_t			read(struct file *filp, char *buffer, size_t buflen);
+	virtual int			ioctl(struct file *filp, int cmd, unsigned long arg);
+
+	/**
+	* Diagnostics - print some basic information about the driver.
+	*/
+	void				print_info();
+
+protected:
+	virtual int			probe();
+
+private:
+	float				_min_distance;
+	float				_max_distance;
+	work_s				_work;
+	RingBuffer			*_reports;
+	bool				_sensor_ok;
+	int				_measure_ticks;
+	bool				_collect_phase;
+	int				_fd;
+	char				_linebuf[10];
+	unsigned			_linebuf_index;
+	hrt_abstime			_last_read;
+
+	orb_advert_t			_range_finder_topic;
+
+	perf_counter_t			_sample_perf;
+	perf_counter_t			_comms_errors;
+	perf_counter_t			_buffer_overflows;
+
+	/**
+	* Initialise the automatic measurement state machine and start it.
+	*
+	* @note This function is called at open and error time.  It might make sense
+	*       to make it more aggressive about resetting the bus in case of errors.
+	*/
+	void				start();
+
+	/**
+	* Stop the automatic measurement state machine.
+	*/
+	void				stop();
+
+	/**
+	* Set the min and max distance thresholds if you want the end points of the sensors
+	* range to be brought in at all, otherwise it will use the defaults SF0X_MIN_DISTANCE
+	* and SF0X_MAX_DISTANCE
+	*/
+	void				set_minimum_distance(float min);
+	void				set_maximum_distance(float max);
+	float				get_minimum_distance();
+	float				get_maximum_distance();
+
+	/**
+	* Perform a poll cycle; collect from the previous measurement
+	* and start a new one.
+	*/
+	void				cycle();
+	int				measure();
+	int				collect();
+	/**
+	* Static trampoline from the workq context; because we don't have a
+	* generic workq wrapper yet.
+	*
+	* @param arg		Instance pointer for the driver that is polling.
+	*/
+	static void			cycle_trampoline(void *arg);
+
+
+};
+
+/*
+ * Driver 'main' command.
+ */
+extern "C" __EXPORT int sf0x_main(int argc, char *argv[]);
+
+SF0X::SF0X(const char *port) :
+	CDev("SF0X", RANGE_FINDER_DEVICE_PATH),
+	_min_distance(SF02F_MIN_DISTANCE),
+	_max_distance(SF02F_MAX_DISTANCE),
+	_reports(nullptr),
+	_sensor_ok(false),
+	_measure_ticks(0),
+	_collect_phase(false),
+	_fd(-1),
+	_linebuf_index(0),
+	_last_read(0),
+	_range_finder_topic(-1),
+	_sample_perf(perf_alloc(PC_ELAPSED, "sf0x_read")),
+	_comms_errors(perf_alloc(PC_COUNT, "sf0x_comms_errors")),
+	_buffer_overflows(perf_alloc(PC_COUNT, "sf0x_buffer_overflows"))
+{
+	/* open fd */
+	_fd = ::open(port, O_RDWR | O_NOCTTY | O_NONBLOCK);
+
+	if (_fd < 0) {
+		warnx("FAIL: laser fd");
+	}
+
+	/* tell it to stop auto-triggering */
+	char stop_auto = ' ';
+	(void)::write(_fd, &stop_auto, 1);
+	usleep(100);
+	(void)::write(_fd, &stop_auto, 1);
+
+	struct termios uart_config;
+
+	int termios_state;
+
+	/* fill the struct for the new configuration */
+	tcgetattr(_fd, &uart_config);
+
+	/* clear ONLCR flag (which appends a CR for every LF) */
+	uart_config.c_oflag &= ~ONLCR;
+	/* no parity, one stop bit */
+	uart_config.c_cflag &= ~(CSTOPB | PARENB);
+
+	unsigned speed = B9600;
+
+	/* set baud rate */
+	if ((termios_state = cfsetispeed(&uart_config, speed)) < 0) {
+		warnx("ERR CFG: %d ISPD", termios_state);
+	}
+
+	if ((termios_state = cfsetospeed(&uart_config, speed)) < 0) {
+		warnx("ERR CFG: %d OSPD\n", termios_state);
+	}
+
+	if ((termios_state = tcsetattr(_fd, TCSANOW, &uart_config)) < 0) {
+		warnx("ERR baud %d ATTR", termios_state);
+	}
+
+	// disable debug() calls
+	_debug_enabled = false;
+
+	// work_cancel in the dtor will explode if we don't do this...
+	memset(&_work, 0, sizeof(_work));
+}
+
+SF0X::~SF0X()
+{
+	/* make sure we are truly inactive */
+	stop();
+
+	/* free any existing reports */
+	if (_reports != nullptr) {
+		delete _reports;
+	}
+}
+
+int
+SF0X::init()
+{
+	int ret = ERROR;
+	unsigned i = 0;
+
+	/* do regular cdev init */
+	if (CDev::init() != OK) {
+		goto out;
+	}
+
+	/* allocate basic report buffers */
+	_reports = new RingBuffer(2, sizeof(range_finder_report));
+
+	if (_reports == nullptr) {
+		warnx("mem err");
+		goto out;
+	}
+
+	/* get a publish handle on the range finder topic */
+	struct range_finder_report zero_report;
+	memset(&zero_report, 0, sizeof(zero_report));
+	_range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &zero_report);
+
+	if (_range_finder_topic < 0) {
+		warnx("advert err");
+	}
+
+	/* attempt to get a measurement 5 times */
+	while (ret != OK && i < 5) {
+
+		if (measure()) {
+			ret = ERROR;
+			_sensor_ok = false;
+		}
+
+		usleep(100000);
+
+		if (collect()) {
+			ret = ERROR;
+			_sensor_ok = false;
+
+		} else {
+			ret = OK;
+			/* sensor is ok, but we don't really know if it is within range */
+			_sensor_ok = true;
+		}
+
+		i++;
+	}
+
+	/* close the fd */
+	::close(_fd);
+	_fd = -1;
+out:
+	return ret;
+}
+
+int
+SF0X::probe()
+{
+	return measure();
+}
+
+void
+SF0X::set_minimum_distance(float min)
+{
+	_min_distance = min;
+}
+
+void
+SF0X::set_maximum_distance(float max)
+{
+	_max_distance = max;
+}
+
+float
+SF0X::get_minimum_distance()
+{
+	return _min_distance;
+}
+
+float
+SF0X::get_maximum_distance()
+{
+	return _max_distance;
+}
+
+int
+SF0X::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+
+	case SENSORIOCSPOLLRATE: {
+			switch (arg) {
+
+			/* switching to manual polling */
+			case SENSOR_POLLRATE_MANUAL:
+				stop();
+				_measure_ticks = 0;
+				return OK;
+
+			/* external signalling (DRDY) not supported */
+			case SENSOR_POLLRATE_EXTERNAL:
+
+			/* zero would be bad */
+			case 0:
+				return -EINVAL;
+
+			/* set default/max polling rate */
+			case SENSOR_POLLRATE_MAX:
+			case SENSOR_POLLRATE_DEFAULT: {
+					/* do we need to start internal polling? */
+					bool want_start = (_measure_ticks == 0);
+
+					/* set interval for next measurement to minimum legal value */
+					_measure_ticks = USEC2TICK(SF0X_CONVERSION_INTERVAL);
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start) {
+						start();
+					}
+
+					return OK;
+				}
+
+			/* adjust to a legal polling interval in Hz */
+			default: {
+					/* do we need to start internal polling? */
+					bool want_start = (_measure_ticks == 0);
+
+					/* convert hz to tick interval via microseconds */
+					unsigned ticks = USEC2TICK(1000000 / arg);
+
+					/* check against maximum rate */
+					if (ticks < USEC2TICK(SF0X_CONVERSION_INTERVAL)) {
+						return -EINVAL;
+					}
+
+					/* update interval for next measurement */
+					_measure_ticks = ticks;
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start) {
+						start();
+					}
+
+					return OK;
+				}
+			}
+		}
+
+	case SENSORIOCGPOLLRATE:
+		if (_measure_ticks == 0) {
+			return SENSOR_POLLRATE_MANUAL;
+		}
+
+		return (1000 / _measure_ticks);
+
+	case SENSORIOCSQUEUEDEPTH: {
+			/* lower bound is mandatory, upper bound is a sanity check */
+			if ((arg < 1) || (arg > 100)) {
+				return -EINVAL;
+			}
+
+			irqstate_t flags = irqsave();
+
+			if (!_reports->resize(arg)) {
+				irqrestore(flags);
+				return -ENOMEM;
+			}
+
+			irqrestore(flags);
+
+			return OK;
+		}
+
+	case SENSORIOCGQUEUEDEPTH:
+		return _reports->size();
+
+	case SENSORIOCRESET:
+		/* XXX implement this */
+		return -EINVAL;
+
+	case RANGEFINDERIOCSETMINIUMDISTANCE: {
+			set_minimum_distance(*(float *)arg);
+			return 0;
+		}
+		break;
+
+	case RANGEFINDERIOCSETMAXIUMDISTANCE: {
+			set_maximum_distance(*(float *)arg);
+			return 0;
+		}
+		break;
+
+	default:
+		/* give it to the superclass */
+		return CDev::ioctl(filp, cmd, arg);
+	}
+}
+
+ssize_t
+SF0X::read(struct file *filp, char *buffer, size_t buflen)
+{
+	unsigned count = buflen / sizeof(struct range_finder_report);
+	struct range_finder_report *rbuf = reinterpret_cast<struct range_finder_report *>(buffer);
+	int ret = 0;
+
+	/* buffer must be large enough */
+	if (count < 1) {
+		return -ENOSPC;
+	}
+
+	/* if automatic measurement is enabled */
+	if (_measure_ticks > 0) {
+
+		/*
+		 * While there is space in the caller's buffer, and reports, copy them.
+		 * Note that we may be pre-empted by the workq thread while we are doing this;
+		 * we are careful to avoid racing with them.
+		 */
+		while (count--) {
+			if (_reports->get(rbuf)) {
+				ret += sizeof(*rbuf);
+				rbuf++;
+			}
+		}
+
+		/* if there was no data, warn the caller */
+		return ret ? ret : -EAGAIN;
+	}
+
+	/* manual measurement - run one conversion */
+	do {
+		_reports->flush();
+
+		/* trigger a measurement */
+		if (OK != measure()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* wait for it to complete */
+		usleep(SF0X_CONVERSION_INTERVAL);
+
+		/* run the collection phase */
+		if (OK != collect()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* state machine will have generated a report, copy it out */
+		if (_reports->get(rbuf)) {
+			ret = sizeof(*rbuf);
+		}
+
+	} while (0);
+
+	return ret;
+}
+
+int
+SF0X::measure()
+{
+	int ret;
+
+	/*
+	 * Send the command to begin a measurement.
+	 */
+	char cmd = SF0X_TAKE_RANGE_REG;
+	ret = ::write(_fd, &cmd, 1);
+
+	if (ret != sizeof(cmd)) {
+		perf_count(_comms_errors);
+		log("write fail %d", ret);
+		return ret;
+	}
+
+	ret = OK;
+
+	return ret;
+}
+
+int
+SF0X::collect()
+{
+	int	ret;
+
+	perf_begin(_sample_perf);
+
+	/* clear buffer if last read was too long ago */
+	uint64_t read_elapsed = hrt_elapsed_time(&_last_read);
+
+	if (read_elapsed > (SF0X_CONVERSION_INTERVAL * 2)) {
+		_linebuf_index = 0;
+	}
+
+	/* read from the sensor (uart buffer) */
+	ret = ::read(_fd, &_linebuf[_linebuf_index], sizeof(_linebuf) - _linebuf_index);
+
+	if (ret < 0) {
+		_linebuf[sizeof(_linebuf) - 1] = '\0';
+		debug("read err: %d lbi: %d buf: %s", ret, (int)_linebuf_index, _linebuf);
+		perf_count(_comms_errors);
+		perf_end(_sample_perf);
+
+		/* only throw an error if we time out */
+		if (read_elapsed > (SF0X_CONVERSION_INTERVAL * 2)) {
+			return ret;
+
+		} else {
+			return -EAGAIN;
+		}
+	}
+
+	_linebuf_index += ret;
+
+	if (_linebuf_index >= sizeof(_linebuf)) {
+		_linebuf_index = 0;
+	}
+
+	_last_read = hrt_absolute_time();
+
+	if (_linebuf[_linebuf_index - 2] != '\r' || _linebuf[_linebuf_index - 1] != '\n') {
+		/* incomplete read, reschedule ourselves */
+		return -EAGAIN;
+	}
+
+	char *end;
+	float si_units;
+	bool valid;
+
+	/* enforce line ending */
+	_linebuf[sizeof(_linebuf) - 1] = '\0';
+
+	if (_linebuf[0] == '-' && _linebuf[1] == '-' && _linebuf[2] == '.') {
+		si_units = -1.0f;
+		valid = false;
+
+	} else {
+		si_units = strtod(_linebuf, &end);
+		valid = true;
+	}
+
+	debug("val (float): %8.4f, raw: %s\n", si_units, _linebuf);
+
+	/* done with this chunk, resetting */
+	_linebuf_index = 0;
+
+	struct range_finder_report report;
+
+	/* this should be fairly close to the end of the measurement, so the best approximation of the time */
+	report.timestamp = hrt_absolute_time();
+	report.error_count = perf_event_count(_comms_errors);
+	report.distance = si_units;
+	report.valid = valid && (si_units > get_minimum_distance() && si_units < get_maximum_distance() ? 1 : 0);
+
+	/* publish it */
+	orb_publish(ORB_ID(sensor_range_finder), _range_finder_topic, &report);
+
+	if (_reports->force(&report)) {
+		perf_count(_buffer_overflows);
+	}
+
+	/* notify anyone waiting for data */
+	poll_notify(POLLIN);
+
+	ret = OK;
+
+	perf_end(_sample_perf);
+	return ret;
+}
+
+void
+SF0X::start()
+{
+	/* reset the report ring and state machine */
+	_collect_phase = false;
+	_reports->flush();
+
+	/* schedule a cycle to start things */
+	work_queue(HPWORK, &_work, (worker_t)&SF0X::cycle_trampoline, this, 1);
+
+	// /* notify about state change */
+	// struct subsystem_info_s info = {
+	// 	true,
+	// 	true,
+	// 	true,
+	// 	SUBSYSTEM_TYPE_RANGEFINDER
+	// };
+	// static orb_advert_t pub = -1;
+
+	// if (pub > 0) {
+	// 	orb_publish(ORB_ID(subsystem_info), pub, &info);
+
+	// } else {
+	// 	pub = orb_advertise(ORB_ID(subsystem_info), &info);
+	// }
+}
+
+void
+SF0X::stop()
+{
+	work_cancel(HPWORK, &_work);
+}
+
+void
+SF0X::cycle_trampoline(void *arg)
+{
+	SF0X *dev = static_cast<SF0X *>(arg);
+
+	dev->cycle();
+}
+
+void
+SF0X::cycle()
+{
+	/* fds initialized? */
+	if (_fd < 0) {
+		/* open fd */
+		_fd = ::open(SF0X_DEFAULT_PORT, O_RDWR | O_NOCTTY | O_NONBLOCK);
+	}
+
+	/* collection phase? */
+	if (_collect_phase) {
+
+		/* perform collection */
+		int collect_ret = collect();
+
+		if (collect_ret == -EAGAIN) {
+			/* reschedule to grab the missing bits, time to transmit 10 bytes @9600 bps */
+			work_queue(HPWORK,
+				   &_work,
+				   (worker_t)&SF0X::cycle_trampoline,
+				   this,
+				   USEC2TICK(1100));
+			return;
+		}
+
+		if (OK != collect_ret) {
+			log("collection error");
+			/* restart the measurement state machine */
+			start();
+			return;
+		}
+
+		/* next phase is measurement */
+		_collect_phase = false;
+
+		/*
+		 * Is there a collect->measure gap?
+		 */
+		if (_measure_ticks > USEC2TICK(SF0X_CONVERSION_INTERVAL)) {
+
+			/* schedule a fresh cycle call when we are ready to measure again */
+			work_queue(HPWORK,
+				   &_work,
+				   (worker_t)&SF0X::cycle_trampoline,
+				   this,
+				   _measure_ticks - USEC2TICK(SF0X_CONVERSION_INTERVAL));
+
+			return;
+		}
+	}
+
+	/* measurement phase */
+	if (OK != measure()) {
+		log("measure error");
+	}
+
+	/* next phase is collection */
+	_collect_phase = true;
+
+	/* schedule a fresh cycle call when the measurement is done */
+	work_queue(HPWORK,
+		   &_work,
+		   (worker_t)&SF0X::cycle_trampoline,
+		   this,
+		   USEC2TICK(SF0X_CONVERSION_INTERVAL));
+}
+
+void
+SF0X::print_info()
+{
+	perf_print_counter(_sample_perf);
+	perf_print_counter(_comms_errors);
+	perf_print_counter(_buffer_overflows);
+	printf("poll interval:  %d ticks\n", _measure_ticks);
+	_reports->print_info("report queue");
+}
+
+/**
+ * Local functions in support of the shell command.
+ */
+namespace sf0x
+{
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+const int ERROR = -1;
+
+SF0X	*g_dev;
+
+void	start();
+void	stop();
+void	test();
+void	reset();
+void	info();
+
+/**
+ * Start the driver.
+ */
+void
+start(const char *port)
+{
+	int fd;
+
+	if (g_dev != nullptr) {
+		errx(1, "already started");
+	}
+
+	/* create the driver */
+	g_dev = new SF0X(port);
+
+	if (g_dev == nullptr) {
+		goto fail;
+	}
+
+	if (OK != g_dev->init()) {
+		goto fail;
+	}
+
+	/* set the poll rate to default, starts automatic data collection */
+	fd = open(RANGE_FINDER_DEVICE_PATH, 0);
+
+	if (fd < 0) {
+		warnx("device open fail");
+		goto fail;
+	}
+
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
+		goto fail;
+	}
+
+	exit(0);
+
+fail:
+
+	if (g_dev != nullptr) {
+		delete g_dev;
+		g_dev = nullptr;
+	}
+
+	errx(1, "driver start failed");
+}
+
+/**
+ * Stop the driver
+ */
+void stop()
+{
+	if (g_dev != nullptr) {
+		delete g_dev;
+		g_dev = nullptr;
+
+	} else {
+		errx(1, "driver not running");
+	}
+
+	exit(0);
+}
+
+/**
+ * Perform some basic functional tests on the driver;
+ * make sure we can collect data from the sensor in polled
+ * and automatic modes.
+ */
+void
+test()
+{
+	struct range_finder_report report;
+	ssize_t sz;
+
+	int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0) {
+		err(1, "%s open failed (try 'sf0x start' if the driver is not running", RANGE_FINDER_DEVICE_PATH);
+	}
+
+	/* do a simple demand read */
+	sz = read(fd, &report, sizeof(report));
+
+	if (sz != sizeof(report)) {
+		err(1, "immediate read failed");
+	}
+
+	warnx("single read");
+	warnx("measurement: %0.2f m", (double)report.distance);
+	warnx("time:        %lld", report.timestamp);
+
+	/* start the sensor polling at 2Hz */
+	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) {
+		errx(1, "failed to set 2Hz poll rate");
+	}
+
+	/* read the sensor 5x and report each value */
+	for (unsigned i = 0; i < 5; i++) {
+		struct pollfd fds;
+
+		/* wait for data to be ready */
+		fds.fd = fd;
+		fds.events = POLLIN;
+		int ret = poll(&fds, 1, 2000);
+
+		if (ret != 1) {
+			errx(1, "timed out waiting for sensor data");
+		}
+
+		/* now go get it */
+		sz = read(fd, &report, sizeof(report));
+
+		if (sz != sizeof(report)) {
+			err(1, "periodic read failed");
+		}
+
+		warnx("periodic read %u", i);
+		warnx("measurement: %0.3f", (double)report.distance);
+		warnx("time:        %lld", report.timestamp);
+	}
+
+	/* reset the sensor polling to default rate */
+	if (OK != ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT)) {
+		errx(1, "failed to set default poll rate");
+	}
+
+	errx(0, "PASS");
+}
+
+/**
+ * Reset the driver.
+ */
+void
+reset()
+{
+	int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0) {
+		err(1, "failed ");
+	}
+
+	if (ioctl(fd, SENSORIOCRESET, 0) < 0) {
+		err(1, "driver reset failed");
+	}
+
+	if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
+		err(1, "driver poll restart failed");
+	}
+
+	exit(0);
+}
+
+/**
+ * Print a little info about the driver.
+ */
+void
+info()
+{
+	if (g_dev == nullptr) {
+		errx(1, "driver not running");
+	}
+
+	printf("state @ %p\n", g_dev);
+	g_dev->print_info();
+
+	exit(0);
+}
+
+} // namespace
+
+int
+sf0x_main(int argc, char *argv[])
+{
+	/*
+	 * Start/load the driver.
+	 */
+	if (!strcmp(argv[1], "start")) {
+		if (argc > 2) {
+			sf0x::start(argv[2]);
+
+		} else {
+			sf0x::start(SF0X_DEFAULT_PORT);
+		}
+	}
+
+	/*
+	 * Stop the driver
+	 */
+	if (!strcmp(argv[1], "stop")) {
+		sf0x::stop();
+	}
+
+	/*
+	 * Test the driver/device.
+	 */
+	if (!strcmp(argv[1], "test")) {
+		sf0x::test();
+	}
+
+	/*
+	 * Reset the driver.
+	 */
+	if (!strcmp(argv[1], "reset")) {
+		sf0x::reset();
+	}
+
+	/*
+	 * Print driver information.
+	 */
+	if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status")) {
+		sf0x::info();
+	}
+
+	errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'");
+}