Maxbotix I2C Sonar Support

8 files changed, 1015 insertions, 1 deletions

diff --git a/apps/drivers/device/i2c.cpp b/apps/drivers/device/i2c.cpp
index a416801eb..c6102a6c1 100644
--- a/apps/drivers/device/i2c.cpp
+++ b/apps/drivers/device/i2c.cpp
@@ -115,6 +115,30 @@ I2C::probe()
 }
 
 int
+I2C::write(const uint8_t *send, unsigned send_len)
+{
+	int ret = OK;
+	
+	I2C_SETFREQUENCY(_dev, _frequency);
+	I2C_SETADDRESS(_dev, _address, 7);
+	ret = I2C_WRITE(_dev, send, send_len);
+	
+	return ret;
+}
+
+int
+I2C::read(uint8_t *recv, unsigned recv_len)
+{
+	int ret = OK;
+	
+	I2C_SETFREQUENCY(_dev, _frequency);
+	I2C_SETADDRESS(_dev, _address, 7);
+	ret = I2C_READ(_dev, recv, recv_len);
+	
+	return ret;
+}
+
+int
 I2C::transfer(const uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len)
 {
 	struct i2c_msg_s msgv[2];
diff --git a/apps/drivers/device/i2c.h b/apps/drivers/device/i2c.h
index 66c34dd7c..874b22301 100644
--- a/apps/drivers/device/i2c.h
+++ b/apps/drivers/device/i2c.h
@@ -86,6 +86,26 @@ protected:
 	virtual int	probe();
 
 	/**
+	 * Perform an I2C write to the device.
+	 *
+	 * @param send		Pointer to bytes to send.
+	 * @param send_len	Number of bytes to send.
+	 * @return		OK if the transfer was successful, -errno
+	 *			otherwise.
+	 */
+	int		write(const uint8_t *send, unsigned send_len);
+	
+	/**
+	 * Perform an I2C read from the device.
+	 *
+	 * @param send		Pointer to bytes to send.
+	 * @param send_len	Number of bytes to send.
+	 * @return		OK if the transfer was successful, -errno
+	 *			otherwise.
+	 */
+	int		read(uint8_t *recv, unsigned recv_len);
+	
+	/**
 	 * Perform an I2C transaction to the device.
 	 *
 	 * At least one of send_len and recv_len must be non-zero.
diff --git a/apps/drivers/drv_range_finder.h b/apps/drivers/drv_range_finder.h
new file mode 100644
index 000000000..420011be5
--- /dev/null
+++ b/apps/drivers/drv_range_finder.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+ *
+ *   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_RANGEFINDER_H
+#define _DRV_RANGEFINDER_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_sensor.h"
+#include "drv_orb_dev.h"
+
+#define RANGE_FINDER_DEVICE_PATH	"/dev/range_finder"
+
+/**
+ * accel report structure.  Reads from the device must be in multiples of this
+ * structure.
+ */
+struct range_finder_report {
+	uint64_t timestamp;
+	float distance; 			/** in meters */
+	uint8_t valid;				/** 1 == within sensor range, 0 = outside sensor range */
+};
+
+/*
+ * ObjDev tag for raw accelerometer data.
+ */
+ORB_DECLARE(sensor_range_finder);
+
+/*
+ * ioctl() definitions
+ *
+ * Accelerometer drivers also implement the generic sensor driver
+ * interfaces from drv_sensor.h
+ */
+
+#define _RANGEFINDERIOCBASE			(0x7900)
+#define __RANGEFINDERIOC(_n)		(_IOC(_RANGEFINDERIOCBASE, _n))
+
+/** set the minimum effective distance of the device */
+#define RANGEFINDERIOCSETMINIUMDISTANCE	__RANGEFINDERIOC(1)
+
+/** set the maximum effective distance of the device */
+#define RANGEFINDERIOCSETMAXIUMDISTANCE	__RANGEFINDERIOC(2)
+
+
+#endif /* _DRV_RANGEFINDER_H */
diff --git a/apps/drivers/mb12xx/Makefile b/apps/drivers/mb12xx/Makefile
new file mode 100644
index 000000000..b5b911be1
--- /dev/null
+++ b/apps/drivers/mb12xx/Makefile
@@ -0,0 +1,42 @@
+############################################################################
+#
+#   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 Maxbotix Sonar driver.
+#
+
+APPNAME		= mb12xx
+PRIORITY	= SCHED_PRIORITY_DEFAULT
+STACKSIZE	= 4096
+
+include $(APPDIR)/mk/app.mk
diff --git a/apps/drivers/mb12xx/mb12xx.cpp b/apps/drivers/mb12xx/mb12xx.cpp
new file mode 100644
index 000000000..d7a3357c8
--- /dev/null
+++ b/apps/drivers/mb12xx/mb12xx.cpp
@@ -0,0 +1,842 @@
+/****************************************************************************
+ *
+ *   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 mb12xx.cpp
+ * @author Greg Hulands
+ *
+ * Driver for the Maxbotix sonar range finders 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 <arch/board/board.h>
+
+#include <systemlib/perf_counter.h>
+#include <systemlib/err.h>
+
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_range_finder.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/subsystem_info.h>
+
+/* Configuration Constants */
+#define MB12XX_BUS 			PX4_I2C_BUS_EXPANSION
+#define MB12XX_BASEADDR 	0x70 /* 7-bit address. 8-bit address is 0xE0 */
+
+/* MB12xx Registers addresses */
+
+#define MB12XX_TAKE_RANGE_REG	0x51		/* Measure range Register */
+#define MB12XX_SET_ADDRESS_1	0xAA		/* Change address 1 Register */
+#define MB12XX_SET_ADDRESS_2	0xA5		/* Change address 2 Register */
+
+/* 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++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+#ifndef CONFIG_SCHED_WORKQUEUE
+# error This requires CONFIG_SCHED_WORKQUEUE.
+#endif
+
+class MB12XX : public device::I2C
+{
+public:
+	MB12XX(int bus = MB12XX_BUS, int address = MB12XX_BASEADDR);
+	~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();
+
+private:
+	float				_min_distance;
+	float				_max_distance;
+	work_s				_work;
+	unsigned			_num_reports;
+	volatile unsigned	_next_report;
+	volatile unsigned	_oldest_report;
+	range_finder_report	*_reports;
+	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.
+	*
+	* @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();
+	
+	/**
+	* Set the min and max distance thresholds if you want the end points of the sensors
+	* range to be bought in at all, otherwise it will use the defaults MB12XX_MIN_DISTANCE
+	* and MB12XX_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);
+	
+	
+};
+
+/* helper macro for handling report buffer indices */
+#define INCREMENT(_x, _lim)	do { _x++; if (_x >= _lim) _x = 0; } while(0)
+
+/*
+ * Driver 'main' command.
+ */
+extern "C" __EXPORT int mb12xx_main(int argc, char *argv[]);
+
+MB12XX::MB12XX(int bus, int address) :
+	I2C("MB12xx", RANGE_FINDER_DEVICE_PATH, bus, address, 100000),
+	_min_distance(MB12XX_MIN_DISTANCE),
+	_max_distance(MB12XX_MAX_DISTANCE),
+	_num_reports(0),
+	_next_report(0),
+	_oldest_report(0),
+	_reports(nullptr),
+	_sensor_ok(false),
+	_measure_ticks(0),
+	_collect_phase(false),
+	_range_finder_topic(-1),
+	_sample_perf(perf_alloc(PC_ELAPSED, "mb12xx_read")),
+	_comms_errors(perf_alloc(PC_COUNT, "mb12xx_comms_errors")),
+	_buffer_overflows(perf_alloc(PC_COUNT, "mb12xx_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));
+}
+
+MB12XX::~MB12XX()
+{
+	/* make sure we are truly inactive */
+	stop();
+
+	/* free any existing reports */
+	if (_reports != nullptr)
+		delete[] _reports;
+}
+
+int
+MB12XX::init()
+{
+	int ret = ERROR;
+
+	/* do I2C init (and probe) first */
+	if (I2C::init() != OK)
+		goto out;
+
+	/* allocate basic report buffers */
+	_num_reports = 2;
+	_reports = new struct range_finder_report[_num_reports];
+
+	if (_reports == nullptr)
+		goto out;
+
+	_oldest_report = _next_report = 0;
+
+	/* get a publish handle on the range finder topic */
+	memset(&_reports[0], 0, sizeof(_reports[0]));
+	_range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &_reports[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 */
+	_sensor_ok = true;
+out:
+	return ret;
+}
+
+int
+MB12XX::probe()
+{
+	// TODO: take a range reading and see if it is between the min and max
+
+	return OK;
+}
+
+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()
+{
+	return _min_distance;
+}
+
+float
+MB12XX::get_maximum_distance()
+{
+	return _max_distance;
+}
+
+int
+MB12XX::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(MB12XX_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(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)
+						start();
+
+					return OK;
+				}
+			}
+		}
+
+	case SENSORIOCGPOLLRATE:
+		if (_measure_ticks == 0)
+			return SENSOR_POLLRATE_MANUAL;
+
+		return (1000 / _measure_ticks);
+
+	case SENSORIOCSQUEUEDEPTH: {
+			/* add one to account for the sentinel in the ring */
+			arg++;
+
+			/* lower bound is mandatory, upper bound is a sanity check */
+			if ((arg < 2) || (arg > 100))
+				return -EINVAL;
+
+			/* allocate new buffer */
+			struct range_finder_report *buf = new struct range_finder_report[arg];
+
+			if (nullptr == buf)
+				return -ENOMEM;
+
+			/* reset the measurement state machine with the new buffer, free the old */
+			stop();
+			delete[] _reports;
+			_num_reports = arg;
+			_reports = buf;
+			start();
+
+			return OK;
+		}
+
+	case SENSORIOCGQUEUEDEPTH:
+		return _num_reports - 1;
+		
+	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 I2C::ioctl(filp, cmd, arg);
+	}
+}
+
+ssize_t
+MB12XX::read(struct file *filp, char *buffer, size_t buflen)
+{
+	unsigned count = buflen / sizeof(struct range_finder_report);
+	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 (_oldest_report != _next_report) {
+				memcpy(buffer, _reports + _oldest_report, sizeof(*_reports));
+				ret += sizeof(_reports[0]);
+				INCREMENT(_oldest_report, _num_reports);
+			}
+		}
+
+		/* if there was no data, warn the caller */
+		return ret ? ret : -EAGAIN;
+	}
+
+	/* manual measurement - run one conversion */
+	/* XXX really it'd be nice to lock against other readers here */
+	do {
+		_oldest_report = _next_report = 0;
+
+		/* trigger a measurement */
+		if (OK != measure()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* wait for it to complete */
+		usleep(MB12XX_CONVERSION_INTERVAL);
+
+		/* run the collection phase */
+		if (OK != collect()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* state machine will have generated a report, copy it out */
+		memcpy(buffer, _reports, sizeof(*_reports));
+		ret = sizeof(*_reports);
+
+	} while (0);
+
+	return ret;
+}
+
+int
+MB12XX::measure()
+{
+	int ret;
+
+	/*
+	 * Send the command to begin a measurement.
+	 */
+	uint8_t cmd[] = {MB12XX_TAKE_RANGE_REG};
+	ret = I2C::write(&cmd[0], 1);
+
+	if (OK != ret)
+	{
+		perf_count(_comms_errors);
+		log("i2c::transfer returned %d", ret);
+		return ret;
+	}
+	ret = OK;
+	
+	return ret;
+}
+
+int
+MB12XX::collect()
+{
+	int	ret = -EIO;
+	
+	/* read from the sensor */
+	uint8_t val[2] = {0, 0};
+	
+	perf_begin(_sample_perf);
+	
+	ret = I2C::read(&val[0], 2);
+	
+	if (ret < 0)
+	{
+		log("error reading from sensor: %d", ret);
+		return ret;
+	}
+	
+	uint16_t distance = val[0] << 8 | val[1];
+	float si_units = (distance * 1.0f)/ 100.0f; /* cm to m */
+	/* this should be fairly close to the end of the measurement, so the best approximation of the time */
+	_reports[_next_report].timestamp = hrt_absolute_time();
+	_reports[_next_report].distance = si_units;
+	_reports[_next_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, &_reports[_next_report]);
+
+	/* post a report to the ring - note, not locked */
+	INCREMENT(_next_report, _num_reports);
+
+	/* if we are running up against the oldest report, toss it */
+	if (_next_report == _oldest_report) {
+		perf_count(_buffer_overflows);
+		INCREMENT(_oldest_report, _num_reports);
+	}
+
+	/* notify anyone waiting for data */
+	poll_notify(POLLIN);
+
+	ret = OK;
+
+out:
+	perf_end(_sample_perf);
+	return ret;
+	
+	return ret;
+}
+
+void
+MB12XX::start()
+{
+	/* reset the report ring and state machine */
+	_collect_phase = false;
+	_oldest_report = _next_report = 0;
+
+	/* 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};
+	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
+MB12XX::stop()
+{
+	work_cancel(HPWORK, &_work);
+}
+
+void
+MB12XX::cycle_trampoline(void *arg)
+{
+	MB12XX *dev = (MB12XX *)arg;
+
+	dev->cycle();
+}
+
+void
+MB12XX::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(MB12XX_CONVERSION_INTERVAL)) {
+
+			/* schedule a fresh cycle call when we are ready to measure again */
+			work_queue(HPWORK,
+				   &_work,
+				   (worker_t)&MB12XX::cycle_trampoline,
+				   this,
+				   _measure_ticks - USEC2TICK(MB12XX_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)&MB12XX::cycle_trampoline,
+		   this,
+		   USEC2TICK(MB12XX_CONVERSION_INTERVAL));
+}
+
+void
+MB12XX::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);
+	printf("report queue:   %u (%u/%u @ %p)\n",
+	       _num_reports, _oldest_report, _next_report, _reports);
+}
+
+/**
+ * Local functions in support of the shell command.
+ */
+namespace mb12xx
+{
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+const int ERROR = -1;
+
+MB12XX	*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 MB12XX(MB12XX_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(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
+
+	if (fd < 0)
+		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 ret;
+
+	int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
+
+	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))
+		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;
+		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);
+	}
+
+	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
+mb12xx_main(int argc, char *argv[])
+{
+	/*
+	 * Start/load the driver.
+	 */
+	if (!strcmp(argv[1], "start"))
+		mb12xx::start();
+	
+	 /*
+	  * Stop the driver
+	  */
+	 if (!strcmp(argv[1], "stop"))
+		 mb12xx::stop();
+
+	/*
+	 * Test the driver/device.
+	 */
+	if (!strcmp(argv[1], "test"))
+		mb12xx::test();
+
+	/*
+	 * Reset the driver.
+	 */
+	if (!strcmp(argv[1], "reset"))
+		mb12xx::reset();
+
+	/*
+	 * Print driver information.
+	 */
+	if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status"))
+		mb12xx::info();
+
+	errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'");
+}
diff --git a/apps/uORB/objects_common.cpp b/apps/uORB/objects_common.cpp
index 3f3476f62..136375140 100644
--- a/apps/uORB/objects_common.cpp
+++ b/apps/uORB/objects_common.cpp
@@ -53,6 +53,9 @@ ORB_DEFINE(sensor_gyro, struct gyro_report);
 #include <drivers/drv_baro.h>
 ORB_DEFINE(sensor_baro, struct baro_report);
 
+#include <drivers/drv_range_finder.h>
+ORB_DEFINE(sensor_range_finder, struct range_finder_report);
+
 #include <drivers/drv_pwm_output.h>
 ORB_DEFINE(output_pwm, struct pwm_output_values);
 
diff --git a/apps/uORB/topics/subsystem_info.h b/apps/uORB/topics/subsystem_info.h
index c3e039d66..c415e832e 100644
--- a/apps/uORB/topics/subsystem_info.h
+++ b/apps/uORB/topics/subsystem_info.h
@@ -71,7 +71,8 @@ enum SUBSYSTEM_TYPE
 	SUBSYSTEM_TYPE_YAWPOSITION = 4096,
 	SUBSYSTEM_TYPE_ALTITUDECONTROL = 16384,
 	SUBSYSTEM_TYPE_POSITIONCONTROL = 32768,
-	SUBSYSTEM_TYPE_MOTORCONTROL = 65536
+	SUBSYSTEM_TYPE_MOTORCONTROL = 65536,
+	SUBSYSTEM_TYPE_RANGEFINDER = 131072
 };
 
 /**
diff --git a/nuttx/configs/px4fmu/nsh/appconfig b/nuttx/configs/px4fmu/nsh/appconfig
index 2bf3283c8..f1f70e228 100644
--- a/nuttx/configs/px4fmu/nsh/appconfig
+++ b/nuttx/configs/px4fmu/nsh/appconfig
@@ -125,6 +125,7 @@ CONFIGURED_APPS += drivers/stm32/adc
 CONFIGURED_APPS += drivers/px4fmu
 CONFIGURED_APPS += drivers/hil
 CONFIGURED_APPS += drivers/gps
+CONFIGURED_APPS += drivers/mb12xx
 
 # Testing stuff
 CONFIGURED_APPS += px4/sensors_bringup