UAVCAN baro driver

1 files changed, 147 insertions, 0 deletions

diff --git a/src/modules/uavcan/sensors/baro.cpp b/src/modules/uavcan/sensors/baro.cpp
new file mode 100644
index 000000000..3afcc3f1c
--- /dev/null
+++ b/src/modules/uavcan/sensors/baro.cpp
@@ -0,0 +1,147 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2014 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @author Pavel Kirienko <pavel.kirienko@gmail.com>
+ */
+
+#include "baro.hpp"
+#include <cmath>
+
+const char *const UavcanBarometerBridge::NAME = "baro";
+
+UavcanBarometerBridge::UavcanBarometerBridge(uavcan::INode& node) :
+device::CDev("uavcan_baro", "/dev/uavcan/baro"),
+_sub_air_data(node)
+{
+}
+
+UavcanBarometerBridge::~UavcanBarometerBridge()
+{
+	if (_class_instance > 0) {
+		(void)unregister_class_devname(BARO_DEVICE_PATH, _class_instance);
+	}
+}
+
+int UavcanBarometerBridge::init()
+{
+	// Init the libuavcan subscription
+	int res = _sub_air_data.start(AirDataCbBinder(this, &UavcanBarometerBridge::air_data_sub_cb));
+	if (res < 0) {
+		log("failed to start uavcan sub: %d", res);
+		return res;
+	}
+
+	// Detect our device class
+	_class_instance = register_class_devname(BARO_DEVICE_PATH);
+	switch (_class_instance) {
+	case CLASS_DEVICE_PRIMARY: {
+		_orb_id = ORB_ID(sensor_baro0);
+		break;
+	}
+	case CLASS_DEVICE_SECONDARY: {
+		_orb_id = ORB_ID(sensor_baro1);
+		break;
+	}
+	default: {
+		log("invalid class instance: %d", _class_instance);
+		(void)unregister_class_devname(BARO_DEVICE_PATH, _class_instance);
+		return -1;
+	}
+	}
+
+	log("inited with class instance %d", _class_instance);
+	return 0;
+}
+
+int UavcanBarometerBridge::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case BAROIOCSMSLPRESSURE: {
+		if ((arg < 80000) || (arg > 120000)) {
+			return -EINVAL;
+		} else {
+			log("new msl pressure %u", _msl_pressure);
+			_msl_pressure = arg;
+			return OK;
+		}
+	}
+	case BAROIOCGMSLPRESSURE: {
+		return _msl_pressure;
+	}
+	default: {
+		return CDev::ioctl(filp, cmd, arg);
+	}
+	}
+}
+
+void UavcanBarometerBridge::air_data_sub_cb(const uavcan::ReceivedDataStructure<uavcan::equipment::air_data::StaticAirData> &msg)
+{
+	auto report = ::baro_report();
+
+	report.timestamp = msg.getUtcTimestamp().toUSec();
+	if (report.timestamp == 0) {
+		report.timestamp = msg.getMonotonicTimestamp().toUSec();
+	}
+
+	report.temperature = msg.static_temperature;
+	report.pressure    = msg.static_pressure / 100.0F;  // Convert to millibar
+
+	/*
+	 * Altitude computation
+	 * Refer to the MS5611 driver for details
+	 */
+	const double T1 = 15.0 + 273.15; // temperature at base height in Kelvin
+	const double a  = -6.5 / 1000;   // temperature gradient in degrees per metre
+	const double g  = 9.80665;       // gravity constant in m/s/s
+	const double R  = 287.05;        // ideal gas constant in J/kg/K
+
+	const double p1 = _msl_pressure / 1000.0;      // current pressure at MSL in kPa
+	const double p = double(msg.static_pressure) / 1000.0; // measured pressure in kPa
+
+	report.altitude = (((std::pow((p / p1), (-(a * R) / g))) * T1) - T1) / a;
+
+	/*
+	 * Publish
+	 */
+	if (_orb_advert >= 0) {
+		orb_publish(_orb_id, _orb_advert, &report);
+	} else {
+		_orb_advert = orb_advertise(_orb_id, &report);
+		if (_orb_advert < 0) {
+			log("ADVERT FAIL");
+		} else {
+			log("advertised");
+		}
+	}
+}