Fresh import of the PX4 firmware sources.

22 files changed, 4656 insertions, 0 deletions

diff --git a/apps/drivers/bma180/Makefile b/apps/drivers/bma180/Makefile
new file mode 100644
index 000000000..cc01b629e
--- /dev/null
+++ b/apps/drivers/bma180/Makefile
@@ -0,0 +1,42 @@
+############################################################################
+#
+#   Copyright (C) 2012 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 BMA180 driver.
+#
+
+APPNAME		 = bma180
+PRIORITY	 = SCHED_PRIORITY_DEFAULT
+STACKSIZE	 = 2048
+
+include $(APPDIR)/mk/app.mk
diff --git a/apps/drivers/bma180/bma180.cpp b/apps/drivers/bma180/bma180.cpp
new file mode 100644
index 000000000..a5d66d86b
--- /dev/null
+++ b/apps/drivers/bma180/bma180.cpp
@@ -0,0 +1,774 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Driver for the Bosch BMA 180 MEMS accelerometer connected via SPI.
+ */
+
+#include <nuttx/config.h>
+
+#include <device/spi.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.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/up_hrt.h>
+
+#include <drivers/drv_accel.h>
+
+extern "C" { __EXPORT int bma180_main(int argc, char *argv[]); }
+
+class BMA180 : public device::SPI
+{
+public:
+	BMA180(int bus, spi_dev_e device);
+	~BMA180();
+
+	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);
+
+	virtual int		open_first(struct file *filp);
+	virtual int		close_last(struct file *filp);
+
+	/**
+	 * Diagnostics - print some basic information about the driver.
+	 */
+	void			print_info();
+
+protected:
+	virtual int		probe();
+
+private:
+
+	struct hrt_call		_call;
+	unsigned		_call_interval;
+
+	unsigned		_num_reports;
+	volatile unsigned	_next_report;
+	volatile unsigned	_oldest_report;
+	struct accel_report	*_reports;
+
+	struct accel_scale	_scale;
+	float			_range_scale;
+
+	unsigned		_reads;
+
+	/**
+	 * Start automatic measurement.
+	 */
+	void			start();
+
+	/**
+	 * Stop automatic measurement.
+	 */
+	void			stop();
+
+	/**
+	 * Static trampoline from the hrt_call context; because we don't have a
+	 * generic hrt wrapper yet.
+	 *
+	 * Called by the HRT in interrupt context at the specified rate if
+	 * automatic polling is enabled.
+	 *
+	 * @param arg		Instance pointer for the driver that is polling.
+	 */
+	static void		measure_trampoline(void *arg);
+
+	/**
+	 * Fetch measurements from the sensor and update the report ring.
+	 */
+	void			measure();
+
+	/**
+	 * Read a register from the BMA180
+	 *
+	 * @param		The register to read.
+	 * @return		The value that was read.
+	 */
+	uint8_t			read_reg(unsigned reg);
+
+	/**
+	 * Write a register in the BMA180
+	 *
+	 * @param reg		The register to write.
+	 * @param value		The new value to write.
+	 */
+	void			write_reg(unsigned reg, uint8_t value);
+
+	/**
+	 * Modify a register in the BMA180
+	 *
+	 * Bits are cleared before bits are set.
+	 *
+	 * @param reg		The register to modify.
+	 * @param clearbits	Bits in the register to clear.
+	 * @param setbits	Bits in the register to set.
+	 */
+	void			modify_reg(unsigned reg, uint8_t clearbits, uint8_t setbits);
+
+	/**
+	 * Set the BMA180 measurement range.
+	 *
+	 * @param max_g		The maximum G value the range must support.
+	 * @return		OK if the value can be supported, -ERANGE otherwise.
+	 */
+	int			set_range(unsigned max_g);
+
+	/**
+	 * Set the BMA180 lowpass filter.
+	 *
+	 * @param frequency	Set the lowpass filter cutoff frequency to no less than
+	 *			this frequency.
+	 * @return		OK if the value can be supported.
+	 */
+	int			set_bandwidth(unsigned frequency);
+};
+
+/* helper macro for handling report buffer indices */
+#define INCREMENT(_x, _lim)	do { _x++; if (_x >= _lim) _x = 0; } while(0)
+
+#define DIR_READ			(1<<7)
+#define DIR_WRITE			(0<<7)
+
+#define ADDR_CHIP_ID			0x00
+#define CHIP_ID				0x03
+
+#define ADDR_ACC_X_LSB			0x02
+#define ADDR_ACC_Y_LSB			0x04
+#define ADDR_ACC_Z_LSB			0x06
+#define ADDR_TEMPERATURE		0x08
+
+#define ADDR_RESET			0x10
+#define SOFT_RESET				0xB6
+
+#define ADDR_BW_TCS			0x20
+#define BW_TCS_BW_MASK				(0xf<<4)
+#define BW_TCS_BW_10HZ				(0<<4)
+#define BW_TCS_BW_20HZ				(1<<4)
+#define BW_TCS_BW_40HZ				(2<<4)
+#define BW_TCS_BW_75HZ				(3<<4)
+#define BW_TCS_BW_150HZ				(4<<4)
+#define BW_TCS_BW_300HZ				(5<<4)
+#define BW_TCS_BW_600HZ				(6<<4)
+#define BW_TCS_BW_1200HZ			(7<<4)
+
+#define ADDR_HIGH_DUR			0x27
+#define HIGH_DUR_DIS_I2C			(1<<0)
+
+#define ADDR_TCO_Z			0x30
+#define TCO_Z_MODE_MASK				0x3
+
+#define ADDR_GAIN_Y			0x33
+#define GAIN_Y_SHADOW_DIS			(1<<0)
+
+#define ADDR_OFFSET_LSB1		0x35
+#define OFFSET_LSB1_RANGE_MASK			(7<<1)
+#define OFFSET_LSB1_RANGE_1G			(0<<1)
+#define OFFSET_LSB1_RANGE_2G			(2<<1)
+#define OFFSET_LSB1_RANGE_3G			(3<<1)
+#define OFFSET_LSB1_RANGE_4G			(4<<1)
+#define OFFSET_LSB1_RANGE_8G			(5<<1)
+#define OFFSET_LSB1_RANGE_16G			(6<<1)
+
+#define ADDR_OFFSET_T			0x37
+#define OFFSET_T_READOUT_12BIT			(1<<0)
+
+/*
+ * Driver 'main' command.
+ */
+extern "C" { int bma180_main(int argc, char *argv[]); }
+
+
+BMA180::BMA180(int bus, spi_dev_e device) :
+	SPI("BMA180", ACCEL_DEVICE_PATH, bus, device, SPIDEV_MODE3, 8000000),
+	_num_reports(0),
+	_next_report(0),
+	_oldest_report(0),
+	_reports(nullptr),
+	_reads(0)
+{
+	// enable debug() calls
+	_debug_enabled = true;
+
+	// default scale factors
+	_scale.x_offset = 0;
+	_scale.x_scale  = 1.0f;
+	_scale.y_offset = 0;
+	_scale.y_scale  = 1.0f;
+	_scale.z_offset = 0;
+	_scale.z_scale  = 1.0f;
+}
+
+BMA180::~BMA180()
+{
+	/* make sure we are truly inactive */
+	stop();
+
+	/* free any existing reports */
+	if (_reports != nullptr)
+		delete[] _reports;
+}
+
+int
+BMA180::init()
+{
+	int ret;
+
+	/* do SPI init (and probe) first */
+	ret = SPI::init();
+
+	/* if probe/setup successful, finish chip init */
+	if (ret == OK) {
+
+		/* perform soft reset (p48) */
+		write_reg(ADDR_RESET, SOFT_RESET);
+
+		/* wait 10us (p49) */
+		usleep(10);
+
+		/* disable I2C interface */
+		modify_reg(ADDR_HIGH_DUR, HIGH_DUR_DIS_I2C, 0);
+
+		/* switch to low-noise mode */
+		modify_reg(ADDR_TCO_Z, TCO_Z_MODE_MASK, 0);
+
+		/* disable 12-bit mode */
+		modify_reg(ADDR_OFFSET_T, OFFSET_T_READOUT_12BIT, 0);
+
+		/* disable shadow-disable mode */
+		modify_reg(ADDR_GAIN_Y, GAIN_Y_SHADOW_DIS, 0);
+	}
+
+	return ret;
+}
+
+int
+BMA180::open_first(struct file *filp)
+{
+	/* reset to manual-poll mode */
+	_call_interval = 0;
+
+	/* allocate basic report buffers */
+	_num_reports = 2;
+	_reports = new struct accel_report[_num_reports];
+	_oldest_report = _next_report = 0;
+
+	/* set default range and lowpass */
+	set_range(4);		/* 4G */
+	set_bandwidth(600);	/* 600Hz */
+
+	return OK;
+}
+
+int
+BMA180::close_last(struct file *filp)
+{
+	/* stop measurement */
+	stop();
+
+	/* free report buffers */
+	if (_reports != nullptr) {
+		delete[] _reports;
+		_num_reports = 0;
+	}
+
+	return OK;
+}
+
+int
+BMA180::probe()
+{
+	if (read_reg(ADDR_CHIP_ID) == CHIP_ID)
+		return OK;
+
+	return -EIO;
+}
+
+ssize_t
+BMA180::read(struct file *filp, char *buffer, size_t buflen)
+{
+	unsigned count = buflen / sizeof(struct accel_report);
+	int ret = 0;
+
+	/* buffer must be large enough */
+	if (count < 1)
+		return -ENOSPC;
+
+	/* if automatic measurement is enabled */
+	if (_call_interval > 0) {
+
+		/*
+		 * While there is space in the caller's buffer, and reports, copy them.
+		 * Note that we may be pre-empted by the measurement code while we are doing this;
+		 * we are careful to avoid racing with it.
+		 */
+		while (count--) {
+			if (_oldest_report != _next_report) {
+				memcpy(buffer, _reports + _oldest_report, sizeof(*_reports));
+				ret += sizeof(_reports[0]);
+				INCREMENT(_oldest_report, _num_reports);
+			}
+		}
+
+		_reads++;
+
+		/* if there was no data, warn the caller */
+		return ret ? ret : -EAGAIN;
+	}
+
+	/* manual measurement */
+	_oldest_report = _next_report = 0;
+	measure();
+
+	/* measurement will have generated a report, copy it out */
+	memcpy(buffer, _reports, sizeof(*_reports));
+	ret = sizeof(*_reports);
+
+	return ret;
+}
+
+int
+BMA180::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+
+	case ACCELIOCSPOLLRATE: {
+			switch (arg) {
+
+				/* switching to manual polling */
+			case ACC_POLLRATE_MANUAL:
+				stop();
+				_call_interval = 0;
+				return OK;
+
+				/* external signalling not supported */
+			case ACC_POLLRATE_EXTERNAL:
+
+				/* zero would be bad */
+			case 0:
+				return -EINVAL;
+
+				/* adjust to a legal polling interval in Hz */
+			default: {
+					/* do we need to start internal polling? */
+					bool want_start = (_call_interval == 0);
+
+					/* convert hz to hrt interval via microseconds */
+					unsigned ticks = 1000000 / arg;
+
+					/* check against maximum sane rate */
+					if (ticks < 1000)
+						return -EINVAL;
+
+					/* update interval for next measurement */
+					/* XXX this is a bit shady, but no other way to adjust... */
+					_call.period = _call_interval;
+
+					/* if we need to start the poll state machine, do it */
+					if (want_start)
+						start();
+
+					return OK;
+				}
+			}
+		}
+
+	case ACCELIOCSQUEUEDEPTH: {
+			/* lower bound is mandatory, upper bound is a sanity check */
+			if ((arg < 2) || (arg > 100))
+				return -EINVAL;
+
+			/* allocate new buffer */
+			struct accel_report *buf = new struct accel_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 ACCELIOCSLOWPASS:
+		return set_bandwidth(arg);
+
+	case ACCELIORANGE:
+		return set_range(arg);
+
+	case ACCELIOCSSAMPLERATE:	/* sensor sample rate is not (really) adjustable */
+	case ACCELIOCSREPORTFORMAT:	/* no alternate report formats */
+		return -EINVAL;
+
+	default:
+		/* give it to the superclass */
+		return SPI::ioctl(filp, cmd, arg);
+	}
+}
+
+uint8_t
+BMA180::read_reg(unsigned reg)
+{
+	uint8_t cmd[2];
+
+	cmd[0] = reg | DIR_READ;
+
+	transfer(cmd, cmd, sizeof(cmd));
+
+	return cmd[1];
+}
+
+void
+BMA180::write_reg(unsigned reg, uint8_t value)
+{
+	uint8_t	cmd[2];
+
+	cmd[0] = reg | DIR_WRITE;
+	cmd[1] = value;
+
+	transfer(cmd, nullptr, sizeof(cmd));
+}
+
+void
+BMA180::modify_reg(unsigned reg, uint8_t clearbits, uint8_t setbits)
+{
+	uint8_t	val;
+
+	val = read_reg(reg);
+	val &= ~clearbits;
+	val |= setbits;
+	write_reg(reg, val);
+}
+
+int
+BMA180::set_range(unsigned max_g)
+{
+	uint8_t rangebits;
+	float rangescale;
+
+	if (max_g > 16) {
+		return -ERANGE;
+
+	} else if (max_g > 8) {		/* 16G */
+		rangebits = OFFSET_LSB1_RANGE_16G;
+		rangescale = 1.98;
+
+	} else if (max_g > 4) {		/* 8G */
+		rangebits = OFFSET_LSB1_RANGE_8G;
+		rangescale = 0.99;
+
+	} else if (max_g > 3) {		/* 4G */
+		rangebits = OFFSET_LSB1_RANGE_4G;
+		rangescale = 0.5;
+
+	} else if (max_g > 2) {		/* 3G */
+		rangebits = OFFSET_LSB1_RANGE_3G;
+		rangescale = 0.38;
+
+	} else if (max_g > 1) {		/* 2G */
+		rangebits = OFFSET_LSB1_RANGE_2G;
+		rangescale = 0.25;
+
+	} else {			/* 1G */
+		rangebits = OFFSET_LSB1_RANGE_1G;
+		rangescale = 0.13;
+	}
+
+	/* adjust sensor configuration */
+	modify_reg(ADDR_OFFSET_LSB1, OFFSET_LSB1_RANGE_MASK, rangebits);
+	_range_scale = rangescale;
+
+	return OK;
+}
+
+int
+BMA180::set_bandwidth(unsigned frequency)
+{
+	uint8_t	bwbits;
+
+	if (frequency > 1200) {
+		return -ERANGE;
+
+	} else if (frequency > 600) {
+		bwbits = BW_TCS_BW_1200HZ;
+
+	} else if (frequency > 300) {
+		bwbits = BW_TCS_BW_600HZ;
+
+	} else if (frequency > 150) {
+		bwbits = BW_TCS_BW_300HZ;
+
+	} else if (frequency > 75) {
+		bwbits = BW_TCS_BW_150HZ;
+
+	} else if (frequency > 40) {
+		bwbits = BW_TCS_BW_75HZ;
+
+	} else if (frequency > 20) {
+		bwbits = BW_TCS_BW_40HZ;
+
+	} else if (frequency > 10) {
+		bwbits = BW_TCS_BW_20HZ;
+
+	} else {
+		bwbits = BW_TCS_BW_10HZ;
+	}
+
+	/* adjust sensor configuration */
+	modify_reg(ADDR_BW_TCS, BW_TCS_BW_MASK, bwbits);
+
+	return OK;
+}
+
+void
+BMA180::start()
+{
+	/* make sure we are stopped first */
+	stop();
+
+	/* reset the report ring */
+	_oldest_report = _next_report = 0;
+
+	/* start polling at the specified rate */
+	hrt_call_every(&_call, 1000, _call_interval, (hrt_callout)&BMA180::measure_trampoline, this);
+}
+
+void
+BMA180::stop()
+{
+	hrt_cancel(&_call);
+}
+
+void
+BMA180::measure_trampoline(void *arg)
+{
+	BMA180 *dev = (BMA180 *)arg;
+
+	/* make another measurement */
+	dev->measure();
+}
+
+void
+BMA180::measure()
+{
+	/*
+	 * This evil is to deal with the stupid layout of the BMA180
+	 * measurement registers vs. the SPI transaction model.
+	 */
+	union {
+		uint8_t bytes[10];
+		uint16_t words[5];
+	} buf;
+
+	/*
+	 * Fetch the full set of measurements from the BMA180 in one pass;
+	 * 7 bytes starting from the X LSB.
+	 */
+	buf.bytes[1] = ADDR_ACC_X_LSB;
+	transfer(&buf.bytes[1], &buf.bytes[1], 8);
+
+	/*
+	 * Adjust and scale results to mg.
+	 *
+	 * Note that we ignore the "new data" bits.  At any time we read, each
+	 * of the axis measurements are the "most recent", even if we've seen
+	 * them before.  There is no good way to synchronise with the internal
+	 * measurement flow without using the external interrupt.
+	 */
+	_reports[_next_report].timestamp = hrt_absolute_time();
+	_reports[_next_report].x = (buf.words[1] >> 2) * _range_scale;
+	_reports[_next_report].y = (buf.words[2] >> 2) * _range_scale;
+	_reports[_next_report].z = (buf.words[3] >> 2) * _range_scale;
+
+	/*
+	 * @todo Apply additional scaling / calibration factors here.
+	 */
+
+	/* post a report to the ring - note, not locked */
+	INCREMENT(_next_report, _num_reports);
+
+	/* if we are running up against the oldest report, fix it */
+	if (_next_report == _oldest_report)
+		INCREMENT(_oldest_report, _num_reports);
+
+	/* notify anyone waiting for data */
+	poll_notify(POLLIN);
+}
+
+void
+BMA180::print_info()
+{
+	printf("reads:          %u\n", _reads);
+	printf("report queue:   %u (%u/%u @ %p)\n",
+	       _num_reports, _oldest_report, _next_report, _reports);
+}
+
+/**
+ * Local functions in support of the shell command.
+ */
+namespace
+{
+
+BMA180	*g_dev;
+
+/*
+ * XXX this should just be part of the generic sensors test...
+ */
+
+int
+test()
+{
+	int fd = -1;
+	struct accel_report report;
+	ssize_t sz;
+	const char *reason = "test OK";
+
+	do {
+
+		/* get the driver */
+		fd = open(ACCEL_DEVICE_PATH, O_RDONLY);
+
+		if (fd < 0) {
+			reason = "can't open driver";
+			break;
+		}
+
+		/* do a simple demand read */
+		sz = read(fd, &report, sizeof(report));
+
+		if (sz != sizeof(report)) {
+			reason = "immediate read failed";
+			break;
+		}
+
+		printf("single read\n");
+		fflush(stdout);
+		printf("time:        %lld\n", report.timestamp);
+		printf("x:           %f\n", report.x);
+		printf("y:           %f\n", report.y);
+		printf("z:           %f\n", report.z);
+
+	} while (0);
+
+	printf("BMA180: %s\n", reason);
+
+	return OK;
+}
+
+int
+info()
+{
+	if (g_dev == nullptr) {
+		fprintf(stderr, "BMA180: driver not running\n");
+		return -ENOENT;
+	}
+
+	printf("state @ %p\n", g_dev);
+	g_dev->print_info();
+
+	return OK;
+}
+
+
+} // namespace
+
+int
+bma180_main(int argc, char *argv[])
+{
+	/*
+	 * Start/load the driver.
+	 *
+	 * XXX it would be nice to have a wrapper for this...
+	 */
+	if (!strcmp(argv[1], "start")) {
+
+		if (g_dev != nullptr) {
+			fprintf(stderr, "BMA180: already loaded\n");
+			return -EBUSY;
+		}
+
+		/* create the driver */
+		g_dev = new BMA180(CONFIG_BMA180_SPI_BUS, (spi_dev_e)CONFIG_BMA180_SPI_DEVICE);
+
+		if (g_dev == nullptr) {
+			fprintf(stderr, "BMA180: driver alloc failed\n");
+			return -ENOMEM;
+		}
+
+		if (OK != g_dev->init()) {
+			fprintf(stderr, "BMA180: driver init failed\n");
+			usleep(100000);
+			delete g_dev;
+			g_dev = nullptr;
+			return -EIO;
+		}
+
+		printf("BMA180: driver started\n");
+		return OK;
+	}
+
+	/*
+	 * Test the driver/device.
+	 */
+	if (!strcmp(argv[1], "test"))
+		return test();
+
+	/*
+	 * Print driver information.
+	 */
+	if (!strcmp(argv[1], "info"))
+		return info();
+
+	fprintf(stderr, "unrecognised command, try 'start', 'test' or 'info'\n");
+	return -EINVAL;
+}
diff --git a/apps/drivers/device/Makefile b/apps/drivers/device/Makefile
new file mode 100644
index 000000000..f7b1fff88
--- /dev/null
+++ b/apps/drivers/device/Makefile
@@ -0,0 +1,38 @@
+############################################################################
+#
+#   Copyright (C) 2012 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.
+#
+############################################################################
+
+#
+# Build the device driver framework.
+#
+
+include $(APPDIR)/mk/app.mk
diff --git a/apps/drivers/device/cdev.cpp b/apps/drivers/device/cdev.cpp
new file mode 100644
index 000000000..6b8bf0c2d
--- /dev/null
+++ b/apps/drivers/device/cdev.cpp
@@ -0,0 +1,396 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Character device base class.
+ */
+
+#include "device.h"
+
+#include <sys/ioctl.h>
+#include <arch/irq.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#ifdef CONFIG_DISABLE_POLL
+# error This driver is not compatible with CONFIG_DISABLE_POLL
+#endif
+
+namespace device
+{
+
+/* how much to grow the poll waiter set each time it has to be increased */
+static const unsigned pollset_increment = 0;
+
+/*
+ * The standard NuttX operation dispatch table can't call C++ member functions
+ * directly, so we have to bounce them through this dispatch table.
+ */
+static int	cdev_open(struct file *filp);
+static int	cdev_close(struct file *filp);
+static ssize_t	cdev_read(struct file *filp, char *buffer, size_t buflen);
+static ssize_t	cdev_write(struct file *filp, const char *buffer, size_t buflen);
+static off_t	cdev_seek(struct file *filp, off_t offset, int whence);
+static int	cdev_ioctl(struct file *filp, int cmd, unsigned long arg);
+static int	cdev_poll(struct file *filp, struct pollfd *fds, bool setup);
+
+/**
+ * Character device indirection table.
+ *
+ * Every cdev we register gets the same function table; we use the private data
+ * field in the inode to store the instance pointer.
+ *
+ * Note that we use the GNU extension syntax here because we don't get designated
+ * initialisers in gcc 4.6.
+ */
+static const struct file_operations cdev_fops = {
+open	: cdev_open,
+close	: cdev_close,
+read	: cdev_read,
+write	: cdev_write,
+seek	: cdev_seek,
+ioctl	: cdev_ioctl,
+poll	: cdev_poll,
+};
+
+CDev::CDev(const char *name,
+	   const char *devname,
+	   int irq) :
+	// base class
+	Device(name, irq),
+	// public
+	// protected
+	// private
+	_devname(devname),
+	_registered(false),
+	_open_count(0)
+{
+	for (unsigned i = 0; i < _max_pollwaiters; i++)
+		_pollset[i] = nullptr;
+}
+
+CDev::~CDev()
+{
+	if (_registered)
+		unregister_driver(_devname);
+}
+
+int
+CDev::init()
+{
+	int ret = OK;
+
+	// base class init first
+	ret = Device::init();
+
+	if (ret != OK)
+		goto out;
+
+	// now register the driver
+	ret = register_driver(_devname, &cdev_fops, 0666, (void *)this);
+
+	if (ret != OK)
+		goto out;
+
+	_registered = true;
+
+out:
+	return ret;
+}
+
+/*
+ * Default implementations of the character device interface
+ */
+int
+CDev::open(struct file *filp)
+{
+	int ret = OK;
+
+	lock();
+	/* increment the open count */
+	_open_count++;
+
+	if (_open_count == 1) {
+
+		/* first-open callback may decline the open */
+		ret = open_first(filp);
+
+		if (ret != OK)
+			_open_count--;
+	}
+
+	unlock();
+
+	return ret;
+}
+
+int
+CDev::open_first(struct file *filp)
+{
+	return OK;
+}
+
+int
+CDev::close(struct file *filp)
+{
+	int ret = OK;
+
+	lock();
+
+	if (_open_count > 0) {
+		/* decrement the open count */
+		_open_count--;
+
+		/* callback cannot decline the close */
+		if (_open_count == 0)
+			ret = close_last(filp);
+
+	} else {
+		ret = -EBADF;
+	}
+
+	unlock();
+
+	return ret;
+}
+
+int
+CDev::close_last(struct file *filp)
+{
+	return OK;
+}
+
+ssize_t
+CDev::read(struct file *filp, char *buffer, size_t buflen)
+{
+	return -ENOSYS;
+}
+
+ssize_t
+CDev::write(struct file *filp, const char *buffer, size_t buflen)
+{
+	return -ENOSYS;
+}
+
+off_t
+CDev::seek(struct file *filp, off_t offset, int whence)
+{
+	return -ENOSYS;
+}
+
+int
+CDev::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+
+		/* fetch a pointer to the driver's private data */
+	case DIOC_GETPRIV:
+		*(void **)(uintptr_t)arg = (void *)this;
+		return OK;
+	}
+
+	return -ENOTTY;
+}
+
+int
+CDev::poll(struct file *filp, struct pollfd *fds, bool setup)
+{
+	int ret = OK;
+
+	/*
+	 * Lock against pollnotify() (and possibly other callers)
+	 */
+	lock();
+
+	if (setup) {
+		/*
+		 * Save the file pointer in the pollfd for the subclass'
+		 * benefit.
+		 */
+		fds->priv = (void *)filp;
+
+		/*
+		 * Handle setup requests.
+		 */
+		ret = store_poll_waiter(fds);
+
+		if (ret == OK) {
+
+			/*
+			 * Check to see whether we should send a poll notification
+			 * immediately.
+			 */
+			fds->revents |= fds->events & poll_state(filp);
+
+			/* yes? post the notification */
+			if (fds->revents != 0)
+				sem_post(fds->sem);
+		}
+
+	} else {
+		/*
+		 * Handle a teardown request.
+		 */
+		ret = remove_poll_waiter(fds);
+	}
+
+	unlock();
+
+	return ret;
+}
+
+void
+CDev::poll_notify(pollevent_t events)
+{
+	/* lock against poll() as well as other wakeups */
+	irqstate_t state = irqsave();
+
+	for (unsigned i = 0; i < _max_pollwaiters; i++)
+		if (nullptr != _pollset[i])
+			poll_notify_one(_pollset[i], events);
+
+	irqrestore(state);
+}
+
+void
+CDev::poll_notify_one(struct pollfd *fds, pollevent_t events)
+{
+	/* update the reported event set */
+	fds->revents |= fds->events & events;
+
+	/* if the state is now interesting, wake the waiter if it's still asleep */
+	/* XXX semcount check here is a vile hack; counting semphores should not be abused as cvars */
+	if ((fds->revents != 0) && (fds->sem->semcount <= 0))
+		sem_post(fds->sem);
+}
+
+pollevent_t
+CDev::poll_state(struct file *filp)
+{
+	/* by default, no poll events to report */
+	return 0;
+}
+
+int
+CDev::store_poll_waiter(struct pollfd *fds)
+{
+	/*
+	 * Look for a free slot.
+	 */
+	for (unsigned i = 0; i < _max_pollwaiters; i++) {
+		if (nullptr == _pollset[i]) {
+
+			/* save the pollfd */
+			_pollset[i] = fds;
+
+			return OK;
+		}
+	}
+
+	return ENOMEM;
+}
+
+int
+CDev::remove_poll_waiter(struct pollfd *fds)
+{
+	for (unsigned i = 0; i < _max_pollwaiters; i++) {
+		if (fds == _pollset[i]) {
+
+			_pollset[i] = nullptr;
+			return OK;
+
+		}
+	}
+
+	puts("poll: bad fd state");
+	return -EINVAL;
+}
+
+static int
+cdev_open(struct file *filp)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->open(filp);
+}
+
+static int
+cdev_close(struct file *filp)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->close(filp);
+}
+
+static ssize_t
+cdev_read(struct file *filp, char *buffer, size_t buflen)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->read(filp, buffer, buflen);
+}
+
+static ssize_t
+cdev_write(struct file *filp, const char *buffer, size_t buflen)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->write(filp, buffer, buflen);
+}
+
+static off_t
+cdev_seek(struct file *filp, off_t offset, int whence)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->seek(filp, offset, whence);
+}
+
+static int
+cdev_ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->ioctl(filp, cmd, arg);
+}
+
+static int
+cdev_poll(struct file *filp, struct pollfd *fds, bool setup)
+{
+	CDev *cdev = (CDev *)(filp->f_inode->i_private);
+
+	return cdev->poll(filp, fds, setup);
+}
+
+} // namespace device
\ No newline at end of file
diff --git a/apps/drivers/device/device.cpp b/apps/drivers/device/device.cpp
new file mode 100644
index 000000000..c14a3234d
--- /dev/null
+++ b/apps/drivers/device/device.cpp
@@ -0,0 +1,225 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Fundamental driver base class for the device framework.
+ */
+
+#include "device.h"
+
+#include <nuttx/arch.h>
+#include <stdio.h>
+#include <unistd.h>
+
+namespace device
+{
+
+/**
+ * Interrupt dispatch table entry.
+ */
+struct irq_entry {
+	int	irq;
+	Device	*owner;
+};
+
+static const unsigned	irq_nentries = 8;		/**< size of the interrupt dispatch table */
+static irq_entry	irq_entries[irq_nentries];	/**< interrupt dispatch table (XXX should be a vector) */
+
+/**
+ * Register an interrupt to a specific device.
+ *
+ * @param irq		The interrupt number to register.
+ * @param owner		The device receiving the interrupt.
+ * @return		OK if the interrupt was registered.
+ */
+static int	register_interrupt(int irq, Device *owner);
+
+/**
+ * Unregister an interrupt.
+ *
+ * @param irq		The previously-registered interrupt to be de-registered.
+ */
+static void	unregister_interrupt(int irq);
+
+/**
+ * Handle an interrupt.
+ *
+ * @param irq		The interrupt being invoked.
+ * @param context	The interrupt register context.
+ * @return		Always returns OK.
+ */
+static int	interrupt(int irq, void *context);
+
+Device::Device(const char *name,
+	       int irq) :
+	// public
+	// protected
+	_name(name),
+	_debug_enabled(false),
+	// private
+	_irq(irq),
+	_irq_attached(false)
+{
+	sem_init(&_lock, 0, 1);
+}
+
+Device::~Device()
+{
+	sem_destroy(&_lock);
+
+	if (_irq_attached)
+		unregister_interrupt(_irq);
+}
+
+int
+Device::init()
+{
+	int ret = OK;
+
+	// If assigned an interrupt, connect it
+	if (_irq) {
+		/* ensure it's disabled */
+		up_disable_irq(_irq);
+
+		/* register */
+		ret = register_interrupt(_irq, this);
+
+		if (ret != OK)
+			goto out;
+
+		_irq_attached = true;
+	}
+
+out:
+	return ret;
+}
+
+void
+Device::interrupt_enable()
+{
+	if (_irq_attached)
+		up_enable_irq(_irq);
+}
+
+void
+Device::interrupt_disable()
+{
+	if (_irq_attached)
+		up_disable_irq(_irq);
+}
+
+void
+Device::interrupt(void *context)
+{
+	// default action is to disable the interrupt so we don't get called again
+	interrupt_disable();
+}
+
+void
+Device::log(const char *fmt, ...)
+{
+	va_list	ap;
+
+	printf("[%s] ", _name);
+	va_start(ap, fmt);
+	vprintf(fmt, ap);
+	va_end(ap);
+	printf("\n");
+	fflush(stdout);
+}
+
+void
+Device::debug(const char *fmt, ...)
+{
+	va_list	ap;
+
+	if (_debug_enabled) {
+		printf("<%s> ", _name);
+		va_start(ap, fmt);
+		vprintf(fmt, ap);
+		va_end(ap);
+		printf("\n");
+		fflush(stdout);
+	}
+}
+
+static int
+register_interrupt(int irq, Device *owner)
+{
+	int ret = -ENOMEM;
+
+	// look for a slot where we can register the interrupt
+	for (unsigned i = 0; i < irq_nentries; i++) {
+		if (irq_entries[i].irq == 0) {
+
+			// great, we could put it here; try attaching it
+			ret = irq_attach(irq, &interrupt);
+
+			if (ret == OK) {
+				irq_entries[i].irq = irq;
+				irq_entries[i].owner = owner;
+			}
+
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static void
+unregister_interrupt(int irq)
+{
+	for (unsigned i = 0; i < irq_nentries; i++) {
+		if (irq_entries[i].irq == irq) {
+			irq_entries[i].irq = 0;
+			irq_entries[i].owner = nullptr;
+		}
+	}
+}
+
+static int
+interrupt(int irq, void *context)
+{
+	for (unsigned i = 0; i < irq_nentries; i++) {
+		if (irq_entries[i].irq == irq) {
+			irq_entries[i].owner->interrupt(context);
+			break;
+		}
+	}
+
+	return OK;
+}
+
+
+} // namespace device
\ No newline at end of file
diff --git a/apps/drivers/device/device.h b/apps/drivers/device/device.h
new file mode 100644
index 000000000..98dbf8bfb
--- /dev/null
+++ b/apps/drivers/device/device.h
@@ -0,0 +1,439 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Definitions for the generic base classes in the device framework.
+ */
+
+#ifndef _DEVICE_DEVICE_H
+#define _DEVICE_DEVICE_H
+
+/*
+ * Includes here should only cover the needs of the framework definitions.
+ */
+#include <nuttx/config.h>
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <poll.h>
+
+#include <nuttx/fs/fs.h>
+
+/**
+ * Namespace encapsulating all device framework classes, functions and data.
+ */
+namespace device __EXPORT 
+{
+
+/**
+ * Fundamental base class for all device drivers.
+ *
+ * This class handles the basic "being a driver" things, including
+ * interrupt registration and dispatch.
+ */
+class __EXPORT Device
+{
+public:
+	/**
+	 * Interrupt handler.
+	 */
+	virtual void	interrupt(void *ctx);	/**< interrupt handler */
+
+protected:
+	const char	*_name;			/**< driver name */
+	bool		_debug_enabled;		/**< if true, debug messages are printed */
+
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param irq		Interrupt assigned to the device.
+	 */
+	Device(const char *name,
+	       int irq = 0);
+	~Device();
+
+	/**
+	 * Initialise the driver and make it ready for use.
+	 *
+	 * @return	OK if the driver initialised OK.
+	 */
+	virtual int	init();
+
+	/**
+	 * Enable the device interrupt
+	 */
+	void		interrupt_enable();
+
+	/**
+	 * Disable the device interrupt
+	 */
+	void		interrupt_disable();
+
+	/**
+	 * Take the driver lock.
+	 *
+	 * Each driver instance has its own lock/semaphore.
+	 *
+	 * Note that we must loop as the wait may be interrupted by a signal.
+	 */
+	void		lock() {
+		do {} while (sem_wait(&_lock) != 0);
+	}
+
+	/**
+	 * Release the driver lock.
+	 */
+	void		unlock() {
+		sem_post(&_lock);
+	}
+
+	/**
+	 * Log a message.
+	 *
+	 * The message is prefixed with the driver name, and followed
+	 * by a newline.
+	 */
+	void		log(const char *fmt, ...);
+
+	/**
+	 * Print a debug message.
+	 *
+	 * The message is prefixed with the driver name, and followed
+	 * by a newline.
+	 */
+	void		debug(const char *fmt, ...);
+
+private:
+	int		_irq;
+	bool		_irq_attached;
+	sem_t		_lock;
+
+	/** disable copy construction for this and all subclasses */
+	Device(const Device &);
+
+	/** disable assignment for this and all subclasses */
+	Device &operator = (const Device &);
+
+	/**
+	 * Register ourselves as a handler for an interrupt
+	 *
+	 * @param irq		The interrupt to claim
+	 * @return		OK if the interrupt was registered
+	 */
+	int		dev_register_interrupt(int irq);
+
+	/**
+	 * Unregister ourselves as a handler for any interrupt
+	 */
+	void		dev_unregister_interrupt();
+
+	/**
+	 * Interrupt dispatcher
+	 *
+	 * @param irq		The interrupt that has been triggered.
+	 * @param context	Pointer to the interrupted context.
+	 */
+	static void	dev_interrupt(int irq, void *context);
+};
+
+/**
+ * Abstract class for any character device
+ */
+class __EXPORT CDev : public Device
+{
+public:
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param devname	Device node name
+	 * @param irq		Interrupt assigned to the device
+	 */
+	CDev(const char *name, const char *devname, int irq = 0);
+
+	/**
+	 * Destructor
+	 */
+	~CDev();
+
+	virtual int	init();
+
+	/**
+	 * Handle an open of the device.
+	 *
+	 * This function is called for every open of the device. The default
+	 * implementation maintains _open_count and always returns OK.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the open is allowed, -errno otherwise.
+	 */
+	virtual int	open(struct file *filp);
+
+	/**
+	 * Handle a close of the device.
+	 *
+	 * This function is called for every close of the device. The default
+	 * implementation maintains _open_count and returns OK as long as it is not zero.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the close was successful, -errno otherwise.
+	 */
+	virtual int	close(struct file *filp);
+
+	/**
+	 * Perform a read from the device.
+	 *
+	 * The default implementation returns -ENOSYS.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param buffer	Pointer to the buffer into which data should be placed.
+	 * @param buflen	The number of bytes to be read.
+	 * @return		The number of bytes read or -errno otherwise.
+	 */
+	virtual ssize_t	read(struct file *filp, char *buffer, size_t buflen);
+
+	/**
+	 * Perform a write to the device.
+	 *
+	 * The default implementation returns -ENOSYS.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param buffer	Pointer to the buffer from which data should be read.
+	 * @param buflen	The number of bytes to be written.
+	 * @return		The number of bytes written or -errno otherwise.
+	 */
+	virtual ssize_t	write(struct file *filp, const char *buffer, size_t buflen);
+
+	/**
+	 * Perform a logical seek operation on the device.
+	 *
+	 * The default implementation returns -ENOSYS.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param offset	The new file position relative to whence.
+	 * @param whence	SEEK_OFS, SEEK_CUR or SEEK_END.
+	 * @return		The previous offset, or -errno otherwise.
+	 */
+	virtual off_t	seek(struct file *filp, off_t offset, int whence);
+
+	/**
+	 * Perform an ioctl operation on the device.
+	 *
+	 * The default implementation handles DIOC_GETPRIV, and otherwise
+	 * returns -ENOTTY. Subclasses should call the default implementation
+	 * for any command they do not handle themselves.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param cmd		The ioctl command value.
+	 * @param arg		The ioctl argument value.
+	 * @return		OK on success, or -errno otherwise.
+	 */
+	virtual int	ioctl(struct file *filp, int cmd, unsigned long arg);
+
+	/**
+	 * Perform a poll setup/teardown operation.
+	 *
+	 * This is handled internally and should not normally be overridden.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param fds		Poll descriptor being waited on.
+	 * @param arg		True if this is establishing a request, false if
+	 *			it is being torn down.
+	 * @return		OK on success, or -errno otherwise.
+	 */
+	virtual int	poll(struct file *filp, struct pollfd *fds, bool setup);
+
+       /**
+        * Test whether the device is currently open.
+        *
+        * This can be used to avoid tearing down a device that is still active.
+        *
+        * @return              True if the device is currently open.
+        */
+       bool            is_open() { return _open_count > 0; }
+
+protected:
+	/**
+	 * Check the current state of the device for poll events from the
+	 * perspective of the file.
+	 *
+	 * This function is called by the default poll() implementation when
+	 * a poll is set up to determine whether the poll should return immediately.
+	 *
+	 * The default implementation returns no events.
+	 *
+	 * @param filp		The file that's interested.
+	 * @return		The current set of poll events.
+	 */
+	virtual pollevent_t poll_state(struct file *filp);
+
+	/**
+	 * Report new poll events.
+	 *
+	 * This function should be called anytime the state of the device changes
+	 * in a fashion that might be interesting to a poll waiter.
+	 *
+	 * @param events	The new event(s) being announced.
+	 */
+	virtual void	poll_notify(pollevent_t events);
+
+	/**
+	 * Internal implementation of poll_notify.
+	 *
+	 * @param fds		A poll waiter to notify.
+	 * @param events	The event(s) to send to the waiter.
+	 */
+	virtual void	poll_notify_one(struct pollfd *fds, pollevent_t events);
+
+	/**
+	 * Notification of the first open.
+	 *
+	 * This function is called when the device open count transitions from zero
+	 * to one.  The driver lock is held for the duration of the call.
+	 *
+	 * The default implementation returns OK.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the open should proceed, -errno otherwise.
+	 */
+	virtual int	open_first(struct file *filp);
+
+	/**
+	 * Notification of the last close.
+	 *
+	 * This function is called when the device open count transitions from
+	 * one to zero.  The driver lock is held for the duration of the call.
+	 *
+	 * The default implementation returns OK.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the open should return OK, -errno otherwise.
+	 */
+	virtual int	close_last(struct file *filp);
+
+private:
+	static const unsigned _max_pollwaiters = 8;
+
+	const char	*_devname;		/**< device node name */
+	bool		_registered;		/**< true if device name was registered */
+	unsigned	_open_count;		/**< number of successful opens */
+
+	struct pollfd	*_pollset[_max_pollwaiters];
+
+	/**
+	 * Store a pollwaiter in a slot where we can find it later.
+	 *
+	 * Expands the pollset as required.  Must be called with the driver locked.
+	 *
+	 * @return		OK, or -errno on error.
+	 */
+	int		store_poll_waiter(struct pollfd *fds);
+
+	/**
+	 * Remove a poll waiter.
+	 *
+	 * @return		OK, or -errno on error.
+	 */
+	int		remove_poll_waiter(struct pollfd *fds);
+};
+
+/**
+ * Abstract class for character device accessed via PIO
+ */
+class __EXPORT PIO : public CDev
+{
+public:
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param devname	Device node name
+	 * @param base		Base address of the device PIO area
+	 * @param irq		Interrupt assigned to the device (or zero if none)
+	 */
+	PIO(const char *name,
+	    const char *devname,
+	    uint32_t base,
+	    int irq = 0);
+	~PIO();
+
+	int		init();
+
+protected:
+
+	/**
+	 * Read a register
+	 *
+	 * @param offset	Register offset in bytes from the base address.
+	 */
+	uint32_t reg(uint32_t offset) {
+		return *(volatile uint32_t *)(_base + offset);
+	}
+
+	/**
+	 * Write a register
+	 *
+	 * @param offset	Register offset in bytes from the base address.
+	 * @param value	Value to write.
+	 */
+	void		reg(uint32_t offset, uint32_t value) {
+		*(volatile uint32_t *)(_base + offset) = value;
+	}
+
+	/**
+	 * Modify a register
+	 *
+	 * Note that there is a risk of a race during the read/modify/write cycle
+	 * that must be taken care of by the caller.
+	 *
+	 * @param offset	Register offset in bytes from the base address.
+	 * @param clearbits	Bits to clear in the register
+	 * @param setbits	Bits to set in the register
+	 */
+	void		modify(uint32_t offset, uint32_t clearbits, uint32_t setbits) {
+		uint32_t val = reg(offset);
+		val &= ~clearbits;
+		val |= setbits;
+		reg(offset, val);
+	}
+
+private:
+	uint32_t	_base;
+};
+
+} // namespace device
+
+#endif /* _DEVICE_DEVICE_H */
\ No newline at end of file
diff --git a/apps/drivers/device/device.h.orig b/apps/drivers/device/device.h.orig
new file mode 100644
index 000000000..5030666e1
--- /dev/null
+++ b/apps/drivers/device/device.h.orig
@@ -0,0 +1,430 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Definitions for the generic base classes in the device framework.
+ */
+
+#ifndef _DEVICE_DEVICE_H
+#define _DEVICE_DEVICE_H
+
+/*
+ * Includes here should only cover the needs of the framework definitions.
+ */
+#include <nuttx/config.h>
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <poll.h>
+
+#include <nuttx/fs/fs.h>
+
+/**
+ * Namespace encapsulating all device framework classes, functions and data.
+ */
+namespace device __EXPORT 
+{
+
+/**
+ * Fundamental base class for all device drivers.
+ *
+ * This class handles the basic "being a driver" things, including
+ * interrupt registration and dispatch.
+ */
+class __EXPORT Device
+{
+public:
+	/**
+	 * Interrupt handler.
+	 */
+	virtual void	interrupt(void *ctx);	/**< interrupt handler */
+
+protected:
+	const char	*_name;			/**< driver name */
+	bool		_debug_enabled;		/**< if true, debug messages are printed */
+
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param irq		Interrupt assigned to the device.
+	 */
+	Device(const char *name,
+	       int irq = 0);
+	~Device();
+
+	/**
+	 * Initialise the driver and make it ready for use.
+	 *
+	 * @return	OK if the driver initialised OK.
+	 */
+	virtual int	init();
+
+	/**
+	 * Enable the device interrupt
+	 */
+	void		interrupt_enable();
+
+	/**
+	 * Disable the device interrupt
+	 */
+	void		interrupt_disable();
+
+	/**
+	 * Take the driver lock.
+	 *
+	 * Each driver instance has its own lock/semaphore.
+	 *
+	 * Note that we must loop as the wait may be interrupted by a signal.
+	 */
+	void		lock() {
+		do {} while (sem_wait(&_lock) != 0);
+	}
+
+	/**
+	 * Release the driver lock.
+	 */
+	void		unlock() {
+		sem_post(&_lock);
+	}
+
+	/**
+	 * Log a message.
+	 *
+	 * The message is prefixed with the driver name, and followed
+	 * by a newline.
+	 */
+	void		log(const char *fmt, ...);
+
+	/**
+	 * Print a debug message.
+	 *
+	 * The message is prefixed with the driver name, and followed
+	 * by a newline.
+	 */
+	void		debug(const char *fmt, ...);
+
+private:
+	int		_irq;
+	bool		_irq_attached;
+	sem_t		_lock;
+
+	/** disable copy construction for this and all subclasses */
+	Device(const Device &);
+
+	/** disable assignment for this and all subclasses */
+	Device &operator = (const Device &);
+
+	/**
+	 * Register ourselves as a handler for an interrupt
+	 *
+	 * @param irq		The interrupt to claim
+	 * @return		OK if the interrupt was registered
+	 */
+	int		dev_register_interrupt(int irq);
+
+	/**
+	 * Unregister ourselves as a handler for any interrupt
+	 */
+	void		dev_unregister_interrupt();
+
+	/**
+	 * Interrupt dispatcher
+	 *
+	 * @param irq		The interrupt that has been triggered.
+	 * @param context	Pointer to the interrupted context.
+	 */
+	static void	dev_interrupt(int irq, void *context);
+};
+
+/**
+ * Abstract class for any character device
+ */
+class __EXPORT CDev : public Device
+{
+public:
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param devname	Device node name
+	 * @param irq		Interrupt assigned to the device
+	 */
+	CDev(const char *name, const char *devname, int irq = 0);
+
+	/**
+	 * Destructor
+	 */
+	~CDev();
+
+	virtual int	init();
+
+	/**
+	 * Handle an open of the device.
+	 *
+	 * This function is called for every open of the device. The default
+	 * implementation maintains _open_count and always returns OK.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the open is allowed, -errno otherwise.
+	 */
+	virtual int	open(struct file *filp);
+
+	/**
+	 * Handle a close of the device.
+	 *
+	 * This function is called for every close of the device. The default
+	 * implementation maintains _open_count and returns OK as long as it is not zero.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the close was successful, -errno otherwise.
+	 */
+	virtual int	close(struct file *filp);
+
+	/**
+	 * Perform a read from the device.
+	 *
+	 * The default implementation returns -ENOSYS.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param buffer	Pointer to the buffer into which data should be placed.
+	 * @param buflen	The number of bytes to be read.
+	 * @return		The number of bytes read or -errno otherwise.
+	 */
+	virtual ssize_t	read(struct file *filp, char *buffer, size_t buflen);
+
+	/**
+	 * Perform a write to the device.
+	 *
+	 * The default implementation returns -ENOSYS.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param buffer	Pointer to the buffer from which data should be read.
+	 * @param buflen	The number of bytes to be written.
+	 * @return		The number of bytes written or -errno otherwise.
+	 */
+	virtual ssize_t	write(struct file *filp, const char *buffer, size_t buflen);
+
+	/**
+	 * Perform a logical seek operation on the device.
+	 *
+	 * The default implementation returns -ENOSYS.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param offset	The new file position relative to whence.
+	 * @param whence	SEEK_OFS, SEEK_CUR or SEEK_END.
+	 * @return		The previous offset, or -errno otherwise.
+	 */
+	virtual off_t	seek(struct file *filp, off_t offset, int whence);
+
+	/**
+	 * Perform an ioctl operation on the device.
+	 *
+	 * The default implementation handles DIOC_GETPRIV, and otherwise
+	 * returns -ENOTTY. Subclasses should call the default implementation
+	 * for any command they do not handle themselves.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param cmd		The ioctl command value.
+	 * @param arg		The ioctl argument value.
+	 * @return		OK on success, or -errno otherwise.
+	 */
+	virtual int	ioctl(struct file *filp, int cmd, unsigned long arg);
+
+	/**
+	 * Perform a poll setup/teardown operation.
+	 *
+	 * This is handled internally and should not normally be overridden.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @param fds		Poll descriptor being waited on.
+	 * @param arg		True if this is establishing a request, false if
+	 *			it is being torn down.
+	 * @return		OK on success, or -errno otherwise.
+	 */
+	virtual int	poll(struct file *filp, struct pollfd *fds, bool setup);
+
+protected:
+	/**
+	 * Check the current state of the device for poll events from the
+	 * perspective of the file.
+	 *
+	 * This function is called by the default poll() implementation when
+	 * a poll is set up to determine whether the poll should return immediately.
+	 *
+	 * The default implementation returns no events.
+	 *
+	 * @param filp		The file that's interested.
+	 * @return		The current set of poll events.
+	 */
+	virtual pollevent_t poll_state(struct file *filp);
+
+	/**
+	 * Report new poll events.
+	 *
+	 * This function should be called anytime the state of the device changes
+	 * in a fashion that might be interesting to a poll waiter.
+	 *
+	 * @param events	The new event(s) being announced.
+	 */
+	virtual void	poll_notify(pollevent_t events);
+
+	/**
+	 * Internal implementation of poll_notify.
+	 *
+	 * @param fds		A poll waiter to notify.
+	 * @param events	The event(s) to send to the waiter.
+	 */
+	virtual void	poll_notify_one(struct pollfd *fds, pollevent_t events);
+
+	/**
+	 * Notification of the first open.
+	 *
+	 * This function is called when the device open count transitions from zero
+	 * to one.  The driver lock is held for the duration of the call.
+	 *
+	 * The default implementation returns OK.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the open should proceed, -errno otherwise.
+	 */
+	virtual int	open_first(struct file *filp);
+
+	/**
+	 * Notification of the last close.
+	 *
+	 * This function is called when the device open count transitions from
+	 * one to zero.  The driver lock is held for the duration of the call.
+	 *
+	 * The default implementation returns OK.
+	 *
+	 * @param filp		Pointer to the NuttX file structure.
+	 * @return		OK if the open should return OK, -errno otherwise.
+	 */
+	virtual int	close_last(struct file *filp);
+
+private:
+	static const unsigned _max_pollwaiters = 8;
+
+	const char	*_devname;		/**< device node name */
+	bool		_registered;		/**< true if device name was registered */
+	unsigned	_open_count;		/**< number of successful opens */
+
+	struct pollfd	*_pollset[_max_pollwaiters];
+
+	/**
+	 * Store a pollwaiter in a slot where we can find it later.
+	 *
+	 * Expands the pollset as required.  Must be called with the driver locked.
+	 *
+	 * @return		OK, or -errno on error.
+	 */
+	int		store_poll_waiter(struct pollfd *fds);
+
+	/**
+	 * Remove a poll waiter.
+	 *
+	 * @return		OK, or -errno on error.
+	 */
+	int		remove_poll_waiter(struct pollfd *fds);
+};
+
+/**
+ * Abstract class for character device accessed via PIO
+ */
+class __EXPORT PIO : public CDev
+{
+public:
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param devname	Device node name
+	 * @param base		Base address of the device PIO area
+	 * @param irq		Interrupt assigned to the device (or zero if none)
+	 */
+	PIO(const char *name,
+	    const char *devname,
+	    uint32_t base,
+	    int irq = 0);
+	~PIO();
+
+	int		init();
+
+protected:
+
+	/**
+	 * Read a register
+	 *
+	 * @param offset	Register offset in bytes from the base address.
+	 */
+	uint32_t reg(uint32_t offset) {
+		return *(volatile uint32_t *)(_base + offset);
+	}
+
+	/**
+	 * Write a register
+	 *
+	 * @param offset	Register offset in bytes from the base address.
+	 * @param value	Value to write.
+	 */
+	void		reg(uint32_t offset, uint32_t value) {
+		*(volatile uint32_t *)(_base + offset) = value;
+	}
+
+	/**
+	 * Modify a register
+	 *
+	 * Note that there is a risk of a race during the read/modify/write cycle
+	 * that must be taken care of by the caller.
+	 *
+	 * @param offset	Register offset in bytes from the base address.
+	 * @param clearbits	Bits to clear in the register
+	 * @param setbits	Bits to set in the register
+	 */
+	void		modify(uint32_t offset, uint32_t clearbits, uint32_t setbits) {
+		uint32_t val = reg(offset);
+		val &= ~clearbits;
+		val |= setbits;
+		reg(offset, val);
+	}
+
+private:
+	uint32_t	_base;
+};
+
+} // namespace device
+
+#endif /* _DEVICE_DEVICE_H */
\ No newline at end of file
diff --git a/apps/drivers/device/i2c.cpp b/apps/drivers/device/i2c.cpp
new file mode 100644
index 000000000..8489db4bb
--- /dev/null
+++ b/apps/drivers/device/i2c.cpp
@@ -0,0 +1,149 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Base class for devices attached via the I2C bus.
+ *
+ * @todo Bus frequency changes; currently we do nothing with the value
+ *       that is supplied.  Should we just depend on the bus knowing?
+ */
+
+#include "i2c.h"
+
+namespace device
+{
+
+I2C::I2C(const char *name,
+	 const char *devname,
+	 int bus,
+	 uint16_t address,
+	 uint32_t frequency,
+	 int irq) :
+	// base class
+	CDev(name, devname, irq),
+	// public
+	// protected
+	// private
+	_bus(bus),
+	_address(address),
+	_frequency(frequency),
+	_dev(nullptr)
+{
+}
+
+I2C::~I2C()
+{
+	if (_dev)
+		up_i2cuninitialize(_dev);
+}
+
+int
+I2C::init()
+{
+	int ret = OK;
+
+	// attach to the i2c bus
+	_dev = up_i2cinitialize(_bus);
+
+	if (_dev == nullptr) {
+		debug("failed to init I2C");
+		ret = -ENOENT;
+		goto out;
+	}
+
+	// call the probe function to check whether the device is present
+	ret = probe();
+
+	if (ret != OK) {
+		debug("probe failed");
+		goto out;
+	}
+
+	// do base class init, which will create device node, etc
+	ret = CDev::init();
+
+	if (ret != OK) {
+		debug("cdev init failed");
+		goto out;
+	}
+
+	// tell the world where we are
+	log("on bus %d at 0x%02x", _bus, _address);
+
+out:
+	return ret;
+}
+
+int
+I2C::probe()
+{
+	// Assume the device is too stupid to be discoverable.
+	return OK;
+}
+
+int
+I2C::transfer(uint8_t *send, unsigned send_len, uint8_t *recv, unsigned recv_len)
+{
+	struct i2c_msg_s msgv[2];
+	unsigned msgs;
+	int ret;
+
+//	debug("transfer out %p/%u  in %p/%u", send, send_len, recv, recv_len);
+
+	msgs = 0;
+
+	if (send_len > 0) {
+		msgv[msgs].addr = _address;
+		msgv[msgs].flags = 0;
+		msgv[msgs].buffer = send;
+		msgv[msgs].length = send_len;
+		msgs++;
+	}
+
+	if (recv_len > 0) {
+		msgv[msgs].addr = _address;
+		msgv[msgs].flags = I2C_M_READ;
+		msgv[msgs].buffer = recv;
+		msgv[msgs].length = recv_len;
+		msgs++;
+	}
+
+	if (msgs == 0)
+		return -EINVAL;
+
+	ret = I2C_TRANSFER(_dev, &msgv[0], msgs);
+
+	return ret;
+}
+
+} // namespace device
\ No newline at end of file
diff --git a/apps/drivers/device/i2c.h b/apps/drivers/device/i2c.h
new file mode 100644
index 000000000..d84f7bd09
--- /dev/null
+++ b/apps/drivers/device/i2c.h
@@ -0,0 +1,116 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Base class for devices connected via I2C.
+ */
+
+#ifndef _DEVICE_I2C_H
+#define _DEVICE_I2C_H
+
+#include "device.h"
+
+#include <nuttx/i2c.h>
+
+namespace device __EXPORT 
+{
+
+/**
+ * Abstract class for character device on I2C
+ */
+class __EXPORT I2C : public CDev
+{
+
+protected:
+	/**
+	 * @ Constructor
+	 *
+	 * @param name		Driver name
+	 * @param devname	Device node name
+	 * @param bus		I2C bus on which the device lives
+	 * @param address	I2C bus address, or zero if set_address will be used
+	 * @param frequency	I2C bus frequency for the device (currently not used)
+	 * @param irq		Interrupt assigned to the device (or zero if none)
+	 */
+	I2C(const char *name,
+	    const char *devname,
+	    int bus,
+	    uint16_t address,
+	    uint32_t frequency,
+	    int irq = 0);
+	~I2C();
+
+	virtual int	init();
+
+	/**
+	 * Check for the presence of the device on the bus.
+	 */
+	virtual int	probe();
+
+	/**
+	 * Perform an I2C transaction to the device.
+	 *
+	 * At least one of send_len and recv_len must be non-zero.
+	 *
+	 * @param send		Pointer to bytes to send.
+	 * @param send_len	Number of bytes to send.
+	 * @param recv		Pointer to buffer for bytes received.
+	 * @param recv_len	Number of bytes to receive.
+	 * @return		OK if the transfer was successful, -errno
+	 *			otherwise.
+	 */
+	int		transfer(uint8_t *send, unsigned send_len,
+				 uint8_t *recv, unsigned recv_len);
+
+	/**
+	 * Change the bus address.
+	 *
+	 * Most often useful during probe() when the driver is testing
+	 * several possible bus addresses.
+	 *
+	 * @param address	The new bus address to set.
+	 */
+	void		set_address(uint16_t address) {
+		_address = address;
+	}
+
+private:
+	int			_bus;
+	uint16_t		_address;
+	uint32_t		_frequency;
+	struct i2c_dev_s	*_dev;
+};
+
+} // namespace device
+
+#endif /* _DEVICE_I2C_H */
diff --git a/apps/drivers/device/pio.cpp b/apps/drivers/device/pio.cpp
new file mode 100644
index 000000000..5179752b5
--- /dev/null
+++ b/apps/drivers/device/pio.cpp
@@ -0,0 +1,72 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Base class for devices accessed via PIO to registers.
+ */
+
+#include "device.h"
+
+namespace device
+{
+
+PIO::PIO(const char *name,
+	 const char *devname,
+	 uint32_t base,
+	 int irq) :
+	// base class
+	CDev(name, devname, irq),
+	// public
+	// protected
+	// private
+	_base(base)
+{
+}
+
+PIO::~PIO()
+{
+	// nothing to do here...
+}
+
+int
+PIO::init()
+{
+	int ret = OK;
+
+	// base class init first
+	ret = CDev::init();
+
+	return ret;
+}
+
+} // namespace device
\ No newline at end of file
diff --git a/apps/drivers/device/spi.cpp b/apps/drivers/device/spi.cpp
new file mode 100644
index 000000000..d0647bef6
--- /dev/null
+++ b/apps/drivers/device/spi.cpp
@@ -0,0 +1,142 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Base class for devices connected via SPI.
+ *
+ * @todo Work out if caching the mode/frequency would save any time.
+ */
+
+#include "spi.h"
+
+#ifndef CONFIG_SPI_EXCHANGE
+# error This driver requires CONFIG_SPI_EXCHANGE
+#endif
+
+namespace device
+{
+
+SPI::SPI(const char *name,
+	 const char *devname,
+	 int bus,
+	 enum spi_dev_e device,
+	 enum spi_mode_e mode,
+	 uint32_t frequency,
+	 int irq) :
+	// base class
+	CDev(name, devname, irq),
+	// public
+	// protected
+	// private
+	_bus(bus),
+	_device(device),
+	_mode(mode),
+	_frequency(frequency),
+	_dev(nullptr)
+{
+}
+
+SPI::~SPI()
+{
+	// XXX no way to let go of the bus...
+}
+
+int
+SPI::init()
+{
+	int ret = OK;
+
+	// attach to the spi bus
+	if (_dev == nullptr)
+		_dev = up_spiinitialize(_bus);
+
+	if (_dev == nullptr) {
+		debug("failed to init SPI");
+		ret = -ENOENT;
+		goto out;
+	}
+
+	// call the probe function to check whether the device is present
+	ret = probe();
+
+	if (ret != OK) {
+		debug("probe failed");
+		goto out;
+	}
+
+	// do base class init, which will create the device node, etc.
+	ret = CDev::init();
+
+	if (ret != OK) {
+		debug("cdev init failed");
+		goto out;
+	}
+
+	// tell the workd where we are
+	log("on bus %d at %d", _bus, _device);
+
+out:
+	return ret;
+}
+
+int
+SPI::probe()
+{
+	// assume the device is too stupid to be discoverable
+	return OK;
+}
+
+int
+SPI::transfer(uint8_t *send, uint8_t *recv, unsigned len)
+{
+
+	if ((send == nullptr) && (recv == nullptr))
+		return -EINVAL;
+
+	/* do common setup */
+	SPI_LOCK(_dev, true);
+	SPI_SETFREQUENCY(_dev, _frequency);
+	SPI_SETMODE(_dev, _mode);
+	SPI_SELECT(_dev, _device, true);
+
+	/* do the transfer */
+	SPI_EXCHANGE(_dev, send, recv, len);
+
+	/* and clean up */
+	SPI_SELECT(_dev, _device, false);
+	SPI_LOCK(_dev, false);
+
+	return OK;
+}
+
+} // namespace device
\ No newline at end of file
diff --git a/apps/drivers/device/spi.h b/apps/drivers/device/spi.h
new file mode 100644
index 000000000..ef382b03c
--- /dev/null
+++ b/apps/drivers/device/spi.h
@@ -0,0 +1,106 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Base class for devices connected via SPI.
+ */
+
+#ifndef _DEVICE_SPI_H
+#define _DEVICE_SPI_H
+
+#include "device.h"
+
+#include <nuttx/spi.h>
+
+namespace device __EXPORT
+{
+
+/**
+ * Abstract class for character device on SPI
+ */
+class __EXPORT SPI : public CDev
+{
+protected:
+	/**
+	 * Constructor
+	 *
+	 * @param name		Driver name
+	 * @param devname	Device node name
+	 * @param bus		SPI bus on which the device lives
+	 * @param device	Device handle (used by SPI_SELECT)
+	 * @param mode		SPI clock/data mode
+	 * @param frequency	SPI clock frequency
+	 * @param irq		Interrupt assigned to the device (or zero if none)
+	 */
+	SPI(const char *name,
+	    const char *devname,
+	    int bus,
+	    enum spi_dev_e device,
+	    enum spi_mode_e mode,
+	    uint32_t frequency,
+	    int irq = 0);
+	~SPI();
+
+	virtual int	init();
+
+	/**
+	 * Check for the presence of the device on the bus.
+	 */
+	virtual int	probe();
+
+	/**
+	 * Perform a SPI transfer.
+	 *
+	 * At least one of send or recv must be non-null.
+	 *
+	 * @param send		Bytes to send to the device, or nullptr if
+	 *			no data is to be sent.
+	 * @param recv		Buffer for receiving bytes from the device,
+	 *			or nullptr if no bytes are to be received.
+	 * @param len		Number of bytes to transfer.
+	 * @return		OK if the exchange was successful, -errno
+	 *			otherwise.
+	 */
+	int		transfer(uint8_t *send, uint8_t *recv, unsigned len);
+
+private:
+	int			_bus;
+	enum spi_dev_e		_device;
+	enum spi_mode_e		_mode;
+	uint32_t		_frequency;
+	struct spi_dev_s	*_dev;
+};
+
+} // namespace device
+
+#endif /* _DEVICE_SPI_H */
diff --git a/apps/drivers/drv_accel.h b/apps/drivers/drv_accel.h
new file mode 100644
index 000000000..bf13b2c32
--- /dev/null
+++ b/apps/drivers/drv_accel.h
@@ -0,0 +1,105 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Accelerometer driver interface.
+ */
+
+#ifndef _DRV_ACCEL_H
+#define _DRV_ACCEL_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+#define ACCEL_DEVICE_PATH	"/dev/accel"
+
+/**
+ * accel report structure.  Reads from the device must be in multiples of this
+ * structure.
+ */
+struct accel_report {
+	float x;
+	float y;
+	float z;
+	uint64_t timestamp;
+};
+
+/** accel scaling factors; Vout = (Vin * Vscale) + Voffset */
+struct accel_scale {
+	float	x_offset;
+	float	x_scale;
+	float	y_offset;
+	float	y_scale;
+	float	z_offset;
+	float	z_scale;
+};
+
+/*
+ * ObjDev tag for raw accelerometer data.
+ */
+ORB_DECLARE(sensor_accel);
+
+/*
+ * ioctl() definitions
+ */
+
+#define _ACCELIOCBASE		(_SNIOCBASE + 0x20)
+#define _ACCELIOC(_n)		(_IOC(_ACCELIOCBASE, _n))
+
+/** set the driver polling rate to (arg) Hz, or one of the ACC_POLLRATE constants */
+#define ACCELIOCSPOLLRATE	_ACCELIOC(0)
+
+#define ACC_POLLRATE_MANUAL		1000000	/**< poll when read */
+#define ACC_POLLRATE_EXTERNAL		1000001	/**< poll when device signals ready */
+
+/** set the internal queue depth to (arg) entries, must be at least 1 */
+#define ACCELIOCSQUEUEDEPTH	_ACCELIOC(1)
+
+/** set the accel internal sample rate to at least (arg) Hz */
+#define ACCELIOCSSAMPLERATE	_ACCELIOC(2)
+
+/** set the accel internal lowpass filter to no lower than (arg) Hz */
+#define ACCELIOCSLOWPASS	_ACCELIOC(3)
+
+/** set the report format to (arg); zero is the standard, 1-10 are reserved, all others are driver-specific. */
+#define ACCELIOCSREPORTFORMAT	_ACCELIOC(4)
+
+/** set the accel scaling constants to the structure pointed to by (arg) */
+#define ACCELIOCSSCALE		_ACCELIOC(5)
+
+/** set the accel measurement range to handle at least (arg) g */
+#define ACCELIORANGE		_ACCELIOC(6)
+
+#endif /* _DRV_ACCEL_H */
diff --git a/apps/drivers/drv_baro.h b/apps/drivers/drv_baro.h
new file mode 100644
index 000000000..4cfb35454
--- /dev/null
+++ b/apps/drivers/drv_baro.h
@@ -0,0 +1,83 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Barometric pressure sensor driver interface.
+ */
+
+#ifndef _DRV_BARO_H
+#define _DRV_BARO_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+#define BARO_DEVICE_PATH	"/dev/baro"
+
+/**
+ * baro report structure.  Reads from the device must be in multiples of this
+ * structure.
+ */
+struct baro_report {
+	float pressure;
+	float altitude;
+	float temperature;
+	uint64_t timestamp;
+};
+
+/*
+ * ObjDev tag for raw barometer data.
+ */
+ORB_DECLARE(sensor_baro);
+
+/*
+ * ioctl() definitions
+ */
+
+#define _BAROIOCBASE		(_SNIOCBASE + 0x10)
+#define _BAROIOC(_n)		(_IOC(_BAROIOCBASE, _n))
+
+/** set the driver polling rate to (arg) Hz, or one of the BARO_POLLRATE constants */
+#define BAROIOCSPOLLRATE	_BAROIOC(0)
+
+#define BARO_POLLRATE_MANUAL		1000000	/**< poll when read */
+#define BARO_POLLRATE_EXTERNAL		1000001	/**< poll when device signals ready */
+
+/** set the internal queue depth to (arg) entries, must be at least 1 */
+#define BAROIOCSQUEUEDEPTH	_BAROIOC(1)
+
+/** set the report format to (arg); zero is the standard, 1-10 are reserved, all others are driver-specific. */
+#define BAROIOCSREPORTFORMAT 	_BAROIOC(2)
+
+#endif /* _DRV_BARO_H */
diff --git a/apps/drivers/drv_gpio.h b/apps/drivers/drv_gpio.h
new file mode 100644
index 000000000..b9684bce1
--- /dev/null
+++ b/apps/drivers/drv_gpio.h
@@ -0,0 +1,64 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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	Generic GPIO ioctl interface.
+ */
+
+#ifndef _DRV_GPIO_H
+#define _DRV_GPIO_H
+
+#include <sys/ioctl.h>
+
+/* 
+ * GPIO defines come from a board-specific header, as they are shared
+ * with board-specific logic.
+ * 
+ * The board-specific header must define:
+ * GPIO_DEVICE_PATH
+ * GPIO_RESET
+ * GPIO_SET_OUTPUT
+ * GPIO_SET_INPUT
+ * GPIO_SET_ALT_1
+ * GPIO_SET_ALT_2
+ * GPIO_SET_ALT_3
+ * GPIO_SET_ALT_4
+ * GPIO_SET
+ * GPIO_CLEAR
+ * GPIO_GET
+ */
+
+/* Include board-specific GPIO definitions as well. */
+#include <arch/board/drv_gpio.h>
+
+#endif /* _DRV_GPIO_H */
\ No newline at end of file
diff --git a/apps/drivers/drv_gyro.h b/apps/drivers/drv_gyro.h
new file mode 100644
index 000000000..21f6493b1
--- /dev/null
+++ b/apps/drivers/drv_gyro.h
@@ -0,0 +1,102 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Gyroscope driver interface.
+ */
+
+#ifndef _DRV_GYRO_H
+#define _DRV_GYRO_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+#define GYRO_DEVICE_PATH	"/dev/gyro"
+
+/**
+ * gyro report structure.  Reads from the device must be in multiples of this
+ * structure.
+ */
+struct gyro_report {
+	float x;
+	float y;
+	float z;
+	uint64_t timestamp;
+};
+
+/** gyro scaling factors; Vout = (Vin * Vscale) + Voffset */
+struct gyro_scale {
+	float	x_offset;
+	float	x_scale;
+	float	y_offset;
+	float	y_scale;
+	float	z_offset;
+	float	z_scale;
+};
+
+/*
+ * ObjDev tag for raw gyro data.
+ */
+ORB_DECLARE(sensor_gyro);
+
+/*
+ * ioctl() definitions
+ */
+
+#define _GYROIOCBASE		(_SNIOCBASE + 0x10)
+#define _GYROIOC(_n)		(_IOC(_GYROIOCBASE, _n))
+
+/** set the driver polling rate to (arg) Hz, or one of the GYRO_POLLRATE constants */
+#define GYROIOCSPOLLRATE	_GYROIOC(0)
+
+#define GYRO_POLLRATE_MANUAL		1000000	/**< poll when read */
+#define GYRO_POLLRATE_EXTERNAL		1000001	/**< poll when device signals ready */
+
+/** set the internal queue depth to (arg) entries, must be at least 1 */
+#define GYROIOCSQUEUEDEPTH	_GYROIOC(1)
+
+/** set the gyro internal sample rate to at least (arg) Hz */
+#define GYROIOCSSAMPLERATE	_GYROIOC(2)
+
+/** set the gyro internal lowpass filter to no lower than (arg) Hz */
+#define GYROIOCSLOWPASS		_GYROIOC(3)
+
+/** set the report format to (arg); zero is the standard, 1-10 are reserved, all others are driver-specific. */
+#define GYROIOCSREPORTFORMAT	_GYROIOC(4)
+
+/** set the gyro scaling constants to (arg) */
+#define GYROIOCSSCALE		_GYROIOC(5)
+
+#endif /* _DRV_GYRO_H */
diff --git a/apps/drivers/drv_mag.h b/apps/drivers/drv_mag.h
new file mode 100644
index 000000000..7e90e9e46
--- /dev/null
+++ b/apps/drivers/drv_mag.h
@@ -0,0 +1,102 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Magnetometer driver interface.
+ */
+
+#ifndef _DRV_MAG_H
+#define _DRV_MAG_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+#define MAG_DEVICE_PATH		"/dev/mag"
+
+/**
+ * mag report structure.  Reads from the device must be in multiples of this
+ * structure.
+ */
+struct mag_report {
+	float x;
+	float y;
+	float z;
+	uint64_t timestamp;
+};
+
+/** mag scaling factors; Vout = (Vin * Vscale) + Voffset */
+struct mag_scale {
+	float	x_offset;
+	float	x_scale;
+	float	y_offset;
+	float	y_scale;
+	float	z_offset;
+	float	z_scale;
+};
+
+/*
+ * ObjDev tag for raw magnetometer data.
+ */
+ORB_DECLARE(sensor_mag);
+
+/*
+ * ioctl() definitions
+ */
+
+#define _MAGIOCBASE		(_SNIOCBASE + 0x30)
+#define _MAGIOC(_n)		(_IOC(_MAGIOBASE, _n))
+
+/** set the driver polling rate to (arg) Hz, or one of the MAG_POLLRATE constants */
+#define MAGIOCSPOLLRATE		_MAGIOC(0)
+
+#define MAG_POLLRATE_MANUAL		1000000	/**< poll when read */
+#define MAG_POLLRATE_EXTERNAL		1000001	/**< poll when device signals ready */
+
+/** set the internal queue depth to (arg) entries, must be at least 1 */
+#define MAGIOCSQUEUEDEPTH	_MAGIOC(1)
+
+/** set the mag internal sample rate to at least (arg) Hz */
+#define MAGIOCSSAMPLERATE	_MAGIOC(2)
+
+/** set the mag internal lowpass filter to no lower than (arg) Hz */
+#define MAGIOCSLOWPASS		_MAGIOC(3)
+
+/** set the report format to (arg); zero is the standard, 1-10 are reserved, all others are driver-specific. */
+#define MAGIOCSREPORTFORMAT	_MAGIOC(4)
+
+/** set the mag scaling constants to the structure pointed to by (arg) */
+#define MAGIOCSSCALE		_MAGIOC(5)
+
+#endif /* _DRV_MAG_H */
diff --git a/apps/drivers/drv_orb_dev.h b/apps/drivers/drv_orb_dev.h
new file mode 100644
index 000000000..bacef1cd3
--- /dev/null
+++ b/apps/drivers/drv_orb_dev.h
@@ -0,0 +1,84 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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.
+ *
+ ****************************************************************************/
+
+#ifndef _DRV_UORB_H
+#define _DRV_UORB_H
+
+/**
+ * @file uORB published object driver.
+ */
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <stdint.h>
+
+/* XXX for ORB_DECLARE used in many drivers */
+#include "../uORB/uORB.h"
+
+/*
+ * ioctl() definitions
+ */
+
+/** path to the uORB control device for pub/sub topics */
+#define TOPIC_MASTER_DEVICE_PATH	"/obj/_obj_"
+
+/** path to the uORB control device for parameter topics */
+#define PARAM_MASTER_DEVICE_PATH	"/param/_param_"
+
+/** maximum ogbject name length */
+#define ORB_MAXNAME		32
+
+#define _ORBIOCBASE		(_DIOCBASE + 0x80)
+#define _ORBIOC(_n)		(_IOC(_ORBIOCBASE, _n))
+
+/*
+ * IOCTLs for the uORB control device
+ */
+
+/** Advertise a new topic described by *(uorb_metadata *)arg */
+#define ORBIOCADVERTISE		_ORBIOC(0)
+
+/*
+ * IOCTLs for individual topics.
+ */
+
+/** Fetch the time at which the topic was last updated into *(uint64_t *)arg */
+#define ORBIOCLASTUPDATE	_ORBIOC(10)
+
+/** Check whether the topic has been updated since it was last read, sets *(bool *)arg */
+#define ORBIOCUPDATED		_ORBIOC(11)
+
+/** Set the minimum interval at which the topic can be seen to be updated for this subscription */
+#define ORBIOCSETINTERVAL	_ORBIOC(12)
+
+#endif /* _DRV_UORB_H */
diff --git a/apps/drivers/drv_pwm_output.h b/apps/drivers/drv_pwm_output.h
new file mode 100644
index 000000000..551f9b1a6
--- /dev/null
+++ b/apps/drivers/drv_pwm_output.h
@@ -0,0 +1,112 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 PWM servo output interface.
+ *
+ * Servo values can be set with the PWM_SERVO_SET ioctl, by writing a
+ * pwm_output_values structure to the device, or by publishing to the
+ * output_pwm ObjDev.
+ * Writing a value of 0 to a channel suppresses any output for that
+ * channel.
+ */
+
+#ifndef _DRV_PWM_OUTPUT_H
+#define _DRV_PWM_OUTPUT_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+/**
+ * Path for the default PWM output device.
+ *
+ * Note that on systems with more than one PWM output path (e.g.
+ * PX4FMU with PX4IO connected) there may be other devices that
+ * respond to this protocol.
+ */
+#define PWM_OUTPUT_DEVICE_PATH	"/dev/pwm_output"
+
+/**
+ * Maximum number of PWM output channels in the system.
+ */
+#define PWM_OUTPUT_MAX_CHANNELS	16
+
+/**
+ * Servo output signal type, value is actual servo output pulse
+ * width in microseconds.
+ */
+typedef uint16_t	servo_position_t;
+
+/**
+ * Servo output status structure.
+ *
+ * May be published to output_pwm, or written to a PWM output
+ * device.
+ */
+struct pwm_output_values {
+	/** desired servo update rate in Hz */
+	uint32_t		update_rate;
+
+	/** desired pulse widths for each of the supported channels */
+	servo_position_t	values[PWM_OUTPUT_MAX_CHANNELS];
+};
+
+/*
+ * ObjDev tag for PWM outputs.
+ */
+ORB_DECLARE(output_pwm);
+
+/*
+ * ioctl() definitions
+ *
+ * Note that ioctls and ObjDev updates should not be mixed, as the
+ * behaviour of the system in this case is not defined.
+ */
+#define _PWM_SERVO_BASE		0x7500
+
+/** arm all servo outputs handle by this driver */
+#define PWM_SERVO_ARM		_IOC(_PWM_SERVO_BASE, 0)
+
+/** disarm all servo outputs (stop generating pulses) */
+#define PWM_SERVO_DISARM	_IOC(_PWM_SERVO_BASE, 1)
+
+/** set a single servo to a specific value */
+#define PWM_SERVO_SET(_servo)	_IOC(_PWM_SERVO_BASE, 0x20 + _servo)
+
+/** get a single specific servo value */
+#define PWM_SERVO_GET(_servo)	_IOC(_PWM_SERVO_BASE, 0x40 + _servo)
+
+
+#endif /* _DRV_PWM_OUTPUT_H */
diff --git a/apps/drivers/drv_rc_input.h b/apps/drivers/drv_rc_input.h
new file mode 100644
index 000000000..532e95fb5
--- /dev/null
+++ b/apps/drivers/drv_rc_input.h
@@ -0,0 +1,89 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 R/C input interface.
+ *
+ */
+
+#ifndef _DRV_RC_INPUT_H
+#define _DRV_RC_INPUT_H
+
+#include <stdint.h>
+#include <sys/ioctl.h>
+
+#include "drv_orb_dev.h"
+
+/**
+ * Path for the default R/C input device.
+ *
+ * Note that on systems with more than one R/C input path (e.g.
+ * PX4FMU with PX4IO connected) there may be other devices that
+ * respond to this protocol.
+ *
+ * Input data may be obtained by subscribing to the input_rc
+ * object, or by poll/reading from the device.
+ */
+#define RC_INPUT_DEVICE_PATH	"/dev/input_rc"
+
+/**
+ * Maximum number of R/C input channels in the system.
+ */
+#define RC_INPUT_MAX_CHANNELS	16
+
+/**
+ * Input signal type, value is a control position from zero to 100
+ * percent.
+ */
+typedef uint8_t		rc_input_t;
+
+/**
+ * R/C input status structure.
+ *
+ * Published to input_rc, may also be published to other names depending
+ * on the board involved.
+ */
+struct rc_input_values {
+	/** number of channels actually being seen */
+	uint32_t		channel_count;
+
+	/** desired pulse widths for each of the supported channels */
+	rc_input_t		values[RC_INPUT_MAX_CHANNELS];
+};
+
+/*
+ * ObjDev tag for R/C inputs.
+ */
+ORB_DECLARE(input_rc);
+
+#endif /* _DRV_RC_INPUT_H */
diff --git a/apps/drivers/ms5611/Makefile b/apps/drivers/ms5611/Makefile
new file mode 100644
index 000000000..d8e67cba2
--- /dev/null
+++ b/apps/drivers/ms5611/Makefile
@@ -0,0 +1,42 @@
+############################################################################
+#
+#   Copyright (C) 2012 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.
+#
+############################################################################
+
+#
+# MS5611 driver
+#
+
+APPNAME		 = ms5611
+PRIORITY	 = SCHED_PRIORITY_DEFAULT
+STACKSIZE	 = 2048
+
+include $(APPDIR)/mk/app.mk
diff --git a/apps/drivers/ms5611/ms5611.cpp b/apps/drivers/ms5611/ms5611.cpp
new file mode 100644
index 000000000..d3c75f755
--- /dev/null
+++ b/apps/drivers/ms5611/ms5611.cpp
@@ -0,0 +1,944 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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 Driver for the MS5611 barometric pressure sensor connected via I2C
+ */
+
+#include <nuttx/config.h>
+
+#include <drivers/device/i2c.h>
+
+#include <sys/types.h>
+#include <stdint.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/up_hrt.h>
+
+#include <drivers/drv_baro.h>
+
+/**
+ * Calibration PROM as reported by the device.
+ */
+#pragma pack(push,1)
+struct ms5611_prom_s {
+	uint16_t factory_setup;
+	uint16_t c1_pressure_sens;
+	uint16_t c2_pressure_offset;
+	uint16_t c3_temp_coeff_pres_sens;
+	uint16_t c4_temp_coeff_pres_offset;
+	uint16_t c5_reference_temp;
+	uint16_t c6_temp_coeff_temp;
+	uint16_t serial_and_crc;
+};
+
+/**
+ * Grody hack for crc4()
+ */
+union ms5611_prom_u {
+	uint16_t c[8];
+	struct ms5611_prom_s s;
+};
+#pragma pack(pop)
+
+class MS5611 : public device::I2C
+{
+public:
+	MS5611(int bus);
+	~MS5611();
+
+	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);
+
+	virtual int		open_first(struct file *filp);
+	virtual int		close_last(struct file *filp);
+
+	/**
+	 * Diagnostics - print some basic information about the driver.
+	 */
+	void			print_info();
+
+protected:
+	virtual int		probe();
+
+private:
+	union ms5611_prom_u	_prom;
+
+	struct work_s		_work;
+	unsigned		_measure_ticks;
+
+	unsigned		_num_reports;
+	volatile unsigned	_next_report;
+	volatile unsigned	_oldest_report;
+	struct baro_report	*_reports;
+
+	bool			_collect_phase;
+	unsigned		_measure_phase;
+
+	int32_t			_dT;
+	int64_t			_temp64;
+
+	int			_orbject;
+
+	unsigned		_reads;
+	unsigned		_measure_errors;
+	unsigned		_read_errors;
+	unsigned		_buf_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.
+	 *
+	 * This is the heart of the measurement state machine.  This function
+	 * alternately starts a measurement, or collects the data from the
+	 * previous measurement.
+	 *
+	 * When the interval between measurements is greater than the minimum
+	 * measurement interval, a gap is inserted between collection
+	 * and measurement to provide the most recent measurement possible
+	 * at the next interval.
+	 */
+	void			cycle();
+
+	/**
+	 * 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);
+
+	/**
+	 * Issue a measurement command for the current state.
+	 *
+	 * @return		OK if the measurement command was successful.
+	 */
+	int			measure();
+
+	/**
+	 * Collect the result of the most recent measurement.
+	 */
+	int			collect();
+
+	/**
+	 * Read the MS5611 PROM
+	 *
+	 * @return		OK if the PROM reads successfully.
+	 */
+	int			read_prom();
+
+	/**
+	 * PROM CRC routine ported from MS5611 application note
+	 *
+	 * @param n_prom	Pointer to words read from PROM.
+	 * @return		True if the CRC matches.
+	 */
+	bool			crc4(uint16_t *n_prom);
+
+};
+
+/* helper macro for handling report buffer indices */
+#define INCREMENT(_x, _lim)	do { _x++; if (_x >= _lim) _x = 0; } while(0)
+
+/*
+ * MS5611 internal constants and data structures.
+ */
+
+/* internal conversion time: 9.17 ms, so should not be read at rates higher than 100 Hz */
+#define MS5611_CONVERSION_INTERVAL	10000	/* microseconds */
+#define MS5611_MEASUREMENT_RATIO	3	/* pressure measurements per temperature measurement */
+
+#define MS5611_ADDRESS_1		0x76    /* address select pins pulled high (PX4FMU series v1.6+) */
+#define MS5611_ADDRESS_2		0x77    /* address select pins pulled low (PX4FMU prototypes) */
+
+#define ADDR_RESET_CMD			0x1E /* read from this address to reset chip (0b0011110 on bus) */
+#define ADDR_CMD_CONVERT_D1		0x48 /* 4096 samples to this address to start conversion (0b01001000 on bus) */
+#define ADDR_CMD_CONVERT_D2		0x58 /* 4096 samples */
+#define ADDR_DATA				0x00 /* address of 3 bytes / 32bit pressure data */
+#define ADDR_PROM_SETUP			0xA0 /* address of 8x 2 bytes factory and calibration data */
+#define ADDR_PROM_C1			0xA2 /* address of 6x 2 bytes calibration data */
+
+/*
+ * Driver 'main' command.
+ */
+extern "C" __EXPORT int ms5611_main(int argc, char *argv[]);
+
+
+MS5611::MS5611(int bus) :
+	I2C("MS5611", BARO_DEVICE_PATH, bus, 0, 400000),
+	_measure_ticks(0),
+	_num_reports(0),
+	_next_report(0),
+	_oldest_report(0),
+	_reports(nullptr),
+	_collect_phase(false),
+	_measure_phase(0),
+	_dT(0),
+	_temp64(0),
+	_reads(0),
+	_measure_errors(0),
+	_read_errors(0),
+	_buf_overflows(0)
+{
+	// enable debug() calls
+	_debug_enabled = true;
+
+	// work_cancel in the dtor will explode if we don't do this...
+	_work.worker = nullptr;
+}
+
+MS5611::~MS5611()
+{
+	/* make sure we are truly inactive */
+	stop();
+
+	/* free any existing reports */
+	if (_reports != nullptr)
+		delete[] _reports;
+}
+
+int
+MS5611::init()
+{
+	int ret;
+
+	/* do I2C init (and probe) first */
+	ret = I2C::init();
+
+	/* assuming we're good, advertise the object */
+	if (ret == OK) {
+		struct baro_report b;
+
+		/* if this fails (e.g. no object in the system) that's OK */
+		memset(&b, 0, sizeof(b));
+		_orbject = orb_advertise(ORB_ID(sensor_baro), &b);
+
+		if (_orbject < 0)
+			debug("failed to create sensor_baro object");
+	}
+
+	return ret;
+}
+
+int
+MS5611::open_first(struct file *filp)
+{
+	/* reset to manual-poll mode */
+	_measure_ticks = 0;
+
+	/* allocate basic report buffers */
+	_num_reports = 2;
+	_reports = new struct baro_report[_num_reports];
+	_oldest_report = _next_report = 0;
+
+	return OK;
+}
+
+int
+MS5611::close_last(struct file *filp)
+{
+	/* stop measurement */
+	stop();
+
+	/* free report buffers */
+	if (_reports != nullptr) {
+		delete[] _reports;
+		_num_reports = 0;
+	}
+
+	_measure_ticks = 0;
+
+	return OK;
+}
+
+int
+MS5611::probe()
+{
+	if (OK == probe_address(MS5611_ADDRESS_1))
+		return OK;
+
+	if (OK == probe_address(MS5611_ADDRESS_2))
+		return OK;
+
+	return -EIO;
+}
+
+int
+MS5611::probe_address(uint8_t address)
+{
+	uint8_t cmd = ADDR_RESET_CMD;
+
+	/* select the address we are going to try */
+	set_address(address);
+
+	/* send reset command */
+	if (OK != transfer(&cmd, 1, nullptr, 0))
+		return -EIO;
+
+	/* wait for PROM contents to be in the device (2.8 ms) */
+	usleep(3000);
+
+	/* read PROM */
+	if (OK != read_prom())
+		return -EIO;
+
+	return OK;
+}
+
+ssize_t
+MS5611::read(struct file *filp, char *buffer, size_t buflen)
+{
+	unsigned count = buflen / sizeof(struct baro_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);
+			}
+		}
+
+		_reads++;
+
+		/* 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 {
+		_measure_phase = 0;
+		_oldest_report = _next_report = 0;
+
+		/* do temperature first */
+		if (OK != measure()) {
+			ret = -EIO;
+			break;
+		}
+
+		usleep(MS5611_CONVERSION_INTERVAL);
+
+		if (OK != collect()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* now do a pressure measurement */
+		if (OK != measure()) {
+			ret = -EIO;
+			break;
+		}
+
+		usleep(MS5611_CONVERSION_INTERVAL);
+
+		if (OK != collect()) {
+			ret = -EIO;
+			break;
+		}
+
+		/* state machine will have generated a report, copy it out */
+		memcpy(buffer, _reports, sizeof(*_reports));
+		ret = sizeof(*_reports);
+		_reads++;
+
+	} while (0);
+
+	return ret;
+}
+
+int
+MS5611::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+
+	case BAROIOCSPOLLRATE: {
+			switch (arg) {
+
+				/* switching to manual polling */
+			case BARO_POLLRATE_MANUAL:
+				stop();
+				_measure_ticks = 0;
+				return OK;
+
+				/* external signalling not supported */
+			case BARO_POLLRATE_EXTERNAL:
+
+				/* zero would be bad */
+			case 0:
+				return -EINVAL;
+
+				/* 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(MS5611_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 BAROIOCSQUEUEDEPTH: {
+			/* lower bound is mandatory, upper bound is a sanity check */
+			if ((arg < 2) || (arg > 100))
+				return -EINVAL;
+
+			/* allocate new buffer */
+			struct baro_report *buf = new struct baro_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 BAROIOCSREPORTFORMAT:
+		return -EINVAL;
+
+	default:
+		/* give it to the superclass */
+		return I2C::ioctl(filp, cmd, arg);
+	}
+}
+
+void
+MS5611::start()
+{
+	/* make sure we are stopped first */
+	stop();
+
+	/* reset the report ring and state machine */
+	_collect_phase = false;
+	_measure_phase = 0;
+	_oldest_report = _next_report = 0;
+
+	/* schedule a cycle to start things */
+	work_queue(&_work, (worker_t)&MS5611::cycle_trampoline, this, 1);
+}
+
+void
+MS5611::stop()
+{
+	work_cancel(&_work);
+}
+
+void
+MS5611::cycle_trampoline(void *arg)
+{
+	MS5611 *dev = (MS5611 *)arg;
+
+	dev->cycle();
+}
+
+void
+MS5611::cycle()
+{
+	/* collection phase? */
+	if (_collect_phase) {
+
+		/* perform collection */
+		if (OK != collect()) {
+			log("FATAL collection error - restarting\n");
+			start();
+			return;
+		}
+
+		/* next phase is measurement */
+		_collect_phase = false;
+
+		/*
+		 * Is there a collect->measure gap?
+		 * Don't inject one after temperature measurements, so we can keep
+		 * doing pressure measurements at something close to the desired rate.
+		 */
+		if ((_measure_phase != 0) &&
+		    (_measure_ticks > USEC2TICK(MS5611_CONVERSION_INTERVAL))) {
+
+			/* schedule a fresh cycle call when we are ready to measure again */
+			work_queue(&_work,
+				   (worker_t)&MS5611::cycle_trampoline,
+				   this,
+				   _measure_ticks - USEC2TICK(MS5611_CONVERSION_INTERVAL));
+
+			return;
+		}
+	}
+
+	/* measurement phase */
+	if (OK != measure()) {
+		log("FATAL measure error - restarting\n");
+		start();
+	}
+
+	/* next phase is collection */
+	_collect_phase = true;
+
+	/* schedule a fresh cycle call when the measurement is done */
+	work_queue(&_work,
+		   (worker_t)&MS5611::cycle_trampoline,
+		   this,
+		   USEC2TICK(MS5611_CONVERSION_INTERVAL));
+}
+
+int
+MS5611::measure()
+{
+	int ret;
+
+	/*
+	 * In phase zero, request temperature; in other phases, request pressure.
+	 */
+	uint8_t	cmd_data = (_measure_phase == 0) ? ADDR_CMD_CONVERT_D2 : ADDR_CMD_CONVERT_D1;
+
+	/*
+	 * Send the command to begin measuring.
+	 */
+	ret = transfer(&cmd_data, 1, nullptr, 0);
+
+	if (OK != ret)
+		_measure_errors++;
+
+	return ret;
+}
+
+int
+MS5611::collect()
+{
+	uint8_t cmd;
+	uint8_t data[3];
+
+	/* read the most recent measurement */
+	cmd = 0;
+
+	/* this should be fairly close to the end of the conversion, so the best approximation of the time */
+	_reports[_next_report].timestamp = hrt_absolute_time();
+
+	if (OK != transfer(&cmd, 1, &data[0], 3)) {
+		_read_errors++;
+		return -EIO;
+	}
+
+	/* fetch the raw value */
+	uint32_t raw = (((uint32_t)data[0]) << 16) | (((uint32_t)data[1]) << 8) | ((uint32_t)data[2]);
+
+	/* handle a measurement */
+	if (_measure_phase == 0) {
+
+		/* temperature calculation */
+		_dT = raw - (((int32_t)_prom.s.c5_reference_temp) * 256);
+		_temp64 = 2000 + (((int64_t)_dT) * _prom.s.c6_temp_coeff_temp) / 8388608;
+
+	} else {
+
+		/* pressure calculation */
+		int64_t offset = (int64_t)_prom.s.c2_pressure_offset * 65536 + ((int64_t)_dT * _prom.s.c4_temp_coeff_pres_offset) / 128;
+		int64_t sens = (int64_t)_prom.s.c1_pressure_sens * 32768 + ((int64_t)_dT * _prom.s.c3_temp_coeff_pres_sens) / 256;
+
+		/* it's pretty cold, second order temperature compensation needed */
+		if (_temp64 < 2000) {
+			/* second order temperature compensation */
+			int64_t temp2 = (((int64_t)_dT) * _dT) >> 31;
+			int64_t tmp_64 = (_temp64 - 2000) * (_temp64 - 2000);
+			int64_t offset2 = (5 * tmp_64) >> 1;
+			int64_t sens2 = (5 * tmp_64) >> 2;
+			_temp64 = _temp64 - temp2;
+			offset = offset - offset2;
+			sens = sens - sens2;
+		}
+
+		int64_t press_int64 = (((raw * sens) / 2097152 - offset) / 32768);
+
+		/* generate a new report */
+		_reports[_next_report].temperature = _temp64 / 100.0f;
+		_reports[_next_report].pressure = press_int64 / 100.0f;
+		/* convert as double for max. precision, store as float (more than enough precision) */
+		_reports[_next_report].altitude = (44330.0 * (1.0 - pow((press_int64 / 101325.0), 0.190295)));
+
+		/* publish it */
+		orb_publish(ORB_ID(sensor_baro), _orbject, &_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) {
+			_buf_overflows++;
+			INCREMENT(_oldest_report, _num_reports);
+		}
+
+		/* notify anyone waiting for data */
+		poll_notify(POLLIN);
+	}
+
+
+	/* update the measurement state machine */
+	INCREMENT(_measure_phase, MS5611_MEASUREMENT_RATIO + 1);
+
+	return OK;
+}
+
+int
+MS5611::read_prom()
+{
+	/* read PROM data */
+	uint8_t prom_buf[2] = {255, 255};
+
+	for (int i = 0; i < 8; i++) {
+		uint8_t cmd = ADDR_PROM_SETUP + (i * 2);
+
+		if (OK != transfer(&cmd, 1, &prom_buf[0], 2))
+			break;
+
+		/* assemble 16 bit value and convert from big endian (sensor) to little endian (MCU) */
+		_prom.c[i] = (((uint16_t)prom_buf[0]) << 8) | ((uint16_t)prom_buf[1]);
+
+	}
+
+	/* calculate CRC and return false */
+	return crc4(&_prom.c[0]) ? OK : -EIO;
+}
+
+bool
+MS5611::crc4(uint16_t *n_prom)
+{
+	int16_t cnt;
+	uint16_t n_rem;
+	uint16_t crc_read;
+	uint8_t n_bit;
+
+	n_rem = 0x00;
+
+	/* save the read crc */
+	crc_read = n_prom[7];
+
+	/* remove CRC byte */
+	n_prom[7] = (0xFF00 & (n_prom[7]));
+
+	for (cnt = 0; cnt < 16; cnt++) {
+		/* uneven bytes */
+		if (cnt & 1) {
+			n_rem ^= (uint8_t)((n_prom[cnt >> 1]) & 0x00FF);
+
+		} else {
+			n_rem ^= (uint8_t)(n_prom[cnt >> 1] >> 8);
+		}
+
+		for (n_bit = 8; n_bit > 0; n_bit--) {
+			if (n_rem & 0x8000) {
+				n_rem = (n_rem << 1) ^ 0x3000;
+
+			} else {
+				n_rem = (n_rem << 1);
+			}
+		}
+	}
+
+	/* final 4 bit remainder is CRC value */
+	n_rem = (0x000F & (n_rem >> 12));
+	n_prom[7] = crc_read;
+
+	/* return true if CRCs match */
+	return (0x000F & crc_read) == (n_rem ^ 0x00);
+}
+
+void
+MS5611::print_info()
+{
+	printf("reads:          %u\n", _reads);
+	printf("measure errors: %u\n", _measure_errors);
+	printf("read errors:    %u\n", _read_errors);
+	printf("read overflows: %u\n", _buf_overflows);
+	printf("poll interval:  %u ticks\n", _measure_ticks);
+	printf("report queue:   %u (%u/%u @ %p)\n",
+	       _num_reports, _oldest_report, _next_report, _reports);
+	printf("dT/temp64:      %d/%lld\n", _dT, _temp64);
+}
+
+/**
+ * Local functions in support of the shell command.
+ */
+namespace
+{
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+const int ERROR = -1;
+
+MS5611	*g_dev;
+
+/*
+ * XXX this should just be part of the generic sensors test...
+ */
+
+
+int
+test_fail(const char *fmt, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "FAIL: ");
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+	fflush(stderr);
+	return ERROR;
+}
+
+int
+test_note(const char *fmt, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "note: ");
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fprintf(stderr, "\n");
+	fflush(stderr);
+	return OK;
+}
+
+/**
+ * Perform some basic functional tests on the driver;
+ * make sure we can collect data from the sensor in polled
+ * and automatic modes.
+ *
+ * @param fd		An open file descriptor on the driver.
+ */
+int
+test(int fd)
+{
+	struct baro_report report;
+	ssize_t sz;
+	int ret;
+
+
+	/* do a simple demand read */
+	sz = read(fd, &report, sizeof(report));
+
+	if (sz != sizeof(report))
+		return test_fail("immediate read failed: %d", errno);
+
+	test_note("single read");
+	test_note("pressure:    %u", (unsigned)report.pressure);
+	test_note("altitude:    %u", (unsigned)report.altitude);
+	test_note("temperature: %u", (unsigned)report.temperature);
+	test_note("time:        %lld", report.timestamp);
+	usleep(1000000);
+
+	/* set the queue depth to 10 */
+	if (OK != ioctl(fd, BAROIOCSQUEUEDEPTH, 10))
+		return test_fail("failed to set queue depth");
+
+	/* start the sensor polling at 2Hz */
+	if (OK != ioctl(fd, BAROIOCSPOLLRATE, 2))
+		return test_fail("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)
+			return test_fail("timed out waiting for sensor data");
+
+		/* now go get it */
+		sz = read(fd, &report, sizeof(report));
+
+		if (sz != sizeof(report))
+			return test_fail("periodic read failed: %d", errno);
+
+		test_note("periodic read %u", i);
+		test_note("pressure:    %u", (unsigned)report.pressure);
+		test_note("altitude:    %u", (unsigned)report.altitude);
+		test_note("temperature: %u", (unsigned)report.temperature);
+		test_note("time:        %lld", report.timestamp);
+	}
+
+	return test_note("PASS");
+	return OK;
+}
+
+int
+info()
+{
+	if (g_dev == nullptr) {
+		fprintf(stderr, "MS5611: driver not running\n");
+		return -ENOENT;
+	}
+
+	printf("state @ %p\n", g_dev);
+	g_dev->print_info();
+
+	return OK;
+}
+
+
+} // namespace
+
+int
+ms5611_main(int argc, char *argv[])
+{
+	/*
+	 * Start/load the driver.
+	 *
+	 * XXX it would be nice to have a wrapper for this...
+	 */
+	if (!strcmp(argv[1], "start")) {
+
+		if (g_dev != nullptr) {
+			fprintf(stderr, "MS5611: already loaded\n");
+			return -EBUSY;
+		}
+
+		/* create the driver */
+		/* XXX HORRIBLE hack - the bus number should not come from here */
+		g_dev = new MS5611(2);
+
+		if (g_dev == nullptr) {
+			fprintf(stderr, "MS5611: driver alloc failed\n");
+			return -ENOMEM;
+		}
+
+		if (OK != g_dev->init()) {
+			fprintf(stderr, "MS5611: driver init failed\n");
+			usleep(100000);
+			delete g_dev;
+			g_dev = nullptr;
+			return -EIO;
+		}
+
+		return OK;
+	}
+
+	/*
+	 * Test the driver/device.
+	 */
+	if (!strcmp(argv[1], "test")) {
+		int fd, ret;
+
+		fd = open(BARO_DEVICE_PATH, O_RDONLY);
+
+		if (fd < 0)
+			return test_fail("driver open failed: %d", errno);
+
+		ret = test(fd);
+		close(fd);
+		return ret;
+	}
+
+	/*
+	 * Print driver information.
+	 */
+	if (!strcmp(argv[1], "info"))
+		return info();
+
+	fprintf(stderr, "unrecognised command, try 'start', 'test' or 'info'\n");
+	return -EINVAL;
+}