/**************************************************************************** * * 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 */ #include "baro.hpp" #include static const orb_id_t BARO_TOPICS[2] = { ORB_ID(sensor_baro0), ORB_ID(sensor_baro1) }; const char *const UavcanBarometerBridge::NAME = "baro"; UavcanBarometerBridge::UavcanBarometerBridge(uavcan::INode& node) : UavcanCDevSensorBridgeBase("uavcan_baro", "/dev/uavcan/baro", BARO_DEVICE_PATH, BARO_TOPICS), _sub_air_data(node) { } int UavcanBarometerBridge::init() { int res = device::CDev::init(); if (res < 0) { return res; } 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; } 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 &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(msg.getSrcNodeID().get(), &report); }